Battery dynamic equalization device and its control method, 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 The present disclosure claims priority to Chinese Patent Application No. 202211543573.X filed on November 30, 2022. The entire content of the above application is 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 the battery dynamic equalization apparatus, and a vehicle.

BACKGROUND ART

[0003] With the development and rapid popularization of electric vehicles, power batteries for electric vehicles are becoming increasingly important. At present, when the power battery of a vehicle is self-heating while the vehicle is driving, the voltage difference between the batteries may gradually increase. This may lead to non-equalization 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 at least to some extent solve one of the technical problems in the related art. Accordingly, a first objective of the present disclosure is to provide a battery dynamic equalization apparatus for realizing dynamic equalization of electric quantity between a first battery pack and a second battery pack during self-heating of the batteries when the vehicle is under driving conditions, thereby improving the battery performance and extending the battery life.

[0005] A second objective of the present disclosure is to provide a control method for a battery dynamic equalization apparatus.

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

[0007] To achieve the aforementioned objective, one embodiment of the first aspect of the present disclosure includes a power battery comprising a first battery pack and a second battery pack connected in series, with a first node provided between the first and second battery packs; a motor controller having a first end connected to the positive terminal of the first battery pack and a second end connected to the negative terminal of the second battery pack; and a motor having a first end connected to the motor controller. The present invention provides a battery dynamic equalization device, which includes a motor, the second end of which of the motor is connected to a first node, and a controller, the controller being connected to a motor controller, and configured to drive the motor by controlling the bridge arm of the motor controller in a first default state, to alternately charge and discharge a first battery pack and a 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 predetermined 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, with a first node provided between the first and second battery packs. 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. In a first default state, the controller is configured to drive the motor by controlling the bridge arm of the motor controller, to alternately charge and discharge the first and second battery packs to achieve self-heating of the first and second battery packs, and to keep the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack below a default threshold. Therefore, the equalization device can achieve dynamic equalization of the amount of electricity between the first battery pack and the second battery pack during the self-heating of the battery 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 above-described embodiments of this disclosure may further include the following additional technical features:

[0010] According to one embodiment of the present disclosure, the motor controller includes a first bridge arm with at least two phases. The first end of each phase of the first bridge arm is connected to the positive terminal of a first battery pack, and the second end of each phase of the first bridge arm is connected to the negative terminal of a second battery pack. The motor includes a first inductor with at least two phases. The first end of each phase of the first inductor is connected to the corresponding first bridge arm, and the second end of each phase of the first inductor is connected to a first node. A neutral wire 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 drive requirement parameters of a power battery, to obtain a target drive current based on the drive requirement parameters, to obtain a target self-heating current based on the temperature requirement parameters, to obtain a target equalization current based on the battery equalization parameters, and to adjust a first control signal for controlling the motor controller based on the target drive current, target self-heating current, target equalization current, and actual phase current to drive the motor and cause the first and second battery packs to self-heat and equalize.

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

[0013] 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 actual 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 motor rotor.

[0014] According to one embodiment of the present disclosure, the controller is further configured to acquire a target heating equalization current based on a target self-heating current and a target equalization current, acquire a motor real-phase current, acquire a common-mode voltage based on the target heating equalization current and the real-phase current, and adjust a first control signal of the motor controller based on the differential-mode voltage and 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 a power battery, to obtain a target equalization current based on the battery equalization parameters, and to 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, voltage difference, and instantaneous power difference between a first battery pack and a second battery pack, respectively.

