SOH Acquisition Method, Battery Management System, Charging and Discharging Device, System and Medium

Abstract

The present application discloses a method for obtaining SOH, a battery management system, a charging and discharging device, a system and a medium, belonging to the technical field of batteries. The method includes: sending a discharge command to the charging and discharging device to instruct the charging and discharging device to switch to a discharge mode, where the discharge mode is that the power battery discharges to the power grid through the charging and discharging device; obtaining first battery state data; when it is detected that the minimum voltage of the single cells in the power battery reaches the discharge cut-off voltage, sending a charging command to the charging and discharging device to instruct the charging and discharging device to switch to a charging mode, where the charging mode is that the power grid charges the power battery through the charging and discharging device; obtaining second battery state data; when it is detected that the maximum voltage of the single cells in the power battery reaches the charging cut-off voltage, controlling the charging and discharging device to stop charging the power battery; obtaining the SOH of the power battery based on the first battery state data and the second battery state data. According to the embodiments of the present application, the accuracy of the obtained SOH is improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a method for obtaining SOH, a battery management system, a charging and discharging device, a system, and a medium. Background Art

[0002] With the development of new energy technologies, the application fields of batteries are becoming increasingly extensive. For example, batteries can be used as power sources to provide power for electrical equipment, thereby reducing the use of non-renewable resources.

[0003] Due to the increasingly extensive application fields of batteries, battery performance has become a major focus of attention. In order to evaluate battery performance, it is necessary to detect the State Of Health (SOH) of the battery. As the usage time increases, the SOH of the battery will change. If one wants to understand the changes in the SOH of the battery throughout its usage life cycle, it is necessary to perform multiple SOH detections on the battery during its usage life cycle.

[0004] At present, external detection devices can be used to collect and process data of the battery, but the external detection devices cannot obtain accurate data inside the battery, resulting in a low accuracy of the obtained SOH of the battery, which is difficult to be used as a reference for battery performance evaluation. Summary of the Invention

[0005] Embodiments of this application provide a method for obtaining SOH, a battery management system, a charging and discharging device, a system, and a medium, which can improve the accuracy of the obtained SOH.

[0006] In a first aspect, embodiments of this application provide a method for obtaining the State Of Health (SOH) of a battery, including: the Battery Management System (BMS) sends a discharge command to the charging and discharging device, and the discharge command is used for the charging and discharging device to switch to a discharge mode, where the discharge mode is that the power battery discharges to the power grid through the charging and discharging device, and the power battery includes more than one battery cell; the BMS obtains first battery state data; when the BMS detects that the lowest voltage of the cell in the power battery reaches the discharge cut-off voltage, the BMS sends a charging command to the charging and discharging device, and the charging command is used for the charging and discharging device to switch to a charging mode, where the charging mode is that the power grid charges the power battery through the charging and discharging device; the BMS obtains second battery state data; when the BMS detects that the highest voltage of the cell in the power battery reaches the charging cut-off voltage, the BMS controls the charging and discharging device to stop charging the power battery; the BMS obtains the SOH of the power battery based on the first battery state data and the second battery state data.

[0007] The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by external detection devices, making the SOH of the power battery obtained from the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of the SOH.

[0008] In some possible embodiments, before sending a charging command to the charge-discharge device, it further includes: when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, controlling the charge-discharge device to stop discharging to the power grid and leaving the power battery static for a first preset duration.

[0009] Leaving the power battery static can reduce or even eliminate the polarization phenomenon, making the second battery state data obtained by the BMS during the subsequent charging process of the power battery more accurate, thereby further improving the accuracy of the SOH obtained based on the first battery state data and the second battery state data.

[0010] In some possible embodiments, the first preset duration is 1 hour.

[0011] In some possible embodiments, after the battery management system BMS sends a discharge command to the charge-discharge device, it further includes: the BMS interacts with the charge-discharge device to enable the charge-discharge device to determine whether the BMS supports the vehicle-to-grid V2G function; in the case where the BMS supports the V2G function, the BMS and the charge-discharge device perform a communication handshake; when the communication handshake between the BMS and the charge-discharge device is successful, the BMS sends a discharge parameter configuration message to the charge-discharge device, and the discharge parameter configuration message includes the discharge voltage and the discharge current.

[0012] The BMS and the charge-discharge device can determine whether to support the V2G function through interaction and perform a communication handshake, enabling the charge-discharge device to switch to the discharge mode under the control of the BMS, so that the BMS can obtain the first battery state data during the process of the power battery discharging to the power grid through the charge-discharge device.

[0013] In some possible embodiments, after sending a charging command to the charge-discharge device, it further includes: the BMS interacts with the charge-discharge device to enable the charge-discharge device to determine whether the BMS supports the V2G function; in the case of supporting the V2G function, the BMS and the charge-discharge device perform a communication handshake; when the communication handshake between the BMS and the charge-discharge device is successful, the BMS sends a charging parameter configuration message to the charge-discharge device, and the charging parameter configuration message includes the charging voltage and the charging current.

[0014] The BMS and the charging and discharging device can interact to determine whether the V2G function is supported and perform communication handshaking, enabling the charging and discharging device to switch to the charging mode under the control of the BMS, so that the BMS can obtain the second battery state data during the process of the power grid charging the power battery through the charging and discharging device.

[0015] In some possible embodiments, after the BMS obtains the SOH of the power battery based on the first battery state data and the second battery state data, it further includes: the BMS sends the SOH of the power battery to the charging and discharging device, so that the charging and discharging device sends the SOH of the power battery to the management device.

[0016] Sending the SOH to the management device enables the management device to manage the SOH of each power battery, facilitating the monitoring and maintenance of the power battery. The management device can also implement SOH notification to the user, enabling the user to timely learn the SOH of the power battery and enhancing the user experience.

[0017] In some possible embodiments, the first battery state data includes the voltage of the battery cell and the current of the battery cell; the second battery state data includes the voltage of the battery cell and the current of the battery cell.

[0018] In a second aspect, an SOH acquisition method provided by an embodiment of the present application includes: the charging and discharging device receives a discharge command sent by a battery management system BMS; the charging and discharging device switches to the discharge mode, and the discharge mode is that the power battery discharges to the power grid through the charging and discharging device, and the power battery includes more than one battery cell; when the BMS detects that the lowest voltage of the single battery in the power battery reaches the discharge cut-off voltage, the charging and discharging device receives a charging command sent by the BMS; the charging and discharging device switches to the charging mode, and the charging mode is that the power grid charges the power battery through the charging and discharging device; when the BMS detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage, the charging and discharging device stops charging the power battery; wherein, the first battery state data obtained by the BMS when the charging and discharging device is in the discharge mode, and the second battery state data obtained by the BMS when the charging and discharging device is in the charging mode are used to obtain the SOH of the power battery.

[0019] The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by external detection devices, making the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of the SOH.

[0020] In some possible embodiments, before the charge-discharge device receives the charging command sent by the BMS, it further includes: when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, the charge-discharge device stops discharging to the power grid, so that the power battery is static for a first preset duration.

[0021] Letting the power battery be static can reduce or even eliminate the polarization phenomenon, making the second battery state data obtained by the BMS during the subsequent charging process of the power battery more accurate, thereby further improving the accuracy of the SOH obtained based on the first battery state data and the second battery state data.

[0022] In some possible embodiments, the first preset duration is 1 hour.

[0023] In some possible embodiments, after the charge-discharge device receives the discharge command sent by the battery management system BMS, it further includes: the charge-discharge device interacts with the BMS to determine whether the BMS supports the vehicle-to-grid V2G function; the charge-discharge device performs a communication handshake with the BMS when the BMS supports the V2G function; the charge-discharge device receives the discharge parameter configuration message sent by the charge-discharge device when the communication handshake with the BMS is successful, and the discharge parameter configuration message includes the discharge voltage and the discharge current.

[0024] The BMS and the charge-discharge device can determine whether to support the V2G function through interaction and perform a communication handshake, so that the charge-discharge device can switch to the discharge mode under the control of the BMS, and the BMS can obtain the first battery state data during the process of the power battery discharging to the power grid through the charge-discharge device.

[0025] In some possible embodiments, after the charge-discharge device receives the charging command sent by the BMS, it further includes: the charge-discharge device interacts with the BMS to determine whether the BMS supports the V2G function; the charge-discharge device performs a communication handshake with the BMS when the BMS supports the V2G function; the charge-discharge device receives the charging parameter configuration message sent by the charge-discharge device when the communication handshake with the BMS is successful, and the charging parameter configuration message includes the charging voltage and the charging current.

