Charging control method and device of power battery, vehicle and storage medium

Abstract

The embodiment of the invention discloses a charging control method and device of a power battery, a vehicle and a storage medium. According to the technical scheme, under the condition that the power battery is charged in the target constant-voltage charging stage, the current adjusting request is sent to the adapter, the current adjusting request comprises the updated charging current applied to the adapter by the vehicle, and finally the power battery is charged according to the updated charging current. And the electric quantity of the power battery reaches the target cut-off electric quantity of the target constant-voltage charging stage. According to the charging control method of the power battery, in the charging process of the target constant-voltage charging stage, the updated charging current is applied to the adapter, so that the maximum value of the single battery voltage corresponding to the updated charging current is close to the cut-off voltage of the target constant-voltage charging stage; according to the invention, the charging speed of the power battery in a low-temperature environment can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of power batteries, and relate to but are not limited to a charging control method, device, vehicle and storage medium for a power battery. Background Art

[0002] With the rapid development of new energy technologies, most of the power batteries in current vehicles use lithium-ion batteries. Under low-temperature conditions, the electrochemical reaction rate of lithium-ion batteries is relatively slow, and the migration speed of lithium ions in the electrolyte is relatively slow, resulting in a large concentration polarization. The battery reaches the cut-off voltage and cut-off current relatively quickly, making the charging capacity of lithium-ion batteries in a low-temperature environment relatively small. Although charging at an extremely low rate can increase the charging capacity at low temperatures, it results in an overly long charging time. That is to say, lithium-ion batteries have a slow charging speed and a long charging time in a low-temperature environment, which affects the user experience.

[0003] Therefore, how to improve the charging speed of power batteries in a low-temperature environment is an urgent problem to be solved. Summary of the Invention

[0004] The charging control method, device, vehicle and storage medium for a power battery provided by the embodiments of the present application can improve the charging speed of the power battery in a low-temperature environment. The charging control method, device, vehicle and storage medium for a power battery provided by the embodiments of the present application are implemented as follows:

[0005] The charging control method for a power battery provided by the embodiments of the present application is applied to a vehicle. The power battery corresponds to at least one constant-voltage charging stage, and different constant-voltage charging stages correspond to different cut-off voltages and cut-off powers. The method includes: when the power battery is charging in a target constant-voltage charging stage, sending a current adjustment request to an adapter, where the current adjustment request includes an updated charging current applied by the vehicle to the adapter, and a first difference between the target cut-off voltage of the target constant-voltage charging stage and the maximum value of the first single-cell voltage is less than or equal to a second difference between the target cut-off voltage and the maximum value of the second single-cell voltage. The maximum value of the first single-cell voltage is the maximum value of the single-cell voltage corresponding to the updated charging current, and the maximum value of the second single-cell voltage is the maximum value of the single-cell voltage corresponding to the charging current before the update; charging the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power of the target constant-voltage charging stage.

[0006] In some embodiments, before sending the current adjustment request to the adapter, the method further includes: determining the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single-cell voltage.

[0007] In some embodiments, the method further includes: when the target cut-off voltage is greater than the maximum value of the second single battery voltage, determining that the updated charging current is greater than the charging current before the update; when the target cut-off voltage is less than the maximum value of the second single battery voltage, determining that the updated charging current is less than the charging current before the update; and when the target cut-off voltage is equal to the maximum value of the second single battery voltage, keeping the charging current before the update unchanged.

[0008] In some embodiments, determining the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single battery voltage includes: when the target cut-off voltage is not equal to the maximum value of the second single battery voltage, obtaining a compensation current according to the ratio of the difference between the target cut-off voltage and the maximum value of the second single battery voltage to the real-time internal resistance value of the single battery in the power battery, and the greater the difference between the target cut-off voltage and the maximum value of the second single battery voltage, the greater the compensation current; and determining the updated charging current as the sum of the charging current before the update and the compensation current.

[0009] In some embodiments, before sending a current adjustment request to the adapter, the method further includes: obtaining the battery temperature and battery power of the power battery; and determining that the power battery is in the target constant voltage charging stage according to the battery temperature, the battery power, and a preset corresponding relationship, where the preset corresponding relationship includes the corresponding relationship between a preset battery temperature range, a preset power range, and a preset constant voltage charging stage.

[0010] In some embodiments, the number of constant voltage charging stages corresponding to the power battery is determined according to the type of the power battery, and different types of power batteries include different numbers of constant voltage charging stages.

[0011] In some embodiments, after charging the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power, the method further includes:

[0012] Entering the next constant voltage charging stage after the target constant voltage charging stage in the at least one constant voltage charging stage.

[0013] The charging control device for a power battery provided by an embodiment of the present application is applied to a vehicle. The power battery corresponds to at least one constant voltage charging stage, and different constant voltage charging stages correspond to different cut-off voltages and cut-off powers. The device includes:

[0014] A sending module, configured to send a current adjustment request to an adapter when the power battery is being charged in a target constant voltage charging stage, where the current adjustment request includes an updated charging current applied by the vehicle to the adapter, a first difference between a target cut-off voltage of the target constant voltage charging stage and a maximum value of a first single-cell voltage is less than or equal to a second difference between the target cut-off voltage and a maximum value of a second single-cell voltage, the maximum value of the first single-cell voltage is the maximum value of the single-cell voltage corresponding to the updated charging current, and the maximum value of the second single-cell voltage is the maximum value of the single-cell voltage corresponding to the charging current before the update;

[0015] A charging module, configured to charge the power battery according to the updated charging current until the power of the power battery reaches a target cut-off power of the target constant voltage charging stage.

[0016] The vehicle provided by an embodiment of the present application includes a memory and a processor, the memory stores a computer program that can run on the processor, and when the processor executes the program, the method described in the embodiment of the present application is implemented.

[0017] The computer-readable storage medium provided by an embodiment of the present application stores a computer program, and when the computer program is executed by a processor, the method provided by the embodiment of the present application is implemented.

[0018] The computer program product provided by an embodiment of the present application includes a computer program, and when the computer program is executed by a processor, the method provided by the embodiment of the present application is implemented.

