Battery charging method and charging and discharging device

Abstract

Embodiments of the present application provide a battery charging method and charging / discharging device capable of ensuring battery safety. The charging / discharging device includes a first DC / DC converter, a unidirectional AC / DC converter, and a control unit. The first DC / DC converter is a unidirectional DC / DC converter. The control unit is configured to: receive a first charging current and, based on the first charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery via an AC power source; receive a first discharging current and, based on the first discharging current, control the battery to discharge power; and receive a second charging current and, based on the second charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery via an AC power source.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery charging method and a charging and discharging device. Background Art

[0002] With the development of the times, electric vehicles have huge market prospects due to their high environmental protection, low noise, low cost of use and other advantages. They can effectively promote energy conservation and emission reduction, which is beneficial to the development and progress of society.

[0003] For electric vehicles and related sectors, battery technology is a crucial factor in their development. Battery safety, in particular, impacts the development and application of battery-related products and influences public acceptance of electric vehicles. Therefore, ensuring battery safety remains a technical challenge that needs to be addressed. Summary of the Invention

[0004] The embodiments of the present application provide a battery charging method and a charging and discharging device, which can ensure the safety performance of the battery.

[0005] In a first aspect, a charging and discharging device is provided, including a first DC / DC converter, a unidirectional AC / DC converter, and a control unit, wherein the first DC / DC converter is a unidirectional DC / DC converter, and the control unit is configured to: receive a first charging current sent by a battery management system (BMS) of a battery, and based on the first charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power supply; receive a first discharging current sent by the BMS, and control the battery to release power based on the first discharging current, wherein the first discharging current is the discharge current sent by the BMS when the first cumulative charge capacity of the battery is greater than or equal to a first cumulative charge capacity threshold and the voltage of a battery cell of the battery does not exceed the full charge voltage of the battery cell; receive a second charging current sent by the BMS, and based on the second charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply, wherein the second charging current is the charging current sent by the BMS when the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold.

[0006] In the embodiment of the present application, during the charging process of the battery, the charging and discharging device can charge and discharge the battery based on the first charging current and the first discharging current sent by the BMS, thereby avoiding problems such as heating and lithium ion aggregation of the battery due to continuous charging, and then avoiding safety problems of the battery caused by heating, lithium ion aggregation and other problems, such as battery combustion or explosion, thereby ensuring the safety performance of the battery.

[0007] Furthermore, the charging and discharging device includes a unidirectional AC / DC converter and a unidirectional DC / DC converter, that is, the structure of the charging and discharging device of the embodiment of the present application is the same as the structure of the existing charging pile. Therefore, the battery can be charged and discharged without changing the structure of the existing charging pile, which greatly reduces the charging cost.

[0008] In some possible embodiments, the control unit is further used to: receive a second discharge current sent by the BMS, and control the battery to release power based on the second discharge current, wherein the second discharge current is the discharge current sent by the BMS when the second cumulative charge of the battery is greater than or equal to a second cumulative charge threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage.

[0009] In the above technical solution, the charging and discharging device completes charging, discharging, and recharging of the battery through information exchange with the BMS, and can then further discharge the battery. In this way, the charging and discharging device of the embodiment of the present application can charge and discharge the battery multiple times, that is, the charging and discharging processes are cyclically performed, achieving gradual charging of the battery while ensuring battery performance.

[0010] In some possible embodiments, the control unit is further used to: receive a charge stop command sent by the BMS; and based on the charge stop command, control the unidirectional AC / DC converter and the first DC / DC converter to cause the AC power supply to stop charging the battery, wherein the charge stop command is a command sent by the BMS when the voltage of the battery cell of the battery exceeds the full charge voltage.

[0011] In some possible embodiments, the charging and discharging device further includes a second DC / DC converter; and the control unit is specifically configured to: based on the first discharge current, control the second DC / DC converter to release the charge of the battery into the energy storage unit.

[0012] The above technical solution releases the battery's power into the energy storage unit, allowing the energy storage unit to perform other operations based on the received power, thus avoiding power waste. Furthermore, the charging and discharging device of the present embodiment adds a second DC / DC converter to the existing charging pile, requiring minimal modification to the existing charging pile, thus reducing costs.

[0013] In some possible embodiments, the second DC / DC converter is a bidirectional DC / DC converter, and the control unit is further used to: when controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the first charging current, control the second DC / DC converter to charge the battery through the energy storage unit; and / or when controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the second charging current, control the second DC / DC converter to charge the battery through the energy storage unit.

[0014] In the above technical solution, the energy storage unit can not only receive the power released by the battery, but also charge the battery. On the one hand, this avoids the problem of being unable to continue to release the battery's power to the energy storage unit due to the power in the energy storage unit reaching full capacity, ensuring the normal progress of the charging process. On the other hand, the energy storage unit uses the power released by the battery to charge the battery, realizing the recycling of battery power and saving electricity. On the other hand, the AC power supply and the energy storage unit charge the battery at the same time, which is conducive to improving the battery charging rate and saving charging time.

[0015] In some possible embodiments, the first charging power with which the energy storage unit charges the battery is determined based on the discharge capacity of the energy storage unit, and the second charging power with which the AC power supply charges the battery is the difference between the required charging power of the battery and the second charging power.

[0016] In some possible embodiments, the control unit is specifically used to: obtain a battery state of charge (SOC) value of the energy storage unit; if the SOC is greater than a state of charge threshold, control the second DC / DC converter to charge the battery through the energy storage unit, and based on the first charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply; and / or if the SOC is greater than a state of charge threshold, control the second DC / DC converter to charge the battery through the energy storage unit, and based on the second charging current, control the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply.

[0017] The above technical solution determines whether to use the energy storage unit to assist the AC power supply to charge the battery according to the SOC of the energy storage unit, thereby improving the charging efficiency of the charging and discharging device when the energy storage unit has sufficient electricity stored.

[0018] In some possible embodiments, a charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

[0019] In the above technical solution, on the basis of ensuring the safety performance of the battery, the charging rate range of the first charging current and / or the second charging current is between 2C and 10C, thereby achieving the purpose of large-current fast charging, thereby increasing the charging amount of the battery during a single charging process, greatly reducing the charging time of the battery, and improving the user experience.

[0020] Furthermore, due to the accumulation of lithium ions at the negative electrode during continuous charging, the charging current is also limited, and thus it is impossible to use a continuous large current to achieve rapid charging of the battery. The technical solution of the embodiment of the present application uses a large current to charge the battery, and discharges the battery after a large current charge to release the lithium ions accumulated at the negative electrode of the battery during the charging process, and then the battery can be charged with a large current again to achieve rapid charging of the battery.

[0021] In some possible embodiments, the discharge rate of the first discharge current ranges from 0.1C to 1C.

[0022] In the above technical solution, the discharge rate of the first discharge current ranges from 0.1C to 1C to achieve low-current discharge, which aims to release the lithium ions accumulated at the negative electrode of the battery through the low-current discharge of the battery without causing excessive loss of the electricity already charged in the battery.

[0023] In some possible embodiments, a ratio of the first cumulative discharge capacity threshold to the first cumulative charge capacity threshold is less than or equal to 10%.

[0024] The above technical solution sets the ratio of the cumulative discharge threshold value during the discharge process and the cumulative charge threshold value during the charging process, which can better control the charge amount of the battery during the charging process and the discharge amount of the battery during the discharge process, so that the discharge amount is smaller and will not cause excessive loss of the charged electricity in the battery.

[0025] In some possible embodiments, at least one of the first charging current, the first discharging current, and the second charging current is determined based on a state parameter of the battery; wherein the state parameter of the battery includes at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge, and battery state of health.

[0026] In the above technical solution, when at least one of the first charging current, the second charging current and the first discharging current is a current determined according to the state parameters of the battery, it can better adapt to the current state parameters of the battery, improve the charging efficiency and / or discharging efficiency of the battery, and will not cause damage to the battery.

[0027] In some possible embodiments, the control unit is specifically used to: periodically receive the first charging current sent by the BMS; and / or periodically receive the first discharging current sent by the BMS; and / or periodically receive the second charging current sent by the BMS.

[0028] In the above technical solution, during the process of single charging and / or single discharging of the battery by the charging and discharging device, the charging current and / or discharging current are periodically sent by the BMS. On the one hand, through this embodiment, the charging and discharging device can charge the battery by regularly adjusting the charging current and / or discharging current to improve the charging and discharging efficiency. On the other hand, the charging and discharging device can also determine that the status of the BMS and the battery is normal through the regularly sent charging current and / or discharging current, so as to continue charging the battery or control the discharging of the battery to ensure the safety performance of the battery.

[0029] In some possible embodiments, the control unit is further used to: receive a first charging voltage sent by the BMS, wherein the first charging voltage and the first charging current are carried in a first battery charging requirement BCL message; and / or, receive a first discharging voltage sent by the BMS, wherein the first discharging voltage and the first discharging current are carried in a second BCL message; and / or, receive a second charging voltage sent by the BMS, wherein the second charging voltage and the second charging current are carried in a third BCL message.

[0030] In the above technical solution, the communication between the charging and discharging device and the BMS is compatible with the existing communication protocol between the charger and the BMS. Therefore, the communication between the charging and discharging device and the BMS is easy to implement and has good application prospects.

[0031] In a second aspect, a battery charging method is provided, which is applied to a charging and discharging device including a first DC / DC converter and a unidirectional AC / DC converter, wherein the first DC / DC converter is a unidirectional DC / DC converter, and the method includes: receiving a first charging current sent by a battery management system (BMS) of the battery, and based on the first charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power supply; receiving a first discharging current sent by the BMS, and controlling the battery to release power based on the first discharging current, wherein the first discharging current is the discharge current sent by the BMS when the first cumulative charge capacity of the battery is greater than or equal to a first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell; receiving a second charging current sent by the BMS, and based on the second charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply, wherein the second charging current is the charging current sent by the BMS when the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold.