[0017] According to one embodiment of the present disclosure, the battery equalization parameter is the discharge capacity difference, and the controller is configured to collect the phase currents of the motor, calculate the neutral wire current of the motor based on the phase currents 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 the discharge capacity difference, and the controller is configured to collect the bus positive current and bus negative current of the power battery, perform an ampere-time integral on the bus positive current of the power battery to obtain the discharge capacity of a first battery pack, perform an ampere-time integral on the bus negative current of the power battery to obtain the discharge capacity of a 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 the discharge capacity difference, and the controller is configured to collect the bus positive current and bus negative current of the motor controller, perform an ampere-time integral on the bus positive current to obtain the discharge capacity of a first battery pack, perform an ampere-time integral on the bus negative current to obtain the discharge capacity of a 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 the bus voltage of the motor controller and the voltage of the first battery pack, calculate the voltage of the second battery pack based on the bus voltage and the voltage of the first battery pack, and determine the 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 the positive and negative battery bus currents of the power battery, the voltage of the first battery pack, and the voltage of the second battery pack, to determine the instantaneous power of the first battery pack based on the positive battery bus current and the voltage of the first battery pack, to determine the instantaneous power of the second battery pack based on the negative battery bus current and the voltage of the second battery pack, and to determine the 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 the required heating power based on temperature requirement parameters, determine the amplitude and frequency of the neutral wire self-heating current 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 this disclosure, the controller is given by the following formula: In*=indc+ipk·sin(2·π·f·t) It is further configured to obtain a target heating equalization current, 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 the bridge arm of the motor controller to equalize the first and second battery packs when it is detected that in a second default state, the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack is greater than or equal to a default threshold.

[0025] To achieve the aforementioned objectives, one embodiment of a second aspect of the present disclosure provides a method for controlling a battery dynamic equalization device. The device includes a power battery, a motor controller, a motor, and a controller, the power battery including a first battery pack and a second battery pack connected in series, with a first node between the first and second battery packs. 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 a controller and, in a first default state, includes 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 keeping the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack below a predetermined threshold.

[0026] In the control method for a battery dynamic equalization apparatus according to an embodiment of the present disclosure, the apparatus 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 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. 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 predetermined state, controlling the motor controller to drive the motor, so as to 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 capacity of the first battery pack and the capacity of the second battery pack less than a predetermined threshold. Therefore, the method can realize dynamic equalization of the electric quantity between the first battery pack and the second battery pack during the self-heating of the battery when the vehicle is under driving conditions, thereby improving the performance of the battery and prolonging the service life of the battery.

[0027] To achieve the aforementioned objectives, an embodiment of the third aspect of the present disclosure provides a vehicle including the battery dynamic equalization apparatus described above.

[0028] In the vehicle according to the embodiment of the present disclosure, the battery dynamic equalization apparatus described above realizes dynamic equalization of the electric quantity between the first battery pack and the second battery pack during the self-heating of the battery when the vehicle is under driving conditions, thereby improving the performance of the battery and prolonging the service life of the battery.

[0029] Some of the further aspects and advantages of the present disclosure are set forth in the following description, and some will become apparent from the following description, or be learned through the practice of the present disclosure. Brief Description of the Drawings

[0030] [Figure 1] This is a schematic block diagram of a battery dynamic equalization device according to one embodiment of the present disclosure. [Figure 2] This is a schematic circuit diagram of a battery dynamic equalization device according to one embodiment of the present disclosure. [Figure 3] This is a schematic diagram illustrating an embodiment of the present disclosure that implements battery dynamic equalization under vehicle driving conditions and self-heating mode. [Figure 4] This is a flowchart illustrating a control method for a battery dynamic equalization device according to one embodiment of the present disclosure. [Figure 5] This is a flowchart illustrating a control method for a battery dynamic equalization device, based on a specific example of the present disclosure. [Figure 6] This is a schematic block diagram of a vehicle according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0031] Embodiments of this disclosure are described in detail below, and examples of embodiments are shown in the accompanying drawings. Throughout this specification, identical or similar elements, or elements having the same or similar function, are represented by the same or similar reference numerals. The embodiments described below with reference to the accompanying drawings are illustrative and intended to illustrate this disclosure and should not be construed as limitations on this disclosure.