[0019] In the charging control method, device, vehicle and storage medium of the power battery provided by the embodiments of the present application, when the power battery is in the target constant voltage charging stage, a current adjustment request is sent to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter. The first difference between the target cut-off voltage and the maximum value of the first single cell voltage in the target constant voltage charging stage is less than or equal to the second difference between the target cut-off voltage and the maximum value of the second single cell voltage. The maximum value of the first single cell voltage is the maximum value of the single cell voltage corresponding to the updated charging current, and the maximum value of the second single cell voltage is the maximum value of the single cell voltage corresponding to the charging current before the update. Finally, the power battery is charged according to the updated charging current until the power of the power battery reaches the target cut-off power of the target constant voltage charging stage. In this charging control method of the power battery, during the charging process in the target constant voltage charging stage, by applying for an updated charging current to the adapter, the maximum value of the single cell voltage corresponding to the updated charging current is close to the cut-off voltage of the target constant voltage charging stage until the cut-off power of the target constant voltage charging stage is reached. Since during the charging process, when the battery voltage exceeds the specified single cell voltage, it will cause the problem of overvoltage of the battery. Overvoltage will cause serious attenuation of the battery capacity and may also cause potential safety problems, resulting in battery fire and explosion. Therefore, charging the power battery based on at least one constant voltage charging stage can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety and solve the technical problems proposed in the background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to explain the technical solutions of the present application.

[0021] Figure 1 It is a schematic flow chart for implementing the charging control method of the power battery provided by an embodiment of the present application;

[0022] Figure 2 It is a schematic flow chart for implementing the charging control method of the power battery provided by another embodiment of the present application;

[0023] Figure 3 It is a schematic overall exemplary flow chart for the charging control method of the power battery provided by an embodiment of the present application;

[0024] Figure 4 It is a schematic exemplary flow chart for the charging control method of the power battery provided by an embodiment of the present application;

[0025] Figure 5Schematic diagram of the relationship between voltage and power corresponding to the constant voltage charging stage of an LFP type power battery provided by an embodiment of the present application;

[0026] Figure 6 Exemplary flowchart of a charging control method for a power battery provided by another embodiment of the present application;

[0027] Figure 7 Schematic diagram of the relationship between voltage and power corresponding to the constant voltage charging stage of an LMFP type power battery provided by an embodiment of the present application;

[0028] Figure 8 Structural schematic diagram of a charging control device for a power battery provided by an embodiment of the present application;

[0029] Figure 9 Structural schematic diagram of a vehicle provided by an embodiment of the present application. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will further describe the specific technical solutions of the present application in detail with reference to the accompanying drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not intended to limit the scope of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0032] In the following descriptions, reference is made to "some embodiments", which describe subsets of all possible embodiments. However, it can be understood that "some embodiments" can be the same subsets or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0033] It should be noted that the terms "first\second\third" involved in the embodiments of the present application are used to distinguish similar or different objects, and do not represent a specific order for the objects. Understandably, "first\second\third" can be interchanged with a specific order or sequence when allowed, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0034] With the rapid development of new energy technologies, most of the power batteries in current vehicles use lithium-ion batteries. The capacity test method for a single lithium-ion battery is usually to first charge at a constant current and then charge at a constant voltage. For example, for a lithium iron phosphate single battery, the usual capacity test method is: constant current charge at 0.33C until the voltage reaches 3.65V, and then after the battery voltage reaches 3.65V, enter the constant voltage charging process. During the constant voltage charging process, when the battery current is less than 0.05C, it is set to full charge.

[0035] However, although the existing constant current-constant voltage charging method can avoid the risk of large current overcharging of the battery in high and low state of charge, at low temperatures, the electrochemical reaction rate of the lithium-ion battery is slow, and the migration speed of lithium ions in the electrolyte is slow, resulting in large concentration polarization. The battery reaches the cut-off voltage and cut-off current quickly, making the charging capacity of the lithium-ion battery small and the energy density low in a low-temperature environment. While charging at an extremely low rate can increase the charging capacity at low temperatures, it leads to too long charging time and cannot effectively avoid risks such as triggering the upper limit voltage of the battery or lithium plating during charging, nor can it be applied to different types of power batteries, such as lithium iron phosphate and lithium manganese iron phosphate, at the same time. That is to say, the charging speed of lithium-ion batteries is slow and the charging time is long in a low-temperature environment, which affects the user experience.

[0036] Therefore, how to improve the charging speed of power batteries in a low-temperature environment is an urgent problem to be solved.

[0037] In view of this, an embodiment of the present application provides a charging control method for a power battery. This method is applied to a vehicle and specifically includes: when the power battery is in the target constant voltage charging stage, sending a current adjustment request to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter. The first difference between the target cut-off voltage in the target constant voltage charging stage and the maximum value of the first single-cell voltage is less than or equal to the second difference between the target cut-off voltage and the maximum value of the second single-cell voltage. The maximum value of the first single-cell voltage is the maximum value of the single-cell voltage corresponding to the updated charging current, and the maximum value of the second single-cell voltage is the maximum value of the single-cell voltage corresponding to the charging current before the update. Finally, charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power in the target constant voltage charging stage. In this charging control method of the power battery, during the charging process in the target constant voltage charging stage, by applying for an updated charging current to the adapter, the maximum value of the single-cell voltage corresponding to the updated charging current approaches the cut-off voltage in the target constant voltage charging stage until the cut-off power in the target constant voltage charging stage is reached. Since during the charging process, when the battery voltage exceeds the specified single-cell voltage, it will cause the problem of battery overvoltage. Overvoltage will cause serious attenuation of the battery capacity and may also cause potential safety problems, resulting in battery fire and explosion. Therefore, charging the power battery based on at least one constant voltage charging stage can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety.

[0038] In order to make the purpose and technical solution of the present application more clear and intuitive, the charging control method, device, vehicle, and storage medium for a power battery provided by the embodiments of the present application will be described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] Please refer to Figure 1 , which is a schematic flowchart of the implementation of the charging control method for a power battery provided by an embodiment of the present application. This method can be applied to a vehicle. The power battery in the vehicle corresponds to at least one constant voltage charging stage, and different constant voltage charging stages correspond to different cut-off voltages and cut-off powers. As Figure 1 shown, this method may include the following steps 101 and 102:

[0040] Step 101, when the power battery is in the target constant voltage charging stage, send a current adjustment request to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter.

[0041] Wherein, a first difference between a target cut-off voltage in a target constant voltage charging stage and a maximum value of a first single cell voltage is less than or equal to a second difference between the target cut-off voltage and a maximum value of a second single cell voltage. The maximum value of the first single cell voltage is the maximum value of the single cell voltage corresponding to an updated charging current, and the maximum value of the second single cell voltage is the maximum value of the single cell voltage corresponding to a charging current before the update.

[0042] It should be understood that a power battery is a core component of an electric vehicle and is used to provide a power source for it. A large number of single cells are included in the power battery, and different vehicle models include different numbers of single cells, generally about 100 strings.