[0032] In a third aspect, a charging and discharging device is provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the method in the above-mentioned second aspect or its various implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0034] Figure 1 This is an architectural diagram of a charging system applicable to an embodiment of the present application;

[0035] Figure 2 This is a schematic flow chart of a battery charging method provided in an embodiment of the present application;

[0036] Figure 3 is a schematic flow chart of another battery charging method provided in an embodiment of the present application;

[0037] Figure 4 is a schematic waveform diagram of the charging current and discharging current of the battery provided in the embodiment of the present application;

[0038] Figure 5is a schematic flow chart of another battery charging method provided in an embodiment of the present application;

[0039] Figure 6 is a schematic flow chart of another battery charging method provided in an embodiment of the present application;

[0040] Figure 7 is a schematic flow chart of another battery charging method provided in an embodiment of the present application;

[0041] Figure 8 is a schematic flow chart of another battery charging method provided in an embodiment of the present application;

[0042] Figure 9 This is a schematic structural block diagram of a battery management system BMS provided in an embodiment of the present application;

[0043] Figure 10 This is a schematic structural block diagram of a charging and discharging device provided in an embodiment of the present application;

[0044] Figure 11 is a schematic structural block diagram of another charging and discharging device provided in an embodiment of the present application;

[0045] Figure 12 This is a schematic structural block diagram of a power conversion unit in the charging and discharging device provided in an embodiment of the present application;

[0046] Figure 13 is a schematic structural block diagram of another power conversion unit provided in an embodiment of the present application;

[0047] Figure 14 is a schematic structural diagram of another power conversion unit provided in an embodiment of the present application;

[0048] Figure 15 is a schematic flow chart of a battery charging method according to an embodiment of the present application;

[0049] Figure 16 It is a schematic structural block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0050] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0051] In the description of this application, it should be noted that, unless otherwise specified, "plurality" means more than two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are merely for the purpose of facilitating the description of this application and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting this application. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the field of new energy, power batteries can serve as the main power source for electrical devices (such as vehicles, ships, or spacecraft), while energy storage batteries can serve as the charging source for electrical devices. The importance of both is self-evident. As an example and not a limitation, in some application scenarios, power batteries can be batteries in electrical devices, and energy storage batteries can be batteries in charging devices. For ease of description, in the following text, power batteries and energy storage batteries can be collectively referred to as batteries.

[0053] Currently, most batteries on the market are rechargeable batteries, the most common of which are lithium batteries, such as lithium-ion batteries or lithium-ion polymer batteries. During the charging process, batteries are generally charged continuously. However, continuous charging can cause lithium deposition and heating. These phenomena not only degrade battery performance and significantly shorten cycle life, but also limit the battery's fast-charging capacity and potentially lead to catastrophic consequences such as combustion and explosion, creating serious safety issues.

[0054] In order to ensure the safety performance of the battery, the present application proposes a new battery charging method and charging system.

[0055] Figure 1 The figure shows an architecture diagram of a charging system applicable to an embodiment of the present application.

[0056] like Figure 1 As shown, the charging system 100 may include: a charging and discharging device 110 and a battery system 120. Optionally, the battery system 120 may be a battery system in an electric vehicle (including a pure electric vehicle and a plug-in hybrid electric vehicle) or a battery system in other application scenarios.

[0057] Optionally, at least one battery pack may be provided in the battery system 120, and the at least one battery pack as a whole may be collectively referred to as a battery 121. In terms of the type of battery, the battery 121 may be any type of battery, including but not limited to: a lithium-ion battery, a lithium metal battery, a lithium-sulfur battery, a lead-acid battery, a nickel-cathode battery, a nickel-metal hydride battery, or a lithium-air battery, etc. In terms of the scale of the battery, the battery 121 in the embodiment of the present application may be a battery core / battery cell, or a battery module or a battery pack. Both the battery module and the battery pack may be formed by connecting multiple batteries in series and parallel. In the embodiment of the present application, the specific type and scale of the battery 121 are not specifically limited.

[0058] In addition, to intelligently manage and maintain the battery 121, prevent overcharging and over-discharging, and extend the battery's service life, the battery system 120 is generally further provided with a battery management system (BMS) 122 for monitoring the status of the battery 121. Optionally, the BMS 122 can be integrated with the battery 121 and provided in the same device / apparatus, or the BMS 122 can be provided as an independent device / apparatus outside the battery 121.

[0059] Specifically, the charging and discharging device 110 is a device for replenishing electric energy for the battery 121 in the battery system 120 and / or controlling the discharge of the battery 121 .

[0060] Optionally, the charging and discharging device 110 in the embodiment of the present application can be a common charging pile, a super charging pile, a charging pile supporting vehicle to grid (V2G) mode, or a charging and discharging device / equipment that can charge and / or discharge a battery. The embodiment of the present application does not limit the specific type and specific application scenario of the charging and discharging device 110.

[0061] Alternatively, as Figure 1 As shown, the charging and discharging device 110 can be connected to the battery 121 through the wire 130 and connected to the BMS 122 through the communication line 140, wherein the communication line 140 is used to realize information exchange between the charging and discharging device 110 and the BMS.

[0062] As an example, the communication line 140 includes, but is not limited to, a controller area network (CAN) communication bus or a daisy chain communication bus.

[0063] Optionally, the charging and discharging device 110 can communicate with the BMS 122 via a wireless network in addition to the communication line 140. The embodiment of the present application does not specifically limit the wired communication type or the wireless communication type between the charging and discharging device and the BMS 122.

[0064] Figure 2 1 shows a schematic flow chart of a battery charging method 200 proposed in an embodiment of the present application. Optionally, the method 200 in the embodiment of the present application may be applied to the above Figure 1 The charging and discharging device 110 and the battery system 120 are shown.

[0065] like Figure 2 As shown, the battery charging method 200 may include the following steps.

[0066] Step 210: The battery management system BMS obtains a first charging current.

[0067] Step 220: The BMS sends a first charging current to the charging and discharging device.

[0068] Step 230: The charging and discharging device charges the battery based on the first charging current.

[0069] Step 240 : If the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a first discharge current.

[0070] Step 250: The BMS sends a first discharge current to the charging and discharging device.

[0071] Step 260: The charge and discharge device controls the battery to discharge based on the first discharge current.

[0072] In an embodiment of the present application, a charging method that can be implemented between a charging and discharging device and a BMS is provided. During the charging process of the battery, the charging and discharging device can charge and discharge the battery based on the first charging current and the first discharging current sent by the BMS, thereby avoiding continuous charging of the battery, thereby avoiding problems such as heating and lithium ion aggregation caused by continuous charging of the battery. Since heating will cause the battery temperature to rise, the crystals generated by the aggregation of lithium ions may pierce the battery, causing electrolyte leakage and battery short circuit. Both the battery temperature rise and the battery short circuit may cause battery safety problems, such as causing the battery to burn or explode. Therefore, through the technical solution of the embodiment of the present application, the charging and discharging device can charge and discharge the battery based on the first charging current and the first discharging current sent by the BMS, which can ensure the safety performance of the battery. In addition, during the continuous charging process, the continuous aggregation of lithium ions will also cause lithium plating problems, affecting the service life and charging capacity of the battery. Therefore, through the technical solution of the embodiment of the present application, the service life and charging capacity of the battery can also be guaranteed.

[0073] Specifically, in steps 210 to 230, the BMS may first enter a charging mode to control the charging and discharging device to charge the battery. First, the BMS obtains a first charging current. After the BMS sends the first charging current to the charging and discharging device, the charging and discharging device charges the battery based on the received first charging current.

[0074] Optionally, the BMS may obtain the first charging current from its own functional unit (e.g., a storage unit or a processing unit), or the BMS may obtain the first charging current from other devices. In some embodiments, the first charging current may be a preset current, which may be a fixed value or may change over time in a preset manner. Alternatively, in other embodiments, the first charging current may be a current determined according to a state parameter of the battery, and the first charging current may change as the state parameter of the battery changes.

[0075] Optionally, the charging and discharging device can be connected to a power supply, which can be an AC power supply and / or a DC power supply. After receiving the information of the first charging current, the charging and discharging device charges the battery through the AC power supply and / or the DC power supply based on the first charging current.

[0076] Furthermore, when the charging and discharging device charges the battery based on the first charging current, the BMS can obtain a first cumulative charge capacity of the battery and determine whether the first cumulative charge capacity is greater than or equal to a first cumulative charge capacity threshold. If the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains the first discharge current.

[0077] Specifically, as above Figure 1As can be seen from the description of the battery in the , a battery can include one or more battery cells. The BMS can monitor the voltage of one or more battery cells in the battery to determine whether the battery has reached a full charge state. Optionally, if the battery includes multiple battery cells, the voltages of the multiple battery cells may be different. In this case, the battery can be fully charged by determining whether the maximum voltage of the battery cell exceeds the full charge voltage of the battery cell. Alternatively, in other methods, in addition to the maximum voltage of the battery cell, other voltages of the battery cell in the battery can also be used to determine whether the battery has reached a full charge state.

[0078] Under the premise that the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, that is, the battery has not reached a fully charged state, if the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold, the BMS obtains a first discharge current, that is, for the battery, it switches from a charging mode to a discharging mode.

[0079] Optionally, the first cumulative charge amount may be a first cumulative charge capacity or a first cumulative charge quantity. Correspondingly, if the first cumulative charge amount is the first cumulative charge capacity, the first cumulative charge amount threshold is the first cumulative charge capacity threshold; if the first cumulative charge amount is the first cumulative charge quantity, the first cumulative charge amount threshold is the first cumulative charge quantity threshold.

[0080] In some embodiments, the first cumulative charge amount threshold may be a preset threshold, which may be a fixed threshold or may change over time in a preset manner.

