Dynamic battery equalization device and control method thereof, and vehicle

Abstract

A dynamic battery equalization apparatus and control method thereof, and a vehicle are provided, the apparatus including: a power battery; an electric motor controller; an electric motor; and a controller connected to the electric motor controller, the controller configured to, in a first predetermined state, control a bridge arm of the electric motor controller to drive the electric motor, alternately charge and discharge the first battery pack and the second battery pack to realize self-heating of the first battery pack and the second battery pack, and make the absolute value of the difference between the capacities of the first battery pack and the second battery pack less than a predetermined threshold.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims priority to Chinese Patent Application No. 202211543573.X, filed on November 30, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the field of battery protection technology, and in particular to a battery dynamic equalization apparatus, a control method for a battery dynamic equalization apparatus, and a vehicle. [Background technology]

[0003] With the development and rapid spread of electric vehicles, the power batteries of electric vehicles are becoming increasingly important. Currently, when a vehicle's power battery self-heats while the vehicle is running, the voltage difference between the batteries may gradually increase. This may lead to uneven voltage distribution between the batteries, which may reduce the battery capacity and shorten the battery life. Summary of the Invention

[0004] The present disclosure is intended to solve at least to some extent one of the technical problems in the related art. Accordingly, a first object of the present disclosure is to provide a battery dynamic equalization device for realizing dynamic equalization of electrical quantities between a first battery pack and a second battery pack during self-heating of the batteries when a vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0005] A second object of the present disclosure is to provide a method for controlling a battery dynamic equalization device.

[0006] A third object of the present disclosure is to provide a vehicle.

[0007] In order to achieve the aforementioned object, one embodiment of a first aspect of the present disclosure provides a power battery, the power battery including a first battery pack and a second battery pack connected in series, with a first node provided between the first battery pack and the second battery pack; a motor controller, a first end of the motor controller connected to a positive electrode of the first battery pack and a second end of the motor controller connected to a negative electrode of the second battery pack; and a motor, a first end of the motor connected to the motor controller. a motor having a first end connected to a first node, the second end of the motor being connected to a first node; and a controller connected to the motor controller, the controller being configured to, in a first default state, control a bridge arm of the motor controller to drive the motor, alternately charge and discharge the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and make an absolute value of a difference between the capacity of the first battery pack and the capacity of the second battery pack less than a default threshold.

[0008] In a battery dynamic equalization device according to an embodiment of the present disclosure, the power battery includes a first battery pack and a second battery pack connected in series, and a first node is provided between the first battery pack and the second battery pack. A first end of a motor controller is connected to the positive electrode of the first battery pack, and a second end of the motor controller is connected to the negative electrode of the second battery pack. The first end of the motor is connected to the motor controller, and the second end of the motor is connected to the first node. The controller is connected to the motor controller. In a first default state, the controller is configured to control a bridge arm of the motor controller to drive the motor, alternately charge and discharge the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and to make the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack less than a default threshold. Therefore, the equalization device realizes dynamic equalization of the electrical quantity between the first battery pack and the second battery pack during self-heating of the batteries when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0009] In addition, the battery dynamic equalization device according to the foregoing embodiment of the present disclosure may further include the following additional technical features.

[0010] According to one embodiment of the present disclosure, the motor controller includes at least two first bridge arms. A first end of each phase of the first bridge arms is connected to a positive terminal of a first battery pack, and a second end of each phase of the first bridge arms is connected to a negative terminal of a second battery pack. The motor includes at least two first inductors. A first end of each phase of the first inductors is connected to a corresponding first bridge arm, and a second end of each phase of the first inductors is connected to a first node. A neutral conductor is drawn from the motor and connected to the first node.

[0011] According to one embodiment of the present disclosure, the controller is configured to collect battery equalization parameters, temperature requirement parameters, and driving requirement parameters of the power battery, obtain a target driving current based on the driving requirement parameters, obtain a target self-heating current based on the temperature requirement parameters, obtain a target equalization current based on the battery equalization parameters, and adjust a first control signal for controlling the motor controller based on the target driving current, the target self-heating current, the target equalization current, and the actual phase current to drive the motor and self-heat and equalize the first battery pack and the second battery pack.

[0012] According to one embodiment of the present disclosure, the controller is configured to acquire a torque output of the motor, a rotational speed of the motor, a voltage of the power battery, and an electrical angle of the rotor of the motor, and when a drive command is received, acquire a target drive current based on the torque output of the motor, the rotational speed of the motor, and the voltage of the power battery, and acquire a differential mode voltage of each phase of the bridge arm based on the target drive current, an actual phase current, and the electrical angle of the rotor of the motor.

[0013] According to an embodiment of the present disclosure, the target drive current is a combination of the d-axis target current and the q-axis target current, the real phase current is a combination of the d-axis actual current and the q-axis actual current, and the controller is configured to perform closed-loop control on the d-axis target current, the d-axis actual current, the q-axis target current, and the q-axis actual current to obtain the d-axis target voltage and the q-axis target voltage, and to obtain the differential mode voltage of each phase of the bridge arm based on the d-axis target voltage, the q-axis target voltage, and the electrical angle of the rotor of the motor.

[0014] According to an embodiment of the present disclosure, the controller is further configured to obtain a target heating equalization current based on the target self-heating current and the target equalization current, obtain an actual phase current of the motor, obtain a common-mode voltage based on the target heating equalization current and the actual phase current, and adjust a first control signal of the motor controller based on the differential-mode voltage and the common-mode voltage of each phase of the bridge arm.

[0015] According to one embodiment of the present disclosure, the controller is configured to collect battery equalization parameters and temperature requirement parameters of the power battery, obtain a target equalization current based on the battery equalization parameters, and obtain a target self-heating current based on the temperature requirement parameters.

[0016] According to one embodiment of the present disclosure, the controller is configured to perform an integral calculation on a battery equalization parameter to obtain a target equalization current, the battery equalization parameter including one of a discharge capacity difference, a voltage difference, and an instantaneous power difference, the discharge capacity difference, the voltage difference, and the instantaneous power difference representing the discharge capacity difference, the voltage difference, and the instantaneous power difference between the first battery pack and the second battery pack, respectively.

[0017] According to one embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller is configured to collect each phase current of the motor, calculate a neutral wire current of the motor based on each phase current of the motor, and integrate the neutral wire current to obtain the discharge capacity difference.