[0032] During the self-heating operation of a vehicle battery, each battery pack is constantly charging and discharging, and the frequency of charging and discharging is high. In reality, there are differences in the state, impedance, temperature characteristics, etc., of each battery unit. When a voltage difference occurs between battery packs, if equalization adjustment is not performed, the inequality between the battery packs will be accelerated. As the self-heating time increases, the voltage difference between battery packs will also gradually increase, and the battery capacity will gradually become equalized (for example, there are two battery packs E1 and E2, one of which is fully charged and the other is discharged), and the driving range will decrease sharply. This can shorten the battery life in the long term. Therefore, to solve the problem of voltage inequality between battery packs during battery self-heating, this disclosure provides a battery dynamic equalization device. When the vehicle is under driving conditions, it is determined whether the initial charge of each battery pack is equalized before the battery's self-heating function is activated, and whether the battery packs are equalized during the self-heating operation. If the charge between the battery packs is not equalized during the self-heating operation, dynamic equalization of the charge between the battery packs can be achieved. This improves battery performance and extends battery life.

[0033] A battery dynamic equalization device, a control method for the battery dynamic equalization device, and a vehicle according to embodiments of the present disclosure will be described below with reference to the attached drawings.

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

[0035] As shown in Figure 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 provided between the first battery pack E1 and the second battery pack E2. The first end of the motor controller 120 is connected to the positive terminal of the first battery pack E1, and the second end of the motor controller 120 is connected to the negative terminal of the second battery pack E2. The first end of the motor 130 is connected to the motor controller 120, and the 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, in a first default state, control the bridge arm of the motor controller 120 to drive the motor 130, 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 keep the absolute value of the difference between the capacity of the first battery pack E1 and the capacity of the second battery pack E2 below a default threshold. The first default state is the 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] Furthermore, as shown in Figure 2, according to one embodiment of the present invention, the motor controller 120 includes a first bridge arm 121 with at least two phases. The first end of each phase of the first bridge arm 121 is connected to the positive terminal of the first battery pack E1, and the 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 a first inductor 131 with at least two phases. The first end of each phase of the first inductor 131 is connected to the corresponding first bridge arm 121, and the second end of each phase of the first inductor 131 is connected to the first node J1. A neutral wire is drawn from the motor 130 and is 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 3-phase, 5-phase, 6-phase, 9-phase, etc. The motor 130 may include multiple winding configurations. The motor coil includes x windings, where x is 1 or greater and is an integer. Each winding includes at least two phases of windings, and each phase of the winding corresponds to a group of bridge arms for control. For illustrative purposes, the motor shown in Figure 2, which is a 3-phase motor, is taken as an example. Initially, the two battery packs of the power battery 110 (first battery pack E1 and second battery pack E2) are connected in series, and each battery pack is formed by connecting multiple battery units (or cells) in series. The two battery packs contain the same battery units. The battery units of the entire power battery 110 are numbered evenly. A positive bus, a negative bus, and a battery pack series connection midpoint lead wire are drawn 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 first bridge arm 121. For example, in Figure 2, A, B, and C are the first bridge arm 121 connected to the three-phase coil (first inductor 131) of the motor 130, and the motor 130's lead neutral wire (neutral wire) is connected to switch K6. Switch K6 is connected to the lead wire of the series connection midpoint J1 of the power battery 110, and the bus capacitor C1 is connected in parallel to the positive and negative buses of the motor controller 120. The positive series switch K5 of the DC charge / discharge port is connected to the positive bus terminal of the motor controller 120, and the positive series switch K4 of the DC charge / discharge port is connected to the neutral lead wire of the motor. The negative series switch K3 of the DC charge / discharge port is connected to the negative bus terminal of the motor controller 120. The positive terminal of capacitor C2 is connected to the positive terminal of the DC charge / discharge port, and the negative terminal of capacitor C2 is connected to the negative bus terminal of the motor controller 120.In the shutdown state, i.e., when the vehicle is neither charging nor driving and the system power is 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 certain operating conditions 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 being charged and discharged, and a 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 under driving conditions 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 upper bridge arm connection can be controlled to be higher. As a result, the electricity in the first battery pack E1 may be sent to the first inductor 130 in the motor for storage and discharged to the second battery pack E2 via the motor's lead neutral wire. 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 capacities of the first battery pack E1 and the second battery pack E2 is reduced to be less than a predetermined threshold. As a result, dynamic equalization of the amount of electricity between the first and second battery packs is achieved during battery self-heating, thereby improving battery performance and extending battery life. The duty cycle refers to the duty cycle of the upper bridge arm connection, and the duty cycles of the upper and lower bridge arms 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, resulting in higher capacity battery packs being discharged more and lower capacity battery packs being discharged less, ensuring a certain dead time based on the characteristics of the power device.