[0081] In other embodiments, the first cumulative charge capacity threshold can also be determined based on the battery status parameters, that is, when the battery status parameters change, the first cumulative charge capacity threshold also changes accordingly. Through this embodiment, the first cumulative charge capacity threshold can better adapt to the current battery status parameters, so as to better control the current charging process, improve the battery charging efficiency, and will not cause damage to the battery.

[0082] Furthermore, in step 240 to step 260 , the BMS obtains a first discharge current and sends the first discharge current to the charge and discharge device, and the charge and discharge device controls the discharge of the battery based on the received first discharge current.

[0083] Optionally, the BMS may obtain the first discharge current from its own functional unit (for example, a storage unit or a processing unit), or the BMS may obtain the first discharge current from other devices. In some embodiments, the first discharge current may be a preset current, which may be a fixed value, or may change over time in a preset manner. Alternatively, in other embodiments, the first discharge current may also be a current determined according to the state parameters of the battery, and the first discharge current changes with changes in the state parameters of the battery. In some embodiments, in the discharge mode or the discharge stage, the electricity of the battery may be transmitted to the energy storage device and / or the power grid, which is conducive to the recycling of electric energy. The energy storage device may be arranged in the charging and discharging device or outside the charging and discharging device, so that it can receive the discharge current of the battery. The embodiment of the present application does not limit the specific arrangement of the energy storage device. Optionally, in the discharge mode, the battery's electricity may also be consumed in other ways. The embodiment of the present application does not limit the specific way of consuming electric energy.

[0084] Furthermore, during the process of the charging and discharging device controlling the battery to discharge, the BMS may obtain a first cumulative discharge capacity of the battery during the discharge process, and determine whether the first cumulative discharge capacity is greater than or equal to a first cumulative discharge capacity threshold.

[0085] Optionally, the first cumulative discharge amount may be the first cumulative discharge capacity or the first cumulative discharge quantity. Correspondingly, if the first cumulative discharge amount is the first cumulative discharge capacity, the first cumulative discharge amount threshold is the first cumulative discharge capacity threshold; if the first cumulative discharge amount is the first cumulative discharge quantity, the first cumulative discharge amount threshold is the first cumulative discharge quantity threshold.

[0086] In some embodiments, the first cumulative discharge amount threshold may be a preset threshold, which may be a fixed threshold or may change over time in a preset manner.

[0087] In other embodiments, the first cumulative discharge capacity threshold value may also be determined based on the battery status parameters, that is, when the battery status parameters change, the first cumulative discharge capacity threshold value also changes accordingly. Through this embodiment, the first cumulative discharge capacity threshold value may be better adapted to the current battery status parameters, so as to better control the current discharge process, improve the battery discharge efficiency, and will not cause damage to the battery.

[0088] When the first accumulated discharge amount is greater than or equal to a first accumulated discharge amount threshold, the charge and discharge device controls the battery to stop discharging.

[0089] Through the above process, the charging and discharging device charges and discharges the battery based on the first charging current and the first discharging current sent by the BMS, thereby avoiding problems such as heating and lithium ion aggregation caused by continuous charging of the battery, and further avoiding battery safety issues such as battery combustion or explosion caused by heating and lithium ion aggregation, thereby ensuring the safety performance of the battery. In addition, after charging the battery to the first cumulative charge capacity based on the first charging current and then discharging the battery power to the first cumulative discharge capacity based on the first discharge current, the lithium ions accumulated at the negative electrode of the battery during the charging process can be released, preventing the problem of lithium plating caused by continuous charging, thereby improving the service life and charging capacity of the battery.

[0090] Regarding battery charging, after one charge and one discharge, the battery may be charged a second time to continue charging the battery.

[0091] Alternatively, as Figure 2 As shown, the battery charging method 200 in the embodiment of the present application may further include the following steps.

[0092] Step 270: If the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold, the BMS obtains a second charging current.

[0093] Step 280: The BMS sends a second charging current to the charging and discharging device.

[0094] Step 290: The charging and discharging device charges the battery based on the second charging current.

[0095] Specifically, in steps 270 to 290 above, when the BMS determines that the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold, the BMS obtains a second charging current and sends the second charging current to the charging and discharging device. The charging and discharging device continues to charge the battery based on the received second charging current. That is, for the battery, the discharge mode re-enters the charging mode. Optionally, other related technical solutions of steps 270 to 290 can be found in the relevant descriptions of steps 210 to 230 above, and will not be elaborated here.

[0096] It is understandable that in the above-mentioned application embodiment, in addition to the current information required for charging and discharging, the voltage information required for charging and discharging is also required for charging and discharging the battery. For example, in steps 210 to 230: the BMS obtains a first charging current and a first charging voltage, and sends the first charging current and the first charging voltage to the charging and discharging device, and the charging and discharging device is used to charge the battery based on the first charging current and the first charging voltage; in steps 240 to 260, the BMS obtains a first discharging current and a first discharging voltage, and sends the first discharging current and the first discharging voltage to the charging and discharging device, and the charging and discharging device is used to discharge the battery based on the first discharging current and the first discharging voltage. The subsequent charging and discharging process can be similar to the above-mentioned charging and discharging process and will not be repeated here.

[0097] Figure 3 A schematic flow chart of another battery charging method 300 provided in an embodiment of the present application is shown.

[0098] like Figure 3 As shown, the battery charging method 300 may further include the following steps in addition to the above steps 210 to 290 .

[0099] Step 310 : If the second cumulative charge capacity of the battery is greater than or equal to the second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a second discharge current.

[0100] Step 320: The BMS sends a second discharge current to the charging and discharging device.

[0101] Step 330: The charge and discharge device controls the battery to discharge based on the second discharge current.

[0102] In the embodiment of the present application, the battery is charged, discharged, recharged, and discharged again through information exchange between the BMS and the charging and discharging device. In this way, the embodiment of the present application can further provide a multi-cycle charging and discharging method, in which the charging and discharging processes are performed in a sequential manner, thereby achieving gradual charging of the battery while ensuring the safety performance of the battery.

[0103] Specifically, in step 310 , when the charging and discharging device charges the battery based on the second charging current, the BMS may obtain a second cumulative charge capacity of the battery and determine whether the second cumulative charge capacity is greater than or equal to a second cumulative charge capacity threshold.

[0104] Optionally, the second cumulative charge capacity may be solely the charge capacity of the battery by the charging and discharging device based on the second charging current, or the second cumulative charge capacity may be the current total charge capacity of the battery. For example, the current total charge capacity of the battery = the charge capacity based on the first charging current + the charge capacity based on the second charging current - the discharge capacity based on the first discharge current. Correspondingly, the second cumulative charge capacity threshold may also be a charge capacity threshold based on a single charge, or a charge capacity threshold based on the total charge capacity.

[0105] Similar to the first cumulative charge amount and the first cumulative charge amount threshold described above, in the embodiment of the present application, the second cumulative charge amount can be the second cumulative charge capacity or the second cumulative charge quantity. Correspondingly, if the second cumulative charge amount is the second cumulative charge capacity, the first cumulative charge amount threshold is the second cumulative charge capacity threshold; if the second cumulative charge amount is the second cumulative charge quantity, the second cumulative charge amount threshold is the second cumulative charge quantity threshold.

[0106] Optionally, in some embodiments, the second cumulative charge amount threshold may be a preset threshold, which may be a fixed threshold or may change in a preset manner over time.

[0107] In other embodiments, the second cumulative charge capacity threshold value may also be determined according to the battery status parameter, that is, when the battery status parameter changes, the second cumulative charge capacity threshold value also changes accordingly.

[0108] Furthermore, in step 310, when the second cumulative charge capacity is greater than or equal to the second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a second discharge current. In steps 320 and 330, the BMS transmits the second discharge current to the charge and discharge device, and the charge and discharge device controls the discharge of the battery based on the received second discharge current.

[0109] Specifically, other related technical solutions in the above steps can be found in the relevant descriptions of steps 240 to 260 above, and will not be elaborated here.

[0110] As an example, Figure 4 A schematic waveform diagram of the charging current and discharging current of a battery provided in an embodiment of the present application is shown.

[0111] like Figure 4As shown, from time t1 to t2, the charge-discharge device charges the battery using a first charging current until the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cells of the battery does not exceed the full charge voltage of the battery cells. From time t2 to t3, the charge-discharge device controls the discharge of the battery using the first discharge current until the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold. Optionally, the duration of the first discharge current may be shorter than the duration of the first charge current. From time t3 to t4, the charge-discharge device continues to charge the battery using a second charging current until the second cumulative charge capacity of the battery is greater than or equal to the second cumulative charge capacity threshold and the voltage of the battery cells of the battery does not exceed the full charge voltage of the battery cells. From time t4 to t5, the charge-discharge device controls the discharge of the battery using the second discharge current until the second cumulative discharge capacity of the battery is greater than or equal to the second cumulative discharge capacity threshold. Optionally, the duration of the second charging current may be shorter than the duration of the first charging current. It will be understood that the above charging and discharging process continues until the battery is fully charged.

[0112] It should be noted that Figure 4 The waveforms of the first charging current, the second charging current, the first discharging current and the second discharging current are schematically shown in FIG. The first charging current from t1 to t2 may be as follows: Figure 4 The constant current shown in FIG. 1 may also be a current that changes with time. Similarly, the second charging current, the first discharging current, and the second discharging current may be as follows: Figure 4 The constant current shown in FIG, or the current can also be a variable current that changes with time. Figure 4 The first charging current and the second charging current schematically shown in the figure are of the same magnitude, and the first discharging current and the second discharging current are of the same magnitude. In addition, the magnitudes of the first charging current and the second charging current may also be different, and the magnitudes of the first discharging current and the second discharging current may also be different. The embodiments of the present application do not specifically limit this.

[0113] Figure 5 A schematic flow chart of another battery charging method 500 provided in an embodiment of the present application is shown.