[0018] According to one embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller is configured to collect bus positive current and bus negative current of the power battery, perform an ampere-hour integration on the bus positive current of the power battery to obtain the discharge capacity of the first battery pack, perform an ampere-hour integration on the bus negative current of the power battery to obtain the discharge capacity of the second battery pack, and obtain the discharge capacity difference based on the discharge capacity of the first battery pack and the discharge capacity of the second battery pack.

[0019] According to one embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller is configured to collect a motor controller bus positive current and a motor controller bus negative current, perform an ampere-hour integration on the bus positive current to obtain a discharge capacity of the first battery pack, perform an ampere-hour integration on the bus negative current to obtain a discharge capacity of the second battery pack, and obtain the discharge capacity difference based on the discharge capacity of the first battery pack and the discharge capacity of the second battery pack.

[0020] According to one embodiment of the present disclosure, the battery equalization parameter is a voltage difference, and the controller is configured to collect a motor controller bus voltage and a voltage of a first battery pack, calculate a voltage of a second battery pack based on the bus voltage and the voltage of the first battery pack, and determine a voltage difference based on the voltage of the first battery pack and the voltage of the second battery pack.

[0021] According to one embodiment of the present disclosure, the battery equalization parameter is an instantaneous power difference, and the controller is configured to collect a power battery bus positive current and a battery bus negative current, a voltage of a first battery pack, and a voltage of a second battery pack, determine an instantaneous power of the first battery pack based on the battery bus positive current and the voltage of the first battery pack, determine an instantaneous power of the second battery pack based on the battery bus negative current and the voltage of the second battery pack, and determine an instantaneous power difference based on the instantaneous power of the first battery pack and the instantaneous power of the second battery pack.

[0022] According to one embodiment of the present disclosure, the controller is configured to obtain a required heating power based on a temperature requirement parameter, determine an amplitude and frequency of a self-heating current in the neutral conductor based on the required heating power, and determine a target self-heating current based on the amplitude and frequency.

[0023] According to one embodiment of the present disclosure, the controller is configured to calculate the following equation: In*=indc+ipk·sin(2·π·f·t) and further configured to obtain a target heating equalization current by In* represents the target heating equalization current, indc represents the target equalization current, ipk represents the amplitude of the target self-heating current, f represents the frequency of the target self-heating current, and t represents the current time.

[0024] According to one embodiment of the present disclosure, the controller is configured to control a bridge arm of the motor controller to equalize the first battery pack and the second battery pack when it is detected that an absolute value of a difference between the capacity of the first battery pack and the capacity of the second battery pack is equal to or greater than a predetermined threshold in a second predetermined state.

[0025] To achieve the above-mentioned object, one embodiment of a second aspect of the present disclosure provides a control method for a battery dynamic equalization device. The device includes a power battery, a motor controller, a motor, and a controller. The power battery includes a first battery pack and a second battery pack connected in series, and a first node is provided between the first battery pack and the second battery pack. A first end of the motor controller is connected to the positive terminal of the first battery pack, and a second end of the motor controller is connected to the negative terminal of the second battery pack. A first end of the motor is connected to the motor controller, and a second end of the motor is connected to the first node. The controller is connected to the motor controller. The method is applied to the controller and includes, in a first default state, controlling the motor controller to drive the motor, alternately charging and discharging the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and making the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack less than a default threshold.

[0026] In a control method for a battery dynamic equalization device according to an embodiment of the present disclosure, the device includes a power battery, a motor controller, a motor, and a controller. The power battery includes a first battery pack and a second battery pack connected in series, with a first node between the first battery pack and the second battery pack. A first end of the motor controller is connected to a positive electrode of the first battery pack, and a second end of the motor controller is connected to a negative electrode of the second battery pack. The first end of the motor is connected to the motor controller, and the second end of the motor is connected to the first node. The controller is connected to the motor controller. The method is applied to the controller and includes controlling the motor controller to drive the motor in a first default state, alternately charging and discharging the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and reducing the absolute value of the difference between the capacities of the first battery pack and the second battery pack to less than a default threshold. Thus, the method achieves dynamic equalization of electrical quantities between the first battery pack and the second battery pack during self-heating of the batteries when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0027] To achieve the aforementioned object, one embodiment of a third aspect of the present disclosure provides a vehicle including the above-described battery dynamic equalization device.

[0028] In a vehicle according to an embodiment of the present disclosure, the above-described battery dynamic equalization device realizes dynamic equalization of electrical charges between the first battery pack and the second battery pack during self-heating of the batteries when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0029] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a schematic block diagram of a battery dynamic equalization device according to one embodiment of the present disclosure; [Figure 2] 1 is a circuit schematic diagram of a dynamic battery equalization device according to one embodiment of the present disclosure; [Figure 3] FIG. 1 is a schematic diagram of implementing battery dynamic equalization under vehicle driving conditions and self-heating mode according to one embodiment of the present disclosure. [Figure 4] 4 is a flow diagram of a method for controlling a battery dynamic equalization device according to one embodiment of the present disclosure. [Figure 5] 1 is a flow chart of a method for controlling a battery dynamic equalization device, in accordance with an illustrative example of the present disclosure. [Figure 6] FIG. 1 is a schematic block diagram of a vehicle according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0031]

[0023] Embodiments of the present disclosure are described in detail below, and examples of embodiments are illustrated in the accompanying drawings. Throughout this specification, identical or similar elements, or elements having identical or similar functions, are represented by identical or similar reference numerals. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to illustrate the present disclosure and should not be construed as limitations on the present disclosure.

[0032] During the self-heating operation of a vehicle battery, each battery pack is constantly charging and discharging, and the charging and discharging frequency is high. In fact, there are differences in the state, impedance, temperature characteristics, etc. of each battery unit. When a voltage difference occurs between the battery packs, if equalization adjustment is not performed, the imbalance between the battery packs will accelerate. As the self-heating time increases, the voltage difference between the battery packs also gradually increases, the battery capacity gradually becomes equalized (for example, there are two battery packs E1 and E2, one of the battery packs is fully charged and the other is powered), and the driving range rapidly decreases. This may shorten the battery life in the long term. Therefore, to solve the voltage imbalance between the battery packs during battery self-heating, the present disclosure provides a dynamic battery equalization device. When the vehicle is in a driving condition, the system determines whether the initial electrical charge of each battery pack is equalized before the battery self-heating function is enabled, and whether the battery packs are equalized during the battery self-heating operation. As a result, if the electrical charge of the battery packs is not equalized during the battery self-heating operation, dynamic equalization of the electrical charge of the battery packs can be achieved. This improves battery performance and extends battery life.

