Battery charging method, controller, charging and discharging system, storage medium and vehicle

Abstract

The present invention discloses a battery charging method, a controller, a charging and discharging system, a storage medium and a vehicle. The battery charging method comprises: obtaining first battery data of a power battery, determining a current charging condition based on the first battery data; when the current charging condition is a high charging condition, determining a target charging current based on a pulse charging strategy, and charging the power battery based on the target charging current. In this solution, when the battery is in a high charging condition, pulse charging is performed based on a pulse charging strategy, which can not only ensure the charging efficiency of the power battery in a high charging state, but also avoid lithium deposition, thereby extending the battery life.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging, and in particular to a battery charging method, a controller, a charging and discharging system, a storage medium and a vehicle. Background Art

[0002] The charging capacity of power batteries is not only affected by the materials and structure of the battery itself, but also by its charging strategy. During the battery charging process, different charging methods and charging currents will lead to different polarization effects inside the battery, and the negative electrode potential of the battery will also be different, which will affect the charging efficiency and charging safety of the battery. The existing battery charging strategy generally controls the charging current to gradually decrease as the charging time increases. It is impossible to dynamically adjust the charging current according to the actual situation to ensure its charging efficiency and charging safety. Summary of the invention

[0003] Embodiments of the present invention provide a battery charging method, a controller, a charging and discharging system, a storage medium and a vehicle to solve the problem of how to improve the battery charging efficiency.

[0004] A battery charging method, comprising:

[0005] Acquire first battery data of a power battery, and determine a current charge condition based on the first battery data;

[0006] When the current charging condition is a high charging condition, a target charging current is determined based on a pulse charging strategy, and the power battery is charged based on the target charging current.

[0007] Preferably, the battery charging method further comprises: when the current charge condition is a low charge condition, determining a target charging current based on a first constant current charging strategy, and charging the power battery based on the target charging current.

[0008] Preferably, the first battery data includes current SOC and / or current voltage;

[0009] The determining the current state of charge based on the first battery data includes:

[0010] If the current SOC is less than a first SOC threshold, and the current voltage is less than a first voltage threshold, determining that the current charge condition is a low charge condition;

[0011] If the current SOC is greater than or equal to a first SOC threshold, or the current voltage is greater than or equal to a first voltage threshold, it is determined that the current charge condition is a high charge condition.

[0012] Preferably, determining the target charging current based on the first constant current charging strategy includes:

[0013] Acquiring second battery data of the power battery, and determining a target constant current charging stage based on the second battery data;

[0014] A first constant current corresponding to the target constant current charging stage is determined as the target charging current.

[0015] Preferably, the target constant current charging stage is a constant current charging stage corresponding to the stage data interval to which the second battery data belongs.

[0016] Preferably, determining the target charging current based on the pulse charging strategy includes:

[0017] Acquiring second battery data of the power battery, and determining a target pulse charging stage based on the second battery data;

[0018] The bidirectional pulse current corresponding to the target pulse charging stage is determined as the target charging current.

[0019] Preferably, the target pulse charging phase is a pulse charging phase corresponding to the phase data interval to which the second battery data belongs.

[0020] Preferably, the stage data interval is an SOC threshold interval and / or a voltage threshold interval.

[0021] Preferably, before acquiring the first battery data of the power battery and determining the current charge condition based on the first battery data, the battery charging method further includes:

[0022] Acquire third battery data of the power battery, and determine a current temperature condition based on the third battery data;

[0023] When the current temperature condition is a low temperature condition, controlling the power battery to heat up, repeatedly performing the step of acquiring the third battery data of the power battery, and determining the current temperature condition based on the third battery data;

[0024] When the current temperature condition is a normal temperature condition, the step of acquiring first battery data of a power battery is performed, and a current charge condition is determined based on the first battery data.

[0025] Preferably, the third battery data includes current temperature;

[0026] The determining the current temperature condition based on the third battery data includes:

[0027] If the current temperature is less than the first temperature threshold, determining that the current temperature operating condition is a low temperature operating condition;

[0028] If the current temperature is greater than or equal to the first temperature threshold, it is determined that the current temperature condition is a normal temperature condition.

[0029] Preferably, controlling the power battery to increase in temperature includes:

[0030] A temperature rise control strategy corresponding to the current temperature is adopted to control the self-heating temperature rise of the power battery.

[0031] Preferably, the temperature rise control strategy corresponding to the current temperature is adopted to control the self-heating temperature rise of the power battery, including:

[0032] If the current temperature is less than a second temperature threshold, controlling the power battery to self-heat and increase temperature based on a self-heating strategy;

[0033] If the current temperature is greater than or equal to the second temperature threshold, the power battery is controlled to self-heat and heat up based on the self-heating strategy, and the power battery is charged based on the second constant current charging strategy.

[0034] Preferably, charging the power battery based on the second constant current charging strategy includes:

[0035] Based on the current temperature and the current SOC, a second constant current is determined, and based on the second constant current, the power battery is charged.

[0036] Preferably, determining the second constant current based on the current temperature and the current SOC includes:

[0037] Based on the current temperature, the current SOC and the constant current mapping data, a second constant current is determined.

[0038] Preferably, the target charging current is less than a safe charging current, and the safe charging current is a charging current corresponding to the first battery data in a battery lithium deposition boundary.

[0039] A controller comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the battery charging method when executing the computer program.

[0040] A charging and discharging system, comprising a charging and discharging circuit and the above-mentioned controller;

[0041] The charging and discharging circuit is used to connect the charging power source and the power battery;

[0042] The controller is connected to the charging and discharging circuit and is used to control the operation of the charging and discharging circuit so that the charging power source charges the power battery.

[0043] Preferably, the charging and discharging circuit comprises at least one bridge arm and at least one inductor, each of the bridge arms comprises an upper bridge power tube and a lower bridge power tube arranged in series, and a connection node between the upper bridge power tube and the lower bridge power tube is connected to a first end of the inductor;

[0044] At least one of the upper bridge power tubes is used to connect the positive electrode of the power battery;

[0045] At least one of the lower bridge power tubes is used to connect the negative electrode of the power battery;

[0046] A second end of at least one of the inductors is used to connect to an inter-battery node of the power battery, where the inter-battery node is a node between two adjacent batteries in the power battery.

[0047] Preferably, the charging and discharging circuit further comprises a capacitor, a first end of the capacitor is used to connect to the positive electrode of the power battery, and a second end of the capacitor is used to connect to the negative electrode of the power battery.

[0048] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the battery charging method is implemented.

[0049] A vehicle comprises the above-mentioned controller, or the above-mentioned charging and discharging system, or the above-mentioned computer-readable storage medium.