[0026] The BMS and the charge-discharge device can determine whether to support the V2G function through interaction and perform a communication handshake, so that the charge-discharge device can switch to the charging mode under the control of the BMS, and the BMS can obtain the second battery state data during the process of the power grid charging the power battery through the charge-discharge device.

[0027] In some possible embodiments, the SOH acquisition method further includes: the charge-discharge device receives the SOH of the power battery sent by the BMS; the charge-discharge device sends the SOH of the power battery to the management device.

[0028] Sending SOH to the management device enables the management device to manage the SOH of each power battery, facilitating the monitoring and maintenance of the power battery. The management device can also implement SOH notifications to users, enabling users to promptly learn the SOH of the power battery and enhancing the user experience.

[0029] In some possible embodiments, the first battery state data includes the voltage of a battery cell and the current of a battery cell; the second battery state data includes the voltage of a battery cell and the current of a battery cell.

[0030] In a third aspect, an embodiment of the present application provides a battery management system, including: a sending module configured to send a discharge command to a charging and discharging device, the discharge command being used for the charging and discharging device to switch to a discharge mode, the discharge mode being that the power battery discharges to the power grid through the charging and discharging device, and the power battery includes more than one battery cell; a data acquisition module configured to acquire first battery state data; the sending module is further configured to send a charging command to the charging and discharging device when it is detected that the lowest voltage of a single battery cell in the power battery reaches the discharge cut-off voltage, the charging command being used for the charging and discharging device to switch to a charging mode, the charging mode being that the power grid charges the power battery through the charging and discharging device; the data acquisition module is further configured to acquire second battery state data; a control module configured to control the charging and discharging device to stop charging the power battery when it is detected that the highest voltage of a single battery cell in the power battery reaches the charging cut-off voltage; a calculation module configured to obtain the SOH of the power battery based on the first battery state data and the second battery state data.

[0031] The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by an external detection device, making the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of the SOH.

[0032] Fourth aspect, an embodiment of the present application provides a charge-discharge device, including: a receiving module, configured to receive a discharge command sent by a battery management system (BMS); a mode switching module, configured to switch to a discharge mode, where the discharge mode is that a power battery discharges to the power grid through the charge-discharge device, and the power battery includes more than one battery cell; the receiving module is further configured to receive a charge command sent by the BMS when the BMS detects that the minimum voltage of the cell battery in the power battery reaches the discharge cut-off voltage; the mode switching module is further configured to switch to a charge mode, where the charge mode is that the power grid charges the power battery through the charge-discharge device; a control module, configured to stop charging the power battery when the BMS detects that the maximum voltage of the cell battery in the power battery reaches the charge cut-off voltage; wherein, the first battery state data obtained by the BMS when the charge-discharge device is in the discharge mode and the second battery state data obtained by the BMS when the charge-discharge device is in the charge mode are used to obtain the state of health (SOH) of the power battery.

[0033] The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by an external detection device, so that the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS is more accurate, improving the accuracy of the SOH.

[0034] Fifth aspect, an embodiment of the present application provides a battery management system, including: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the SOH acquisition method of the first aspect is implemented.

[0035] Sixth aspect, an embodiment of the present application provides a charge-discharge device, including: a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the SOH acquisition method of the second aspect is implemented.

[0036] Seventh aspect, an embodiment of the present application provides a system for obtaining the state of health (SOH) of a battery, including the battery management system of the fifth aspect and the charge-discharge device of the sixth aspect.

[0037] Eighth aspect, an embodiment of the present application provides a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the method for detecting the state of health of a battery of the first aspect is implemented.

[0038] Ninth aspect, an embodiment of the present application provides a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the method for detecting the state of health of a battery of the second aspect is implemented.

[0039] The embodiments of the present application provide a method for obtaining SOH, a battery management system, a charging and discharging device, a system and a medium. The BMS sends a discharging command and a charging command to the charging and discharging device, enabling the charging and discharging device to switch to the discharging mode and the charging mode. When the charging and discharging device switches to the discharging mode, the power battery discharges to the power grid through the charging and discharging device. During the process of the power battery discharging to the power grid through the charging and discharging device, the BMS can obtain the first battery state data. When the charging and discharging device switches to the charging mode, the power grid charges the power battery through the charging and discharging device. In the case where the power grid charges the power battery through the charging and discharging device, the BMS can obtain the second battery state data. The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by external detection devices, making the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of SOH. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic diagram of an example of the application scenario of the SOH obtaining method provided by the embodiments of the present application;

[0042] Figure 2 It is a flowchart of an embodiment of the SOH obtaining method applied to the BMS provided by the present application;

[0043] Figure 3 It is a flowchart of another embodiment of the SOH obtaining method applied to the BMS provided by the present application;

[0044] Figure 4 It is a flowchart of yet another embodiment of the SOH obtaining method applied to the BMS provided by the present application;

[0045] Figure 5 It is a flowchart of an embodiment of the SOH obtaining method applied to the charging and discharging device provided by the present application;

[0046] Figure 6 It is a flowchart of another embodiment of the SOH obtaining method applied to the charging and discharging device provided by the present application;

[0047] Figure 7 It is a flowchart of yet another embodiment of the SOH obtaining method applied to the charging and discharging device provided by the present application;

[0048] Figure 8It is a flowchart of an example of the SOH acquisition process provided by an embodiment of the present application;

[0049] Figure 9 It is a flowchart of another example of the SOH acquisition process provided by an embodiment of the present application;

[0050] Figure 10 It is a schematic structural diagram of an embodiment of the BMS provided by the present application;

[0051] Figure 11 It is a schematic structural diagram of another embodiment of the BMS provided by the present application;

[0052] Figure 12 It is a schematic structural diagram of an embodiment of the charge and discharge device provided by the present application;

[0053] Figure 13 It is a schematic structural diagram of another embodiment of the charge and discharge device provided by the present application;

[0054] Figure 14 It is a schematic hardware structure diagram of an embodiment of the BMS provided by the present application;

[0055] Figure 15 It is a schematic hardware structure diagram of an embodiment of the charge and discharge device provided by the present application. Detailed implementation manners

[0056] The features and exemplary embodiments of various aspects of the present application will be described in detail below. To make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present application by showing examples of the present application.

[0057] With the development of new energy technologies, the application fields of batteries are becoming more and more extensive. Batteries can be used as power sources to provide power for electrical equipment. For example, power batteries can be used as the power source of vehicles. As a power source, the performance of power batteries has become a major focus. The State Of Health (SOH) of power batteries can evaluate the health status of power batteries, which is of great significance for the use and maintenance of power batteries. As the usage time increases, the SOH of power batteries will change. If one wants to understand the changes in the SOH of power batteries throughout their usage life cycle, multiple SOH detections of power batteries need to be carried out during the usage life cycle.

[0058] At present, external detection devices can be used to collect and process data of power batteries, but the external detection devices cannot obtain accurate data inside the power batteries, resulting in low accuracy of the SOH of the power batteries obtained, and it is difficult to be used as a reference for battery performance evaluation.

[0059] The embodiments of the present application provide a method for obtaining SOH, a battery management system, a charging and discharging device, a system and a medium, and use a charging and discharging device capable of realizing bidirectional energy exchange between the power grid and the power battery to detect the SOH of the power battery, so as to obtain accurate SOH of the power battery.

[0060] The method for obtaining SOH provided by the embodiments of the present application may involve a vehicle and a charging and discharging device. The vehicle includes a power battery and a battery management system (Battery Management System, BMS). Figure 1 It is a schematic diagram of an example of the application scenario of the method for obtaining SOH provided by the embodiments of the present application. As Figure 1 shown, the charging and discharging device 11 can communicate and interact with the BMS 13 in the vehicle 12 (represented by hollow arrows) for charging and discharging, and the charging and discharging device 11 can exchange energy with the power battery 14 in the vehicle (represented by time-limited arrows).

[0061] The charging and discharging device 11 can realize bidirectional energy exchange between the power grid and the power battery, and can support the vehicle-to-grid (V2G) function. That is, the power grid can charge the power battery 14 through the charging and discharging device 11, and the power battery 14 can also discharge to the power grid through the charging and discharging device 11. The charging and discharging device 11 can include devices such as charging piles and charging stations, which are not limited here.