[0033] DETAILED DESCRIPTION OF THE INVENTION A battery dynamic equalization apparatus, a control method for a battery dynamic equalization apparatus, and a vehicle according to embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0034] FIG. 1 is a schematic block diagram of a dynamic battery equalization apparatus according to one embodiment of the present disclosure.

[0035] As shown in FIG. 1, the battery dynamic equalization device may include a power battery 110, a motor controller 120, a motor 130, and a controller 140.

[0036] The power battery 110 includes a first battery pack E1 and a second battery pack E2 connected in series, with a first node J1 between the first battery pack E1 and the second battery pack E2. A first end of a motor controller 120 is connected to the positive terminal of the first battery pack E1, and a second end of the motor controller 120 is connected to the negative terminal of the second battery pack E2. A first end of a motor 130 is connected to the motor controller 120, and a second end of the motor 130 is connected to the first node J1. The controller 140 is connected to the motor controller, and is configured to control the bridge arm of the motor controller 120 to drive the motor 130 in a first default state, alternately charge and discharge the first battery pack E1 and the second battery pack E2 to achieve self-heating of the first battery pack E1 and the second battery pack E2, and make the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 less than a default threshold. The first default state is a state of self-heating and equalization of the power batteries when the vehicle is under driving conditions. The default threshold may be determined based on actual cases.

[0037] Further, as shown in FIG. 2 , according to one embodiment of the present invention, the motor controller 120 includes at least two first bridge arms 121. A first end of each phase of the first bridge arm 121 is connected to the positive terminal of the first battery pack E1, and a second end of each phase of the first bridge arm 121 is connected to the negative terminal of the second battery pack E2. The motor 130 includes at least two first inductors 131. A first end of each phase of the first inductor 131 is connected to a corresponding first bridge arm 121, and a second end of each phase of the first inductor 131 is connected to a first node J1. A neutral wire is drawn from the motor 130 and connected to the first node J1.

[0038] Specifically, the motor 130 may include a permanent magnet synchronous motor, an asynchronous motor, or another type of motor. The motor 130 may be three-phase, five-phase, six-phase, nine-phase, etc. The motor 130 may include multiple windings. The motor coil includes x windings, where x is greater than or equal to 1 and is an integer. Each winding includes at least two phases, and each phase of the winding corresponds to a group of bridge arms for control. For illustrative purposes, the windings shown in FIG. 2 and a three-phase motor are taken as an example. First, the two battery packs (first battery pack E1 and second battery pack E2) of the power battery 110 are connected in series, and each battery pack is formed by connecting multiple battery units (or cells) in series. The two battery packs include the same battery units. The battery units throughout the power battery 110 are numbered evenly. A positive bus, a negative bus, and a battery pack series connection midpoint lead wire are led out from the power battery 110. The positive and negative buses of the power battery 110 are connected to the positive and negative buses of the motor controller 120 by switches K2 and K1, respectively. The motor controller 120 includes at least one phase of a first bridge arm 121. For example, in FIG. 2, A, B, and C are the first bridge arms 121 connected to the three-phase coils (first inductor 131) of the motor 130, and the neutral lead wire (neutral wire) of the motor 130 is connected to switch K6. Switch K6 is connected to the series connection midpoint J1 lead wire of the power battery 110, and bus capacitor C1 is connected in parallel to the positive and negative buses of the motor controller 120. The positive pole series connection switch K5 of the DC charging / discharging port is connected to the bus positive pole of the motor controller 120, and the positive pole series connection switch K4 of the DC charging / discharging port is connected to the motor's lead-out neutral line. The negative pole series connection switch K3 of the DC charging / discharging port is connected to the bus negative pole of the motor controller 120. The positive pole of capacitor C2 is connected to the positive pole of the DC charging / discharging port, and the negative pole of capacitor C2 is connected to the bus negative pole of the motor controller 120.In a shutdown state, i.e., when the vehicle is not being charged or driven and the system is powered off, switches K1, K2, K3, K4, K5, and K6 are all open. When the vehicle is in a first default state, i.e., when the vehicle is under some operating condition and a self-heating request signal is received, switch K6 is controlled to close, and the power battery 110 may perform self-heating. During self-heating, each battery pack is constantly charged and discharged, and the controller 140 (not shown) may adjust and control the duty cycle of each phase of the bridge arm of the motor controller 120 to equalize the first battery pack E1 and the second battery pack E2. For example, when the vehicle is in a driving condition and the first battery pack E1 has a high capacity and the second battery pack E2 has a low capacity, the duty cycle of the connection of the upper bridge arm can be controlled to be high, so that the electricity of the first battery pack E1 can be transmitted to the first inductor 130 in the motor for storage and discharged to the second battery pack E2 through the neutral wire of the motor. That is, by alternately charging and discharging the first battery pack E1 and the second battery pack E2, the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 is reduced to be less than a predetermined threshold, thereby realizing dynamic equalization of the amount of electricity between the first battery pack E1 and the second battery pack E2 during battery self-heating, thereby improving battery performance and extending battery life. Duty cycle refers to the duty cycle of the upper bridge arm connection, and the duty cycles of the upper bridge arm and the lower bridge arm are complementary. For example, if the upper bridge arm is connected for 70% of the total duration, the lower bridge arm is connected for 30% of the total duration, so that battery packs with higher capacities are discharged more and battery packs with lower capacities are discharged less, and a certain dead time may be ensured based on the characteristics of the power devices.

[0039] A dynamic battery equalization device according to the present disclosure is described in detail below.

[0040] According to one embodiment of the present disclosure, the controller 140 is configured to collect battery equalization parameters, temperature requirement parameters, and driving requirement parameters of the power battery 110, obtain a target driving current based on the driving requirement parameters, obtain a target self-heating current based on the temperature requirement parameters, obtain a target equalization current based on the battery equalization parameters, and adjust a first control signal for controlling the motor controller based on the target driving current, the target self-heating current, the target equalization current, and the actual phase current to drive the motor and cause the first battery pack E1 and the second battery pack E2 to self-heat and equalize.