[0114] like Figure 5 As shown, the battery charging method 500 may further include the following steps in addition to the above steps 210 to 290 .

[0115] Step 510: If the voltage of a battery cell of the battery exceeds the full charge voltage of the battery cell, the BMS sends a charge stop command to the charging and discharging device.

[0116] Step 520: The charging and discharging device stops charging the battery.

[0117] Specifically, as described above, the BMS can monitor the voltage of one or more battery cells in a battery to determine whether the battery has reached a full charge state. Alternatively, in some embodiments, the BMS can determine whether the battery has reached a full charge state by determining whether the maximum voltage of a battery cell exceeds the full charge voltage of the battery cell. When the maximum voltage of a battery cell exceeds the full charge voltage of the battery cell, indicating that the battery has reached a full charge state, the BMS then sends a charge stop command to the charging and discharging device. This charge stop command is used to instruct the charging and discharging device to stop charging the battery, so that the charging and discharging device stops charging the battery.

[0118] Optionally, step 510 and step 520 may be performed during the charging stage of the battery. In other words, when the BMS enters the charging mode and the charging and discharging device receives the charging current sent by the BMS, during the process of charging the battery, the BMS may obtain the voltage of the battery cell of the battery to determine whether the battery has reached a fully charged state. Once the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell, the BMS sends a charging stop command to the charging and discharging device to cause the charging and discharging device to stop charging the battery.

[0119] therefore, Figure 5 It is only schematically shown that step 510 and step 520 are performed after step 290, that is, performed during the second charging process. It can be understood that step 510 and step 520 can also be performed during any charging process of multiple charging and discharging.

[0120] Optionally, in the above method embodiment, since a charging and discharging device is used to charge, discharge, and recharge the battery, safety problems caused by continuous charging to the battery can be prevented. Furthermore, the charging current in the above method can be a large current to increase the charging amount of the battery during a single charging process and achieve the purpose of fast charging.

[0121] In addition, due to the accumulation of lithium ions at the negative electrode during continuous charging, the charging current is also limited, so it is impossible to use a continuous large current to achieve fast charging of the battery. The technical solution of the embodiment of the present application uses a large current to charge the battery, and discharges the battery after a large current charging to release the lithium ions accumulated at the negative electrode of the battery during the charging process, and then the battery can be charged with a large current again to achieve fast charging of the battery.

[0122] Specifically, in the above method, the first charging current and / or the second charging current may be a large current. In addition, after the charging and discharging device charges the battery based on the second charging current, the charging current of the subsequent charging process may also be a large current.

[0123] Optionally, in order to achieve high-current fast charging, the charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

[0124] Furthermore, in the embodiment of the present application, the discharge current is a small current, which is intended to release the lithium ions accumulated at the negative electrode of the battery through the small current discharge of the battery without causing excessive loss of the electricity already charged in the battery.

[0125] Specifically, the first discharge current and / or the second discharge current in the above method may be a small current. In addition, after the charge and discharge device controls the discharge of the battery based on the second discharge current, the discharge current in the subsequent discharge process may also be a small current.

[0126] Optionally, in order to achieve low-current discharge, the charging rate of the first discharge current and / or the second discharge current is in a range of 0.1C to 1C.

[0127] Optionally, in the above method, in order to better control the charge amount of the battery during the charging process and the discharge amount of the battery during the discharging process, the ratio of the cumulative discharge amount threshold during the discharge process and the cumulative charge amount threshold during the charging process can be set so that the discharge amount is smaller without causing excessive loss of the charged electricity in the battery.

[0128] As an example, in the above method, the ratio of the first cumulative discharge amount threshold to the first cumulative charge amount threshold is less than or equal to 10%, and / or the ratio of the second cumulative discharge amount threshold to the second cumulative charge amount threshold is less than or equal to 10%.

[0129] In addition, after the charge and discharge device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the ratio of the cumulative discharge capacity threshold to the cumulative charge capacity threshold in the subsequent charge and discharge process may also be less than or equal to 10%.

[0130] It should be noted that the above ratio of 10% can also be adjusted as the application scenario and application requirements change, and this application does not limit the specific value of this ratio.

[0131] Optionally, in the above method embodiment, the first charging current and the second charging current obtained by the BMS may be the same or different. The first charging current and / or the second charging current may be a preset current, or the first charging current and / or the second charging current may also be a current determined according to the state parameters of the battery. When the state parameters of the battery change, the first charging current and / or the second charging current may be different currents corresponding to different state parameters. The state parameters of the battery include at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge (SOC) and battery state of health (SOH), etc.

[0132] Similarly, the first discharge current and the second discharge current obtained by the BMS may be the same or different. The first discharge current and / or the second discharge current may be a preset current, or the first discharge current and / or the second discharge current may also be a current determined according to the state parameters of the battery.

[0133] If at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current is a current determined according to the state parameters of the battery, it can better adapt to the current state parameters of the battery, improve the charging efficiency and / or discharging efficiency of the battery, and will not cause damage to the battery.

[0134] In addition, after the charging and discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the charging current and / or discharging current in the subsequent charging and discharging process can also be a preset current, or can also be a current determined according to the battery status parameters.

[0135] Figure 6 A schematic flow chart of another battery charging method 600 provided in an embodiment of the present application is shown.

[0136] Based on the above Figure 2 The method 200 shown, as Figure 6 As shown, the above step 210 may include:

[0137] Step 610: The BMS obtains state parameters of the battery and determines a first charging current according to the state parameters.

[0138] Step 240 above may include:

[0139] Step 640: If the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains the battery status parameter and determines the first discharge current according to the status parameter.

[0140] Step 270 above may include:

[0141] Step 670: If the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold, the BMS obtains the battery status parameter and determines the second charging current according to the status parameter.

[0142] In addition, other steps of the method 600 in the embodiment of the present application can be found in the above Figure 2 The description of the embodiments shown will not be repeated here.

[0143] Specifically, in the embodiment of the present application, the first charging current, the first discharging current, and the second charging current are all currents determined based on the battery state parameters. At different time periods, the BMS can obtain different battery state parameters and determine the current charging current and discharging current based on the state parameters.

[0144] Optionally, there are multiple ways to determine the charging current and discharging current based on the battery state parameters. As an example, a mapping relationship between the battery state parameters and the charging current and discharging current can be obtained. Based on this mapping relationship, the specific charging current and discharging current are determined using the battery state parameters. The mapping relationship can be a mapping relationship obtained by fitting a large amount of experimental data, with high credibility and accuracy. The mapping relationship can specifically be a mapping table, a mapping diagram, or a mapping formula. In addition, in other examples, a dedicated neural network model can be trained based on a large amount of experimental data. The neural network model can output the charging current and discharging current based on the input battery state parameters.

[0145] Optionally, in addition to the charging current and the discharging current, in the above method embodiment, the first cumulative charge threshold and the second cumulative charge threshold may be the same or different. The first cumulative discharge threshold and the second cumulative discharge threshold may be the same or different. At least one of the first cumulative charge threshold, the second cumulative charge threshold, the first cumulative discharge threshold, and the second cumulative discharge threshold may be a preset threshold. Alternatively, at least one of the first cumulative charge threshold, the second cumulative charge threshold, the first cumulative discharge threshold, and the second cumulative discharge threshold may also be a threshold determined based on a battery status parameter.

[0146] In addition, after the charging and discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the cumulative discharge capacity threshold and the cumulative charge capacity threshold in the subsequent charging and discharging process can be preset thresholds or thresholds determined according to the battery status parameters.

[0147] Through the above-mentioned application embodiment, if at least one of the first cumulative charge amount threshold, the second cumulative charge amount threshold, the first cumulative discharge amount threshold and the second cumulative discharge amount threshold is a threshold determined according to the state parameters of the battery, it can better adapt to the current state parameters of the battery, so as to better control the current charging process and / or discharging process, ensure the charging amount and discharging amount, and achieve efficient charging of the battery.

[0148] Optionally, in the above method embodiment, at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current may be a current obtained periodically or irregularly by the BMS. As an example, at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current may be a current determined periodically or irregularly by the BMS based on the state parameters of the battery, and the current changes as the state parameters of the battery change. Specifically, the BMS may periodically obtain the state parameters of the battery to determine at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current; or, the BMS obtains the state parameters of the battery in real time, and when the state parameters change irregularly, the BMS determines at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current based on the irregularly changing state parameters.

[0149] Further, on this basis, the BMS sends at least one of the first charging current, the second charging current, the first discharging current and the second discharging current to the charging and discharging device periodically or irregularly, so that the charging and discharging device charges the battery or controls the discharging of the battery based on the periodically sent current.

[0150] In this implementation, during a single charge and / or discharge of a battery by the charge and discharge device, the charge current and / or discharge current are sent periodically or irregularly by the BMS. This implementation allows for regular or irregular adjustment of the charge current and / or discharge current to improve charge and discharge efficiency. Furthermore, the regular or irregularly sent charge current and / or discharge current can indicate that the BMS and battery are in normal condition, allowing the charge and discharge device to continue charging the battery or controlling the discharge of the battery. Therefore, in this implementation, if the charge and discharge device does not receive the regular or irregularly sent charge current and / or discharge current by the BMS, the charge and discharge device can stop charging the battery and / or stop controlling the discharge of the battery to ensure battery safety.

[0151] Figure 7 A schematic flow chart of another battery charging method 700 provided in an embodiment of the present application is shown.

[0152] Based on the above Figure 2 The method 200 shown, as Figure 7 As shown, the above step 210 may include:

[0153] Step 710: The BMS periodically obtains a first charging current.

[0154] Step 220 above may include:

[0155] Step 720: The BMS periodically sends a first charging current to the charging and discharging device.

[0156] Step 240 above may include:

[0157] Step 740 : If the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, periodically obtain a first discharge current.