[0050] The above-mentioned battery charging method, controller, charging and discharging system, storage medium and vehicle determine their current charge condition based on the first battery data. When the current charge condition is a high charge condition, the power battery is charged with a target charging current determined based on the pulse charging strategy, which can not only ensure the charging efficiency of the power battery in a high charge state, but also avoid lithium deposition, thereby extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0052] Figure 1 is a first flow chart of a battery charging method in one embodiment of the present invention;

[0053] Figure 2 is a second flow chart of a battery charging method according to an embodiment of the present invention;

[0054] Figure 3 yes Figure 1A flow chart of step S102;

[0055] Figure 4 is a third flow chart of a battery charging method in one embodiment of the present invention;

[0056] Figure 5 is a schematic diagram of a charging strategy in one embodiment of the present invention;

[0057] Figure 6 is a schematic diagram showing the change of negative electrode potential with SOC under different charging strategies in one embodiment of the present invention;

[0058] Figure 7 is a schematic diagram showing the variation of the resistance of the self-heating pulse with SOC at different frequencies in one embodiment of the present invention;

[0059] Figure 8 Schematic diagram of a charging and discharging system in one embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] The battery charging method provided in an embodiment of the present invention can be applied in a charging and discharging system to charge a power battery connected to the charging and discharging system. The charging and discharging system here is a charging and discharging system that can realize charging and self-heating functions. In this example, the battery charging method is specifically applicable to a controller (hereinafter referred to as ECU) or a battery management system (hereinafter referred to as BMS) in the charging and discharging system, which can control the charging power supply to charge the power battery according to the measured data of the power battery. The charging power supply here can be but is not limited to a charging pile.

[0062] In one embodiment, if Figure 1 As shown, a battery charging method is provided, which is described by taking the application of the method in ECU as an example, and includes the following steps:

[0063] S101: Acquire first battery data of a power battery, and determine a current charge condition based on the first battery data;

[0064] S102: When the current charging condition is a high charging condition, determine a target charging current based on a pulse charging strategy, and charge the power battery based on the target charging current.

[0065] The first battery data is the battery data collected in real time, specifically the data used to determine the charging condition. The target charging current is the charging current that needs to be controlled by the charging power source to charge the power battery.

[0066] The current charge condition is a condition used to reflect the charge state of the power battery. As an example, the current charge condition may be any one of a high charge condition and a low charge condition, wherein the high charge condition refers to a condition in which the battery charge is high, and vice versa, the low charge condition refers to a condition in which the battery charge is low.

[0067] As an example, in step S101, the ECU may obtain the first battery data of the power battery through the BMS. The first battery data here may be, but is not limited to, the current SOC and current voltage corresponding to the power battery, and other data that can directly or indirectly calculate its state of charge. The current SOC is the SOC of the power battery detected at the current moment. The current voltage is the voltage across the power battery detected at the current moment. The ECU may compare the first battery data with the high-charge condition. If the first battery data meets the high-charge condition, the current charge condition is determined to be a high-charge condition; conversely, if the first battery data does not meet the high-charge condition, the current charge condition is determined to be a low-charge condition. The high-charge condition here is a pre-set condition for evaluating whether the power battery is in a high-charge condition.

[0068] Among them, the pulse charging strategy is a strategy used to control the battery to charge based on a bidirectional pulse current when the battery is under high charge conditions.

[0069] As an example, in step S102, when the current charging condition is a high charging condition, the ECU uses a pulse charging strategy, processes the measured data collected by the strategy, determines the bidirectional pulse current of the measured data, and determines the bidirectional pulse current as the target charging current corresponding to the high charging condition. After determining the target charging current, the ECU can charge the power battery based on the target charging current, that is, under the high charging condition, the power battery is charged based on the bidirectional pulse current to ensure the charging efficiency of the power battery and avoid the negative electrode lithium deposition phenomenon of the power battery during the charging process, thereby extending the battery life. The bidirectional pulse current here refers to the interval setting of the positive pulse current and the negative pulse current. The positive pulse here is a pulse whose lower limit voltage of the pulse waveform is greater than a preset threshold value (such as 0), and the negative pulse is a pulse whose lower limit voltage of the pulse waveform is less than a preset threshold value (such as 0). In addition, the pulse whose lower limit voltage of the pulse waveform is equal to the preset threshold value (such as 0) can be determined as a zero pulse. When the power battery is in a high charge condition, the battery polarization effect is more obvious, and the acceptable charging current of the battery is small. A slightly larger charging current may cause lithium deposition at the negative electrode of the battery, resulting in accelerated battery life decay and even safety problems. At this time, a bidirectional pulse current is used as the target charging current for charging. The positive pulse current is used to ensure its charging efficiency, and the negative pulse current set at intervals is used to achieve automatic depolarization to avoid lithium deposition at the negative electrode of the battery, thereby extending the battery life.

[0070] In this example, the bidirectional pulse current refers to the interval setting of the positive pulse current and the negative pulse current, which can be specifically set to charge based on the positive pulse current within a preset period, and charge based on the negative pulse current between two adjacent preset periods. For example, a negative pulse is separated between every two preset periods to play the role of automatic depolarization. The waveform of the bidirectional pulse current can be in different forms such as but not limited to sine waves, square waves, pulses, increasing waves and decreasing waves, preferably sine waves. The frequency of the bidirectional pulse current is given according to the maximum value of the charging speed obtained without lithium precipitation. Depending on the usage scenario, it can be a fixed frequency or it can change dynamically with the SOC. The frequency selection range of the fixed frequency pulse includes but is not limited to: 1Hz, 10Hz, 25Hz, 50Hz, 100Hz, 200Hz, etc., taking into account lithium precipitation, charging speed, the impact on battery aging and life, noise, stability, etc., preferably 100Hz.

[0071] In this embodiment, the current charge condition is determined based on the first battery data. When the current charge condition is a high charge condition, the power battery is charged with a target charging current determined based on the pulse charging strategy. This can not only ensure the charging efficiency of the power battery in a high charge state, but also avoid lithium deposition, thereby extending the battery life.

[0072] In one embodiment, the battery charging method further includes:

[0073] When the current charge condition is a low charge condition, a target charging current is determined based on a first constant current charging strategy, and the power battery is charged based on the target charging current.

[0074] The first constant current charging strategy is a strategy for controlling the battery to be charged based on the first constant current when the battery is in a low charge condition.

[0075] As an example, when the current charge condition is a low charge condition, the ECU can execute the first constant current charging strategy, process the measured data collected by the strategy, determine the first constant current corresponding to the measured data, and determine the first constant current as the target charging current corresponding to the low charge condition. When the power battery is in a low charge condition, it can be determined that the charge state of the power battery is low and the risk of lithium plating is low, and the first constant current determined by the first constant current charging strategy is determined as the target charging current. After determining the target charging current, the ECU can charge the power battery based on the target charging current, that is, under the low charge condition, the power battery is charged based on the first constant current to ensure the charging efficiency of the power battery.