[0041] Specifically, the controller 140 is configured to collect battery equalization parameters for the power battery 110 when the battery pack needs to be equalized, temperature requirement parameters for the power battery 110 during self-heating of the power battery 110, and driving requirement parameters for the vehicle when the vehicle is driving. After the battery equalization parameters, temperature requirement parameters, and driving requirement parameters are obtained, a target driving current may be obtained based on the driving requirement parameters. For example, the target driving current may be obtained based on the driving torque of the motor 130, the motor rotation speed, the bus voltage, etc. The target self-heating current is obtained based on the temperature requirement parameters. For example, a table lookup method may be used. In the table, the temperature requirement parameters and the target self-heating current have a one-to-one correspondence, and the target self-heating current may be determined based on the temperature requirement parameters. A larger temperature requirement parameter indicates a larger target self-heating current. A smaller temperature requirement parameter indicates a smaller target self-heating current. The target equalization current is obtained based on the battery equalization parameters. After the target driving current, target self-heating current, and target equalization current are obtained, a first control signal for controlling the motor controller may be adjusted based on the target driving current, target self-heating current, target equalization current, and the current actual phase current. For example, when the vehicle is in a driving condition and the power battery 110 is self-heating, the first battery pack E1 has a higher capacity and the second battery pack E2 has a lower capacity, and the first control signal for controlling the motor controller causes the first battery pack E1 to be discharged more and the second battery pack E2 to be discharged less. Therefore, when the vehicle is in a driving condition and the power battery 110 is self-heating, the capacities of the first battery pack E1 and the second battery pack E2 tend to be equalized.

[0042] According to one embodiment of the present disclosure, the controller 140 is configured to acquire the torque output of the motor 130, the rotational speed of the motor 130, the voltage of the power battery 110, and the electrical angle of the rotor of the motor 130, and when a drive command is received, acquire a target drive current based on the torque output of the motor 130, the rotational speed of the motor 130, and the voltage of the power battery 110, and acquire a differential mode voltage of each phase of the bridge arm based on the target drive current, the actual phase current, and the electrical angle of the rotor of the motor 130.

[0043] Furthermore, according to one embodiment of the present disclosure, the target drive current is a combination of the d-axis target current and the q-axis target current, the real phase current is a combination of the d-axis actual current and the q-axis actual current, and the controller 140 is configured to perform closed-loop control on the d-axis target current, the d-axis actual current, the q-axis target current, and the q-axis actual current to obtain the d-axis target voltage and the q-axis target voltage, and to obtain the differential mode voltage of each phase of the bridge arm based on the d-axis target voltage, the q-axis target voltage, and the electrical angle of the rotor of the motor 130.

[0044] Specifically, during control of a permanent magnet synchronous motor, a coordinate system is established on the motor's rotor to achieve control characteristics similar to those of a DC motor. The coordinate system rotates synchronously with the rotor. The direction of the rotor's magnetic field is the d-axis, and the direction perpendicular to the rotor's magnetic field is the q-axis. To achieve good control characteristics, the mathematical model of the motor may be transformed under the coordinate system to achieve separation between the d-axis and q-axis. That is, a coordinate transformation may be performed on each phase current of the motor 130 to obtain the motor's d-axis and q-axis currents. The d-axis and q-axis currents are used to drive the vehicle. As shown in FIG. 3, the motor has a total of p phase currents, i1, i2, and ∼ip. After performing a coordinate transformation on each phase current, the motor's d-axis current id and q-axis current iq are obtained. The actual phase current is the composite value of the actual d-axis current id and the actual q-axis current iq. The motor torque output Te*, the motor rotation speed W, the voltage Udc of the power battery 110, and the motor rotor electrical angle θ are obtained. When a drive command is received and the vehicle is in a driving condition, a target drive current may be obtained based on the motor torque output Te*, the motor rotation speed W, and the voltage Udc of the power battery 110. The target drive current is a composite value of the d-axis target current and the q-axis target current. The d-axis target voltage Ud may be obtained by performing PID closed-loop control based on the d-axis target current id* and the d-axis actual current id, and the q-axis target voltage Uq may be obtained by performing PID closed-loop control based on the q-axis target current iq* and the q-axis actual current iq. After the d-axis target voltage Ud and the q-axis target voltage Uq are obtained, an inverse coordinate transformation is performed based on the target voltage Ud, the target voltage Uq, and the motor rotor electrical angle θ, and then differential-mode voltages U1, U2, ..., Up of each phase of the bridge arm are obtained.

[0045] According to an embodiment of the present disclosure, the controller 140 is further configured to obtain a target heating equalization current based on the target self-heating current and the target equalization current, obtain an actual phase current of the motor, obtain a common-mode voltage based on the target heating equalization current and the actual phase current, and adjust a first control signal of the motor controller based on the differential-mode voltage and the common-mode voltage of each phase of the bridge arm.

[0046] Specifically, as shown in FIG. 3, after the vehicle receives the self-heating power command and the battery equalization command, the command resolution module 2 obtains the target heating equalization current in* based on the target self-heating current and the target equalization current indc. For example, for a p-phase (p+1)-wire motor, the currents of each phase of the motor are collected to obtain the p-phase current (i1, i2, ..., iP). The direction of current flow into the motor is positive, and i1 + i2 + ... + iP + in = 0 is satisfied, where i is the neutral current of the motor. The magnitude of each phase current may be collected by a current sensor, and after the phase currents of the motor are obtained, the neutral current in of the motor may be calculated by in = -i1 - i2 - ... - iP. The common-mode voltage is obtained based on the target heating equalization current in* and the actual phase currents. That is, after the actual neutral current in is obtained, the common-mode voltage Un controlled by the p-phase bridge arm is obtained by PR closed-loop control based on the target heating equalization current in* and the actual neutral current in. To adjust the first control signal of the motor controller, the PWM duty cycle of each phase of the p-phase bridge arm is adjusted based on the common-mode voltage Un and the differential-mode voltages (U1, U2, ..., Up) of each phase of the motor bridge arm, so that the vehicle achieves self-heating of the power battery and equalization of the electrical quantity between the battery packs under driving conditions.

[0047] According to one embodiment of the present disclosure, the controller 140 is configured to collect battery equalization parameters and temperature requirement parameters of the power battery 110, obtain a target equalization current based on the battery equalization parameters, and obtain a target self-heating current based on the temperature requirement parameters.

[0048] Further, according to one embodiment of the present disclosure, the controller 140 is configured to perform an integral calculation on the battery equalization parameters to obtain the target equalization current, the battery equalization parameters including one of a discharge capacity difference, a voltage difference, and an instantaneous power difference, where the discharge capacity difference, the voltage difference, and the instantaneous power difference represent the discharge capacity difference, the voltage difference, and the instantaneous power difference between the first battery pack E1 and the second battery pack E2, respectively.