[0043] In some embodiments, the number of constant voltage charging stages corresponding to different types of power batteries is usually also different. The types of power batteries generally include ternary materials, lithium iron phosphate, lithium manganese iron phosphate, etc. The number of corresponding constant voltage charging stages can be set according to experience or preset, and the present application does not limit this.

[0044] In some embodiments, when the power battery is in the target constant voltage charging stage, the vehicle can determine whether to increase or decrease the charging current applied to the adapter according to the magnitude relationship between the target cut-off voltage in the target constant voltage charging stage and the maximum value of the second single cell voltage, and determine the value of the charging current that needs to be increased or decreased based on the difference between the two, so as to determine the updated charging current value that needs to be applied to the adapter, so that the first difference between the target cut-off voltage and the maximum value of the first single cell voltage is less than or equal to the second difference between the target cut-off voltage and the maximum value of the second single cell voltage. That is to say, the vehicle can dynamically determine the updated charging current applied to the adapter according to the gap between the target cut-off voltage and the maximum value of the second single cell voltage, and send a corresponding current adjustment request to the adapter.

[0045] Optionally, the target cut-off voltage is the charging voltage required by the power battery in the target constant voltage charging stage, which can be set according to experience, determined according to the charging scenario, different charging scenarios can correspond to different target charging currents, or determined based on the current battery charging curve. Specifically, the present application does not limit this. Different constant voltage charging stages correspond to different cut-off voltages.

[0046] Optionally, the current adjustment request sent by the vehicle to the adapter can be similar to a communication packet. After receiving the communication packet, the adapter can parse the updated charging current included therein and adjust its output current according to the updated charging current.

[0047] Step 102: Charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power at the target constant voltage charging stage.

[0048] In some embodiments, the adapter receives the updated charging current and charges the power battery according to the updated charging current. Meanwhile, the battery management system of the vehicle real-time feedbacks the voltage of each single battery. The system continuously calculates the voltage difference and dynamically adjusts the charging current to ensure the smooth progress of the charging process and avoid overcharging. When the maximum voltage of the first single battery, that is, the maximum voltage of the single battery corresponding to the updated charging current, reaches the target cut-off voltage, the target cut-off voltage remains unchanged and the charging continues until the power of the power battery reaches the target cut-off power at the target constant voltage charging stage.

[0049] Further, if the target constant voltage charging stage is not the last constant voltage charging stage, after the power of the power battery reaches the target cut-off power, enter the next constant voltage charging stage to continue charging.

[0050] In this embodiment, when the power battery is in the target constant voltage charging stage, a current adjustment request is sent to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter. The first difference between the target cut-off voltage of the target constant voltage charging stage and the maximum voltage of the first single battery is less than or equal to the second difference between the target cut-off voltage and the maximum voltage of the second single battery. The maximum voltage of the first single battery is the maximum voltage of the single battery corresponding to the updated charging current, and the maximum voltage of the second single battery is the maximum voltage of the single battery corresponding to the charging current before the update. Finally, the power battery is charged according to the updated charging current until the power of the power battery reaches the target cut-off power at the target constant voltage charging stage. In the charging control method of this power battery, during the charging process in the target constant voltage charging stage, by applying for the updated charging current to the adapter, the maximum voltage of the single battery corresponding to the updated charging current is close to the cut-off voltage of the target constant voltage charging stage until it is charged to the cut-off power of the target constant voltage charging stage. Since during the charging process, when the battery voltage exceeds the specified single battery voltage, it will cause the problem of battery overvoltage. Overvoltage will cause serious attenuation of the battery capacity and may also cause potential safety problems, resulting in battery fire and explosion. Therefore, charging the power battery based on at least one constant voltage charging stage can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety.

[0051] Based on the above embodiments, Figure 2 is a schematic flowchart of the implementation process of the charging control method for the power battery provided in another embodiment of this application. As Figure 2 shown, the method may include the following steps:

[0052] Step 201, obtain the battery temperature and the state of charge of the power battery.

[0053] It should be understood that the vehicle includes a Battery Management System (BMS). The BMS can intelligently manage and maintain each battery cell, monitor the state of the battery, and prevent the battery from overcharging and over-discharging to extend the service life of the battery.

[0054] In some embodiments, the BMS can monitor the temperature of the power battery in real time through built-in or external temperature sensors. Generally, these sensors are installed at different positions of the battery pack to ensure accurate measurement of the temperature of the entire battery system. During the measurement process, the temperature data collected by the sensors will be transmitted to the BMS.

[0055] Exemplarily, the charging temperature of the power battery is usually between 0°C and 45°C; the discharging temperature is usually between -20°C and 60°C.

[0056] Optionally, if the battery temperature is too high or too low, the BMS may activate the cooling system or the heating system, or take other measures (such as restricting the charging current) to protect the battery.

[0057] In some embodiments, the state of charge (SOC) of the battery refers to the percentage of the electric energy currently contained in the battery, and is usually used to represent the charging state of the battery. The BMS can obtain the SOC of the battery in the following ways:

[0058] (1) By measuring the voltage of the battery and combining it with the discharge curve of the battery, the state of charge of the battery can be roughly estimated.

[0059] (2) The BMS monitors the charging and discharging currents, integrates and calculates the charge and discharge amounts of the battery, and estimates the SOC in combination with the initial state of charge.

[0060] (3) The BMS may use a mathematical model based on the battery characteristics to estimate the SOC. This model takes into account multiple factors such as the voltage, temperature, and current of the battery, so as to provide more accurate SOC data.

[0061] (4) Since the relationship between the voltage of the battery and the SOC is non-linear, the BMS will regularly perform SOC calibration to improve the estimation accuracy. This is usually carried out under specific charging or discharging states, and the deviation of the model is corrected by comparing with the known SOC value.

[0062] Exemplarily, when the SOC is 0%, it means the battery is fully discharged, and when the SOC is 100%, it means the battery is fully charged. Generally, it is most beneficial for the battery life to keep the SOC between 20% and 80%.

[0063] In some embodiments, the BMS typically communicates with the vehicle's control system, such as the vehicle control unit and the charging control unit of an electric vehicle, to report the battery temperature and battery charge in real time. Alternatively, some battery management systems provide an Application Programming Interface (API) that allows querying parameters such as the battery temperature, SOC, voltage, and current through software.

[0064] Step 202: Based on the battery temperature, battery charge, and a preset corresponding relationship, determine that the power battery is in the target constant voltage charging stage. The preset corresponding relationship includes the corresponding relationship between the preset battery temperature range, preset charge range, and preset constant voltage charging stage.