[0158] Step 250 above may include:

[0159] Step 750: The BMS periodically sends a first discharge current to the charging and discharging device.

[0160] Step 270 above may include:

[0161] Step 770: If the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold, periodically obtain a second charging current.

[0162] Step 280 above may include:

[0163] Step 780: The BMS periodically sends the second charging current to the charging and discharging device.

[0164] In addition, other steps of the method 700 in the embodiment of the present application can be found in the above Figure 2 The description of the embodiments shown will not be repeated here.

[0165] In the embodiment of the present application, the BMS may periodically obtain the first charging current, the first discharging current, and the second charging current. Correspondingly, the BMS may periodically send the first charging current, the first discharging current, and the second charging current to the charging and discharging device.

[0166] It is understandable that in the above embodiment, in addition to the current information required for charging and discharging, the voltage information required for charging and discharging is also required for charging and discharging the battery. The method for obtaining the voltage required for charging and discharging does not impose any limitation on the embodiment of the present invention.

[0167] Optionally, in the above method embodiment, the communication between the BMS and the charging and discharging device is compatible with the existing communication protocol between the charger and the BMS. Therefore, the communication between the BMS and the charging and discharging device is easy to implement and has good application prospects.

[0168] Specifically, based on the above method embodiment, the BMS may further obtain at least one of a first charging voltage, a second charging voltage, a first discharging voltage, and a second discharging voltage, and send at least one of the first charging voltage, the second charging voltage, the first discharging voltage, and the second discharging voltage to the charging and discharging device, wherein the first charging current and the first charging voltage are carried in a first battery charging requirement (BCL) message, and / or the first discharging current and the first discharging voltage are carried in a second BCL message, and / or the second charging current and the second charging voltage are carried in a third BCL message, and / or the second discharging current and the second discharging voltage are carried in a fourth BCL message.

[0169] In addition, after the charging and discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the charging current, charging voltage, discharging current and discharging voltage in the subsequent charging and discharging process can also be carried in the BCL message and sent to the charging and discharging device through the BMS.

[0170] Figure 8 A schematic flow chart of another battery charging method 800 provided in an embodiment of the present application is shown.

[0171] like Figure 8 As shown, the battery charging method 800 may include the following steps.

[0172] Step 810: The BMS obtains a first charging current and a first charging voltage.

[0173] Step 820: The BMS sends a first BCL message to the charging and discharging device. The first BCL message carries a first charging current and a first charging voltage.

[0174] Step 830: The charging and discharging device charges the battery based on the first charging current and the first charging voltage.

[0175] Step 840 : If the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a first discharge current and a first discharge voltage.

[0176] Step 850: The BMS sends a second BCL message to the charging and discharging device. The second BCL message carries the first discharge current and the second discharge voltage.

[0177] Step 860: The charge and discharge device controls the discharge of the battery based on the first discharge current and the second discharge voltage.

[0178] Step 870: If the first accumulated discharge amount of the battery is greater than or equal to the first accumulated discharge amount threshold, the BMS obtains a second charging current and a second charging voltage.

[0179] Step 880: The BMS sends a third BCL message to the charging and discharging device. The third BCL message carries the second charging current and the second charging voltage.

[0180] Step 890: The charging and discharging device charges the battery based on the second charging current and the second charging voltage.

[0181] In an embodiment of the present application, the battery charging requirement BCL message in the existing communication protocol between the charger and the BMS is used, and the BMS sends the charging current and the discharging current to the charging and discharging device, and the charging and discharging device charges the battery or controls the battery discharging based on the received charging current and the discharging current.

[0182] Optionally, in the BCL message, the range of the charging voltage (including the above-mentioned first charging voltage and second charging voltage) is different from that of the discharging voltage (including the above-mentioned first discharging voltage and second discharging voltage), and the range of the charging current (including the above-mentioned first charging current and second charging current) is different from that of the discharging current (including the above-mentioned first discharging current and second discharging current). In the BCL message received by the charging and discharging device, it can be judged whether it belongs to the charging voltage and charging current, or the discharging voltage and discharging current by the magnitude of the voltage and current carried therein.

[0183] Optionally, the BMS may determine the charging voltage and the discharging voltage according to the state parameters of the battery, or the charging voltage and the discharging voltage may be preset values.

[0184] Optionally, in some embodiments, the BMS may periodically obtain the charging current and charging voltage, and periodically send BCL messages carrying the charging current and charging voltage to the charging and discharging device. Similarly, the BMS may periodically obtain the discharging current and discharging voltage, and periodically send BCL messages carrying the discharging current and discharging voltage to the charging and discharging device. In this embodiment, the method for periodically sending BCL messages may be the same as the method for periodically sending BCL messages in existing standards.

[0185] In the above embodiment, the information interaction message of the charging and discharging current and / or voltage is used as an example. It can be understood that in order to realize the charging and discharging of the battery, in addition to the processing of the charging and discharging stages, it can also include the handshake interaction between the vehicle and the charger before charging and discharging, the parameter configuration interaction of charging and discharging, etc. The embodiment of the present invention does not make specific limitations on this.

[0186] Optionally, the communication protocol between the charger and the BMS includes a communication protocol in a vehicle to grid (V2G) mode and a grid to vehicle (G2V) mode.

[0187] Combined with the above Figures 2 to 8The specific embodiment of the battery charging method provided by the present application is described below. Figures 9 to 12 The specific embodiments of the relevant devices provided in this application are described. It can be understood that the relevant descriptions in the following device embodiments can refer to the aforementioned method embodiments. For the sake of brevity, they are not repeated here.

[0188] Figure 9 FIG1 shows a schematic structural block diagram of a battery management system BMS 900 according to an embodiment of the present application. Figure 9 As shown, the BMS 900 includes: an acquiring unit 910 , a sending unit 920 and a processing unit 930 .

[0189] In one embodiment of the present application, the acquisition unit 910 is used to acquire a first charging current; the sending unit 920 is used to send the first charging current to the charging and discharging device so that the charging and discharging device charges the battery based on the first charging current; the processing unit 930 is used to determine that when the first cumulative charge amount of the battery is greater than or equal to the first cumulative charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the acquisition unit 910 is also used to acquire a first discharge current; the sending unit 920 is also used to send the first discharge current to the charging and discharging device so that the charging and discharging device controls the discharge of the battery based on the first discharge current; optionally, when the processing unit 930 is also used to determine that the first cumulative discharge amount of the battery is greater than or equal to the first cumulative discharge amount threshold, the acquisition unit 910 is also used to acquire a second charging current; the sending unit 920 is also used to send the second charging current to the charging and discharging device so that the charging and discharging device charges the battery based on the second charging current.

[0190] Optionally, the processing unit 930 is further used to determine that when the second cumulative charge capacity of the battery is greater than or equal to a second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the acquisition unit 910 is also used to obtain a second discharge current; the sending unit 920 is also used to send the second discharge current to the charging and discharging device so that the charging and discharging device controls the discharge of the battery based on the second discharge current.

[0191] Optionally, the processing unit 930 is further configured to determine whether the voltage of a battery cell of the battery exceeds the full charge voltage of the battery cell, and the sending unit 920 is further configured to send a charge stop command to the charging and discharging device, wherein the charge stop command is configured to instruct the charging and discharging device to stop charging the battery.

[0192] Optionally, the charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

[0193] Optionally, the discharge rate of the first discharge current and / or the second discharge current ranges from 0.1C to 1C.

[0194] Optionally, the ratio of the first cumulative discharge capacity threshold to the first cumulative charge capacity threshold is less than or equal to 10%, and / or the ratio of the second cumulative discharge capacity threshold to the second cumulative charge capacity threshold is less than or equal to 10%.

[0195] Optionally, the acquisition unit 910 is used to acquire the state parameters of the battery and determine the first charging current based on the state parameters; and / or, the acquisition unit 910 is used to acquire the state parameters of the battery and determine the first discharging current based on the state parameters; and / or, the acquisition unit 910 is used to acquire the state parameters of the battery and determine the first discharging current based on the state parameters; wherein the state parameters of the battery include at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge and battery health status.

[0196] Optionally, the acquisition unit 910 is used to periodically acquire a first charging current, and the sending unit 920 is used to periodically send the first charging current to the charging and discharging device; and / or, the acquisition unit 910 is used to periodically acquire a first discharging current, and the sending unit 920 is used to periodically send the first discharging current to the charging and discharging device; and / or, the acquisition unit 910 is used to periodically acquire a second charging current, and the sending unit 920 is used to periodically send the second charging current to the charging and discharging device.

[0197] Optionally, the acquisition unit 910 is further used to acquire a first charging voltage, and the sending unit 920 is further used to send the first charging voltage to the charging and discharging device, wherein the first charging current and the first charging voltage are carried in a first battery charging requirement BCL message; and / or, the acquisition unit 910 is further used to acquire a first discharging voltage, and the sending unit 920 is further used to send the first discharging voltage to the charging and discharging device, wherein the first discharging current and the first discharging voltage are carried in a second BCL message; and / or, the sending unit 920 is further used to acquire a second charging voltage, and the sending unit 920 is further used to send the second charging voltage to the charging and discharging device, wherein the second charging current and the second charging voltage are carried in a third BCL message, and / or, the acquisition unit 910 is further used to acquire a second discharging voltage, and the sending unit 920 is further used to send the second discharging voltage to the charging and discharging device, wherein the second discharging current and the second discharging voltage are carried in a fourth BCL message.

[0198] Figure 10 FIG. 1 shows a schematic structural block diagram of a charge-discharge device 1000 according to an embodiment of the present application. Figure 10 As shown, the charging and discharging device 1000 includes: a receiving unit 1010 and a processing unit 1020.