[0062] The power battery 14 can be used as a power source of the vehicle 12. The power battery can include more than one battery cell. The battery cells in the power battery 14 can be connected in series, in parallel or in a hybrid connection, which is not limited here.

[0063] The BMS 13 can monitor various state parameters of the power battery 14 to obtain the usage state of the power battery 14, regulate the working state of the power battery 14, protect the safety of the power battery 14, and improve the performance of the power battery 14.

[0064] The method for obtaining SOH in the embodiments of the present application will be specifically described below.

[0065] The embodiments of the present application provide a method for obtaining SOH, which can be applied to the BMS. Figure 2 It is a flowchart of an embodiment of the method for obtaining SOH applied to the BMS provided by the present application. As Figure 2 shown, the method for obtaining SOH may include steps S201 to step S206.

[0066] In step S201, the BMS sends a discharge command to the charge and discharge device.

[0067] The discharge command is used for the charge and discharge device to switch to the discharge mode. The discharge mode is that the power battery discharges to the power grid through the charge and discharge device. When the charge and discharge device switches to the discharge mode, the charge and discharge device uses the energy of the power battery to discharge to the power grid.

[0068] In step S202, the BMS obtains the first battery state data.

[0069] The BMS obtains the first battery state data during the process of the power battery discharging to the power grid through the charge and discharge device. That is, the first battery state data is the battery state data during the discharge process of the power battery. The BMS will obtain the first battery state data of the power battery multiple times during the process of the power battery discharging to the power grid through the charge and discharge device. For example, the BMS can periodically obtain the first battery state data during the process of the power battery discharging to the power grid through the charge and discharge device. The state of the power battery during the discharge process can be determined through the first battery state data obtained multiple times.

[0070] In some examples, the first battery state data may include the voltage of the battery cell and the current of the battery cell. The first battery state data obtained by the BMS is more accurate than the state data of the power battery collected by external detection devices.

[0071] In step S203, when the BMS detects that the minimum voltage of the battery cells in the power battery reaches the discharge cut-off voltage, the BMS sends a charge command to the charge and discharge device.

[0072] The discharge cut-off voltage is the minimum value of the voltage of the battery cells required for SOH detection, which can be set according to the characteristics of the power battery such as model and type, as well as the requirements of SOH detection, and is not limited here.

[0073] When the power battery includes one battery cell, and the voltage of this battery cell reaches the discharge cut-off voltage, the BMS sends a charge command to the charge and discharge device.

[0074] When the power battery includes more than two battery cells, if the voltage of any selected battery cell is compared with the discharge cut-off voltage, it may occur that the voltage of this battery cell reaches the discharge cut-off voltage while the voltages of other battery cells are lower than the discharge cut-off voltage, thus having an adverse impact on the safety and health of the power battery. Therefore, when the minimum voltage of more than two battery cells reaches the discharge cut-off voltage, the BMS sends a charge command to the charge and discharge device.

[0075] The charging command is used to switch the charge-discharge device to the charging mode. The charging mode is that the power grid charges the power battery through the charge-discharge device. When the charge-discharge device switches to the charging mode, the charge-discharge device uses the power of the power grid to charge the power battery.

[0076] In step S204, the BMS obtains the second battery status data.

[0077] The BMS obtains the second battery status data during the process of the power grid charging the power battery through the charge-discharge device. That is, the second battery status data is the battery status data during the charging process of the power battery. The BMS will obtain the second battery status data of the power battery multiple times during the process of the power grid charging the power battery through the charge-discharge device. For example, the BMS can periodically obtain the second battery status data during the process of the power grid charging the power battery through the charge-discharge device. The state of the power battery during the discharge process can be determined through the second battery status data obtained multiple times.

[0078] In some examples, the second battery status data may include the voltage of the battery cell and the current of the battery cell. The second battery status data obtained by the BMS is more accurate than the status data of the power battery collected by external detection devices.

[0079] In step S205, when the BMS detects that the highest voltage of the battery cells in the power battery reaches the charging cut-off voltage, the BMS controls the charge-discharge device to stop charging the power battery.

[0080] The charging cut-off voltage is the maximum value of the voltage of the battery cell required for SOH detection, which can be set according to the characteristics of the power battery such as model and type, as well as the requirements of SOH detection, and is not limited here. When the BMS detects that the highest voltage of the battery cells in the power battery reaches the charging cut-off voltage, the BMS controls the charge-discharge device to exit the charging mode, that is, controls the charge-discharge device to stop the power grid from charging the power battery through the charge-discharge device.

[0081] Specifically, when the BMS detects that the highest voltage of the battery cells in the power battery reaches the charging cut-off voltage, the BMS can send a charging stop command to the charge-discharge device to control the charge-discharge device to stop charging the power battery, that is, stop the power grid from charging the power battery through the charge-discharge device.

[0082] When the power battery includes one battery cell and the voltage of this battery cell reaches the charging cut-off voltage, the BMS controls the charge-discharge device to stop charging the power battery, and the charging process of the power battery ends.

[0083] When the power battery includes more than two battery cells, if the voltage of any one battery cell is compared with the charging cut-off voltage, it may occur that the voltage of this battery cell reaches the charging cut-off voltage while the voltages of other battery cells are higher than the charging cut-off voltage, thus having an adverse impact on the safety and health of the power battery. Therefore, when the highest voltage among more than two battery cells reaches the charging cut-off voltage, the BMS controls the charge and discharge device to stop charging the power battery, and the charging process of the power battery ends.

[0084] In step S206, the BMS obtains the SOH of the power battery based on the first battery state data and the second battery state data.

[0085] The state of the power battery during the discharge process can be determined through the first battery state data, and the state of the power battery during the charging process can be determined through the second battery state data. Combining the state of the power battery during the discharge process and the state of the power battery during the charging process, the SOH of the power battery can be obtained.

[0086] Here, there is no limitation on the specific algorithm for obtaining the SOH based on the first battery state data and the second battery state data. Any content that can obtain the SOH based on the state data of the power battery during the discharge process and the state data of the power battery during the charging process is within the protection scope of the embodiments of this application.

[0087] In the embodiments of this application, the BMS sends a discharge command and a charging command to the charge and discharge device, enabling the charge and discharge device to switch to the discharge mode and the charging mode. When the charge and discharge device switches to the discharge mode, the power battery discharges to the power grid through the charge and discharge device. During the process of the power battery discharging to the power grid through the charge and discharge device, the BMS can obtain the first battery state data. When the charge and discharge device switches to the charging mode, the power grid charges the power battery through the charge and discharge device. In the case where the power grid charges the power battery through the charge and discharge device, the BMS can obtain the second battery state data. The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by external detection devices, making the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of the SOH.

[0088] In some embodiments, the charge and discharge device may send a SOH detection request instruction to the BMS. In response to the received SOH detection request instruction, the BMS executes the above step S201, that is, the BMS sends a discharge command to the charge and discharge device.

[0089] In some examples, the SOH detection request instruction may be generated by the charge and discharge device in response to the user's input of the SOH detection mode.

[0090] In some other examples, the SOH detection request instruction can be generated by the charge and discharge device in response to the SOH detection mode instruction sent by the cloud server. The SOH detection mode instruction can be generated by the cloud server in response to the SOH detection mode selection instruction of the user terminal. The SOH detection mode selection instruction can be generated by the user terminal in response to the user's SOH detection mode input.

[0091] In some embodiments, in response to the SOH detection request instruction, the BMS can detect whether the SOH detection protocol is stored in the BMS. The SOH detection protocol allows the BMS to interact with the charge and discharge device to perform SOH detection on the power battery. Specifically, performing SOH detection on the power battery can be achieved by obtaining battery state data during the process of the charge and discharge device realizing the energy exchange between the power grid and the power battery, so as to obtain the SOH based on the battery state data.

[0092] In some embodiments, the BMS sends the SOH of the power battery to the charge and discharge device, so that the charge and discharge device sends the SOH of the power battery to the management device. The management device can manage the SOH of each power battery, facilitating the monitoring and maintenance of the power battery. The management device can include devices such as a cloud server and a user terminal. When the management device includes a cloud server, the cloud server can also send the received SOH to the user terminal, so that the user terminal notifies the user by means such as display and sound.

[0093] In order to make the obtained second battery state data more accurate, the power battery can be left standing for a period of time before the charge and discharge device charges the power battery. Figure 3 This is a flowchart of another embodiment of the SOH acquisition method applied to the BMS provided by this application. Figure 3 Different from Figure 2 is that Figure 3 the SOH acquisition method shown can further include step S207.