[0049] Specifically, the controller 140 collects battery equalization parameters of the power battery 110 and temperature requirement parameters of the power battery 110. The battery equalization parameters of the power battery 110 may include a discharge capacity difference ΔQ. An integral calculation is performed on the discharge capacity difference ΔQ to obtain a target equalization current. After the target equalization current is obtained, a target self-heating current may be obtained based on the temperature requirement parameter when the power battery 110 is self-heating. For example, if the current temperature requirement parameter is large, the target self-heating current will be high, and if the current temperature requirement parameter is small, the target self-heating current will be low.

[0050] The battery equalization parameters of the power battery 110 may further include a voltage difference ΔU. The target equalization current is obtained by integrating the voltage difference ΔU between the first battery pack E1 and the second battery pack E2, and the target self-heating current is obtained based on a temperature requirement parameter when the power battery 110 is self-heating. For example, if the current temperature requirement parameter is large, the target self-heating current is high, and if the current temperature requirement parameter is small, the target self-heating current is low.

[0051] The battery equalization parameters of the power battery 110 may further include an instantaneous power difference ΔP. A target equalization current is obtained by integrating the instantaneous power difference ΔP between the first battery pack E1 and the second battery pack E2, and a target self-heating current is obtained based on a temperature requirement parameter when the power battery 110 is self-heating. For example, if the current temperature requirement parameter is large, the target self-heating current is high, and if the current temperature requirement parameter is small, the target self-heating current is low.

[0052] According to one embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller 140 is configured to collect each phase current of the motor 130, calculate a neutral wire current of the motor 130 based on each phase current of the motor 130, and integrate the neutral wire current to obtain the discharge capacity difference.

[0053] Specifically, the motor 130 is an M-phase, N-wire motor. For example, in a 6-phase, 7-wire motor, the current of each phase of the motor 130 is collected to obtain six phase currents (i a , i b , i c , iu , iv , and i w ). If the direction of current flowing into the motor 130 is the positive direction, then i a + i b + i c + iu + iv + i w + in = 0 is satisfied, where in is the neutral current of the motor 130. The phase currents of the motor 130 are collected by the controller 140. For example, the magnitudes of the phase currents i a , ib , ic , iu , iv , and i w may be collected by a current sensor. After the phase currents of the motor 130 are obtained, the neutral current in of the motor 130 may be calculated by in = -i a - ib - ic - iu - iv - i w . After the neutral current in of the motor 130 is acquired, it may be integrated to obtain the discharge capacity difference ΔQ between the first battery pack E1 and the second battery pack E2. A phase-shift control technique is used for motor control (the troughs and peaks of the PWM count values ​​of each phase of the bridge arm are sampled, and phase-shift control can realize multi-stage sampling of the carrier period). The MCU collects the motor's phase current through the zero-crossing points and cycle points of the carrier period of each phase of the bridge arm. This phase current is used to calculate the motor's neutral current, improving the sampling time per unit period of the motor's neutral current and more accurately calculating the discharge capacity difference between the two battery packs. The phase-shift control technique reduces the current ripple of the motor's neutral line, reducing electromagnetic compatibility (EMC) interference and noise vibration harshness (NVH). The update period of the discharge capacity difference ΔQ is based on the carrier period of each bridge arm. Additionally, each phase current of the motor and the neutral current of the motor are sampled and the integral of the neutral current of the motor during the self-heating period is calculated and updated once.

[0054] According to another embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller 140 is configured to collect the bus positive current and the bus negative current of the power battery 110, perform an ampere-hour integration on the bus positive current of the power battery 110 to obtain the discharge capacity of the first battery pack E1, perform an ampere-hour integration on the bus negative current of the power battery 110 to obtain the discharge capacity of the second battery pack E2, and obtain the discharge capacity difference based on the discharge capacity of the first battery pack E1 and the discharge capacity of the second battery pack E2.

[0055] Specifically, during self-heating of the power battery 110, the controller 140 may collect the bus positive current and the bus negative current of the power battery 110, perform ampere-hour integration on the bus positive current and the bus negative current of the power battery 110, i.e., perform ampere-hour integration on the bus negative current of the power battery 110 to calculate the cumulative discharge capacity Q2, perform ampere-hour integration on the bus positive current of the power battery 110 to calculate the cumulative discharge capacity Q1, and after obtaining the discharge capacities Q1 and Q2, obtain a discharge capacity difference ΔQ based on the discharge capacity Q1 of the first battery pack E1 and the discharge capacity Q2 of the second battery pack E2. The bus positive current and the bus negative current of the power battery terminals may be collected by a battery management system (BMS), and the current holes of the bus positive and negative terminals of the battery packs and the voltage sampling circuits of each battery unit are directly integrated into the BMS without any additional devices.

[0056] According to another embodiment of the present disclosure, the battery equalization parameter is a discharge capacity difference, and the controller 140 is configured to collect a bus positive current of the motor controller 120 and a bus negative current of the motor controller 120, perform an ampere-hour integration on the bus positive current of the motor controller 120 to obtain the discharge capacity of the first battery pack E1, perform an ampere-hour integration on the bus negative current of the motor controller 120 to obtain the discharge capacity of the second battery pack E2, and obtain the discharge capacity difference based on the discharge capacity of the first battery pack E1 and the discharge capacity of the second battery pack E2.

[0057] Specifically, during self-heating of the power battery 110, the controller 140 may collect the bus positive current and the bus negative current of the motor controller 120, perform ampere-hour integration on the bus positive current and the bus negative current of the motor controller 120, i.e., perform ampere-hour integration on the bus positive current of the motor controller 120 to calculate the cumulative discharge capacity Q1, and perform ampere-hour integration on the bus negative current of the motor controller 120 to calculate the cumulative discharge capacity Q2, and after obtaining the discharge capacities Q1 and Q2, obtain the discharge capacity difference ΔQ based on the discharge capacity Q1 of the first battery pack E1 and the discharge capacity Q2 of the second battery pack E2. The bus positive current of the motor controller 120 and the bus negative current of the motor controller 120 may be collected by the MCU, which can avoid the switching time and interference of the power devices and collect the current more accurately.

[0058] According to one embodiment of the present disclosure, the battery equalization parameter is a voltage difference, and the controller 140 is configured to collect a bus voltage of the motor controller 120 and a voltage of the second battery pack E2, calculate a voltage of the first battery pack E1 based on the bus voltage and the voltage of the second battery pack E2, and determine a voltage difference based on the voltage of the first battery pack E1 and the voltage of the second battery pack E2.