[0199] In one embodiment of the present application, the receiving unit 1010 is used to receive a first charging current sent by a battery management system BMS; the processing unit 1020 is used to charge the battery based on the first charging current; the receiving unit 1010 is also used to receive a first discharge current sent by the BMS, and the processing unit 1020 is also used to control the discharge of the battery based on the first discharge current, wherein the first discharge current is the discharge current sent by the BMS when the first cumulative charge amount of the battery is greater than or equal to the first cumulative charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell; the receiving unit 1010 is also used to receive a second charging current sent by the BMS, and the processing unit 1020 is also used to charge the battery based on the second charging current, wherein the second charging current is the charging current sent by the BMS when the first cumulative discharge amount of the battery is greater than or equal to the first cumulative discharge amount threshold.

[0200] Optionally, the receiving unit 1010 is further used to receive a second discharge current sent by the BMS, and the processing unit 1020 is further used to control the battery discharge based on the second discharge current, wherein the second discharge current is the discharge current sent by the BMS when the second cumulative charge capacity of the battery is greater than or equal to the second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell.

[0201] Optionally, the receiving unit 1010 is further configured to receive a charge stop command sent by the BMS, and the processing unit 1020 is configured to stop charging the battery, wherein the charge stop command is a command sent by the BMS when the voltage of a battery cell exceeds the full charge voltage of the battery cell.

[0202] Optionally, the charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

[0203] Optionally, the discharge rate of the first discharge current and / or the second discharge current ranges from 0.1C to 1C.

[0204] Optionally, the ratio of the first cumulative discharge capacity threshold to the first cumulative charge capacity threshold is less than or equal to 10%, and / or the ratio of the second cumulative discharge capacity threshold to the second cumulative charge capacity threshold is less than or equal to 10%.

[0205] Optionally, at least one of the first charging current, the first discharging current and the second charging current is determined by the BMS based on battery status parameters; wherein the battery status parameters include at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge and battery health status.

[0206] Optionally, the receiving unit 1010 is used to periodically receive a first charging current sent by the BMS; and / or, the receiving unit 1010 is used to periodically receive a first discharging current sent by the BMS; and / or, the receiving unit 1010 is used to periodically receive a second charging current sent by the BMS.

[0207] Optionally, the receiving unit 1010 is further used to receive a first charging voltage sent by the BMS, wherein the first charging voltage and the first charging current are carried in a first battery charging requirement BCL message; and / or, the receiving unit 1010 is further used to receive a first discharging voltage sent by the BMS, wherein the first discharging voltage and the first discharging current are carried in a second BCL message; and / or, the receiving unit 1010 is further used to receive a second charging voltage sent by the BMS, wherein the second charging voltage and the second charging current are carried in a third BCL message; and / or, the receiving unit 1010 is further used to receive a second discharging voltage sent by the BMS, wherein the second discharging voltage and the second discharging current are carried in a fourth BCL message.

[0208] Combined with the above Figures 2 to 10 The present application provides a method and device embodiment for battery charging based on information interaction between a charging and discharging device and a BMS. For the charging and discharging device, it can charge the battery and control the discharge of the battery through different hardware architectures.

[0209] Figure 11 A schematic structural block diagram of another charging and discharging device provided in an embodiment of the present application is shown.

[0210] like Figure 11 As shown, the charging and discharging device 1100 may include: a control unit 1110 and a power conversion unit 1120 .

[0211] In one embodiment, the control unit 1110 is used to receive a first charging current sent by the BMS, and based on the first charging current, control the power conversion unit 1120 to charge the battery; the control unit 1110 is also used to receive a first discharging current sent by the BMS, and based on the first discharging current, control the power conversion unit 1120 to discharge the battery, wherein the first discharging current is the discharge current sent by the BMS when the first cumulative charge capacity of the battery is greater than or equal to a first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell; the control unit 1110 is also used to receive a second charging current sent by the BMS, and based on the second charging current, control the power conversion unit 1120 to charge the battery, wherein the second charging current is the charging current sent by the BMS when the first cumulative discharge capacity of the battery is greater than or equal to the first cumulative discharge capacity threshold.

[0212] Specifically, the power conversion unit 1120 may include high-voltage components for implementing high-power electrical energy conversion, and the control unit 1110 may include low-voltage circuits for implementing control functions of the high-voltage components in the power conversion unit 1120. In addition, the control unit 1110 may also establish a communication connection with the BMS. For example, as an example but not a limitation, the control unit 1110 may establish a communication connection with the BMS via a communication bus, or the control unit 1110 may also establish a communication connection with the BMS via a wireless network.

[0213] Optionally, as an example, Figure 12 A schematic structural block diagram of a power conversion unit 1120 provided in an embodiment of the present application is shown.

[0214] like Figure 12 As shown, the power conversion unit 1120 can be connected to an alternating current (AC) power source and a battery, wherein the power conversion unit 1120 includes a unidirectional alternating current / direct current (AC / DC) converter 1210 and a first direct current / direct current (DC / DC) converter 1220. The first DC / DC converter 1220 is a unidirectional DC / DC converter.

[0215] from Figure 12 As can be seen, the first end of the unidirectional AC / DC converter 1210 can be connected to an AC power source, the second end of the unidirectional AC / DC converter 1210 can be connected to the first end of the first DC / DC converter 1220, and the second end of the first DC / DC converter 1220 can be connected to a battery to achieve current transmission between the battery and the AC power source.

[0216] In this case, the BMS can send a first charging current to the control unit 1110. Accordingly, the control unit 1110 can be used to receive the first charging current sent by the BMS and, based on the first charging current, control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through an AC power supply.

[0217] Moreover, when the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS may send a first discharge current to the control unit 1110, and the control unit 1110 may be used to receive the first discharge current and control the battery to release power based on the first discharge current.

[0218] The above-mentioned charging and discharging device, during the process of charging the battery, can charge and discharge the battery based on the first charging current and the first discharging current sent by the BMS, thereby avoiding continuous charging of the battery, thereby avoiding problems such as heating and lithium ion aggregation caused by continuous charging of the battery. Since heat will cause the battery temperature to rise, the crystals produced by the aggregation of lithium ions may pierce the battery, causing electrolyte leakage and battery short circuit. Battery temperature rise and battery short circuit may cause battery safety problems, such as causing battery combustion or explosion. Therefore, the charging and discharging device charges and discharges the battery based on the first charging current and the first discharging current sent by the BMS, which can ensure the safety performance of the battery. In addition, during the continuous charging process, the continuous aggregation of lithium ions will also cause lithium plating problems, affecting the service life and charging capacity of the battery. Therefore, the above-mentioned charging and discharging device can also ensure the service life and charging capacity of the battery.

[0219] Furthermore, the charging and discharging device includes a unidirectional AC / DC converter and a unidirectional DC / DC converter. In this way, the structure of the charging and discharging device of the embodiment of the present application is the same as the structure of the existing charging pile. That is to say, the battery can be charged and discharged without changing the structure of the existing charging pile, which greatly reduces the charging cost.

[0220] When the first cumulative discharge amount of the battery is greater than or equal to the first cumulative discharge amount threshold, optionally, the control unit 1110 can also be used to receive a second charging current sent by the BMS, and based on the second charging current, control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through an AC power supply.

[0221] When the control unit 1110 controls the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through an AC power source, the control unit 1110 may control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 in sequence.

[0222] In addition to the first charging current, the first discharging current and the second charging current, when the second cumulative charging capacity of the battery is greater than or equal to the second cumulative charging capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage, the BMS can also send a second discharging current to the control unit 1110. Accordingly, the control unit 1110 can also be used to receive the second discharging current sent by the BMS and control the battery to release power based on the second discharging current.

[0223] During the battery's cyclic charging and discharging process, when the voltage of a battery cell exceeds the full charge voltage, the BMS may send a charge stop command to the control unit 1110. This charge stop command is used to instruct the charging and discharging device to stop charging the battery. Accordingly, the control unit 1110 is used to receive the charge stop command sent by the BMS and, based on the charge stop command, control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to stop the AC power supply from charging the battery.

[0224] In this technical solution, when the voltage of a battery cell exceeds the full charge voltage, the control unit controls the AC / DC converter and the first DC / DC converter by receiving a charge stop command to stop the AC power supply from charging the battery, thereby preventing the battery from being overcharged and further ensuring the safety performance of the battery.

[0225] Alternatively, as Figure 13 As shown, the power conversion unit 1120 may further include a second DC / DC converter 1230. Specifically, a second terminal of the second DC / DC converter 1230 may be connected to the battery and a second terminal of the first DC / DC converter 1220, respectively.

[0226] Based on this, the control unit 1100 can be specifically configured to: based on the first discharge current, control the second DC / DC converter 1230 to discharge the battery's power into the energy storage unit. This technical solution discharges the battery's power into the energy storage unit, allowing the energy storage unit to perform other operations based on the received power, thus avoiding power waste.

[0227] Alternatively, the energy storage unit may be a low-power energy storage unit. For example, the energy storage unit may be a super battery or a lithium carbonate battery. By configuring the energy storage unit as a low-power energy storage unit, the cost of the charging system can be reduced.

[0228] Optionally, the energy storage unit may be provided independently of the charging and discharging device 1110, or the charging and discharging device 1110 may also include the energy storage unit. Figure 14 As shown, the energy storage unit can be a part of the power conversion unit 1120, or it can be a unit independent of the power conversion unit 1120 and connected to the power conversion unit 1120 through wires. This embodiment of the present application does not specifically limit this.

[0229] For the convenience of description, the following describes the solution of the embodiment of the present application by taking the energy storage unit 1240 as a part of the power conversion unit 1120 as an example.

[0230] from Figure 14It can be seen that in the power conversion unit 1120, the first end of the unidirectional AC / DC converter 1210 is connected to the AC power supply, and the second end is connected to the first end of the first DC / DC converter 1220. The second end of the first DC / DC converter 1220 is respectively connected to the battery and the second end of the second DC / DC converter 1230. The first end of the second DC / DC converter 1230 is connected to the energy storage unit 1240.