[0039] The battery dynamic equalization device described herein 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 drive requirement parameters of the power battery 110, obtain a target drive current based on the drive 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 drive current, target self-heating current, target equalization current, and 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, and vehicle drive requirement parameters when the vehicle is running. After the battery equalization parameters, temperature requirement parameters, and drive requirement parameters are obtained, a target drive current may be obtained based on the drive requirement parameters. For example, the target drive current may be obtained based on the drive torque of the motor 130, the rotational speed of the motor, 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, there is a one-to-one correspondence between the temperature requirement parameters and the target self-heating current, 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 drive 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 drive current, target self-heating current, target equalization current, and the current actual phase current. For example, when the vehicle is under driving conditions 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 discharge more and the second battery pack E2 to discharge less. Therefore, when the vehicle is under driving conditions and the power battery 110 is self-heating, the capacities of the first battery pack E1 and the second battery pack E2 tend to become equal.

[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, to 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 to acquire the 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 actual 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 the control of a permanent magnet synchronous motor, a coordinate system is established on the motor rotor to obtain 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 obtain good control characteristics, the motor's mathematical model may be transformed under the coordinate system to achieve separation of 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 d-axis current and q-axis current of the motor. The d-axis current and q-axis current are used to drive the vehicle. As shown in Figure 3, the motor has a total of p phase currents, i1, i2, ~ip. After the coordinate transformation is performed on each phase current, the motor's d-axis current id and q-axis current iq are obtained. The actual phase current is the combined value of the actual d-axis current id and the actual q-axis current iq. The motor torque output Te*, motor rotational speed W, 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 under drive conditions, a target drive current may be obtained based on the motor torque output Te*, motor rotational speed W, and voltage Udc of the power battery 110. The target drive current is the combined 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, the differential mode voltages U1, U2, ..., Up of each phase of the bridge arm are obtained after an inverse coordinate transformation is performed based on the target voltage Ud, target voltage Uq, and the motor rotor electrical angle θ.

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

[0046] Specifically, as shown in Figure 3, after the vehicle receives a self-heating power command and a battery equalization command, the target heating equalization current in* is obtained via the command resolution module 2 based on the target self-heating current and the target equalization current indc. For example, in a p-phase (p+1) line motor, the currents of each phase of the motor are collected to obtain the p-phase current (i1, i2, ..., ip). The direction in which current flows into the motor is positive, and i1 + i2 + ... + ip + in = 0 is satisfied, where in is the neutral line current of the motor. The magnitude of each phase current may be collected by a current sensor, and after the currents of each phase of the motor are obtained, the neutral line 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 current. Specifically, after the actual neutral wire current in is obtained, a 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 wire current in. To adjust the first control signal of the motor controller, the PWM duty cycle of each phase in the p-phase of the 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's bridge arm, so that the vehicle achieves self-heating of the power battery and equalization of the amount of electricity between 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, to obtain a target equalization current based on the battery equalization parameters, and to obtain a target self-heating current based on the temperature requirement parameters.

[0048] Furthermore, according to one embodiment of the present disclosure, the controller 140 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, voltage difference, and instantaneous power difference between a first battery pack E1 and a second battery pack E2, respectively.

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

[0050] The battery equalization parameter 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 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.

[0051] The battery equalization parameter of the power battery 110 may further include an instantaneous power difference ΔP. The 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 the target self-heating current is 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.