[0094] In step S207, when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, it controls the charge and discharge device to stop discharging to the power grid and leaves the power battery standing for a first preset duration.

[0095] When the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, the BMS controls the charge and discharge device to exit the discharge mode, that is, controls the charge and discharge device to stop the power battery from discharging to the power grid through the charge and discharge device.

[0096] Specifically, when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, the BMS can send a discharge stop instruction to the charge and discharge device to control the charge and discharge device to stop discharging to the power grid, that is, stop the power battery from discharging to the power grid through the charge and discharge device.

[0097] Since polarization phenomenon will occur after the power battery discharges for a long time, in order to avoid the influence of the polarization phenomenon on the state data of the second battery during the charging process, the power battery can be statically placed for a first preset duration. The first preset duration can be set according to the characteristics of the power battery such as model and type, as well as the static placement requirements, which are not limited herein. For example, the first preset duration can be 1 hour.

[0098] Specifically, the BMS can send a charging command to the charging and discharging device after a first preset duration after sending a discharge stop command to the charging and discharging device, so that the power battery is statically placed for the first preset duration after stopping discharging.

[0099] The static placement of the power battery can reduce or even eliminate the polarization phenomenon, making the state data of the second battery obtained by the BMS during the subsequent charging process of the power battery more accurate, thereby further improving the accuracy of the SOH obtained based on the state data of the first battery and the state data of the second battery.

[0100] After the BMS sends a discharge command and a charging command to the charging and discharging device, the BMS can interact with the charging and discharging device to determine whether the BMS supports the vehicle-to-grid (V2G) function. When the BMS supports the V2G function, the power grid and the power battery can perform bidirectional energy exchange through the charging and discharging device. Figure 4 This is a flowchart of another embodiment of the SOH acquisition method applied to the BMS provided in this application. Figure 4 Different from Figure 2 is that Figure 4 the SOH acquisition method shown may further include steps S208 to S210 and steps S211 to S213.

[0101] In step S208, the BMS interacts with the charging and discharging device to enable the charging and discharging device to determine whether the BMS supports the vehicle-to-grid V2G function.

[0102] Specifically, the charging and discharging device can send a CDC message to the BMS. If the BMS supports the V2G function, in response to the CDC message, the BMS feeds back a BDC message to the charging and discharging device. If the charging and discharging device can receive the BDC message within the timeout duration, it is determined that the BMS supports the V2G function. If the BMS does not support the V2G function, the BMS does not respond, that is, the BMS will not feed back a BDC message to the charging and discharging device. If the charging and discharging device does not receive the BDC message within the timeout duration, it is determined that the BMS does not support the V2G function.

[0103] In step S209, when the V2G function is supported, the BMS performs a communication handshake with the charging and discharging device.

[0104] If the BMS supports the V2G function, it can further communicate and handshake with the charging and discharging device. After the communication handshake is successful, subsequent configurations and the discharging process can be carried out.

[0105] Specifically, the communication handshake process between the BMS and the charging and discharging device is as follows:

[0106] a1. The charging and discharging device sends a charger handshake message, i.e., the CHM message, to the BMS, that is, the BMS receives the CHM message sent by the charging and discharging device.

[0107] a2. The BMS sends a BMS handshake message, i.e., the BHM message, to the charging and discharging device.

[0108] a3. The charging and discharging device sends a charger identification message, i.e., the CRM message, to the BMS, that is, the BMS receives the CRM message sent by the charging and discharging device.

[0109] a4. The BMS sends a BMS identification message, i.e., the BRM message, to the charging and discharging device.

[0110] In step S210, when the communication handshake between the BMS and the charging and discharging device is successful, the BMS sends a discharging parameter configuration message to the charging and discharging device.

[0111] The BMS stores the discharging parameter configuration information required for SOH detection. The discharging parameter configuration information is used to instruct the charging and discharging device to make the power battery discharge to the power grid through the charging and discharging device according to the discharging parameter configuration information. The discharging parameter configuration message includes the discharging voltage and the discharging current. That is, the charging and discharging device makes the power battery discharge to the power grid through the charging and discharging device according to the discharging voltage and the discharging current.

[0112] In step S211, the BMS interacts with the charging and discharging device to enable the charging and discharging device to determine whether the BMS supports the V2G function.

[0113] For the specific content of step S211, refer to the specific content of step S208 above, which will not be elaborated here.

[0114] In step S212, when the BMS supports the V2G function, it conducts a communication handshake with the charging and discharging device.

[0115] For the specific content of step S212, refer to the specific content of step S209 above, which will not be elaborated here.

[0116] In step S213, when the communication handshake between the BMS and the charging and discharging device is successful, the BMS sends a charging parameter configuration message to the charging and discharging device.

[0117] The BMS stores the charging parameter configuration information required for SOH detection. The charging parameter configuration information is used to instruct the charge-discharge device to enable the power grid to discharge the power battery through the charge-discharge device according to the charging parameter configuration information. The charging parameter configuration message includes the charging voltage and the charging current. That is, the charge-discharge device enables the power grid to charge the power battery according to the charging voltage and the charging current.

[0118] In some examples, after performing step S208 and step S209, steps S211 and step S212 can also be omitted, that is, only one judgment on whether the BMS supports the V2G function and one communication handshake between the BMS and the charge-discharge device can also be performed.

[0119] In some other embodiments, the BMS can also first send a charging command to the charge-discharge device to switch the charge-discharge device to the charging mode, and the BMS obtains the second battery state data. The cut-off condition of the charging mode can be that the BMS detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage. The BMS then sends a discharge command to the charge-discharge device to switch the charge-discharge device to the discharge mode, and the BMS obtains the first battery state data. The SOH of the power battery is obtained based on the first battery state data and the second state data. The cut-off condition of the discharge mode can be that the BMS detects that the lowest voltage of the single battery in the power battery reaches the discharge cut-off voltage.

[0120] That is to say, in the embodiments of the present application, the order of the BMS sending the discharge command and the charging command to the charge-discharge device is not limited, that is, the order of the charge-discharge device switching to the discharge mode and the charging mode is not limited.

[0121] In the case where the BMS first sends a charging command to the charge-discharge device and then sends a discharge command to the charge-discharge device, that is, first performs the charging process and then performs the discharge process, the charging process, the discharge process, and the interactions involved in the charging process and the discharge process can refer to the relevant content in the above embodiments, and will not be elaborated here.

[0122] For example, in the case where the BMS first sends a charging command to the charge-discharge device, when the BMS detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage, the charge-discharge device is controlled to stop charging the power battery, and the power battery is left static for the first preset duration. When the static duration of the power battery reaches the first preset duration, the BMS then sends a discharge command to the charge-discharge device.

[0123] The embodiments of the present application also provide a method for obtaining SOH, which can be applied to the charge-discharge device. Figure 5 It is a flowchart of an embodiment of the method for obtaining SOH applied to the charge-discharge device in the present application. As Figure 5 shown, the method for obtaining SOH can include steps S301 to S305.

[0124] In step S301, the charge-discharge device receives a discharge command sent by the BMS.

[0125] For the specific content of the discharge command, refer to the relevant descriptions in the above embodiments, which will not be elaborated here.

[0126] In step S302, the charge-discharge device switches to the discharge mode.

[0127] The discharge mode is that the power battery discharges to the power grid through the charge-discharge device, that is, the power battery discharges outward. For the specific content of the discharge mode, refer to the relevant descriptions in the above embodiments, which will not be elaborated here.

[0128] During the process of the power battery discharging to the power grid through the charge-discharge device, the BMS obtains the first battery state data of the power battery. In some examples, the first battery state data includes the voltage and current of the battery cells.

[0129] In step S303, when the BMS detects that the minimum voltage of the battery cells in the power battery reaches the discharge cut-off voltage, the charge-discharge device receives a charge command sent by the BMS.

[0130] For the specific content such as the minimum voltage of the battery cells reaching the discharge cut-off voltage and the charge command, refer to the relevant descriptions in the above embodiments, which will not be elaborated here.

[0131] In step S304, the charge-discharge device switches to the charge mode.

[0132] The charge mode is that the power grid charges the power battery through the charge-discharge device, that is, charges the power battery. For the specific content of the charge mode, refer to the relevant descriptions in the above embodiments, which will not be elaborated here.

[0133] During the process of the power grid charging the power battery through the charge-discharge device, the BMS obtains the second battery state data of the power battery. In some examples, the second battery state data includes the voltage and current of the battery cells.