[0231] Furthermore, before discharging the battery, the control unit 1110 can control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to turn off the mode of charging the battery, and control the second DC / DC converter 1230 to start the mode of discharging to the energy storage unit 1240.

[0232] In one implementation, the second DC / DC converter 1230 may be a unidirectional DC / DC converter.

[0233] In another implementation, considering that the battery releases power to the energy storage unit, since the amount of power that can be stored in the energy storage power supply is limited, it may happen that the energy storage unit is full and the battery cannot release power. Figure 14 , the second DC / DC converter 1230 can be a bidirectional DC / DC converter.

[0234] In this case, in addition to controlling the second DC / DC converter 1230 to discharge the battery's electricity into the energy storage unit 1240, the control unit 1110 may also control the second DC / DC converter 1230 to charge the battery through the energy storage unit 1240 while controlling the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through the AC power source based on the first charging current. Alternatively, the control unit 1110 may also control the second DC / DC converter 1230 to charge the battery through the energy storage unit 1240 while controlling the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through the AC power source based on the second charging current.

[0235] In the above technical solution, the energy storage unit can not only receive the power released by the battery, but also charge the battery. On the one hand, this avoids the problem of being unable to continue to release the battery's power to the energy storage unit due to the power in the energy storage unit reaching full capacity, ensuring the normal progress of the charging process. On the other hand, the energy storage unit uses the power released by the battery to charge the battery, realizing the recycling of battery power and saving electricity. On the other hand, the AC power supply and the energy storage unit charge the battery at the same time, which is conducive to improving the battery charging rate and saving charging time.

[0236] Optionally, the first charging current may be different from the current used by the energy storage unit 1240 to charge the battery. Similarly, the second charging current may also be different from the current used by the energy storage unit 1240 to charge the battery. For example, the first charging current may be greater than the current used by the energy storage unit 1240 to charge the battery. For example, the charge rate used by the energy storage unit 1240 to charge the battery may be less than 0.5C1, where C1 is the capacity of the energy storage unit 1240.

[0237] based on Figure 14 When the power conversion unit 1120 charges the battery, as a possible embodiment, the control unit 1110 can control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through the AC power supply under any conditions, and control the second DC / DC converter 1230 to charge the battery through the energy storage unit 1240.

[0238] In another possible embodiment, the control unit 1110 may first obtain the SOC of the energy storage unit 1240, and then determine that the AC power supply charges the battery based on the SOC of the energy storage unit 1240, or determine that the AC power supply and the energy storage unit 1240 charge the battery at the same time based on the SOC of the energy storage unit 1240.

[0239] Optionally, the energy storage unit 1240 may send a first message to the control unit 1110 , where the first message includes the SOC of the energy storage unit 1240 , so that the control unit 1110 may acquire the SOC of the energy storage unit 1240 .

[0240] Optionally, the energy storage unit 1240 may store the SOC in the cloud, so that the control unit 1110 may obtain the SOC of the energy storage unit 1240 from the cloud.

[0241] Specifically, if the SOC of the energy storage unit 1240 is greater than or equal to the state of charge threshold, the control unit 1110 can not only control the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220 to charge the battery through the AC power supply, but also control the second DC / DC converter 1230 to charge the battery through the energy storage unit 1240.

[0242] If the SOC of energy storage unit 1240 is less than the state of charge threshold, control unit 1110 may control only unidirectional AC / DC converter 1210 and first DC / DC converter 1220 to charge the battery via the AC power source. Alternatively, when the SOC of energy storage unit 1240 is less than the state of charge threshold, control unit 1110 may send a charging request message to other devices, causing them to charge energy storage unit 1240 until the SOC of energy storage unit 1240 is greater than or equal to the state of charge threshold. Thereafter, the AC power source and energy storage unit 1240 may charge the battery simultaneously.

[0243] The state of charge threshold may be a fixed value. Alternatively, the state of charge threshold may be a variable value. For example, the state of charge threshold may change with time, environmental factors (such as temperature), and other factors.

[0244] The state of charge threshold may be preset on the control unit 1110 , or may be sent to the control unit 1110 by the energy storage unit.

[0245] The above technical solution determines whether to use the energy storage unit to assist the AC power supply to charge the battery according to the SOC of the energy storage unit, thereby improving the charging efficiency of the charging and discharging device when the energy storage unit has sufficient electricity stored.

[0246] When the AC power source and energy storage unit 1240 are simultaneously charging the battery, the first charging power of energy storage unit 1240 is W1, and the second charging power of the AC power source is W2, where W2 is the difference between the required charging power of the battery and W1. Optionally, the first charging power W1 can be determined before the second charging power W2.

[0247] W1 may be determined based on the discharge capacity of the energy storage unit 1240. In addition, W1 may also be determined based on the current state of the energy storage unit 1240, such as the ampere-hours of the energy storage unit 1240, the temperature of the energy storage unit 1240, and the like.

[0248] Optionally, the AC power source includes but is not limited to a power grid, which can be used to provide three-phase AC power. The power grid can provide enough power to charge the battery and can also receive more power released by the battery.

[0249] Alternatively, in other embodiments, the AC power supply may also be a single-phase AC power supply. The embodiments of the present application do not limit the specific type of the AC power supply.

[0250] In addition, the relevant technical solutions regarding the charging current, discharging current, cumulative charging amount, cumulative discharging amount, cumulative charging amount threshold, cumulative discharging amount threshold, etc. in the embodiments of the present application can be found in the relevant description above and will not be elaborated here.

[0251] Figure 15 The schematic flow chart of the battery charging method 1500 of the embodiment of the present application is shown. The method 1500 can be applied to a charging and discharging device including a first DC / DC converter and a unidirectional AC / DC converter, for example, Figure 12 In the charging and discharging device including the unidirectional AC / DC converter 1210 and the first DC / DC converter 1220. It should be understood that the method embodiment and the device embodiment correspond to each other, and similar descriptions can refer to the device embodiment.

[0252] like Figure 15 As shown, the battery charging method 1500 may include the following steps:

[0253] In 1510 , a first charging current sent by the BMS is received, and based on the first charging current, a unidirectional AC / DC converter and a first DC / DC converter are controlled to charge the battery through an AC power source.

[0254] In 1520, a first discharge current sent by the BMS is received, and the battery is controlled to release power based on the first discharge current, wherein the first discharge current is the discharge current sent by the BMS when the first cumulative charge capacity of the battery is greater than or equal to the first cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell.

[0255] In 1530, a second charging current sent by the BMS is received, and based on the second charging current, the unidirectional AC / DC converter and the first DC / DC converter are controlled to charge the battery through the AC power supply, wherein the second charging current is the charging current sent by the BMS when the first cumulative discharge amount of the battery is greater than or equal to the first cumulative discharge amount threshold.

[0256] Optionally, in some embodiments, method 1500 further includes: receiving a second discharge current sent by the BMS, and controlling the battery to release power based on the second discharge current, wherein the second discharge current is the discharge current sent by the BMS when the second cumulative charge of the battery is greater than or equal to the second cumulative charge threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage.

[0257] Optionally, in some embodiments, method 1500 further includes: receiving a charge stop command sent by the BMS; and based on the charge stop command, controlling the unidirectional AC / DC converter and the first DC / DC converter so that the AC power supply stops charging the battery, wherein the charge stop command is a command sent by the BMS when the voltage of a battery cell of the battery exceeds the full charge voltage.

[0258] Optionally, in some embodiments, the charging and discharging device further includes a second DC / DC converter, such as Figure 13 and Figure 14 The second DC / DC converter 1230 controls the battery to release power based on the first discharge current, including: controlling the second DC / DC converter to release the power of the battery into the energy storage unit based on the first discharge current.

[0259] Optionally, in some embodiments, the second DC / DC converter is a bidirectional DC / DC converter, and method 1500 further includes: when controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the first charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit; and / or when controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the second charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit.

[0260] Optionally, in some embodiments, the first charging power of the energy storage unit to charge the battery is determined according to the discharge capacity of the energy storage unit, and the second charging power of the AC power supply to charge the battery is the difference between the required charging power of the battery and the second charging power.

[0261] Optionally, in some embodiments, charging the battery includes: obtaining a battery state of charge (SOC) value of the energy storage unit; if the SOC is greater than a state of charge threshold, controlling the second DC / DC converter to charge the battery through the energy storage unit, and based on a first charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power supply; and / or if the SOC is greater than a state of charge threshold, controlling the second DC / DC converter to charge the battery through the energy storage unit, and based on the second charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power supply.

[0262] Optionally, in some embodiments, the charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

[0263] Optionally, in some embodiments, the discharge rate of the first discharge current ranges from 0.1C to 1C.

[0264] Optionally, in some embodiments, the ratio of the first cumulative discharge capacity threshold to the first cumulative charge capacity threshold is less than or equal to 10%.

[0265] Optionally, in some embodiments, at least one of the first charging current, the first discharging current and the second charging current is determined based on battery status parameters; wherein the battery status parameters include at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge and battery health status.

[0266] Optionally, in some embodiments, receiving a first charging current sent by a BMS of a battery includes: periodically receiving the first charging current sent by the BMS; and / or, receiving a first discharging current sent by the BMS includes: periodically receiving the first discharging current sent by the BMS; and / or, receiving a second charging current sent by the BMS includes: periodically receiving the second charging current sent by the BMS.

[0267] Optionally, in some embodiments, method 1500 further includes: receiving a first charging voltage sent by the BMS, wherein the first charging voltage and the first charging current are carried in a first BCL message; and / or, receiving a first discharging voltage sent by the BMS, wherein the first discharging voltage and the first discharging current are carried in a second BCL message; and / or, receiving a second charging voltage sent by the BMS, wherein the second charging voltage and the second charging current are carried in a third BCL message.