[0065] In some embodiments, the number of constant voltage charging stages corresponding to the power battery is determined according to the type of the power battery. Different types of power batteries include different numbers of constant voltage charging stages. For example, a lithium iron phosphate (LFP) type power battery includes 3 constant voltage charging stages, and a lithium manganese iron phosphate (LMFP) type power battery includes 4 constant voltage charging stages.

[0066] In some embodiments, the vehicle presets the corresponding relationship between the preset battery temperature range, preset charge range, and preset constant voltage charging stage. The vehicle compares the actually obtained battery temperature and SOC value with the preset temperature range and preset charge range in the preset corresponding relationship to determine the constant voltage charging stage in which the power battery is located.

[0067] Step 203: When the power battery is charged in the target constant voltage charging stage, determine the updated charging current according to the difference between the target cut-off voltage and the maximum value of the voltage of the second single battery. The maximum value of the voltage of the second single battery is the maximum value of the voltage of the single battery corresponding to the charging current before the update.

[0068] In some embodiments, different constant voltage charging stages correspond to different cut-off voltages. When the power battery is charged in the target constant voltage charging stage, first determine the target cut-off voltage (Vtarget) corresponding to the target constant voltage charging stage. Optionally, the target cut-off voltage is the charging voltage required by the power battery in the target constant voltage charging stage, which can be set according to experience, determined according to the charging scenario, different charging scenarios can correspond to different target charging currents, or determined based on the current battery charging curve. Specifically, the present application does not limit this.

[0069] In some embodiments, when the power battery is in the target constant voltage charging stage, the real-time voltage values of all the single cells in the power battery can be collected, and the maximum voltage value in the power battery is selected as the maximum voltage (Vmax) of the second single cell.

[0070] In some embodiments, different constant voltage charging stages also correspond to different initial charging currents I0. When the power battery enters different constant voltage charging stages for charging, it will initially apply to the adapter for the initial charging current and then adjust according to the updated charging current.

[0071] In some embodiments, first, according to the magnitude relationship between the target cut-off voltage and the maximum voltage of the second single cell, it is determined whether to increase or decrease the charging current applied to the adapter. For example, when the target cut-off voltage is greater than the maximum voltage of the second single cell, it is determined that the updated charging current is greater than the charging current before the update; when the target cut-off voltage is less than the maximum voltage of the second single cell, it is determined that the updated charging current is less than the charging current before the update; when the target cut-off voltage is equal to the maximum voltage of the second single cell, the charging current before the update remains unchanged.

[0072] In a possible implementation manner, when the target cut-off voltage is not equal to the maximum voltage of the second single cell, according to the ratio of the difference between the target cut-off voltage and the maximum voltage of the second single cell to the real-time internal resistance value of the single cell in the power battery, a compensation current is obtained. The greater the difference between the target cut-off voltage and the maximum voltage of the second single cell, the greater the compensation current. That is to say, during the charging process, the difference between the maximum voltage (Vmax) of the second single cell and the target cut-off voltage (Vtarget) in the power battery is compared, and according to the ratio of the difference between Vtarget and Vmax to the real-time internal resistance value R of the single cell in the power battery, a compensation current ΔI is obtained, that is, ΔI = (Vtarget - Vmax) / R.

[0073] Optionally, when calculating the compensation current, the real-time internal resistance value R of the single cell in the power battery can use the maximum internal resistance value.

[0074] In another possible implementation manner, during the charging process of the power battery, due to the influence of battery temperature, voltage, etc., the internal resistance is constantly changing, and many factors need to be considered. At the same time, the connection relationship of the single cells in the power battery is also relatively complex. Therefore, for the calculation of the compensation current, a control algorithm can also be used. For example, the difference between Vtarget and Vmax is input into a preset control algorithm to obtain the corresponding compensation current ΔI.

[0075] Among them, the preset control algorithms include but are not limited to the Proportional Integral Differential (PID) algorithm, the Fuzzy Control algorithm, the Neural Network Control algorithm, etc.

[0076] The PID control algorithm is a control algorithm that combines the three links of proportional, integral, and differential. In process control, it controls according to the proportion, integral, and differential of the deviation, and has the advantages of simple principle, easy to implement, wide application range, independent control parameters, and simple selection of parameters. The PID algorithm can calculate the control signal by comparing the real-time state of the battery, such as voltage, current, and power, with the set target value, and adjust the output of the charging device to achieve dynamic control of the charging process.

[0077] The fuzzy control algorithm refers to the algorithm used to control the voltage and frequency of the inverter. In the charging field, the fuzzy control algorithm simulates expert experience through language rules, such as "increase the current if the voltage error is large", and can achieve dynamic adjustment without relying on an accurate model; the fuzzy controller can process multiple input variables such as voltage, current, temperature, and SOC (state of charge) at the same time, and can monitor the battery state in real time to avoid problems such as overcharging, over-discharging, and gas evolution. For example, in the charging of lithium-ion batteries, the fuzzy control can be used to adjust the polarization voltage to make the charging current dynamically adapt to the change of SOC.

[0078] The application of the neural network control algorithm in charging technology can improve charging efficiency, safety, and intelligence level, especially in dealing with complex non-linear problems, dynamic environment adaptation, and big data-driven decision-making. By using the neural network to monitor the charging state and battery health of electric vehicles in real time, the wireless charging power can be dynamically adjusted to ensure transmission stability and reduce energy loss. By using the neural network and reinforcement learning to generate an equalization strategy according to the health state of the battery pack, the difference in charge and discharge capacity can be reduced, and the overall system efficiency can be improved.

[0079] Optionally, the three control algorithms in the above examples can be used alone or in combination, and this application does not make any limitations in this regard.

[0080] Furthermore, it is determined that the updated charging current is the sum of the charging current before update and the compensation current. Exemplarily, assume that the charging current before update is the initial charging current I0, then the updated charging current is I0 + ΔI. When Vtarget is greater than Vmax, ΔI is positive, and the updated charging current becomes larger; when Vtarget is less than Vmax, ΔI is negative, and the updated charging current becomes smaller.

[0081] It should be noted that when the power battery leaves the factory, each single battery is set with a factory upper limit voltage value Vs, and the target cut-off voltage Vtarget is usually between Vs and Vmax.

[0082] Optionally, the vehicle can also continuously monitor the real-time maximum single-cell voltage Vmax of the power battery, and use the difference between Vmax and Vtarget as the feedback input of the control algorithm to continuously update the updated charging current.

[0083] Step 204: Send a current adjustment request to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter.