[0076] In one embodiment, the first battery data includes a current SOC and / or a current voltage;

[0077] The determining the current state of charge based on the first battery data includes:

[0078] If the current SOC is less than a first SOC threshold, and the current voltage is less than a first voltage threshold, determining that the current charge condition is a low charge condition;

[0079] If the current SOC is greater than or equal to a first SOC threshold, or the current voltage is greater than or equal to a first voltage threshold, it is determined that the current charge condition is a high charge condition.

[0080] The first SOC threshold is a pre-set SOC threshold for defining different charge conditions, specifically a SOC threshold for distinguishing low charge conditions from high charge conditions. The first voltage threshold is a pre-set voltage threshold for defining different charge conditions, specifically a voltage threshold for distinguishing low charge conditions from high charge conditions.

[0081] As an example, the ECU determines the current SOC and current voltage corresponding to the power battery from the first battery data, compares the current SOC with the first SOC threshold, and compares the current voltage with the first voltage threshold; when the current SOC is less than the first SOC threshold and the current voltage is less than the first voltage threshold, it can be determined that the state of charge of the power battery is low, and the potential difference between the positive and negative electrodes of the power battery is small, therefore, the current charge condition is determined to be a low charge condition; when the current SOC is greater than or equal to the first SOC threshold or the current voltage is greater than or equal to the first voltage threshold, it can be determined that the state of charge of the power battery is high, or the potential difference between the positive and negative electrodes of the power battery is large, therefore, the current charge condition is determined to be a high charge condition.

[0082] In this example, the current charge condition can be determined by the current SOC, the current voltage, or the current SOC and the current voltage, depending on the actual situation.

[0083] In one embodiment, if Figure 2 As shown, the determining the target charging current based on the first constant current charging strategy includes:

[0084] S201: Acquire second battery data of the power battery, and determine a target constant current charging stage based on the second battery data;

[0085] S202: Determine a first constant current corresponding to the target constant current charging stage as a target charging current.

[0086] Among them, the second battery data is the battery data collected in real time, specifically the data used to determine the charging current of the charging power supply to charge the power battery. The target constant current charging stage is the constant current charging stage that matches the second battery data. As an example, based on the first constant current charging strategy, multiple constant current charging stages are pre-set, and the stage evaluation conditions and the first constant current current corresponding to each constant current charging stage are set. The stage evaluation conditions here are the conditions for evaluating whether the constant current charging stage can be entered, and the first constant current current is the charging current corresponding to the constant current charging stage.

[0087] As an example, when the current charging condition is a low charging condition, the ECU processes the second battery data based on the first constant current charging strategy corresponding to the low charging condition, determines the first constant current matching the second battery data, and determines the first constant current as the target charging current. Specifically, the ECU compares the second battery data with the stage evaluation conditions corresponding to the pre-set multiple constant current charging stages. If the second battery data matches any stage evaluation condition, the constant current charging stage corresponding to the stage evaluation condition is determined as the target constant current charging stage, and then the first constant current corresponding to the target constant current charging stage is determined as the target charging current. In this example, the stage evaluation conditions corresponding to the pre-set multiple constant current charging stages and the corresponding first constant current current are different. According to the comparison result of the second battery data and the stage evaluation condition, the corresponding constant current charging stage and the first constant current current can be determined, and the first constant current current is determined as the target charging current for charging the battery.

[0088] In one embodiment, the target constant current charging stage is a constant current charging stage corresponding to the stage data interval to which the second battery data belongs.

[0089] As an example, based on the first constant current charging strategy, multiple constant current charging stages are pre-set, and stage evaluation conditions and the first constant current current corresponding to each constant current charging stage are set. The stage evaluation conditions here can be a stage data interval, and the stage data interval here is a pre-set numerical range for evaluating whether a certain constant current charging stage can be entered.

[0090] As an example, after obtaining the second battery data of the power battery, the ECU compares the second battery data with the stage data intervals corresponding to multiple constant current charging stages; if the second battery data matches the stage data interval corresponding to a constant current charging stage, the constant current charging stage corresponding to the stage data interval to which the second battery data belongs is determined as the target constant current charging stage, and the first constant current corresponding to the target constant current charging stage is determined as the target charging current.

[0091] For example, N constant current charging stages are preset, N≧2, and the stage data interval corresponding to the i-th constant current charging stage is , and the first constant current corresponding to the i-th constant current charging stage is After receiving the second battery data, the ECU can compare the second battery data with the pre-set N stage data intervals. Compare; if the second battery data is in the third stage data interval The third constant current charging stage is determined as the target constant current charging stage, and the first constant current current corresponding to the target constant current charging stage is determined as The target charging current is determined, and the power battery is charged based on the target charging current ... and so on, until it is detected that the power battery exits the low-charge condition or meets other charging termination conditions, and the charging process is terminated.

[0092] In one embodiment, if Figure 3 As shown, step S102, i.e., determining the target charging current based on the pulse charging strategy, includes:

[0093] S301: Acquire second battery data of the power battery, and determine a target pulse charging stage based on the second battery data;

[0094] S302: Determine the bidirectional pulse current corresponding to the target pulse charging stage as the target charging current.

[0095] The target pulse charging stage is a pulse charging stage that matches the second battery data. As an example, based on the pulse charging strategy, multiple pulse charging stages are pre-set, and the stage evaluation conditions and bidirectional pulse current corresponding to each pulse charging stage are set. The stage evaluation conditions here are conditions for evaluating whether the pulse charging stage can be entered, and the bidirectional pulse current is the charging current of the pulse charging stage.

[0096] As another example, when the current charging condition is a high charging condition, the ECU processes the second battery data based on the pulse charging strategy corresponding to the high charging condition, determines the bidirectional pulse current that matches the second battery data, and determines the bidirectional pulse current as the target charging current. Specifically, the ECU compares the second battery data with the stage evaluation conditions corresponding to the pre-set multiple pulse charging stages. If the second battery data matches any stage evaluation condition, the pulse charging stage corresponding to the stage evaluation condition is determined as the target pulse charging stage, and then the bidirectional pulse current corresponding to the target pulse charging stage is determined as the target charging current. In this example, the stage evaluation conditions corresponding to the pre-set multiple pulse charging stages and their corresponding bidirectional pulse currents are different. According to the comparison result of the second battery data and the stage evaluation conditions, the corresponding pulse charging stage and bidirectional pulse current can be determined, and the bidirectional pulse current can be determined as the target charging current for charging the battery.

[0097] In one embodiment, the target pulse charging phase is a pulse charging phase corresponding to the phase data interval to which the second battery data belongs.

[0098] As an example, based on the pulse charging strategy, multiple pulse charging stages are pre-set, and stage evaluation conditions and bidirectional pulse currents corresponding to each pulse charging stage are set. The stage evaluation conditions here can be stage data intervals, and the stage data intervals here are pre-set numerical ranges for evaluating whether a certain pulse charging stage can be entered.