[0134] In step S305, when the BMS detects that the maximum voltage of the battery cells in the power battery reaches the charge cut-off voltage, the charge-discharge device stops charging the power battery.

[0135] For the specific content of the maximum voltage of the battery cells reaching the charge cut-off voltage, refer to the relevant descriptions in the above embodiments, which will not be elaborated here.

[0136] Specifically, when the BMS detects that the highest voltage of a single battery in the power battery reaches the charging cut-off voltage, the BMS can send a charging stop command to the charge-discharge device to control the charge-discharge device to stop charging the power battery, that is, to stop the power grid from charging the power battery through the charge-discharge device.

[0137] The first battery state data obtained by the BMS when the charge-discharge device is in the discharge mode and the second battery state data obtained by the BMS when the charge-discharge device is in the charging mode are used to obtain the SOH of the power battery. That is, the BMS can obtain the SOH of the power battery based on the first battery state data and the second battery state data.

[0138] In the embodiments of the present application, the charge-discharge device receives the discharge command and the charging command sent by the BMS and can switch to the discharge mode and the charging mode. When the charge-discharge device switches to the discharge mode, the power battery discharges to the power grid through the charge-discharge device. During the process of the power battery discharging to the power grid through the charge-discharge device, the BMS can obtain the first battery state data. When the charge-discharge device switches to the charging mode, the power grid charges the power battery through the charge-discharge device. In the case where the power grid charges the power battery through the charge-discharge device, the BMS can obtain the second battery state data. The first battery state data and the second battery state data obtained by the BMS are more accurate than the battery state data obtained by external detection devices, making the SOH of the power battery obtained by using the first battery state data and the second battery state data obtained by the BMS more accurate and improving the accuracy of the SOH. <[

[0139] In some embodiments, the charge-discharge device can send a SOH detection request instruction to the BMS. In response to the received SOH detection request instruction, the BMS can send a discharge command to the charge-discharge device.

[0140] In some examples, the SOH detection request instruction can be generated by the charge-discharge device in response to the user's SOH detection mode input.

[0141] In other examples, the SOH detection request instruction can be generated by the charge-discharge device in response to the SOH detection mode instruction sent by the cloud server. The SOH detection mode instruction can be generated by the cloud server in response to the SOH detection mode selection instruction of the user terminal. The SOH detection mode selection instruction can be generated by the user terminal in response to the user's SOH detection mode input.

[0142] It should be noted that there is a possible error in the original text where "<[

[0139] " should probably be "

[0139] ", and this has been corrected in the translation.In some embodiments, the SOH detection request instruction is used to instruct the BMS to detect whether it has a stored SOH detection protocol. The SOH detection protocol allows the BMS to interact with the charging and discharging device to perform SOH detection on the power battery. The SOH detection of the power battery can be specifically implemented by obtaining battery status data during the energy exchange between the power grid and the power battery by the charging and discharging device, thereby obtaining the SOH based on the battery status data.

[0143] In order to make the acquired second battery status data more accurate, the power battery may be left to stand for a period of time before the charging and discharging device charges the power battery. Figure 6 This is a flowchart of another embodiment of the SOH acquisition method applied to a charging and discharging device provided in the present application. Figure 6 and Figure 5 The difference is that Figure 6 The illustrated SOH acquisition method may further include step S306 .

[0144] In step S306 , when the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, the charging and discharging device stops discharging to the grid, so that the power battery rests for a first preset time period.

[0145] Specifically, when the BMS detects that the lowest voltage of a power battery cell has reached the discharge cutoff voltage, it can send a discharge stop command to the charge-discharge device. In response to this discharge stop command, the charge-discharge device stops discharging energy from the power battery to the grid and allows the power battery to rest for a first preset time. This means that the discharge device can switch back to charging mode after the first preset time has elapsed since the discharge mode ended.

[0146] In some examples, the charging command is received by the charging and discharging device after the power battery stops discharging and remains stationary for a first preset period of time.

[0147] The specific content of the first preset time length can be referred to the relevant description in the above embodiment, which will not be repeated here. In some examples, the first preset time length can be 1 hour.

[0148] Leaving the power battery at rest can reduce or even eliminate the polarization phenomenon of the power battery, making the second battery status data obtained by the BMS during the subsequent charging process of the power battery more accurate, thereby further improving the accuracy of the SOH obtained based on the first battery status data and the second battery status data.

[0149] In some embodiments, the charging and discharging device receives the SOH of the power battery sent by the BMS. The charging and discharging device sends the SOH of the power battery to the management device. The specific content of the management device can be found in the relevant description of the above embodiments and will not be repeated here.

[0150] After the BMS sends a discharge command and a charge command to the charge and discharge device, the charge and discharge device can interact with the BMS to determine whether the BMS supports the V2G function. When the BMS supports the V2G function, the power grid and the power battery can perform two-way energy exchange through the charge and discharge device. Figure 7 It is a flowchart of another embodiment of the SOH acquisition method applied to the charge and discharge device provided by this application.

[0151] Figure 7 Different from Figure 5 is that Figure 7 The SOH acquisition method shown may further include steps S307 to S309 and steps S310 to S312.

[0152] In step S307, the charge and discharge device interacts with the BMS to determine whether the BMS supports the vehicle-to-grid V2G function.

[0153] For the specific content of step S307, reference can be made to the relevant description of step S208 in the above embodiment, which will not be elaborated here.

[0154] In step S308, when the BMS supports the V2G function, the charge and discharge device performs a communication handshake with the BMS.

[0155] For the specific content of step S308, reference can be made to the relevant description of step S209 in the above embodiment, which will not be elaborated here.

[0156] In step S309, when the communication handshake between the charge and discharge device and the BMS is successful, the charge and discharge device receives the discharge parameter configuration message sent by the charge and discharge device.

[0157] The discharge parameter configuration message includes the discharge voltage and the discharge current.

[0158] For the specific content of step S309, reference can be made to the relevant description of step S210 in the above embodiment, which will not be elaborated here.

[0159] In step S310, the charge and discharge device interacts with the BMS to determine whether the BMS supports the V2G function.

[0160] For the specific content of step S310, reference can be made to the relevant description of step S208 in the above embodiment, which will not be elaborated here.

[0161] In step S311, when the BMS supports the V2G function, the charge and discharge device performs a communication handshake with the BMS.

[0162] For the specific content of step S311, reference can be made to the relevant description of step S209 in the above embodiment, which will not be elaborated here.

[0163] In step S312, when the communication handshake between the charging and discharging device and the BMS is successful, the charging and discharging device receives the charging parameter configuration message sent by the charging and discharging device.

[0164] The charging parameter configuration message includes the charging voltage and charging current.

[0165] The specific content of step S312 can be found in the relevant description of step S213 in the above embodiment, which will not be repeated here.

[0166] In some examples, after executing step S307 and step S308, step S310 and step S311 may be omitted, that is, only one determination of whether the BMS supports the V2G function and one communication handshake between the BMS and the charging and discharging device may be performed.

[0167] In other embodiments, the charging and discharging device may first switch to charging mode, and the BMS may obtain second battery status data. The charging mode may be terminated when the BMS detects that the highest voltage of the power battery's cells reaches the charging cut-off voltage. The charging and discharging device then switches to discharging mode, and the BMS obtains first battery status data. The state of health (SOH) of the power battery is obtained based on the first and second battery status data. The discharge mode may be terminated when the BMS detects that the lowest voltage of the power battery's cells reaches the discharging cut-off voltage.

[0168] That is to say, in the embodiment of the present application, the order in which the BMS sends the discharge command and the charge command to the charging and discharging device is not limited, that is, the order in which the charging and discharging device switches to the discharge mode and the charging mode is not limited.

[0169] When the charging and discharging device is first switched to the charging mode and then switched to the discharging mode, the charging process in the charging mode, the discharging process in the discharging mode, and the interaction between the charging process and the discharging process can all be referred to the relevant contents in the above embodiments and will not be repeated here.

[0170] For example, if the BMS first sends a charge command to the charging and discharging device, and the BMS detects that the highest voltage of the power battery cells has reached the charge cut-off voltage, the charging and discharging device stops charging the power battery and places the power battery in a rest state for a first preset time. When the rest time reaches the first preset time, the charging and discharging device switches to the discharge mode.

[0171] For ease of understanding, two examples are used below to illustrate the process of SOH acquisition in the embodiments of the present application.