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

[0053] Specifically, motor 130 is an M-phase N-wire motor. For example, in a 6-phase 7-wire motor, the currents of each phase of motor 130 are collected to obtain the six phase currents (ia, ib, ic, iu, iv, and iw). If the direction in which current flows into motor 130 is considered positive, then ia + ib + ic + iu + iv + iw + in = 0 is satisfied, where in is the neutral wire current of motor 130. The phase currents of motor 130 are collected by controller 140. For example, the magnitudes of the phase currents ia, ib, ic, iu, iv, and iw may be collected by current sensors, and after the phase currents of motor 130 are obtained, the neutral wire current in of motor 130 may be calculated by in = -ia - ib - ic - iu - iv - iw. After the neutral wire current in of motor 130 is obtained, the neutral wire current in may be integrated to obtain the discharge capacity difference ΔQ between the first battery pack E1 and the second battery pack E2. For motor control, phase shift control technique is used (the troughs and peaks of the PWM count values ​​of each phase of the bridge arm are sampled, and phase shift control can achieve multi-stage sampling of the carrier period). The MCU collects the phase current of the motor through the zero-crossing and cycle points of the carrier period of each phase of the bridge arm, and each phase current is used to calculate the neutral wire current of the motor, improve the sampling time in a unit period of the motor's neutral wire current, and more accurately calculate the discharge difference between the two battery packs. Phase shift control technique can reduce the current ripple of the motor's neutral wire, and can reduce 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. In addition, the phase currents of the motor and the neutral wire current of the motor are sampled, and the integral of the neutral wire current of the motor during the self-heating cycle is calculated and updated once.

[0054] According to another embodiment of the present disclosure, the battery equalization parameter is the discharge capacity difference, and the controller 140 is configured to collect the bus positive current and bus negative current of the power battery 110, perform an ampere-time integral on the bus positive current of the power battery 110 to obtain the discharge capacity of the first battery pack E1, perform an ampere-time integral 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 the self-heating of the power battery 110, the controller 140 may collect the bus positive and bus negative currents of the power battery 110, perform ampere-time integration on the bus positive and bus negative currents of the power battery 110, i.e., perform ampere-time integration on the bus negative current of the power battery 110 to calculate the cumulative discharge capacity Q2, and perform ampere-time integration on the bus positive current of the power battery 110 to calculate the cumulative discharge capacity Q1. After obtaining the discharge capacities Q1 and Q2, the controller 140 may 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 and bus negative currents of the power battery terminals may also be collected by a battery management system (BMS), and the current holes of the bus positive and bus negative terminals of the battery pack, as well as the voltage sampling circuits of each battery unit, are directly integrated into the BMS without additional devices.

[0056] According to another embodiment of the present disclosure, the battery equalization parameter is the discharge capacity difference, and the controller 140 is configured to collect the bus positive current and bus negative current of the motor controller 120, perform an ampere-time integral on the bus positive current of the motor controller 120 to obtain the discharge capacity of the first battery pack E1, perform an ampere-time integral 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 the self-heating of the power battery 110, the controller 140 may collect the positive and negative bus currents of the motor controller 120, perform ampere-time integration on the positive and negative bus currents of the motor controller 120, i.e., perform ampere-time integration on the positive bus current of the motor controller 120 to calculate the cumulative discharge capacity Q1, and perform ampere-time integration on the negative bus current of the motor controller 120 to calculate the cumulative discharge capacity Q2. After obtaining the discharge capacities Q1 and Q2, the controller 140 may 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 positive and negative bus currents of the motor controller 120 may also be collected by the MCU, which allows for more accurate current collection while avoiding the switching time and interference of the power devices.

[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 the bus voltage of the motor controller 120 and the voltage of the second battery pack E2, calculate the voltage of the first battery pack E1 based on the bus voltage and the voltage of the second battery pack E2, and determine the 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 neutral wire voltage to ground of the motor (voltage of the second battery pack E2), where the bus voltage of the motor controller 120 is the sum of the voltage of the first battery pack E1 and the voltage of the second battery pack E2. After the bus voltage of the motor controller 120 and the voltage 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, the 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 the instantaneous power difference, and the controller 140 is configured to collect the positive bus current and negative battery bus current of the power battery 110, the voltage of the first battery pack E1, and the voltage of the second battery pack E2, to determine the instantaneous power of the first battery pack E1 based on the positive battery bus current and the voltage of the first battery pack E1, to determine the instantaneous power of the second battery pack based on the negative battery bus current and the voltage of the second battery pack, and to determine the 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 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, or 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, and after the instantaneous power of each battery pack has been calculated, the instantaneous power difference Δp may be determined 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 the required heating power based on temperature requirement parameters, determine the amplitude and frequency of the neutral wire self-heating current based on the required heating power, and determine the target self-heating current based on the amplitude and frequency.