[0099] As an example, after obtaining the second battery data of the power battery, the ECU can compare the second battery data with the phase data intervals corresponding to multiple pulse charging phases; if the second battery data matches the phase data interval corresponding to any pulse charging phase, the pulse charging phase corresponding to the phase data interval to which the second battery data belongs is determined as the target pulse charging phase, and the bidirectional pulse current corresponding to the target pulse charging phase is determined as the target charging current.

[0100] For example, N pulse charging stages are preset, N≧2, and the stage data interval corresponding to the i-th pulse charging stage is , and the bidirectional pulse current corresponding to the i-th pulse charging stage is After receiving the second battery data, the ECU can compare the second battery data with the pre-set N stage data intervals. Compare; if the second battery data is in the third stage data interval The bidirectional pulse current corresponding to the third pulse charging stage is The target charging current is determined, and the power battery is charged based on the target charging current ... and so on, until the high charge condition is exited or other charging termination conditions are met, and the charging process is terminated.

[0101] In one embodiment, the phase data interval is an SOC threshold interval and / or a voltage threshold interval.

[0102] Among them, the SOC threshold interval is a pre-set SOC threshold for evaluating whether the second battery data falls into a certain charging stage, and each SOC threshold interval corresponds to a lower SOC threshold and an upper SOC threshold. The charging stage here can be a constant current charging stage or a pulse charging stage. Since the battery charge gradually increases during the charging process of the power battery, in two adjacent charging stages, the lower SOC threshold corresponding to the previous charging stage is the same as the upper SOC threshold corresponding to the next charging stage, which is the boundary SOC threshold between the two adjacent charging stages.

[0103] As an example, the SOC threshold intervals corresponding to multiple constant current charging stages increase in sequence, and the corresponding first constant current currents decrease in sequence. For example, the ECU may compare the current SOC in the second battery data with the SOC threshold interval corresponding to the i-1th constant current charging stage. If the current SOC is within the SOC threshold interval corresponding to the i-1th constant current charging stage, the first constant current current corresponding to the i-1th constant current charging stage is increased. The target charging current is determined. The processing between multiple pulse charging stages is the same as above, and will not be described here one by one to avoid repetition.

[0104] Among them, the voltage threshold interval is a pre-set voltage threshold for evaluating whether the second battery data falls into a certain charging stage, and each voltage threshold interval corresponds to a lower voltage threshold and an upper voltage threshold. The charging stage here can be a constant current charging stage or a pulse charging stage. Since the battery voltage of the power battery gradually increases during the charging process, in two adjacent charging stages, the lower voltage threshold corresponding to the previous charging stage is the same as the upper voltage threshold corresponding to the next charging stage, which is the boundary voltage threshold between the two adjacent charging stages.

[0105] As an example, the voltage threshold intervals corresponding to multiple pulse charging stages increase successively, and the corresponding bidirectional pulse currents decrease successively. For example, the ECU may compare the current voltage in the second battery data with the voltage threshold interval corresponding to the i-th pulse charging stage. If the current voltage is within the voltage threshold interval corresponding to the i-th pulse charging stage, the bidirectional pulse current corresponding to the i-th pulse charging stage is determined as the target charging current. The processing between multiple constant current charging stages is the same as above, and to avoid repetition, it is not described one by one here.

[0106] In one embodiment, if Figure 4 As shown, before acquiring the first battery data of the power battery and determining the current charge condition based on the first battery data, the battery charging method further includes:

[0107] S401: Acquire third battery data of the power battery, and determine a current temperature condition based on the third battery data;

[0108] S402: when the current temperature condition is a low temperature condition, controlling the power battery to heat up, repeatedly performing the step of acquiring third battery data of the power battery, and determining the current temperature condition based on the third battery data;

[0109] S403: When the current temperature condition is a normal temperature condition, the step of acquiring first battery data of the power battery is performed, and a current charge condition is determined based on the first battery data.

[0110] The third battery data is battery data collected in real time, specifically data used to determine the temperature condition. The current temperature condition is a condition used to reflect the temperature state of the power battery. As an example, the current temperature condition can be any one of a normal temperature condition and a low temperature condition, where the normal temperature condition is a condition that does not meet the low temperature standard, and the low temperature condition is a condition that meets the low temperature standard.

[0111] As an example, in step S401, the ECU may obtain the third battery data of the power battery, and evaluate whether it meets the low temperature standard based on the third battery data. When the third battery data does not meet the low temperature standard, it may be determined that its current temperature condition is a normal temperature condition; conversely, when the third battery data meets the low temperature standard, it may be determined that its current temperature condition is a low temperature condition.

[0112] As an example, in step S402, when the current temperature condition is a low temperature condition, the ECU can determine that the temperature of the power battery is low. If the power battery is charged directly, the risk of lithium plating at the negative electrode of the battery will be greater. Therefore, it is necessary to execute a pre-set temperature rise control strategy to control the temperature rise of the power battery so that the temperature of the power battery cell increases, which helps to ensure the subsequent charging efficiency and reduce the risk of lithium plating at the negative electrode. In this example, the temperature rise of the power battery can be controlled by, but not limited to, DC self-heating of the internal resistance of the battery, or by AC self-heating or an external heating device. It is understandable that after controlling the temperature rise of the power battery, the ECU needs to repeat step S401 until it is determined that the current temperature condition is a normal temperature condition.

[0113] As an example, in step S403, when the current temperature condition is a normal temperature condition, the ECU can determine that the temperature of the power battery is higher than a preset low temperature standard. At this time, the risk of low-temperature lithium deposition is low, and step S101 and subsequent steps can be executed, that is, it is necessary to obtain the first battery data of the power battery, so as to determine the current charge condition based on the first battery data, and then adopt different charging strategies for charging, so as to achieve constant current charging under low charge conditions and pulse charging under high charge conditions, which can not only ensure the charging efficiency, but also avoid the phenomenon of negative electrode lithium deposition of the battery caused by low temperature, high charge and other conditions.

[0114] In one embodiment, the third battery data includes current temperature;

[0115] Step S401, i.e. determining the current temperature condition based on the third battery data, includes:

[0116] If the current temperature is less than the first temperature threshold, determining that the current temperature operating condition is a low temperature operating condition;

[0117] If the current temperature is greater than or equal to the first temperature threshold, it is determined that the current temperature condition is a normal temperature condition.

[0118] The current temperature is the temperature of the power battery detected at the current moment. The first temperature threshold is a pre-set temperature threshold for distinguishing between normal temperature conditions and low temperature conditions, specifically a temperature threshold for evaluating whether the low temperature standard is met, for example, the first temperature threshold can be set to 10°C or 15°C.