[0172] In this example, the charging and discharging device is first switched to the discharging mode and then switched to the charging mode. Figure 8 This is a flow chart of an example of the SOH acquisition process provided in the embodiment of the present application. Figure 8As shown, the SOH acquisition process includes steps S401 to S427.

[0173] In step S401, the charge-discharge device receives an SOH detection mode input.

[0174] In step S402, the charge-discharge device sends an SOH detection request command to the BMS in response to the SOH detection mode input.

[0175] In step S403, the BMS sends a discharge command to the charge-discharge device in response to the SOH detection request command.

[0176] In step S404, the charge-discharge device sends a CDC message to the BMS.

[0177] In step S405, the BMS supports the V2G function and feeds back a BDC message to the charge-discharge device.

[0178] In step S406, the charge-discharge device sends a CHM message to the BMS.

[0179] In step S407, in response to the CHM message, the BMS sends a BHM message to the charge-discharge device.

[0180] In step S408, the charge-discharge device sends a CRM message to the BMS.

[0181] In step S409, the BMS sends a BRM message to the charge-discharge device.

[0182] In step S410, the BMS sends a discharge parameter configuration message to the charge-discharge device.

[0183] In step S411, the charge-discharge device switches to the discharge mode and discharges the power battery to the power grid through the charge-discharge device according to the discharge parameter configuration message.

[0184] In step S412, the BMS obtains the first battery state data during the process of discharging the power battery to the power grid through the charge-discharge device.

[0185] In step S413, when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, the BMS sends a discharge stop command to the charge-discharge device.

[0186] In step S414, the charge-discharge device stops discharging the power battery to the power grid in response to the discharge stop command and makes the power battery stand still for the first preset duration.

[0187] In step S415, the BMS sends a charging command to the charge-discharge device.

[0188] In step S416, the charge-discharge device sends a CDC message to the BMS.

[0189] In step S417, the BMS supports the V2G function and feeds back a BDC message to the charge-discharge device.

[0190] In step S418, the charge-discharge device sends a CHM message to the BMS.

[0191] In step S419, the BMS sends a BHM message to the charge-discharge device.

[0192] In step S420, the charge-discharge device sends a CRM message to the BMS.

[0193] In step S421, the BMS sends a BRM message to the charge-discharge device.

[0194] In step S422, the BMS sends a charging parameter configuration message to the charge-discharge device.

[0195] In step S423, the charge-discharge device switches to the charging mode and realizes the charging of the power battery by the power grid through the charge-discharge device according to the charging parameter configuration message.

[0196] In step S424, during the process of the power grid charging the power battery through the charge-discharge device, the BMS obtains the second battery state data.

[0197] In step S425, when the BMS detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage, the BMS sends a charging stop instruction to the charge-discharge device.

[0198] In step S426, in response to the charging stop instruction, the charge-discharge device stops the charging of the power battery by the power grid.

[0199] In step S427, the BMS obtains the SOH based on the first battery state data and the second battery state data.

[0200] In this example, the charge-discharge device first switches to the charging mode and then switches to the discharging mode. Figure 9 It is a flowchart of another example of the SOH acquisition process provided by the embodiment of the present application. As Figure 9 shown, this SOH acquisition process includes steps S501 to step S527.

[0201] In step S501, the charge-discharge device receives an SOH detection mode input.

[0202] In step S502, in response to the SOH detection mode input, the charge-discharge device sends an SOH detection request instruction to the BMS.

[0203] In step S503, in response to the SOH detection request instruction, the BMS sends a charging command to the charge and discharge device.

[0204] In step S504, the charge and discharge device sends a CDC message to the BMS.

[0205] In step S505, the BMS supports the V2G function and feeds back a BDC message to the charge and discharge device.

[0206] In step S506, the charge and discharge device sends a CHM message to the BMS.

[0207] In step S507, the BMS sends a BHM message to the charge and discharge device.

[0208] In step S508, the charge and discharge device sends a CRM message to the BMS.

[0209] In step S509, the BMS sends a BRM message to the charge and discharge device.

[0210] In step S510, the BMS sends a charging parameter configuration message to the charge and discharge device.

[0211] In step S511, the charge and discharge device switches to the charging mode and realizes the charging of the power battery by the power grid through the charge and discharge device according to the charging parameter configuration message.

[0212] In step S512, during the process of the power grid charging the power battery through the charge and discharge device, the BMS obtains the second battery state data.

[0213] In step S513, when the BMS detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage, the BMS sends a charging stop instruction to the charge and discharge device.

[0214] In step S514, in response to the charging stop instruction, the charge and discharge device stops the charging of the power grid to the power battery and makes the power battery stand still for the first preset duration.

[0215] In step S515, the BMS sends a discharging command to the charge and discharge device.

[0216] In step S516, the charge and discharge device sends a CDC message to the BMS.

[0217] In step S517, the BMS supports the V2G function and feeds back a BDC message to the charge and discharge device.

[0218] In step S518, the charge and discharge device sends a CHM message to the BMS.

[0219] In step S519, the BMS sends a BHM message to the charge and discharge device.

[0220] In step S520, the charge and discharge device sends a CRM message to the BMS.

[0221] In step S521, the BMS sends a BRM message to the charge and discharge device.

[0222] In step S522, the BMS sends a discharge parameter configuration message to the charge and discharge device.

[0223] In step S523, the charge and discharge device switches to the discharge mode and realizes the charging of the power battery to the power grid through the charge and discharge device according to the discharge parameter configuration message.

[0224] In step S524, during the process of the power battery discharging to the power grid through the charge and discharge device, the BMS acquires the first battery state data.

[0225] In step S525, when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage, the BMS sends a discharge stop command to the charge and discharge device.

[0226] In step S526, in response to the discharge stop command, the charge and discharge device stops the discharge of the power battery to the power grid.

[0227] In step S527, the BMS acquires the SOH based on the first battery state data and the second battery state data.

[0228] The embodiment of the present application also provides a battery management system BMS. Figure 10 It is a schematic structural diagram of an embodiment of the BMS provided by the present application. As Figure 10 shown, the BMS 600 may include a sending module 601, a data acquisition module 602, a control module 603, and a calculation module 604.

[0229] The sending module 601 can be used to send a discharge command to the charge and discharge device.

[0230] The discharge command is used for the charge and discharge device to switch to the discharge mode. The discharge mode is that the power battery discharges to the power grid through the charge and discharge device. The power battery includes more than one battery cell.

[0231] The data acquisition module 602 can be used to acquire the first battery state data.

[0232] In some examples, the first battery state data includes the voltage and current of the battery cell.

[0233] The sending module 601 can also be used to send a charge command to the charge and discharge device when it detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage.

[0234] The charging command is used to switch the charge-discharge device to the charging mode. The charging mode is that the power grid charges the power battery through the charge-discharge device.

[0235] The data acquisition module 602 can also be used to acquire the second battery status data.

[0236] In some examples, the second battery status data includes the voltage of the battery cell and the current of the battery cell.

[0237] The control module 603 can be used to control the charge-discharge device to stop charging the power battery when it detects that the highest voltage of the single battery in the power battery reaches the charging cut-off voltage.

[0238] The calculation module 604 can be used to obtain the SOH of the power battery based on the first battery status data and the second battery status data.

[0239] In the embodiments of the present application, the BMS sends a discharge command and a charging command to the charge-discharge device, so that the charge-discharge device can be switched to the discharge mode and the charging mode. When the charge-discharge device is switched to the discharge mode, the power battery discharges to the power grid through the charge-discharge device. During the process of the power battery discharging to the power grid through the charge-discharge device, the BMS can acquire the first battery status data. When the charge-discharge device is switched to the charging mode, the power grid charges the power battery through the charge-discharge device. In the case where the power grid charges the power battery through the charge-discharge device, the BMS can acquire the second battery status data. The first battery status data and the second battery status data obtained by the BMS are more accurate than the battery status data obtained by external detection devices, so that the SOH of the power battery obtained by using the first battery status data and the second battery status data obtained by the BMS is more accurate, improving the accuracy of the SOH.

[0240] In some embodiments, the control module 603 can also be used to control the charge-discharge device to stop discharging to the power grid and keep the power battery static for the first preset duration when the BMS detects that the lowest voltage of the single battery in the power battery reaches the discharge cut-off voltage.

[0241] In some examples, the first preset duration is 1 hour.

[0242] Figure 11 It is a schematic structural diagram of another embodiment of the BMS provided by the present application. Figure 11 Different from Figure 10 is that Figure 11 The BMS 600 shown can also include a receiving module 605.