[0268] Figure 16 FIG1 shows a schematic structural block diagram of an electronic device 1600 according to an embodiment of the present application. Figure 16 As shown, the electronic device 1600 includes a memory 1610 and a processor 1620, wherein the memory 1610 is used to store computer programs, and the processor 1620 is used to read the computer programs and execute the methods of the various embodiments of the present application based on the computer programs.

[0269] Optionally, the electronic device 1600 may be used for any one or more of a BMS and a charging and discharging device. In the embodiments of the present application, in addition to the processor in the charging and discharging device reading the corresponding computer program and executing the corresponding charging method of the charging and discharging device in the various embodiments described above based on the computer program, the processor in the BMS may also read the corresponding computer program and execute the corresponding charging method of the BMS in the various embodiments described above based on the computer program.

[0270] In addition, embodiments of the present application further provide a readable storage medium for storing a computer program for executing the methods of the various embodiments of the present application. Optionally, the computer program may be a computer program in the aforementioned charging and discharging device and / or BMS.

[0271] It should be understood that the specific examples in this article are only intended to help those skilled in the art better understand the embodiments of the present application, and are not intended to limit the scope of the embodiments of the present application.

[0272] It should also be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0273] It should also be understood that the various implementation methods described in this specification can be implemented individually or in combination, and the embodiments of the present application are not limited to this.

[0274] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A charging and discharging device, characterized in that: The system comprises a first DC / DC converter, a unidirectional AC / DC converter, and a control unit, wherein the first DC / DC converter is a unidirectional DC / DC converter, and the control unit is configured to: receiving a first charging current sent by a battery management system (BMS) of the battery, and controlling the unidirectional AC / DC converter and the first DC / DC converter based on the first charging current to charge the battery through an AC power source; receiving a first discharge current sent by the BMS, and controlling the battery to release power based on the first discharge current, wherein the first discharge current is the discharge current sent by the BMS when a first cumulative charge capacity of the battery is greater than or equal to a first cumulative charge capacity threshold and a voltage of a battery cell of the battery does not exceed a full charge voltage of the battery cell; receiving a second charging current sent by the BMS, and controlling the unidirectional AC / DC converter and the first DC / DC converter based on the second charging current to charge the battery through the AC power supply, wherein the second charging current is the charging current sent by the BMS when a first cumulative discharge amount of the battery is greater than or equal to a first cumulative discharge amount threshold; The charging and discharging device further includes a second DC / DC converter, wherein the second DC / DC converter is a bidirectional DC / DC converter; The control unit is further specifically configured to: Based on the first discharge current, controlling the second DC / DC converter to release the power of the battery into the energy storage unit; When controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power source based on the first charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit; and / or When controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the second charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit; The first charging power of the energy storage unit for charging the battery is determined according to the discharge capacity of the energy storage unit, and the second charging power of the AC power supply for charging the battery is the difference between the required charging power of the battery and the first charging power.

2. The charge and discharge device according to claim 1, wherein: The control unit is further configured to: receiving a second discharge current sent by the BMS, and controlling the battery to release power based on the second discharge current, wherein the second discharge current is the discharge current sent by the BMS when the second cumulative charge capacity of the battery is greater than or equal to a second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage.

3. The charge and discharge device according to claim 1 or 2, characterized in that: The control unit is further configured to: receiving a charge stop command sent by the BMS; Based on the charge stop command, the unidirectional AC / DC converter and the first DC / DC converter are controlled to stop the AC power source from charging the battery, wherein the charge stop command is a command sent by the BMS when the voltage of the battery cell of the battery exceeds the full charge voltage.

4. The charge and discharge device according to claim 1 or 2, characterized in that: The control unit is specifically used for: Obtaining a battery state of charge (SOC) value of the energy storage unit; If the SOC is greater than a state of charge threshold, controlling the second DC / DC converter to charge the battery through the energy storage unit, and based on the first charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply; and / or If the SOC is greater than a state of charge threshold, the second DC / DC converter is controlled to charge the battery through the energy storage unit, and based on the second charging current, the unidirectional AC / DC converter and the first DC / DC converter are controlled to charge the battery through the AC power supply.

5. The charge and discharge device according to claim 1 or 2, characterized in that: The charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

6. The charge and discharge device according to claim 1 or 2, characterized in that: The discharge rate of the first discharge current ranges from 0.1C to 1C.

7. The charge and discharge device according to claim 1 or 2, characterized in that: A ratio of the first cumulative discharge amount threshold to the first cumulative charge amount threshold is less than or equal to 10%.

8. The charge and discharge device according to claim 1 or 2, characterized in that: At least one of the first charging current, the first discharging current, and the second charging current is determined according to a state parameter of the battery; The battery status parameter includes at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge and battery health status.

9. The charge and discharge device according to claim 1 or 2, characterized in that: The control unit is specifically used for: regularly receiving the first charging current sent by the BMS; and / or, regularly receiving the first discharge current sent by the BMS; and / or, The second charging current sent by the BMS is periodically received.

10. The charge and discharge device according to claim 1 or 2, characterized in that: The control unit is further configured to: receiving a first charging voltage sent by the BMS, wherein the first charging voltage and the first charging current are carried in a first battery charging requirement message; and / or, receiving a first discharge voltage sent by the BMS, wherein the first discharge voltage and the first discharge current are carried in a second battery charging requirement message; and / or, A second charging voltage sent by the BMS is received, wherein the second charging voltage and the second charging current are carried in a third battery charging requirement message.

11. A method for charging a battery, characterized in that: Applied to a charging and discharging device including a first DC / DC converter and a unidirectional AC / DC converter, wherein the first DC / DC converter is a unidirectional DC / DC converter, the method includes: receiving a first charging current sent by a battery management system (BMS) of the battery, and controlling the unidirectional AC / DC converter and the first DC / DC converter based on the first charging current to charge the battery through an AC power source; receiving a first discharge current sent by the BMS, and controlling the battery to release power based on the first discharge current, wherein the first discharge current is the discharge current sent by the BMS when a first cumulative charge capacity of the battery is greater than or equal to a first cumulative charge capacity threshold and a voltage of a battery cell of the battery does not exceed a full charge voltage of the battery cell; receiving a second charging current sent by the BMS, and controlling the unidirectional AC / DC converter and the first DC / DC converter based on the second charging current to charge the battery through the AC power supply, wherein the second charging current is the charging current sent by the BMS when a first cumulative discharge amount of the battery is greater than or equal to a first cumulative discharge amount threshold; The charging and discharging device further includes a second DC / DC converter, which is a bidirectional DC / DC converter. The controlling the battery to release power based on the first discharge current includes: Based on the first discharge current, controlling the second DC / DC converter to release the power of the battery into the energy storage unit; When controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through an AC power source based on the first charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit; and / or When controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply based on the second charging current, controlling the second DC / DC converter to charge the battery through the energy storage unit; The first charging power of the energy storage unit for charging the battery is determined according to the discharge capacity of the energy storage unit, and the second charging power of the AC power supply for charging the battery is the difference between the required charging power of the battery and the first charging power.

12. The method according to claim 11, characterized in that The method further comprises: receiving a second discharge current sent by the BMS, and controlling the battery to release power based on the second discharge current, wherein the second discharge current is the discharge current sent by the BMS when the second cumulative charge capacity of the battery is greater than or equal to a second cumulative charge capacity threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage.

13. The method according to claim 11 or 12, characterized in that The method further comprises: receiving a charge stop command sent by the BMS; Based on the charge stop command, the unidirectional AC / DC converter and the first DC / DC converter are controlled to stop the AC power source from charging the battery, wherein the charge stop command is a command sent by the BMS when the voltage of the battery cell of the battery exceeds the full charge voltage.

14. The method according to claim 11 or 12, characterized in that The charging of the battery comprises: Obtaining a battery state of charge (SOC) value of the energy storage unit; If the SOC is greater than a state of charge threshold, controlling the second DC / DC converter to charge the battery through the energy storage unit, and based on the first charging current, controlling the unidirectional AC / DC converter and the first DC / DC converter to charge the battery through the AC power supply; and / or If the SOC is greater than a state of charge threshold, the second DC / DC converter is controlled to charge the battery through the energy storage unit, and based on the second charging current, the unidirectional AC / DC converter and the first DC / DC converter are controlled to charge the battery through the AC power supply.

15. The method according to claim 11 or 12, characterized in that The charging rate of the first charging current and / or the second charging current ranges from 2C to 10C.

16. The method according to claim 11 or 12, characterized in that The discharge rate of the first discharge current ranges from 0.1C to 1C.

17. The method according to claim 11 or 12, characterized in that A ratio of the first cumulative discharge amount threshold to the first cumulative charge amount threshold is less than or equal to 10%.

18. The method according to claim 11 or 12, characterized in that At least one of the first charging current, the first discharging current, and the second charging current is determined according to a state parameter of the battery; The battery status parameter includes at least one of the following parameters: battery temperature, battery voltage, battery current, battery state of charge and battery health status.

19. The method according to claim 11 or 12, characterized in that The receiving a first charging current sent by a battery management system BMS of the battery includes: regularly receiving the first charging current sent by the BMS; and / or, The receiving a first discharge current sent by the BMS includes: regularly receiving the first discharge current sent by the BMS; and / or, The receiving a second charging current sent by the BMS includes: The second charging current sent by the BMS is periodically received.

20. The method according to claim 11 or 12, characterized in that The method further comprises: receiving a first charging voltage sent by the BMS, wherein the first charging voltage and the first charging current are carried in a first battery charging requirement message; and / or, receiving a first discharge voltage sent by the BMS, wherein the first discharge voltage and the first discharge current are carried in a second battery charging requirement message; and / or, A second charging voltage sent by the BMS is received, wherein the second charging voltage and the second charging current are carried in a third battery charging requirement message.

21. A charging and discharging device, characterized in that: include: The method comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program to execute the battery charging method according to any one of claims 11 to 20.

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