[0119] As an example, the ECU can obtain the current temperature corresponding to the power battery and compare the current temperature with the first temperature threshold; when the current temperature is less than the first temperature threshold, it can be determined that the current temperature of the power battery reaches the low temperature standard, and its current temperature condition can be determined to be a low temperature condition; when the current temperature is greater than or equal to the first temperature threshold, it can be determined that the current temperature of the power battery does not reach the low temperature standard, and its current temperature condition can be determined to be a normal temperature condition. In this example, according to the comparison result of the current temperature and the first temperature threshold, the corresponding current temperature condition can be quickly determined.

[0120] In one embodiment, controlling the power battery to increase in temperature includes:

[0121] A temperature rise control strategy corresponding to the current temperature is adopted to control the self-heating temperature rise of the power battery.

[0122] As an example, the system pre-sets multiple temperature rise control strategies, each temperature rise control strategy corresponds to a temperature range and a temperature rise control strategy for controlling the battery temperature rise within the temperature range. After obtaining the current temperature of the power battery, the ECU can compare the current temperature with multiple temperature ranges, determine the temperature rise control strategy to which the temperature range to which the current temperature belongs belongs, execute the temperature rise control strategy, and control the power battery to enter the self-heating mode so that the power battery can self-heat and heat up. Among them, the self-heating mode is a mode of self-heating using the components inside the battery assembly, specifically controlling the resistance inside the battery for DC self-heating and AC self-heating to heat the battery. For example, when the charging and discharging system is provided with a charging and discharging circuit connected to the power battery, when the charging and discharging circuit is working, the power battery can enter the self-heating mode.

[0123] In this example, the charging and discharging circuit can divide the power battery into two battery packs arranged in series, which are respectively determined as the first battery pack and the second battery pack. In the self-heating mode, the first battery pack is controlled to discharge and the second battery pack is charged. Then, the second battery pack is controlled to discharge and the first battery pack is charged. By staggered control of the charging and discharging of the two battery packs, continuous safe, stable and efficient self-heating is achieved under the premise of ensuring the stability of the total voltage of the two battery packs and the continuity of the current. Compared with the currently widely used external heating methods such as PTC heating, heating film and DC heat pump mode, this external heating method has the problems of slow heating speed, low heating efficiency, and easy to cause uneven heating of the power battery to produce inconsistency. By controlling the power battery itself to charge and discharge to increase its temperature, its heating efficiency is effectively improved, and the problem of uneven heating is avoided, thereby improving its overall temperature rise effect.

[0124] In one embodiment, the adopting of the temperature rise control strategy corresponding to the current temperature to control the self-heating temperature rise of the power battery includes:

[0125] If the current temperature is less than a second temperature threshold, controlling the power battery to self-heat and increase temperature based on a self-heating strategy;

[0126] If the current temperature is greater than or equal to the second temperature threshold, the power battery is controlled to self-heat and heat up based on the self-heating strategy, and the power battery is charged based on the second constant current charging strategy.

[0127] The second temperature threshold is a preset temperature threshold for distinguishing between general low temperature conditions and ultra-low temperature conditions. The second temperature threshold is less than the first temperature threshold and can be set to -20°C. As an example, when the current temperature is less than the first temperature threshold and the ECU needs to control the power battery to heat up, it needs to further compare the current temperature with the second temperature threshold so as to execute different measures based on the comparison result.

[0128] The self-heating strategy is a strategy for controlling the self-heating of the battery under low temperature conditions. The second constant current charging strategy is a strategy for controlling the battery to be charged based on a constant current under low temperature conditions.

[0129] As an example, when the current temperature is lower than the second temperature threshold, the ECU determines that the cell temperature of the power battery is in an ultra-low temperature condition, the activity of the internal materials of the power battery is low, the risk of negative electrode lithium plating during the charging process is high, and the charging effect is poor. At this time, a self-heating strategy can be executed to control the self-heating and temperature rise of the power battery, specifically, controlling the charge and discharge circuit to complete the self-heating operation to increase the activity of the internal materials of the power battery and avoid negative electrode lithium plating during the subsequent charging process.

[0130] As an example, when the current temperature is greater than or equal to the second temperature threshold, that is, when the current temperature is between the second temperature threshold and the first temperature threshold, the ECU determines that the cell temperature of the power battery is in a general low temperature condition, and while controlling the self-heating temperature rise of the power battery based on the self-heating strategy, the ECU processes the measured data based on the second constant current charging strategy, determines the second constant current, and then charges the power battery based on the second constant current to ensure its charging efficiency. In other words, when the ECU is in a general low temperature condition, the power battery can enter the self-heating mode superimposed on the constant current charging mode, specifically controlling the charge and discharge circuit to perform self-heating, and obtaining the self-heating current corresponding to the self-heating mode; and based on the second constant current charging strategy, the corresponding first constant current is determined, and the self-heating current is coupled and superimposed with the first constant current to determine as the target charging current that finally flows through the power battery, which not only avoids the risk of lithium plating at the negative electrode, but also ensures the charging efficiency.

[0131] In one embodiment, charging the power battery based on the second constant current charging strategy includes:

[0132] Based on the current temperature and the current SOC, a second constant current is determined, and based on the second constant current, the power battery is charged.

[0133] As an example, the ECU charges the power battery based on the second constant current charging strategy, specifically, based on the current temperature and the current SOC, dynamically determines the constant current that matches the current temperature and the current SOC as the second constant current, and controls the charging power supply to charge the power battery based on the second constant current to ensure its charging efficiency and avoid the phenomenon of lithium plating at the negative electrode. In this example, the ECU can read the preset constant current determination rule, use the current temperature and the current SOC as input parameters of the constant current determination rule, and determine the second constant current according to the constant current determination rule, so as to control the charging power supply to charge the power battery based on the second constant current, so as to ensure its charging efficiency and avoid the phenomenon of lithium plating at the negative electrode.

[0134] In one embodiment, determining the second constant current based on the current temperature and the current SOC includes:

[0135] Based on the current temperature, the current SOC and the constant current mapping data, a second constant current is determined.

[0136] Among them, the constant current mapping data is pre-set data used to reflect the corresponding relationship between temperature, SOC and constant current. The corresponding constant current can be determined according to the combination of different temperatures and different SOCs. The constant current is pre-tested to determine the charging current that can ensure its charging efficiency and avoid lithium plating at the negative electrode.

[0137] As an example, the ECU charges the power battery based on the second constant current charging strategy, specifically based on the current temperature, the current SOC and the pre-set constant current mapping data, the constant current recorded in the constant current mapping data that matches the current temperature and the current SOC is determined as the second constant current, and the charging power supply is controlled to charge the power battery based on the second constant current to ensure its charging efficiency and avoid lithium plating at the negative electrode.

[0138] In one embodiment, the target charging current is less than a safe charging current, and the safe charging current is a charging current corresponding to the first battery data in a battery lithium deposition boundary.