[0243] The sending module 601 and the receiving module 605 can be used to interact with the charge-discharge device to enable the charge-discharge device to determine whether the BMS 600 supports the vehicle-to-grid V2G function.

[0244] The sending module 601 and the receiving module 605 can also be used to perform communication handshake with a charging and discharging device when the BMS supports the V2G function.

[0245] The sending module 601 can also be used to send a discharge parameter configuration message to the charging and discharging device when the communication handshake with the charging and discharging device is successful.

[0246] The discharge parameter configuration message includes a discharge voltage and a discharge current.

[0247] The sending module 601 can also be used to send a charging parameter configuration message to the charging and discharging device when the communication handshake with the charging and discharging device is successful.

[0248] The charging parameter configuration message includes a charging voltage and a charging current.

[0249] In some embodiments, the sending module 601 can also be used to send the SOH of the power battery to the charging and discharging device, so that the charging and discharging device sends the SOH of the power battery to the management device.

[0250] An embodiment of the present application also provides a charging and discharging device. Figure 12 It is a schematic structural diagram of an embodiment of the charging and discharging device provided by the present application. As Figure 12 shown, the charging and discharging device 700 can include a receiving module 701, a mode switching module 702, and a control module 703.

[0251] The receiving module 701 can be used to receive a discharge command sent by a battery management system BMS.

[0252] The mode switching module 702 can be used to switch to a discharge mode.

[0253] The discharge mode is that the power battery discharges to the power grid through the charging and discharging device. The power battery includes more than one battery cell.

[0254] The receiving module 701 can also be used to receive a charging command sent by the BMS when the BMS detects that the minimum voltage of the single battery in the power battery reaches the discharge cut-off voltage.

[0255] The mode switching module 702 can also be used to switch to a charging mode.

[0256] The charging mode is that the power grid charges the power battery through the charging and discharging device.

[0257] The control module 703 can be used to stop charging the power battery when the BMS detects that the maximum voltage of the single battery in the power battery reaches the charging cut-off voltage.

[0258] Among them, the first battery state data acquired by the BMS when the charging and discharging device 700 is in the discharging mode, and the second battery state data acquired by the BMS when the charging and discharging device 700 is in the charging mode are used to obtain the SOH of the power battery.

[0259] In some examples, the first battery state data includes the voltage of the battery cell and the current of the battery cell. The second battery state data includes the voltage of the battery cell and the current of the battery cell.

[0260] In the embodiments of the present application, the charging and discharging device receives the discharging command and the charging command sent by the BMS, and can switch to the discharging mode and the charging mode. When the charging and discharging device switches to the discharging mode, the power battery discharges to the power grid through the charging and discharging device. During the process of the power battery discharging to the power grid through the charging and discharging device, the BMS can acquire the first battery state data. When the charging and discharging device switches to the charging mode, the power grid charges the power battery through the charging and discharging device. In the case where the power grid charges the power battery through the charging and discharging device, the BMS can acquire the second battery state data. The first battery state data and the second battery state data acquired by the BMS are more accurate than the battery state data acquired by the external detection device, making the SOH of the power battery obtained by using the first battery state data and the second battery state data acquired by the BMS more accurate, and improving the accuracy of the SOH.

[0261] In some embodiments, the control module 703 can also be used to stop discharging to the power grid when the BMS detects that the minimum voltage of the battery cell in the power battery reaches the discharging cut-off voltage, so as to make the power battery stand still for the first preset duration.

[0262] In some examples, the first preset duration is 1 hour.

[0263] Figure 13 It is a schematic structural diagram of another embodiment of the charging and discharging device provided by the present application. Figure 13 Different from Figure 12 is that Figure 13 the charging and discharging device shown may further include a sending module 704.

[0264] The receiving module 701 and the sending module 704 can be used to interact with the BMS to determine whether the BMS supports the vehicle-to-grid V2G function.

[0265] The receiving module 701 and the sending module 704 can also be used to perform a communication handshake with the BMS when the BMS supports the V2G function;

[0266] The receiving module 701 can also be used to receive the discharging parameter configuration message sent by the charging and discharging device when the communication handshake with the BMS is successful.

[0267] The discharge parameter configuration message includes the discharge voltage and the discharge current.

[0268] The receiving module 701 can also be used to receive the charging parameter configuration message sent by the charging and discharging device when the communication handshake with the BMS is successful.

[0269] The charging parameter configuration message includes the charging voltage and the charging current.

[0270] In some embodiments, the receiving module 701 can also be used to receive the SOH of the power battery sent by the BMS.

[0271] The sending module 704 can also be used to receive the SOH of the power battery sent by the BMS.

[0272] An embodiment of the present application also provides a BMS. Figure 14 It is a schematic hardware structure diagram of an embodiment of the BMS provided by the present application. As Figure 14 shown, the BMS 800 includes a memory 801, a processor 802, and a computer program stored on the memory 801 and executable on the processor 802.

[0273] In one example, the above-mentioned processor 802 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0274] The memory 801 may include a read-only memory (ROM), a random access memory (RAM), a disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described in reference to the SOH acquisition method applied to the BMS according to the embodiments of the present application.

[0275] The processor 802 runs the computer program corresponding to the executable program code by reading the executable program code stored in the memory 801, so as to implement the SOH acquisition method applied to the BMS in the above embodiments.

[0276] In one example, the BMS 800 may further include a communication interface 803 and a bus 804. Among them, as Figure 14As shown, the memory 801, the processor 802, and the communication interface 803 are connected via the bus 804 to complete communication with each other.

[0277] The communication interface 803 is mainly used to implement communication between various modules, devices, units, and / or equipment in the embodiments of the present application. Input devices and / or output devices can also be accessed through the communication interface 803.

[0278] The bus 804 includes hardware, software, or both, coupling the components of the BMS 800 to each other. By way of example and not limitation, the bus 804 can include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses or a combination of two or more of these. In suitable cases, the bus 804 can include one or more buses. Although the embodiments of the present application describe and illustrate specific buses, the present application contemplates any suitable bus or interconnect.

[0279] The embodiments of the present application also provide a charge and discharge device. Figure 15 It is a schematic hardware structure diagram of an embodiment of the charge and discharge device provided by the present application. As Figure 15 shown, the charge and discharge device 900 includes a memory 901, a processor 902, and a computer program stored on the memory 901 and executable on the processor 902.

[0280] In one example, the above-mentioned processor 902 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be one or more integrated circuits configured to implement the embodiments of the present application.

[0281] The memory 901 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described in reference to the SOH acquisition method applied to the charge-discharge device according to the embodiments of the present application.

[0282] The processor 902 runs a computer program corresponding to the executable program code by reading the executable program code stored in the memory 901, so as to implement the SOH acquisition method applied to the charge-discharge device in the above embodiments.

[0283] In one example, the charge-discharge device 900 may further include a communication interface 903 and a bus 904. Among them, as Figure 15 shown, the memory 901, the processor 902, and the communication interface 903 are connected through the bus 904 and complete communication with each other.

[0284] The communication interface 903 is mainly used to implement communication between various modules, devices, units and / or devices in the embodiments of the present application. The input device and / or output device may also be accessed through the communication interface 903.

[0285] The bus 904 includes hardware, software, or both, and couples components of the charge and discharge device 900 together. By way of example and not limitation, the bus 904 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industrial Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses or a combination of two or more of these. Where appropriate, the bus 904 may include one or more buses. Although embodiments of the present application describe and illustrate specific buses, the present application contemplates any suitable bus or interconnect.

[0286] Embodiments of the present application also provide a SOH acquisition system. The SOH acquisition system may include the BMS and the charge and discharge device in the above embodiments. For the specific contents of the BMS, the charge and discharge device, the SOH acquisition method executed by the BMS, the SOH acquisition method executed by the charge and discharge device, etc., reference may be made to the relevant descriptions in the above embodiments, and details are not repeated here.

[0287] The embodiments of the present application also provide a computer-readable storage medium, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the SOH acquisition methods applied to the BMS or the SOH acquisition methods applied to the charge and discharge device in the above embodiments can be implemented, and the same technical effects can be achieved. To avoid repetition, details are not described here. Among them, the above computer-readable storage medium may include a non-transitory computer-readable storage medium, such as a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc, etc., which is not limited herein.