[0059] Specifically, the controller 140 may collect the bus voltage of the motor controller 120 and the motor neutral voltage to ground (the voltage of the second battery pack E2), where the bus voltage of the motor controller 120 is the sum of the voltages of the first battery pack E1 and the second battery pack E2. After the bus voltage of the motor controller 120 and the voltages of the second battery pack E2 are obtained, the voltage of the first battery pack E1 may be calculated by subtracting the voltage of the second battery pack E2 from the bus voltage of the motor controller 120. After the voltages of the first battery pack E1 and the second battery pack E2 are obtained, a voltage difference ΔU may be determined based on the voltages of the first battery pack E1 and the second battery pack E2.

[0060] According to one embodiment of the present disclosure, the battery equalization parameter is an instantaneous power difference, and the controller 140 is configured to collect a bus positive current and a battery bus negative current of the power battery 110, a voltage of the first battery pack E1, and a voltage of the second battery pack E2, determine an instantaneous power of the first battery pack E1 based on the battery bus positive current and the voltage of the first battery pack E1, determine an instantaneous power of the second battery pack based on the battery bus negative current and the voltage of the second battery pack, and determine an instantaneous power difference based on the instantaneous power of the first battery pack and the instantaneous power of the second battery pack.

[0061] Specifically, the controller 140 may collect the bus positive current of the power battery 110, the bus negative current of the power battery, the voltage of the first battery pack E1, and the voltage of the second battery pack E2, and may determine the instantaneous power p1 of the first battery pack E1 based on the product of the voltage of the first battery pack E1 and the bus positive current of the power battery 110, and may determine the instantaneous power p2 of the second battery pack E2 based on the product of the voltage of the second battery pack E2 and the bus negative current of the power battery. After the instantaneous power of each battery pack is calculated, the controller 140 may determine an instantaneous power difference Δp based on the instantaneous power p1 of the first battery pack E1 and the instantaneous power p2 of the second battery pack E2.

[0062] According to one embodiment of the present disclosure, the controller 140 is configured to obtain a required heating power based on the temperature requirement parameter, determine an amplitude and frequency of a self-heating current in the neutral conductor based on the required heating power, and determine a target self-heating current based on the amplitude and frequency.

[0063] Furthermore, according to one embodiment of the present disclosure, the controller 140 may be configured to: In*=indc+ipk·sin(2·π·f·t) (1) and further configured to obtain a target heating equalization current by In* represents the target heating equalization current, indc represents the target equalization current, ipk represents the amplitude of the target self-heating current, f represents the frequency of the target self-heating current, and t represents the current time.

[0064] Specifically, after the self-heating request signal of the power battery 110 is obtained, it may be determined whether the self-heating function needs to be enabled based on the current temperature of the power battery 110. If the current temperature of the power battery 110 is low, a self-heating program of the power battery 110 may be initiated to ensure the power supply capability of the power battery 110. The required heating power may be determined based on the heating requirement of the power battery 110, i.e., the temperature requirement parameter when the power battery 110 is self-heating. For example, if the current temperature of the power battery 110 is low, the required heating power will be high. For example, if the current temperature of the power battery 110 is high, the required heating power will be low. After the required heating power is obtained, the amplitude i pk and frequency f of the self-heating current of the neutral conductor may be determined based on the amplitude of the required heating power. After the amplitude i pk and frequency f of the self-heating current of the neutral conductor are obtained, a target self-heating current may be determined based on the amplitude i pk and frequency f. According to the above equation (1), the target heating equalization current In* may be determined based on the target equalization current indc, the amplitude ipk and frequency f of the target self-heating current, and the current time.

[0065] Note that the required heating power corresponding to the temperature requirement parameters of the power battery 110, the amplitude ipk of the target self-heating current, and the frequency f of the target self-heating current are first calibrated on the bench and may generally be obtained by a table lookup method or a linear fitting method.

[0066] According to one embodiment of the present disclosure, the controller 140 is configured to control the bridge arm of the motor controller to equalize the first battery pack E1 and the second battery pack E2 when it is detected that the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 is equal to or greater than a predetermined threshold in the second predetermined state.

[0067] Specifically, if it is detected that the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 is equal to or greater than the predetermined threshold, it means that the current difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 is large and the power battery 110 is not in an equalization state. That is, in the second predetermined state (a state in which the power battery 110 only performs electrical quantity equalization), the bridge arm of the motor controller 120 may be controlled to equalize the first battery pack E1 and the second battery pack E2, so that the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 becomes small. For example, if the first battery pack E1 has a larger capacity and the second battery pack E2 has a smaller capacity, the discharge time of the first battery pack E1 may be made longer and the charge time of the second battery pack E2 may be made longer to achieve capacity equalization between the first battery pack E1 and the second battery pack E2.

[0068] In summary, in a battery dynamic equalization device according to an embodiment of the present disclosure, the power battery includes a first battery pack and a second battery pack connected in series, and a first node is provided between the first battery pack and the second battery pack. A first end of a motor controller is connected to a positive electrode of the first battery pack, and a second end of the motor controller is connected to a negative electrode of the second battery pack. A first end of the motor is connected to the motor controller, and a second end of the motor is connected to the first node. The controller is connected to the motor controller. In a first default state, the controller is configured to control a bridge arm of the motor controller to drive the motor, alternately charge and discharge the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and to make the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack less than a default threshold. Therefore, the equalization device can realize dynamic equalization of the electrical quantity between the first battery pack and the second battery pack during self-heating of the batteries when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0069] Corresponding to the above embodiment, the present disclosure further provides a control method for a battery dynamic equalization device.

[0070] As shown in FIG. 4, a control method for a battery dynamic equalization device according to an embodiment of the present disclosure includes the following steps.

[0071] S1: In a first default state, the motor controller is controlled to alternately charge and discharge the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and to make the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack less than a default threshold.

[0072] The control method according to the present disclosure will now be described with reference to FIG.

[0073] As a specific example, a method for controlling a battery dynamic equalization device according to the present disclosure may include the following steps.

[0074] S100: The MCU acquires a battery self-heating request signal and starts a battery self-heating program.

[0075] S101: Determine whether self-heating is required based on the current battery temperature. If yes, execute step S102; if no, execute step S108.

[0076] S102: Control the switch module of the battery dynamic equalization device to close.

[0077] S103: Determine the required heating power based on the battery temperature, determine the amplitude and frequency of the self-heating current, and determine the initial bias current based on the initial voltage or capacity of the battery pack.

[0078] S104: Determine whether a battery active equalization command is received. If yes, execute step S105; if no, execute step S110.