[0139] Among them, the battery lithium plating boundary is a pre-set data table for evaluating the mapping relationship between different battery data and their safe charging current. The safe charging current here is the maximum value of the charging current that the charging power supply can provide to the power battery when it is in a certain working condition. Understandably, if the charging current of the charging power supply to charge the power battery exceeds the maximum charging current, the power battery is very likely to undergo lithium plating. Therefore, in actual application, it is necessary to ensure that the target charging current corresponding to the charging and discharging system is less than its safe charging current to avoid lithium plating at the negative electrode of the power battery due to excessive charging current.

[0140] As an example, when the ECU determines the target charging current based on the first constant current charging strategy or the pulse charging strategy, it is necessary to compare the target charging current with the safe charging current. If the target charging current is less than the safe charging current, the power battery can be charged based on the target charging current to ensure charging safety and avoid lithium plating at the negative electrode, thereby extending the battery life.

[0141] As an example, after acquiring the first battery data of the power battery, the ECU can compare the first battery data with the stage data intervals corresponding to the multiple charging stages preset by the system. If the first battery data is within any stage data interval, the charging stage corresponding to the stage data interval is determined as the target charging stage; and the charging current corresponding to the target charging stage is determined as the target charging current. In this example, the stage data intervals and charging currents corresponding to the multiple charging stages are preset to facilitate subsequent stage charging, that is, according to the stage data interval to which the first battery data belongs, the corresponding target charging current is determined to achieve charging based on the preset charging current in each charging stage to ensure its charging efficiency. When the current charge condition determined based on the first battery data is a low charge condition, its charging stage is a constant current charging stage, and its corresponding charging current is a first constant current current; when the current charge condition determined based on the first battery data is a high charge condition, its charging stage is a pulse charging stage, and its corresponding charging current is a bidirectional pulse current. Generally speaking, when pre-setting the stage data intervals and charging currents corresponding to multiple charging stages, it is necessary to ensure that the charging current corresponding to each stage data interval is less than the safe charging current corresponding to the stage data interval, so as to ensure that the subsequently determined target charging current is less than the corresponding safe charging current, thereby avoiding lithium plating in the power battery and extending the battery life.

[0142] For example, the battery lithium plating boundary is a mapping curve used to reflect that the safe charging current decreases as the battery SOC increases. It can be divided into multiple charging stages according to different SOC thresholds. The stage data interval corresponding to each charging stage is the interval determined by two adjacent SOC thresholds, that is, each SOC threshold interval corresponds to a lower SOC threshold and an upper SOC threshold. When setting the charging current of multiple charging stages, the charging current corresponding to the upper SOC threshold in each stage data interval can be set to be less than the corresponding safe charging current, and the charging current corresponding to other SOCs in the stage data interval is less than or equal to the charging current corresponding to the upper SOC threshold, thereby ensuring that the charging current corresponding to the entire charging stage is less than the corresponding safe charging current, which helps to avoid lithium plating in the power battery and thus prolong the battery life.

[0143] For example, the ECU can obtain the first battery data of the power battery, the first battery data includes but is not limited to the current SOC, the current voltage and the current temperature, etc., and the current charging condition can be determined based on the current SOC and the current voltage; when the current SOC is less than the first SOC threshold, and the current voltage is less than the first voltage threshold, it is determined that it does not meet the high charging condition condition, and the current charging condition is determined to be a low charging condition. Constant current charging corresponding to multiple constant current charging stages can be started in sequence. In the process of charging based on the first constant current corresponding to the i-th constant current charging stage, if the detected current SOC is in the SOC threshold interval corresponding to the i+1-th constant current charging stage, or the current voltage is in the voltage threshold interval corresponding to the i+1-th constant current charging stage, it is determined that it can jump to the i+1-th constant current charging stage, and the first constant current corresponding to the i+1-th constant current charging stage is determined as the target charging current. Similarly, when the current SOC is greater than or equal to the first SOC threshold, or the current voltage is greater than or equal to the first voltage threshold, it is determined that the high charge condition is met, and the current charge condition is determined to be a high charge condition. The pulse charging corresponding to multiple pulse charging stages can be started in sequence. In the process of charging based on the bidirectional pulse current corresponding to the jth pulse charging stage, if the detected current SOC is in the SOC threshold interval corresponding to the j+1th pulse charging stage, or the current voltage is in the voltage threshold interval corresponding to the j+1th pulse charging stage, it is determined that it can jump to the j+1th pulse charging stage, and the pulse charging current corresponding to the j+1th pulse charging stage is determined as the target charging current. Figure 5 As shown, multiple voltage thresholds V1, V2, V3...Vn can be pre-set, and two adjacent voltage thresholds are used to define the voltage threshold interval corresponding to a certain charging stage; and multiple SOC thresholds SOC1, SOC2, SOC3...SOCn are set, and two adjacent SOC thresholds are used to define the SOC threshold interval corresponding to a certain charging stage. The voltage threshold interval corresponding to the i-th charging stage is , and its corresponding SOC threshold interval is , and the corresponding charging current is ; When the charging reaches the trigger condition, it automatically switches to the next charging stage, and the current jumps to In particular, the trigger condition includes, but is not limited to, the current SOC reaching the SOC threshold interval corresponding to the next stage, or the current voltage reaching the voltage threshold interval corresponding to the next stage. When any of the conditions is met, the current jump event is triggered.

[0144] Figure 5 A schematic diagram of the bidirectional pulse charging strategy is given. The dotted line is the battery lithium deposition boundary for the state of charge formulated at a certain temperature. When the power battery is in a low-charge condition, the first constant current corresponding to multiple constant-current charging stages, and when the power battery is in a high-charge condition, the bidirectional pulse current corresponding to multiple pulse charging stages are all within the battery lithium deposition boundary. Figure 5 The charging strategy shown can significantly reduce the risk of lithium plating in the battery. For example, when the power battery meets the high charge condition, multi-step pulse charging can be performed based on the bidirectional pulse current corresponding to multiple pulse charging stages, and four different pulse charging stages are divided in sequence. The bidirectional pulse currents in these stages are different. This scheme only shows four different stages. There can be multiple different pulse charging stages according to actual needs, and the spans of the SOC threshold intervals and / or voltage threshold intervals in these different pulse charging stages can be the same or different. The enlarged view of the pulse waveform is shown in the two sub-figures in the lower left corner. This scheme lists sine waves (left) and square waves (right), and the waveforms of the bidirectional pulse current in this example include but are not limited to different forms such as sine waves, square waves, triangle waves, exponential waves, sawtooth waves and composite waveforms. The frequency, duty cycle, amplitude, etc. of these waveforms can be adjusted according to actual conditions. Here, the pulse system is defined as follows: the pulse whose lower limit current of the waveform is lower than 0 is named "negative pulse", the pulse whose lower limit voltage of the waveform is equal to 0 is named "zero pulse", and the pulse whose lower limit voltage of the waveform is greater than 0 is named "positive pulse". Different pulse systems such as "negative pulse", "zero pulse" or "positive pulse" can be selected according to the situation. In addition, during the charging process, the frequency, duty cycle, amplitude and pulse system can be constant, or they can be constantly changing and adaptively adjusted.