[0288] It should be clear that the various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments. For the BMS embodiments, the charge and discharge device embodiments, the SOH acquisition system embodiments, and the computer-readable storage medium embodiments, the relevant parts can be referred to the description part of the method embodiments. The present application is not limited to the specific steps and structures described above and shown in the figures. Those skilled in the art can make various changes, modifications, and additions, or change the order between steps after understanding the spirit of the present application. And, for the sake of brevity, the detailed description of known method technologies is omitted here.

[0289] As described above, various aspects of the present application have been described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each block in the flowchart and / or block diagram, and the combination of blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, so as to generate a machine, such that these instructions executed by the processor of the computer or other programmable data processing devices enable the implementation of the functions / actions specified in one or more blocks of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can also be implemented by dedicated hardware that executes the specified functions or actions, or can be implemented by the combination of dedicated hardware and computer instructions.

[0290] Those skilled in the art should understand that the above embodiments are all exemplary rather than restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on the study of the drawings, the description, and the claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other devices or steps; the quantifier "one" does not exclude a plurality; the terms "first" and "second" are used to label names rather than to indicate any particular order. Any reference signs in the claims should not be construed as limiting the scope of protection. The functions of multiple parts appearing in the claims can be implemented by a single hardware or software module. The fact that certain technical features appear in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A method for obtaining battery health status SOH, characterized in that: include: The battery management system (BMS) sends a discharge command to the charge-discharge device, wherein the discharge command is used to switch the charge-discharge device to a discharge mode, wherein the discharge mode is for the power battery to discharge to the power grid through the charge-discharge device, and the power battery includes one or more battery cells; The BMS acquires first battery status data; When the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, the BMS sends a charging command to the charging and discharging device, where the charging command is used to switch the charging and discharging device to a charging mode in which the power grid charges the power battery through the charging and discharging device; The BMS acquires second battery status data; When the BMS detects that the highest voltage of the single cells in the power battery reaches the charging cut-off voltage, the BMS controls the charging and discharging device to stop charging the power battery; The BMS acquires the SOH of the power battery based on the first battery status data and the second battery status data; After the battery management system BMS sends a discharge command to the charging and discharging device, the method further includes: The BMS interacts with the charging and discharging device, so that the charging and discharging device determines whether the BMS supports a vehicle-to-grid (V2G) function; When the BMS supports the V2G function, the BMS performs a communication handshake with the charging and discharging device; When the BMS successfully communicates with the charging and discharging device, the BMS sends a discharge parameter configuration message to the charging and discharging device, where the discharge parameter configuration message includes a discharge voltage and a discharge current. After sending the charging command to the charging and discharging device, the method further includes: The BMS interacts with the charging and discharging device, so that the charging and discharging device determines whether the BMS supports the V2G function; When the V2G function is supported, the BMS performs a communication handshake with the charging and discharging device; When the BMS successfully communicates with the charging and discharging device, it sends a charging parameter configuration message to the charging and discharging device, where the charging parameter configuration message includes a charging voltage and a charging current.

2. The method according to claim 1, characterized in that Before sending the charging command to the charging and discharging device, the method further includes: When the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, the BMS controls the charge and discharge device to stop discharging to the power grid and places the power battery at rest for a first preset time period.

3. The method according to claim 2, characterized in that The first preset duration is 1 hour.

4. The method according to claim 1, wherein After the BMS acquires the SOH of the power battery based on the first battery status data and the second battery status data, the method further includes: The BMS sends the SOH of the power battery to the charging and discharging device, so that the charging and discharging device sends the SOH of the power battery to a management device.

5. The method according to any one of claims 1 to 4, characterized in that The first battery status data includes the voltage of the battery cell and the current of the battery cell; The second battery status data includes a voltage of a battery cell and a current of a battery cell.

6. A method for obtaining battery health status SOH, characterized in that: include: The charging and discharging device receives the discharge command sent by the battery management system BMS; The charging and discharging device is switched to a discharging mode, wherein the discharging mode is that the power battery discharges to the power grid through the charging and discharging device, and the power battery includes one or more battery cells; When the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, the charging and discharging device receives a charging command sent by the BMS; The charging and discharging device is switched to a charging mode, in which the power grid charges the power battery through the charging and discharging device; When the BMS detects that the highest voltage of the single cells in the power battery reaches the charge cut-off voltage, the charging and discharging device stops charging the power battery; Wherein, the first battery status data acquired by the BMS when the charging and discharging device is in the discharging mode, and the second battery status data acquired by the BMS when the charging and discharging device is in the charging mode are used to acquire the SOH of the power battery; After the charging and discharging device receives the discharge command sent by the battery management system BMS, the method further includes: The charging and discharging device interacts with the BMS to determine whether the BMS supports a vehicle-to-grid (V2G) function; The charging and discharging device performs a communication handshake with the BMS when the BMS supports the V2G function; When the communication handshake between the charging and discharging device and the BMS is successful, the charging and discharging device receives a discharge parameter configuration message sent by the charging and discharging device, where the discharge parameter configuration message includes a discharge voltage and a discharge current; After the charging and discharging device receives the charging command sent by the BMS, the method further includes: The charging and discharging device interacts with the BMS to determine whether the BMS supports the V2G function; The charging and discharging device performs a communication handshake with the BMS when the BMS supports the V2G function; When the communication handshake between the charging and discharging device and the BMS is successful, the charging and discharging device receives a charging parameter configuration message sent by the charging and discharging device, where the charging parameter configuration message includes a charging voltage and a charging current.

7. The method according to claim 6, characterized in that Before the charging and discharging device receives the charging command sent by the BMS, the method further includes: When the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, the charging and discharging device stops discharging to the power grid, so that the power battery rests for a first preset time period.

8. The method according to claim 7, characterized in that The first preset duration is 1 hour.

9. The method according to claim 6, characterized in that Also includes: The charging and discharging device receives the SOH of the power battery sent by the BMS; The charging and discharging device sends the SOH of the power battery to a management device.

10. The method according to any one of claims 6 to 9, characterized in that The first battery status data includes the voltage of the battery cell and the current of the battery cell; The second battery status data includes a voltage of a battery cell and a current of a battery cell.

11. A battery management system implemented using the method according to any one of claims 1 to 4, characterized in that: include: a sending module, configured to send a discharge command to the charging and discharging device, wherein the discharge command is used to switch the charging and discharging device to a discharge mode, wherein the discharge mode is for a power battery to discharge to a power grid through the charging and discharging device, wherein the power battery includes one or more battery cells; A data acquisition module, configured to acquire first battery status data; The sending module is further configured to send a charging command to the charging and discharging device when detecting that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage, wherein the charging command is configured to cause the charging and discharging device to switch to a charging mode in which the power grid charges the power battery via the charging and discharging device; The data acquisition module is further used to acquire second battery status data; a control module, configured to control the charging and discharging device to stop charging the power battery when detecting that the highest voltage of a single cell in the power battery reaches the charging cut-off voltage; A calculation module is configured to obtain the SOH of the power battery based on the first battery status data and the second battery status data.

12. A charge-discharge device implemented using the method according to any one of claims 6 to 9, characterized in that: include: A receiving module is used to receive a discharge command sent by the battery management system BMS; a mode switching module, configured to switch to a discharge mode, wherein the discharge mode is that the power battery discharges to a power grid through the charge and discharge device, and the power battery includes one or more battery cells; The receiving module is further configured to receive a charging command sent by the BMS when the BMS detects that the lowest voltage of the single cells in the power battery reaches the discharge cut-off voltage; The mode switching module is further configured to switch to a charging mode, wherein the charging mode is that the power grid charges the power battery through the charging and discharging device; a control module, configured to stop charging the power battery when the BMS detects that the highest voltage of a single cell in the power battery reaches a charge cut-off voltage; The first battery status data acquired by the BMS when the charging and discharging device is in the discharging mode and the second battery status data acquired by the BMS when the charging and discharging device is in the charging mode are used to acquire the SOH of the power battery.

13. A battery management system, characterized in that: include: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the battery health status SOH acquisition method according to any one of claims 1 to 5 is implemented.

14. A charging and discharging device, characterized in that: include: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the battery health status SOH acquisition method according to any one of claims 6 to 10 is implemented.

15. A battery health status SOH acquisition system, characterized in that: It comprises the battery management system as claimed in claim 13 and the charging and discharging device as claimed in claim 14.

16. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the battery health status SOH acquisition method according to any one of claims 1 to 5 is implemented.

17. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the battery health status SOH acquisition method according to any one of claims 6 to 10 is implemented.

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