[0079] S105: Collect each phase current of the motor, calculate the neutral wire current value of the motor based on the phase current value of the motor, integrate the neutral wire current value in N1 self-heating cycles to obtain the discharge capacity difference, perform PID calculation on the discharge capacity difference to obtain a new neutral wire self-heating equalization current, perform battery dynamic equalization control based on the new neutral wire self-heating equalization current, perform N2 self-heating cycles, then set the neutral wire self-heating equalization current to zero, and clear the PID integral value of the discharge capacity difference, where PID calculation on the discharge capacity difference is not performed during the N2 self-heating cycles, N1 and N2 are positive integers, and N2 is much greater than N1 (e.g., N2=100N1).

[0080] S106: Obtain the target heating equalization current value and the actual phase current value, perform PI or PR closed-loop control, and calculate the duty cycle of the self-heating bridge arm.

[0081] S107: The battery self-heating program is terminated.

[0082] S108: Adjust the battery self-heating target current value to zero based on the battery heating requirement.

[0083] S109: Control the switch module of the battery dynamic equalization device to open, and execute step S107.

[0084] S110: Set the self-heating dynamic equalization current to zero, clear the PID integral value of the dynamic voltage or discharge capacity difference of the battery pack, and execute step S106.

[0085] It should be noted that for details not disclosed in the control method of the battery dynamic equalization apparatus according to the embodiment of the present disclosure, please refer to the details disclosed in the battery dynamic equalization apparatus according to the embodiment of the present disclosure, and the details will not be described herein.

[0086] In a control method for a battery dynamic equalization device according to an embodiment of the present disclosure, the device includes a power battery, a motor controller, a motor, and a controller. The power battery includes a first battery pack and a second battery pack connected in series, with a first node between the first battery pack and the second battery pack. A first end of the motor controller is connected to a positive electrode of the first battery pack, and a second end of the motor controller is connected to a negative electrode of the second battery pack. The first end of the motor is connected to the motor controller, and the second end of the motor is connected to the first node. The controller is connected to the motor controller. The method is applied to the controller and includes controlling the motor controller to drive the motor in a first default state, alternately charging and discharging the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and reducing the absolute value of the difference between the capacities of the first battery pack and the second battery pack to less than a default threshold. Therefore, the method can achieve dynamic equalization of electrical quantities between the first battery pack and the second battery pack during self-heating of the batteries when the vehicle is under any condition, thereby improving battery performance and extending battery life.

[0087] Corresponding to the above-described embodiment, the present disclosure further provides a vehicle.

[0088] As shown in FIG. 6, a vehicle 200 according to one embodiment of the present disclosure may include the battery dynamic equalization device 100 described above.

[0089] In a vehicle according to an embodiment of the present disclosure, the inclusion of the above-described battery dynamic equalization device achieves dynamic equalization of the electrical charge between the first battery pack and the second battery pack during self-heating of the battery when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0090] It should be noted that the logic and / or steps shown in the flowcharts or otherwise described herein, e.g., ordered listings that can be thought of as executable instructions used to implement logical functions, may be implemented in any computer-readable medium used by, or in combination with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or another system that can obtain instructions from and execute instructions from an instruction execution system, apparatus, or device). In the context of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate, or transmit a program used by, or in combination with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include electrical connections having one or more wires (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memories (CD-ROMs). In addition, the computer-readable medium can also be paper or other suitable medium on which the program may be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, then editing, interpreting, or otherwise processing as needed, and then storing it in computer memory.

[0091] It should be understood that portions of the present disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above-described implementations, steps or methods may be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, when steps or methods are implemented by hardware, as in another implementation, they may be implemented by any one or combination of techniques known in the art, such as discrete logic circuitry including logic gate circuits for implementing logical functions of data signals, dedicated integrated circuits including appropriate combinations of logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0092] In the description herein, a description using terms such as "one embodiment," "some embodiments," "example," "particular example," or "some examples" means that a particular feature, structure, material, or characteristic described with reference to an embodiment or example is included in at least one embodiment or example of the disclosure. Exemplary references to such terms herein do not necessarily refer to the same embodiment or example. In addition, the described particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more of the embodiments or examples.

[0093] Additionally, the terms "first" and "second" are used for descriptive purposes only and should not be construed to denote or imply the relative importance or quantity of the indicated technical features. Thus, a feature qualified by "first" or "second" may explicitly denote or implicitly include at least one of such features. In the description of this disclosure, "plurality" means at least two, e.g., two or three, unless explicitly specified.

[0094] It should be noted that in this disclosure, the terms "attach," "connect," "connection," and "secure" should be understood broadly unless expressly specified and limited otherwise. For example, unless expressly specified otherwise, a connection may be a fixed connection, a detachable connection, or an integral connection, may be a mechanical connection or an electrical connection, and may be a direct connection, an indirect connection through an intermediary, or an internal communication or an interactive relationship between two elements. Those skilled in the art can understand the specific meaning of the terms in this disclosure based on the specific circumstances.

[0095] Although the embodiments of the present disclosure have been shown and described above, it can be understood that the foregoing embodiments are examples and should not be understood as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions, or variations to the foregoing embodiments within the scope of the present disclosure.

Claims

1. a power battery, the power battery comprising a first battery pack and a second battery pack connected in series, a first node being provided between the first battery pack and the second battery pack; a motor controller, a first end of the motor controller connected to a positive terminal of the first battery pack and a second end of the motor controller connected to a negative terminal of the second battery pack; a motor, a first end of the motor connected to the motor controller and a second end of the motor connected to the first node; a controller connected to the motor controller, configured to, in a first predetermined state, control a bridge arm of the motor controller to drive the motor, alternately charge and discharge the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and make an absolute value of a difference between a capacity of the first battery pack and a capacity of the second battery pack less than a predetermined threshold; 1. A dynamic battery equalization device comprising:

2. 2. The battery dynamic equalization apparatus of claim 1, wherein the motor controller comprises at least two phases of first bridge arms, a first end of each phase of the first bridge arms connected to the positive pole of the first battery pack and a second end of each phase of the first bridge arms connected to the negative pole of the second battery pack; the motor comprises at least two phases of first inductors, a first end of each phase of the first inductors connected to a corresponding first bridge arm and a second end of each phase of the first inductors connected to the first node; and a neutral conductor is drawn from the motor and connected to the first node.