[0145] Figure 6 The changes of the negative electrode potential with the state of charge of the lithium battery using this charging strategy are listed. When the power battery is in a high charge condition, the frequencies of the multi-step pulse charging state are set to 20Hz, 50Hz and 100Hz respectively, and a control group (no pulse) is set up. The changes of the negative electrode potential with SOC are detected, and it is found that the negative electrode potential is higher than 0, which means that no lithium plating occurs. It can also be found that the higher the frequency, the higher the negative electrode potential. This rule can be used to formulate charging strategies.

[0146] Figure 7 The resistance values ​​measured in the self-heating pulse charging experiment with different frequencies vary with SOC. It is easy to understand that the resistance value of the power battery (the resistance value in the figure is the normalized resistance value) basically does not change with the change of SOC, and compared with the non-pulse charging, the battery resistance decreases a lot after the introduction of the self-heating pulse, indicating that the self-heating pulse has a great effect on depolarization, which can delay the time to reach the cut-off voltage, enable the use of higher current charging, and reduce the charging time. The higher the frequency, the smaller the resistance value, and the more significant the depolarization effect.

[0147] It should be understood that the order of execution of the steps in the above embodiment does not necessarily 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 embodiment of the present invention.

[0148] In one embodiment, a controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the battery charging method in the above embodiment is implemented, for example Figure 1 Steps S101-S102 shown, or Figure 2-Figure 4 To avoid repetition, it will not be described here.

[0149] In one embodiment, a charging and discharging system is provided, which includes a charging and discharging circuit and the controller in the above embodiment; the charging and discharging circuit is used to connect a charging power source and a power battery; the controller is connected to the charging and discharging circuit and is used to control the operation of the charging and discharging circuit so that the charging power source charges the power battery.

[0150] The charge and discharge circuit is a circuit for realizing charge or discharge control. The charge and discharge circuit is arranged between the charging power source and the power battery, and can control the charging power source to charge the power battery, and can also control the power battery to discharge to the power load. The charge and discharge circuit is a circuit that can realize constant current charging and pulse charging. For example, the charge and discharge circuit can be realized by, but not limited to, a DCDC converter or other circuits that can realize pulse charging.

[0151] As an example, the charge and discharge circuit is used to connect the charging power supply and the power battery. The controller is connected to the charge and discharge circuit. The target charging current can be determined according to the first battery data corresponding to the power battery collected in real time, and the charging power supply can be controlled to charge the power battery based on the target charging current. Since the target charging current is less than the corresponding safety charging current in the battery lithium deposition boundary, the power battery is charged based on the target charging current, which effectively avoids the phenomenon of negative electrode lithium deposition in the power battery during the charging process due to excessive charging current, thereby extending the battery life.

[0152] In one embodiment, the charge and discharge circuit includes at least one bridge arm and at least one inductor L1, each bridge arm includes an upper bridge power tube T1 and a lower bridge power tube T2 arranged in series, and a connection node between the upper bridge power tube T1 and the lower bridge power tube T2 is connected to a first end of an inductor L1;

[0153] At least one upper bridge power tube T1 is used to connect the positive electrode of the power battery, at least one lower bridge power tube T2 is used to connect the negative electrode of the power battery, and the second end of at least one inductor L1 is used to connect the inter-battery node of the power battery, where the inter-battery node is a node between two adjacent batteries in the power battery.

[0154] As an example, the charging and discharging circuit includes at least one bridge arm and at least one inductor L1, each bridge arm includes an upper bridge power tube T1 and a lower bridge power tube T2 arranged in series, the connection node between the upper bridge power tube T1 and the lower bridge power tube T2 is the midpoint of the bridge arm, and the midpoint of each bridge arm is connected to the first end of an inductor L1; at least one upper bridge power tube T1 can be connected to the positive electrode of the power battery through the first switch K1, at least one lower bridge power tube T2 can be connected to the negative electrode of the power battery through the second switch K2, and the second end of at least one inductor L1 can be connected to the inter-battery node of the power battery through the third switch K3, and the inter-battery node is the node between two adjacent batteries in the power battery.

[0155] When the power battery is divided into a first battery pack and a second battery pack based on the inter-battery node connected to the first inductor L1, the working process of the charge and discharge system entering the self-heating mode is as follows: (1) Control the first switch K1, the upper bridge power tube T1 and the third switch K3 to be turned on, and the lower bridge power tube T2 to be turned off, so that the first heating circuit formed by the first battery pack and the inductor L1 is turned on, the first battery pack is discharged, and the second battery pack is charged through the freewheeling diode connected in parallel with the lower bridge power tube T2; (2) Control the second switch K2, the lower bridge power tube T2 and the third switch K3 to be turned on, and the upper bridge power tube T1 to be turned off, so that the second heating circuit formed by the second battery pack and the inductor L1 is turned on, the second battery pack is discharged, and the first battery pack is charged through the freewheeling diode connected in parallel with the upper bridge power tube T1. In this example, by controlling the on and off of the first switch K1, the second switch K2, the third switch K3, the upper bridge power tube T1 and the lower bridge power tube T2, the power battery can realize self-heating operation, the circuit structure is simple, the cost is low, and different needs can be met.

[0156] In this example, when the two ends of the power battery are connected to the charging power supply through the first switch K1 and the second switch K2, and connected to the charging and discharging circuit through the first switch K1, the second switch K2 and the third switch K3, when the above switches are all turned on, the second constant current can be determined based on the second constant current charging strategy, and the charging power supply can be controlled to charge the power battery based on the second constant current, and the charging and discharging circuit can be controlled to work at the same time, so that the power battery can complete the self-heating operation, so that self-heating and charging can be carried out at the same time. In addition, the above charging and discharging circuit does not require a third-party charging pile or energy storage component, which is simple and efficient; the controller here is configured to control the multi-phase bridge arm and the on and off of the switch to enable the first battery pack and the second battery pack to realize alternating charging and discharging, and to achieve continuous safe, stable and efficient self-heating under the premise of ensuring the total voltage of the first battery pack and the second battery pack is stable and the current is continuous.

[0157] In one embodiment, the charge and discharge circuit further includes a capacitor C1 , a first end of the capacitor C1 is used to connect to the positive electrode of the power battery, and a second end of the capacitor C2 is used to connect to the negative electrode of the power battery.

[0158] As an example, the charging and discharging circuit also includes a capacitor C1, and the two ends of the capacitor are respectively connected to the positive and negative electrodes of the power battery. During the process of alternating charging and discharging of the power battery through the first battery pack and the second battery pack, the capacitor C2 can store energy and discharge to cooperate with the power battery to complete the self-heating operation.