[0084] Among them, the first difference between the target cut-off voltage in the target constant-voltage charging stage and the maximum value of the first single-cell voltage is less than or equal to the second difference between the target cut-off voltage and the maximum value of the second single-cell voltage. The maximum value of the first single-cell voltage is the maximum value of the single-cell voltage corresponding to the updated charging current, and the maximum value of the second single-cell voltage is the maximum value of the single-cell voltage corresponding to the charging current before the update.

[0085] In some embodiments, after determining the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single-cell voltage in the previous step, a current adjustment request can be sent to the adapter. Optionally, the current adjustment request can be similar to a communication packet. After receiving the communication packet, the adapter can parse the updated charging current contained therein and adjust its output current according to the updated charging current.

[0086] Step 205: Charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power in the target constant-voltage charging stage.

[0087] In some embodiments, the adapter receives the updated charging current and charges the power battery according to the updated charging current. At the same time, the battery management system of the vehicle real-time feedbacks the voltage of each single battery. The system continuously calculates the voltage difference and dynamically adjusts the charging current to ensure the smooth progress of the charging process and avoid overcharging. When the maximum value of the first single-cell voltage, that is, the maximum value of the single-cell voltage corresponding to the updated charging current reaches the target cut-off voltage, the target cut-off voltage remains unchanged and the charging continues until the power of the power battery reaches the target cut-off power in the target constant-voltage charging stage.

[0088] It should be noted that the target cut-off power reached by the power battery of the power battery needs to be determined in real time in combination with the temperature and power of the battery. That is to say, not only the power needs to be charged to the target cut-off power, but also the temperature needs to meet the preset corresponding relationship mentioned in the above embodiments to complete the charging task of the target constant-voltage charging stage.

[0089] Step 206: Enter the next constant voltage charging stage after the target constant voltage charging stage in at least one constant voltage charging stage.

[0090] In some embodiments, after the power of the power battery reaches the target cut-off power, enter the next constant voltage charging stage after the target constant voltage charging stage, and update the corresponding cut-off voltage to continue charging until the power battery is charged to 100% SOC, then terminate the charging process.

[0091] In this embodiment, first obtain the battery temperature and battery power of the power battery, and determine that the power battery is in the target constant voltage charging stage according to the battery temperature, battery power and the preset corresponding relationship. The preset corresponding relationship includes the corresponding relationship between the preset battery temperature range, preset power range and preset constant voltage charging stage. When the power battery is in the target constant voltage charging stage, determine the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single-cell battery voltage. The maximum value of the second single-cell battery voltage is the maximum value of the single-cell battery voltage corresponding to the charging current before the update. Then send a current adjustment request to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter. Finally, charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power of the target constant voltage charging stage, and enter the next constant voltage charging stage after the target constant voltage charging stage in at least one constant voltage charging stage. By comparing the gap between Vmax and Vtarget, the updated charging current is adjusted in real time, and finally it is ensured that the charging voltage of the power battery remains in an approximately constant state, which can maximize the charging rate of the power battery within the lithium plating curve, shorten the charging time, improve the charging speed and user experience; by introducing voltage parameters to control the charging current, the speed at which the battery reaches the cut-off voltage can be slowed down, and the number of lithium ions released from the positive electrode material can be increased, thereby improving the charging capacity and energy density of the lithium-ion battery; by adjusting the number of constant voltage charging stages, it is applicable to different types of power batteries such as LFP and LMFP, with good versatility; and there is no need to change the existing electric vehicle and charging pile hardware, and it can be directly realized by software upgrade, reducing the implementation cost; it can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety.

[0092] Based on the above embodiments, Figure 3 This is an overall exemplary flowchart of the charging control method for a power battery provided by an embodiment of the present application. As Figure 3 shown, the method may include the following steps:

[0093] Step 301: Obtain the battery temperature and battery power of the power battery.

[0094] In some embodiments, the BMS can monitor the temperature of the power battery in real time through built-in or external temperature sensors. Generally, these sensors are installed at different positions in the battery pack to ensure accurate measurement of the temperature of the entire battery system. During the measurement process, the sensors will transmit the collected temperature data to the BMS.

[0095] Exemplarily, the charging temperature of the power battery is usually between 0°C and 45°C; the discharging temperature is usually between -20°C and 60°C.

[0096] In some embodiments, SOC refers to the percentage of the electric energy currently contained in the battery, and is usually used to represent the charging state of the battery. The BMS can obtain the SOC of the battery in the following ways:

[0097] (1) By measuring the voltage of the battery and combining it with the discharge curve of the battery, the power of the battery can be roughly estimated.

[0098] (2) The BMS monitors the charging and discharging currents, integrates and calculates the charge and discharge amounts of the battery, and estimates the SOC in combination with the initial power.

[0099] (3) The BMS may use a mathematical model based on battery characteristics to estimate the SOC. This model takes into account multiple factors such as the voltage, temperature, and current of the battery, thereby providing more accurate SOC data.

[0100] (4) Since the relationship between the voltage of the battery and the SOC is not linear, the BMS will perform SOC correction regularly to improve the estimation accuracy. This is usually carried out under specific charging or discharging states, and the deviation of the model is corrected by comparing with the known SOC value.

[0101] In some embodiments, the BMS usually communicates with the vehicle control system, such as the vehicle control unit and charging control unit of an electric vehicle, to report the battery temperature and battery power in real time. Or some battery management systems will provide API interfaces, allowing query of parameters such as the battery temperature, SOC, voltage, and current through software.

[0102] Step 302, determine whether the power battery is in the Nth constant voltage charging stage.

[0103] In some embodiments, the number of constant voltage charging stages corresponding to the power battery is determined according to the type of the power battery, and different types of power batteries include different numbers of constant voltage charging stages. For example, a lithium iron phosphate (LFP) type power battery includes 3 constant voltage charging stages, and a lithium manganese iron phosphate (LMFP) type power battery includes 4 constant voltage charging stages.

[0104] In some embodiments, a corresponding relationship is preset in the vehicle among a preset battery temperature range, a preset power range, and a preset constant-voltage charging stage. The vehicle compares the actually obtained battery temperature and SOC value with the preset temperature range and preset power range in the preset corresponding relationship to determine that the power battery is in the Nth constant-voltage charging stage.

[0105] Step 303: Charge with the initial charging current I0.

[0106] In some embodiments, different constant-voltage charging stages also correspond to different initial charging currents I0. When the power battery enters different constant-voltage charging stages for charging, it will initially apply for the initial charging current I0 from the adapter and then adjust according to the updated charging current.

[0107] Step 304: Determine whether Vmax is equal to Vtarget? If Vmax is equal to Vtarget, execute Step 305; otherwise, execute Step 306.