3. The controller: collecting battery equalization parameters, temperature requirement parameters, and drive requirement parameters for the power battery; obtaining a target drive current based on the drive requirement parameters; obtaining a target self-heating current based on the temperature requirement parameters; and obtaining a target equalization current based on the battery equalization parameters; adjusting a first control signal for controlling the motor controller based on the target drive current, the target self-heating current, the target equalization current, and an actual phase current to drive the motor and self-heat and equalize the first battery pack and the second battery pack; 3. The battery dynamic equalization device of claim 2, configured to:

4. The controller: obtaining a torque output of the motor, a rotational speed of the motor, a voltage of the power battery, and an electrical angle of a rotor of the motor; When a drive command is received, the target drive current is obtained based on the torque output of the motor, the rotational speed of the motor, and the voltage of the power battery, and the differential mode voltage of each phase of the bridge arm is obtained based on the target drive current, the actual phase current, and the electrical angle of the rotor of the motor.

4. The battery dynamic equalization device of claim 3, configured to:

5. the target drive current is a combination of a d-axis target current and a q-axis target current, the actual phase current is a combination of a d-axis actual current and a q-axis actual current, and the controller performing closed-loop control on the d-axis target current, the d-axis actual current, the q-axis target current, and the q-axis actual current to obtain a d-axis target voltage and a q-axis target voltage; The differential mode voltage of each phase of the bridge arm is obtained based on the d-axis target voltage, the q-axis target voltage, and the electrical angle of the rotor of the motor.

5. The battery dynamic equalization device of claim 4, configured to:

6. The controller: obtaining a target heating equalization current based on the target self-heating current and the target equalization current; obtaining a real phase current of the motor; obtaining a common mode voltage based on the target heating equalization current and the actual phase current; adjusting the first control signal of the motor controller based on the differential mode voltage and the common mode voltage of each phase of a bridge arm; 6. The battery dynamic equalization device of claim 5, further configured to:

7. The controller: collecting the battery equalization parameters and the temperature requirement parameters of the power battery; Obtaining the target equalization current based on the battery equalization parameters, and obtaining the target self-heating current based on the temperature requirement parameters.

7. The battery dynamic equalization device of claim 3, configured to:

8. 8. The dynamic battery equalization apparatus of claim 7, wherein the controller is configured to perform an integral calculation on the battery equalization parameters to obtain the target equalization current, the battery equalization parameters including one of a discharge capacity difference, a voltage difference, and an instantaneous power difference, the discharge capacity difference, the voltage difference, and the instantaneous power difference representing a discharge capacity difference, a voltage difference, and an instantaneous power difference between the first battery pack and the second battery pack, respectively.

9. the battery equalization parameter is a discharge capacity difference; 9. The battery dynamic equalization apparatus of claim 8, wherein the controller is configured to collect each phase current of the motor, calculate a neutral current of the motor based on each phase current of the motor, and integrate the neutral current to obtain the discharge capacity difference.

10. the battery equalization parameter is the discharge capacity difference; 10. The battery dynamic equalization apparatus of claim 8, wherein the controller is configured to collect a bus positive current and a bus negative current of the power battery, perform an ampere-hour integration on the bus positive current of the power battery to obtain a discharged capacity of the first battery pack, perform an ampere-hour integration on the bus negative current of the power battery to obtain a discharged capacity of the second battery pack, and obtain the discharged capacity difference based on the discharged capacity of the first battery pack and the discharged capacity of the second battery pack.

11. the battery equalization parameter is the discharge capacity difference; 11. The battery dynamic equalization apparatus of claim 8, wherein the controller is configured to collect a bus positive current of the motor controller and a bus negative current of the motor controller, perform an ampere-hour integration on the bus positive current to obtain the discharged capacity of the first battery pack, perform an ampere-hour integration on the bus negative current to obtain the discharged capacity of the second battery pack, and obtain the discharged capacity difference based on the discharged capacity of the first battery pack and the discharged capacity of the second battery pack.

12. the battery equalization parameter is the voltage difference; 12. The battery dynamic equalization apparatus of claim 8, wherein the controller is configured to collect a bus voltage of the motor controller and a voltage of the second battery pack, calculate a voltage of the first battery pack based on the bus voltage and the voltage of the second battery pack, and determine the voltage difference based on the voltage of the first battery pack and the voltage of the second battery pack.

13. the battery equalization parameter is the instantaneous power difference; 13. The battery dynamic equalization apparatus of claim 8, wherein the controller is configured to collect the bus positive current and the bus negative current of the power battery, the voltage of the first battery pack, and the voltage of the second battery pack, determine an instantaneous power of the first battery pack based on the bus positive current and the voltage of the first battery pack, determine an instantaneous power of the second battery pack based on the bus negative current and the voltage of the second battery pack, and determine the instantaneous power difference based on the instantaneous power of the first battery pack and the instantaneous power of the second battery pack.

14. 14. The battery dynamic equalization apparatus of claim 7, wherein the controller is configured to obtain a required heating power based on the temperature requirement parameter, determine an amplitude and a frequency of a self-heating current in the neutral conductor based on the required heating power, and determine a target self-heating current based on the amplitude and the frequency.

15. The controller is configured to: In*=indc+ipk・sin(2・π・f・t) and further configured to obtain the target heating equalization current by 15. The battery dynamic equalization apparatus of claim 14, wherein In* represents the target heating equalization current, indc represents the target equalization current, ipk represents the amplitude of the target self-heating current, f represents the frequency of the target self-heating current, and t represents time.

16. 16. The dynamic battery equalization apparatus of claim 1, wherein the controller is configured to control the bridge arm of the motor controller to equalize the first battery pack and the second battery pack when it is detected that the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack is equal to or greater than the predetermined threshold in a second predetermined state.

17. A method for controlling a battery dynamic equalization device, the battery dynamic equalization device comprising: a power battery; a motor controller; a motor; and a controller; the power battery comprising a first battery pack and a second battery pack connected in series; a first node between the first battery pack and the second battery pack; a first end of the motor controller connected to a positive terminal of the first battery pack; a second end of the motor controller connected to a negative terminal of the second battery pack; a first end of the motor connected to the motor controller; a second end of the motor connected to the first node; and the controller connected to the motor controller; the method is applied to the controller; In a first predetermined state, controlling the motor controller to drive the motor, and alternately charging and discharging the first battery pack and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, so that an absolute value of a difference between a capacity of the first battery pack and a capacity of the second battery pack is less than a predetermined threshold value. A control method comprising:

18. A vehicle comprising a dynamic battery equalization device according to any one of claims 1 to 16.

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