[0159] like Figure 8 As shown, the power battery is divided into two half packs, namely the first battery pack and the second battery pack. A voltage sensor, a current sensor and a temperature sensor are installed between the two battery packs to monitor the state changes of the charge and discharge system in real time so as to control the charge and discharge according to the detected first battery data. In this example, the BMS is connected to the voltage sensor, the current sensor and the temperature sensor to collect the first battery data; a fuse is connected between the power battery and the charge and discharge circuit to protect the circuit from short circuit and burn out the circuit components; Figure 8 The part in the right frame is the charging and discharging circuit, which can be specifically understood as a pulse charging start controller, which is used to execute the command issued by the BMS to achieve the change of the current size and direction in the circuit according to the control strategy. The device does not require a third-party charging pile or energy storage element, and is simple and efficient. This solution comprehensively considers safety and charging speed, is efficient and economical, and has high universality.

[0160] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the battery charging method in the above embodiment is implemented, for example Figure 1 Steps S101-S102 shown, or Figure 2-Figure 4 To avoid repetition, it will not be described here.

[0161] In one embodiment, a vehicle is provided, including the controller in the above embodiment, or the charging and discharging system in the above embodiment, or the computer-readable storage medium in the above embodiment, which will not be described again here to avoid repetition.

[0162] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0163] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0164] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A battery charging method, characterized in that: include: Acquire third battery data of the power battery, and determine the current temperature condition based on the third battery data, wherein the third battery data includes the current temperature; When the current temperature condition is a low temperature condition, a temperature rise control strategy corresponding to the current temperature is adopted to control the power battery to enter a self-heating mode so that the power battery is heated by self-heating. The self-heating mode refers to a mode in which, when the charging and discharging circuit divides the power battery into two battery packs arranged in series, one battery pack is alternately controlled to discharge the other battery pack; When the current temperature condition is a normal temperature condition, obtaining first battery data of the power battery, and determining a current charge condition based on the first battery data; When the current charging condition is a high charging condition, a target charging current is determined based on a pulse charging strategy, and the power battery is charged based on the target charging current.

2. The battery charging method according to claim 1, characterized in that: The battery charging method further comprises: When the current charge condition is a low charge condition, a target charging current is determined based on a first constant current charging strategy, and the power battery is charged based on the target charging current.

3. The battery charging method according to claim 2, characterized in that: The first battery data includes a current SOC and / or a current voltage; The determining the current state of charge based on the first battery data includes: If the current SOC is less than a first SOC threshold, and the current voltage is less than a first voltage threshold, determining that the current charge condition is a low charge condition; If the current SOC is greater than or equal to a first SOC threshold, or the current voltage is greater than or equal to a first voltage threshold, it is determined that the current charge condition is a high charge condition.

4. The battery charging method according to claim 2, characterized in that: The determining the target charging current based on the first constant current charging strategy includes: Acquiring second battery data of the power battery, and determining a target constant current charging stage based on the second battery data; A first constant current corresponding to the target constant current charging stage is determined as the target charging current.

5. The battery charging method according to claim 4, characterized in that: The target constant current charging stage is a constant current charging stage corresponding to the stage data interval to which the second battery data belongs.

6. The battery charging method according to claim 1, characterized in that: The determining of the target charging current based on the pulse charging strategy includes: Acquiring second battery data of the power battery, and determining a target pulse charging stage based on the second battery data; The bidirectional pulse current corresponding to the target pulse charging stage is determined as the target charging current.

7. The battery charging method according to claim 6, characterized in that: The target pulse charging phase is a pulse charging phase corresponding to the phase data interval to which the second battery data belongs.

8. The battery charging method according to claim 5 or 7, characterized in that: The stage data interval is an SOC threshold interval and / or a voltage threshold interval.

9. The battery charging method according to claim 1, characterized in that: The third battery data includes current temperature; The determining the current temperature condition based on the third battery data includes: If the current temperature is less than a first temperature threshold, determining that the current temperature operating condition is a low temperature operating condition; If the current temperature is greater than or equal to the first temperature threshold, it is determined that the current temperature condition is a normal temperature condition.

10. The battery charging method according to claim 1, characterized in that: The adopting the temperature rise control strategy corresponding to the current temperature to control the self-heating temperature rise of the power battery includes: If the current temperature is less than a second temperature threshold, controlling the power battery to self-heat and increase temperature based on a self-heating strategy; If the current temperature is greater than or equal to the second temperature threshold, the power battery is controlled to self-heat and heat up based on the self-heating strategy, and the power battery is charged based on the second constant current charging strategy.

11. The battery charging method according to claim 10, characterized in that: The charging of the power battery based on the second constant current charging strategy includes: Based on the current temperature and the current SOC, a second constant current is determined, and based on the second constant current, the power battery is charged.

12. The battery charging method according to claim 11, characterized in that: The determining of the second constant current based on the current temperature and the current SOC includes: Based on the current temperature, the current SOC and the constant current mapping data, a second constant current is determined.

13. The battery charging method according to claim 1, 2, 3, 4, 5, 6, 7, 9, 10, 11 or 12, characterized in that: The target charging current is less than the safe charging current, and the safe charging current is the charging current corresponding to the first battery data in the battery lithium deposition boundary.

14. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the battery charging method according to any one of claims 1 to 13 is implemented.

15. A charging and discharging system, characterized in that: The charging and discharging system comprises a charging and discharging circuit and the controller according to claim 14; The charging and discharging circuit is used to connect the charging power source and the power battery; The controller is connected to the charging and discharging circuit and is used to control the operation of the charging and discharging circuit so that the charging power source charges the power battery.

16. The charging and discharging system according to claim 15, characterized in that: The charging and discharging circuit includes at least one bridge arm and at least one inductor, each of the bridge arms includes an upper bridge power tube and a lower bridge power tube arranged in series, and a connection node between the upper bridge power tube and the lower bridge power tube is connected to a first end of the inductor; At least one of the upper bridge power tubes is used to connect the positive electrode of the power battery; At least one of the lower bridge power tubes is used to connect the negative electrode of the power battery; A second end of at least one of the inductors is used to connect to an inter-battery node of the power battery, where the inter-battery node is a node between two adjacent batteries in the power battery.

17. The charging and discharging system according to claim 16, characterized in that: The charging and discharging circuit further includes a capacitor, a first end of the capacitor is used to connect to the positive electrode of the power battery, and a second end of the capacitor is used to connect to the negative electrode of the power battery.

18. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the battery charging method according to any one of claims 1 to 13 is implemented.

19. A vehicle, characterized in that: It includes the controller as claimed in claim 14, or the charging and discharging system as claimed in any one of claims 15 to 17, or the computer-readable storage medium as claimed in claim 18.

Images