[0108] Among them, Vmax is the maximum value of the single-cell battery voltage corresponding to the charging current before update, and Vtarget is the cut-off voltage of the Nth constant-voltage charging stage.

[0109] Step 305: Constant-voltage charge the power battery according to Vtarget, and collect the battery temperature and battery power in Step 301 in real time until the charge reaches the cut-off power of the Nth constant-voltage charging stage.

[0110] Step 306: Input the pressure difference between Vmax and Vtarget into the control algorithm.

[0111] Optionally, the control algorithm includes but is not limited to PID algorithm, fuzzy control algorithm, neural network control algorithm, etc.

[0112] Step 307: Calculate the compensation current ΔI based on the control algorithm.

[0113] Step 308: Adjust the current to I0 + ΔI. Then repeat Step 304.

[0114] In some embodiments, it is determined that the updated charging current is I0 + ΔI. When Vtarget is greater than Vmax, ΔI is positive, and the updated charging current becomes larger; when Vtarget is less than Vmax, ΔI is negative, and the updated charging current becomes smaller.

[0115] Step 309: Jump to the N + 1 constant-voltage charging stage.

[0116] Step 310: Charge the power battery to 100%.

[0117] In this embodiment, by comparing the difference between Vmax and Vtarget, the updated charging current is adjusted in real time, ultimately ensuring that the charging voltage of the power battery remains in an approximately constant state. This can maximize the charging rate of the power battery within the lithium plating curve, shorten the charging time, and improve the charging speed and user experience. Since during the charging process, if the battery voltage exceeds the specified single-cell battery voltage, it will cause overvoltage problems in the battery. Overvoltage will lead to serious attenuation of the battery capacity and may also cause potential safety problems, resulting in battery fire and explosion. Therefore, based on at least one constant-voltage charging stage, constant-voltage charging of the power battery can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety.

[0118] Based on the above embodiment, assume that the type of the power battery is the LFP system. The LFP system includes 3 constant-voltage charging stages, the current battery temperature of the power battery is 10 °C, and the state of charge (SOC) of the battery is 50%. Please refer to Figure 4 , which is an exemplary flowchart of the charging control method for a power battery provided in an embodiment of the present application. As Figure 4 shown, the method may include the following steps:

[0119] Step 401: According to the battery temperature of 10 °C and the battery SOC of 50%, it is determined that the power battery is currently in the second constant-voltage charging stage, and the cut-off voltage Vtarget of this second constant-voltage charging stage is 3.55 V.

[0120] It should be noted that the type of the power battery can be obtained through the BMS system of the vehicle, that is, the chemical system is LFP. Assume that the number of constant-voltage charging stages of LFP is 3. The relationship between the voltage and the battery charge corresponding to the constant-voltage charging stages of the LFP type power battery is as Figure 5 shown. The abscissa is the battery charge, and the ordinate is the voltage. Among them, the cut-off voltage corresponding to the first constant-voltage charging stage CV1 is V1, and the cut-off charge is charge 1; the cut-off voltage corresponding to the second constant-voltage charging stage CV2 is V2, and the cut-off charge is charge 2; the cut-off voltage corresponding to the third constant-voltage charging stage CV3 is V3, and the cut-off charge is charge 3, and charge 3 is 100%.

[0121] Step 402: Charge the power battery with an initial charging current I0 = 1C according to the SOC of 50%.

[0122] Step 403: During the charging process of the second constant-voltage charging stage, compare the difference between the maximum value Vmax of the real-time voltage of the single cell and the cut-off voltage Vtarget, use the difference between Vtarget and Vmax as the input of the neural network control algorithm, and calculate the compensation current ΔI.

[0123] Among them, the control algorithm takes the neural network control algorithm as an example.

[0124] Exemplarily, the real-time voltage values of all single cells in the power battery are collected. For example, the voltage range is 3.42V to 3.52V. The maximum real-time voltage value of 3.52V of the single cells in the power battery is selected as Vmax. Then, the difference of 0.03V between Vtarget = 3.55V and Vmax = 3.52V is input into the neural network control algorithm to obtain a compensation current ΔI = 0.03C.

[0125] Step 404, determine that the updated charging current is I0 + ΔI = 1.03C.

[0126] Among them, when Vtarget is greater than Vmax, ΔI is positive, and the charging current increases; when Vtarget is less than Vmax, ΔI is negative, and the charging current decreases.

[0127] Step 405, determine whether the power battery is charged to the cut-off power of the second constant voltage charging stage, such as 80%. If not, execute Step 406; otherwise, execute Step 407.

[0128] Step 406, use the neural network control algorithm to adjust the updated charging current in real time by comparing the gap between Vmax and Vtarget to ensure that the charging voltage is maintained at an approximately constant 3.55V state until the charge reaches SOC = 80%.

[0129] Step 407, when the charge reaches 80%, then jump to the third constant voltage charging platform CV3, update the cut-off voltage Vtarget to 3.8V, and then return to Step 403 to repeat the above steps until the charge reaches 100%.

[0130] As another example, assume that the type of the power battery is the LMFP system. The LMFP system includes 4 constant voltage charging stages. The current battery temperature of the power battery is 20°C, and the battery state of charge SOC is 70%. Please refer to Figure 6 , which is an exemplary flow chart of the charging control method for the power battery provided by another embodiment of the present application. As Figure 6 shown, the method may include the following steps:

[0131] Step 601, according to the battery temperature of 20°C and the battery state of charge of 70%, determine that the power battery is currently in the third constant voltage charging stage, and the cut-off voltage Vtarget of this third constant voltage charging stage is 4.10V.

[0132] It should be noted that the type of the power battery can be obtained through the BMS system of the vehicle, that is, the chemical system is LMFP. Assume that the number of constant voltage charging stages of LMFP is 4. The relationship between the voltage and the state of charge corresponding to the constant voltage charging stage of the LMFP type power battery is asFigure 7 As shown, the abscissa is the battery charge and the ordinate is the voltage. Among them, the cut-off voltage corresponding to the first constant voltage charging stage CV1 is V1, and the cut-off charge is charge 1; the cut-off voltage corresponding to the second constant voltage charging stage CV2 is V2, and the cut-off charge is charge 2; the cut-off voltage corresponding to the third constant voltage charging stage CV3 is V3, and the cut-off charge is charge 3; the cut-off voltage corresponding to the fourth constant voltage charging stage CV4 is V4, and the cut-off charge is charge 4, and charge 4 is 100%.

[0133] Step 602: Give the power battery an initial charging current I0 = 0.9C for charging according to the SOC of 70%.