[0063] Furthermore, according to one embodiment of the present disclosure, the controller 140 is given by the following formula: In*=indc+ipk·sin(2·π·f·t) (1) It is further configured to obtain a target heating equalization current, 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 a self-heating request signal for 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, the power battery's self-heating program may be started to ensure the power supply capacity of the power battery 110, and the required heating power may be determined based on the heating requirements of the power battery 110, i.e., the temperature requirement parameters 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 ipk and frequency f of the neutral wire self-heating current may be determined based on the amplitude of the required heating power, and after the amplitude ipk and frequency f of the neutral wire self-heating current are obtained, the target self-heating current may be determined based on the amplitude ipk and frequency f. The target heating equalization current In* may be determined by equation (1) above, based on the target equalization current indc, the amplitude ipk and frequency f of the target self-heating current, and the current-time.

[0065] It should be noted 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 is first calibrated on a 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 capacities of the first battery pack E1 and the second battery pack E2 when it is detected that in a second default state the absolute value of the difference between the capacities of the first battery pack E1 and the second battery pack E2 is greater than or equal to a default threshold.

[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 greater than or equal to a 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. In other words, in the second default state (a state in which the power battery 110 performs only 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, and as a result, 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 smaller. 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 charging time of the second battery pack E2 may be made longer, in order to equalize the capacities between the first battery pack E1 and the second battery pack E2.

[0068] In summary, in a battery dynamic equalization device according to embodiments of the present disclosure, the power battery includes a first battery pack and a second battery pack connected in series, with a first node provided between the first and second battery packs. A first end of a 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 a motor is connected to the motor controller, and a second end of a motor is connected to the first node. A controller is connected to the motor controller. In a first default state, the controller is configured to drive the motor by controlling the bridge arm of the motor controller, to alternately charge and discharge the first and second battery packs to achieve self-heating of the first and second battery packs, and to keep the absolute difference between the capacity of the first battery pack and the capacity of the second battery pack below a default threshold. Therefore, the equalization device can achieve dynamic equalization of the amount of electricity between the first battery pack and the second battery pack during the self-heating of the battery when the vehicle is under driving conditions, thereby improving battery performance and extending battery life.

[0069] In accordance with the embodiments described above, this disclosure further provides a method for controlling a battery dynamic equalization device.

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

[0071] S1: In the first default state, the motor controller alternately charges and discharges the first battery pack and the second battery pack to achieve self-heating of the first and second battery packs, and controls the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack to be less than a predetermined threshold.

[0072] The control method according to this disclosure will be described below with reference to Figure 5.

[0073] As a specific example, the control method for a battery dynamic equalization device according to this disclosure may include the following steps:

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

[0075] S101: Determine whether self-heating is required based on the current battery temperature. If yes, perform step S102; otherwise, perform step S108.

[0076] S102: Control the switch module of the battery dynamic equalizer 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 if a battery active equalization command has been received. If yes, perform step S105; otherwise, perform step S110.

[0079] S105: Collect the phase currents of the motor, calculate the neutral wire current value of the motor based on the phase current values ​​of the motor, integrate the neutral wire current value during 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. Here, 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 larger 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: Ends the battery self-heating program.

[0082] S108: Based on the battery heating requirements, adjust the battery self-heating target current value to zero.

[0083] S109: Control the switch module of the battery dynamic equalizer to open and perform 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 perform step S106.