[0134] Step 603: During the charging process of the third constant voltage charging stage, compare the difference between the maximum real-time voltage Vmax of the single battery and the cut-off voltage Vtarget, take the difference between Vtarget and Vmax as the input of the PID control algorithm, and calculate the compensation current ΔI.

[0135] Among them, the control algorithm takes the PID control algorithm as an example.

[0136] Exemplarily, collect the real-time voltage values of all single batteries in the power battery. For example, the voltage range is 3.95V to 4.15V. Select the maximum real-time voltage value 4.15V of the single battery in the power battery as Vmax. Then, input the difference -0.05V between Vtarget = 4.10V and Vmax = 4.15V into the PID control algorithm to obtain the compensation current ΔI = -0.1C.

[0137] Step 604: Determine that the updated charging current is I0 + ΔI = 0.8C.

[0138] Among them, when Vtarget is greater than Vmax, ΔI is positive, and the charging current becomes larger; when Vtarget is less than Vmax, ΔI is negative, and the charging current becomes smaller.

[0139] Step 605: Determine whether the power battery is charged to the cut-off charge of the third constant voltage charging stage, such as 90%. If not, execute Step 606; otherwise, execute Step 607.

[0140] Step 606: Use the PID control algorithm to adjust the updated charging current in real time by comparing the difference between Vmax and Vtarget to ensure that the charging voltage is maintained at an approximately constant 4.10V state until the charge reaches SOC of 90%.

[0141] Step 607: When the battery is charged to 90%, jump to the fourth constant voltage charging platform CV4, update the cut-off voltage Vtarget to 4.25V, and then return to Step 603. Repeat the above steps until the battery is charged to 100%.

[0142] In summary, in the charging control method of the power battery provided by the embodiment of the present application, during the charging process in the target constant voltage charging stage, by applying for an updated charging current from the adapter, the maximum value of the single-cell voltage corresponding to the updated charging current is close to the cut-off voltage of the target constant voltage charging stage until the battery is charged to the cut-off power of the target constant voltage charging stage. Since during the charging process, if the battery voltage exceeds the specified single-cell voltage, it will cause the problem of overvoltage of the battery. Overvoltage will cause serious attenuation of the battery capacity and may also cause potential safety problems, resulting in battery fire and explosion. Therefore, charging the power battery based on at least one constant voltage charging stage can maximize the charging speed of the power battery in a low-temperature environment on the premise of ensuring battery safety.

[0143] It should be understood that although each step in the above flowcharts is shown sequentially according to the arrow indication, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise clearly stated in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the above flowcharts may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

[0144] Based on the foregoing embodiments, the embodiment of the present application provides a charging control device for a power battery. The device includes each module included and each unit included in each module, and can be implemented by a processor; of course, it can also be implemented by specific logic circuits. During the implementation process, the processor can be a central processing unit, a microprocessor, a digital signal processor, or a field programmable gate array, etc.

[0145] Figure 8 For the structural schematic diagram of the charging control device for the power battery provided by an embodiment of the present application, as Figure 8 shown, the charging control device for the power battery includes a sending module 801 and a charging module 802, where:

[0146] A sending module 801, configured to send a current adjustment request to an adapter when the power battery is in the target constant voltage charging stage, where the current adjustment request includes an updated charging current applied by the vehicle to the adapter, and a first difference between a target cut-off voltage of the target constant voltage charging stage and a maximum value of a first single cell voltage is less than or equal to a second difference between the target cut-off voltage and a maximum value of a second single cell voltage, the maximum value of the first single cell voltage is the maximum value of the single cell voltage corresponding to the updated charging current, and the maximum value of the second single cell voltage is the maximum value of the single cell voltage corresponding to the charging current before the update;

[0147] A charging module 802, configured to charge the power battery according to the updated charging current until the power of the power battery reaches a target cut-off power of the target constant voltage charging stage.

[0148] In some embodiments, the device further includes: a determining module. The determining module is configured to determine the updated charging current according to a difference between the target cut-off voltage and the maximum value of the second single cell voltage.

[0149] In some embodiments, the device further includes: a maintaining module. The determining module is further configured to determine that the updated charging current is greater than the charging current before the update when the target cut-off voltage is greater than the maximum value of the second single cell voltage; the determining module is further configured to determine that the updated charging current is less than the charging current before the update when the target cut-off voltage is less than the maximum value of the second single cell voltage; the maintaining module is configured to keep the charging current before the update unchanged when the target cut-off voltage is equal to the maximum value of the second single cell voltage.

[0150] In some embodiments, the determining module is specifically configured to: when the target cut-off voltage is not equal to the maximum value of the second single cell voltage, obtain a compensation current according to a ratio of a difference between the target cut-off voltage and the maximum value of the second single cell voltage to a real-time internal resistance value of a single cell in the power battery, and the greater the difference between the target cut-off voltage and the maximum value of the second single cell voltage, the greater the compensation current; determine that the updated charging current is the sum of the charging current before the update and the compensation current.

[0151] In some embodiments, the device further includes: an acquisition module and a judgment module. The acquisition module is configured to acquire the battery temperature and the battery power of the power battery; the judgment module is configured to judge, according to the battery temperature, the battery power, and a preset corresponding relationship, that the power battery is in the target constant voltage charging stage, where the preset corresponding relationship includes the corresponding relationship between a preset battery temperature range, a preset power range, and a preset constant voltage charging stage.

[0152] In some embodiments, the number of constant voltage charging stages corresponding to the power battery is determined according to the type of the power battery, and different types of power batteries include different numbers of constant voltage charging stages.

[0153] In some embodiments, the device further includes: an entry module. The entry module is configured to enter the next constant voltage charging stage after the target constant voltage charging stage among the at least one constant voltage charging stage.

[0154] The description of the above device embodiments is similar to the description of the above method embodiments and has similar beneficial effects to the method embodiments. For the technical details not disclosed in the device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0155] It should be noted that in the embodiments of the present application Figure 8 The division of the modules of the charging control device of the power battery shown is schematic, and is only a logical function division. In actual implementation, there may be other division methods. In addition, each functional unit in the various embodiments of the present application may be integrated in one processing unit, or may exist physically alone, or two or more units may be integrated in one unit. The above integrated unit may be implemented in the form of hardware, or may be implemented in the form of a software functional unit. It may also be implemented in the form of a combination of software and hardware.

[0156] It should be noted that in the embodiments of the present application, if the above method is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application, in essence, or the part that makes a contribution to the related technology, may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing an electronic device to execute all or part of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disc that can store program codes. In this way, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0157] An embodiment of the present application provides a vehicle, and its internal structure diagram can be as Figure 9 shown. The vehicle includes a processor, a memory, and a network interface connected through a system bus. Among them, the processor of the vehicle is used to provide computing and control capabilities. The memory of the vehicle includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the vehicle is used to store data. The network interface of the vehicle is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above method is implemented.

[0158] An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the method provided in the above embodiment are implemented.

[0159] An embodiment of the present application provides a computer program product containing instructions. When it runs on a computer, it causes the computer to execute the steps in the method provided in the above method embodiment.

[0160] Those skilled in the art can understand that Figure 9 the structure shown in

[0161] is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the vehicle to which the solution of the present application is applied. The specific vehicle may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements. Figure 9 In one embodiment, the charging control device of the power battery provided by the present application can be implemented in the form of a computer program, and the computer program can run on a vehicle as

[0162] shown. Each program module constituting the above device can be stored in the memory of the vehicle. The computer program constituted by each program module causes the processor to execute the steps in the methods of the various embodiments of the present application described in this specification.

[0163] It should be understood that the "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the appearances of "in one embodiment" or "in an embodiment" or "in some embodiments" throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The serial numbers of the embodiments of the present application above are only for description and do not represent the advantages or disadvantages of the embodiments. The above descriptions of the various embodiments tend to emphasize the differences between the various embodiments, and their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated herein again.

[0164] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, object A and / or object B can represent: the individual existence of object A, the simultaneous existence of object A and object B, and the individual existence of object B.

[0165] It should be noted that in this article, the term "comprise", "include" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0166] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The above-described embodiments are merely illustrative. For example, the division of the modules is only a logical function division, and there can be other division methods in actual implementation. For example, multiple modules or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling or communication connection between the components shown or discussed with each other can be through some interfaces, and the indirect coupling or communication connection of the devices or modules can be electrical, mechanical or other forms.

[0167] The modules described above as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network elements; some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0168] In addition, in each embodiment of the present application, all the functional modules may be integrated in one processing unit, or each module may be separately used as a unit, or two or more modules may be integrated in one unit; the above-mentioned integrated modules may be implemented in the form of hardware, or in the form of a combination of hardware and software functional units.

[0169] Those of ordinary skill in the art can understand that all or part of the steps to implement the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes: removable storage devices, read-only memory (ROM), magnetic disks, or optical disks and other various media that can store program codes.

[0170] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiments of the present application essentially or the part that contributes to the related technology can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to enable an electronic device to execute all or part of the methods described in various embodiments of the present application. And the foregoing storage medium includes: removable storage devices, ROM, magnetic disks, or optical disks and other various media that can store program codes.

[0171] The methods disclosed in several method embodiments provided by the present application can be arbitrarily combined without conflict to obtain new method embodiments.

[0172] The features disclosed in several product embodiments provided by the present application can be arbitrarily combined without conflict to obtain new product embodiments.

[0173] The features disclosed in several method or device embodiments provided by the present application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0174] As described above, it is only the implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A charging control method for a power battery, characterized in that, Applied to a vehicle, the power battery corresponds to at least one constant voltage charging stage, and different constant voltage charging stages correspond to different cut-off voltages and cut-off powers. The method includes: When the power battery is charged in the target constant voltage charging stage, send a current adjustment request to the adapter. The current adjustment request includes the updated charging current applied by the vehicle to the adapter. The first difference between the target cut-off voltage of the target constant voltage charging stage and the maximum value of the first single battery voltage is less than or equal to the second difference between the target cut-off voltage and the maximum value of the second single battery voltage. The maximum value of the first single battery voltage is the maximum value of the single battery voltage corresponding to the updated charging current, and the maximum value of the second single battery voltage is the maximum value of the single battery voltage corresponding to the charging current before the update. Charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power of the target constant voltage charging stage.

2. The method according to claim 1, wherein Before sending the current adjustment request to the adapter, the method further includes: Determine the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single battery voltage.

3. The method according to claim 2, characterized in that, The method further includes: When the target cut-off voltage is greater than the maximum value of the second single battery voltage, determine that the updated charging current is greater than the charging current before the update. When the target cut-off voltage is less than the maximum value of the second single battery voltage, determine that the updated charging current is less than the charging current before the update. When the target cut-off voltage is equal to the maximum value of the second single battery voltage, keep the charging current before the update unchanged.

4. The method according to claim 3, wherein The determining the updated charging current according to the difference between the target cut-off voltage and the maximum value of the second single battery voltage includes: When the target cut-off voltage is not equal to the maximum value of the second single battery voltage, obtain a compensation current according to the ratio of the difference between the target cut-off voltage and the maximum value of the second single battery voltage to the real-time internal resistance value of the single battery in the power battery. The greater the difference between the target cut-off voltage and the maximum value of the second single battery voltage, the greater the compensation current. Determine that the updated charging current is the sum of the charging current before the update and the compensation current.

5. The method according to claim 1, characterized in that, Before sending the current adjustment request to the adapter, the method further includes: Obtain the battery temperature and battery power of the power battery. Judge that the power battery is in the target constant voltage charging stage according to the battery temperature, the battery power and a preset corresponding relationship. The preset corresponding relationship includes the corresponding relationship between a preset battery temperature range, a preset power range and a preset constant voltage charging stage.

6. The method according to claim 1, wherein The number of constant voltage charging stages corresponding to the power battery is determined according to the type of the power battery, and different types of power batteries include different numbers of constant voltage charging stages.

7. The method according to claim 1, wherein After charging the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power, the method further includes: Enter the next constant-voltage charging stage after the target constant-voltage charging stage in the at least one constant-voltage charging stage.

8. A charging control device for a power battery, characterized in that, Applied to a vehicle, a power battery corresponds to at least one constant-voltage charging stage, and different constant-voltage charging stages correspond to different cut-off voltages and cut-off powers. The device includes: A sending module, configured to send a current adjustment request to an adapter when the power battery is being charged in a target constant-voltage charging stage. The current adjustment request includes an updated charging current applied by the vehicle to the adapter. A first difference between a target cut-off voltage of the target constant-voltage charging stage and a maximum value of a first single-cell voltage is less than or equal to a second difference between the target cut-off voltage and a maximum value of a second single-cell voltage. The maximum value of the first single-cell voltage is the maximum value of the single-cell voltage corresponding to the updated charging current, and the maximum value of the second single-cell voltage is the maximum value of the single-cell voltage corresponding to the charging current before the update. A charging module, configured to charge the power battery according to the updated charging current until the power of the power battery reaches the target cut-off power of the target constant-voltage charging stage.

9. A vehicle, comprising a memory and a processor, the memory storing a computer program that can run on the processor, characterized in that, When the processor executes the program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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