[0085] For details not disclosed in the control method of the battery dynamic equalization device according to the embodiments of this disclosure, please refer to the details disclosed in the battery dynamic equalization device according to the embodiments of this disclosure. Details are not described herein.

[0086] A control method for a battery dynamic equalization device according to an embodiment of the present disclosure includes a power battery, a motor controller, a motor, and a controller, wherein the power battery includes a first battery pack and a second battery pack connected in series, with a first node provided between the first and second battery packs. 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. A 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, alternatingly charging and discharging the first and second battery packs to achieve self-heating of the first and second battery packs, 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. Therefore, the method can achieve dynamic equalization of the amount of electricity between the first battery pack and the second battery pack during battery self-heating when the vehicle is under any conditions, thereby improving battery performance and extending battery life.

[0087] In accordance with the embodiments described above, this disclosure further provides a vehicle.

[0088] As shown in Figure 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 battery dynamic equalization device enables dynamic equalization of the amount of electricity 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 logic and / or steps shown in the flowchart or otherwise described herein, such as an ordered list that can be considered as executable instructions used to perform a logical function, may specifically 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 an instruction execution system, apparatus, or device and execute those instructions). In the context of this specification, “computer-readable medium” may be any device that contains, stores, communicates, propagates, or transmits programs used by or in combination with an instruction execution system, apparatus, or device. More specific examples (a non-exclusive list) of computer-readable media include electrical connection components with 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), optical fiber devices, and portable compact disk read-only memory (CD-ROM). In addition, since programs can be acquired electronically, for example by optically scanning paper or other media, then editing, interpreting, or otherwise processing them as necessary, and then storing them in computer memory, computer-readable media can also be paper or other suitable media on which programs can be printed.

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

[0092] In this specification, any description using terms such as “one embodiment,” “several embodiments,” “example,” “specific example,” or “several examples” means that a particular feature, structure, material, or property described with reference to an embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, illustrative descriptions of the aforementioned terms do not necessarily refer to the same embodiment or example. In addition, any particular feature, structure, material, or property described may be combined in an appropriate manner in any one or more of the embodiments or examples.

[0093] In addition, the terms “first” and “second” are used for illustrative purposes only and should not be construed as indicating or suggesting relative importance or the quantity of the technical features described. Accordingly, features limited by “first” or “second” may explicitly describe or implicitly include at least one of such features. In this disclosure, “plural” means at least two, for example, two or three, unless expressly specified.

[0094] In this disclosure, the terms “attach,” “connect,” “connect,” and “fix” should be understood broadly unless otherwise expressly specified. For example, unless otherwise expressly specified, a connection may be a fixed connection, a detachable connection, or an integrated connection; it may be a mechanical connection or an electrical connection; it may be a direct connection, an indirect connection through an intermediary, or an internal communication or interaction relationship between two elements. Those skilled in the art will be able to understand the specific meaning of the terms in this disclosure based on the specific context.

[0095] While embodiments of the Disclosure have been shown and described above, it should be understood that these embodiments are illustrative and should not be construed as limiting the Disclosure. Those skilled in the art may modify, alter, replace, or change the embodiments described above within the scope of the Disclosure.

Claims

1. A power battery comprising 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 wherein 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 motor, wherein 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, A controller, wherein the controller is connected to the motor controller, and the controller is configured to, in a first default state, control the 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 keep the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack below a predetermined threshold, and It is equipped with, The motor controller comprises a first bridge arm with at least two phases, the first end of each phase of the first bridge arm being connected to the positive terminal of the first battery pack, the second end of each phase of the first bridge arm being connected to the negative terminal of the second battery pack, the motor comprises a first inductor with at least two phases, the first end of each phase of the first inductor being connected to the corresponding first bridge arm, the second end of each phase of the first inductor being connected to the first node, a neutral wire being drawn from the motor, and the neutral wire being connected to the first node, The aforementioned controller The battery equalization parameters, temperature requirement parameters, and drive requirement parameters of the aforementioned power battery are collected. Based on the aforementioned drive requirement parameters, a target drive current is obtained; based on the aforementioned temperature requirement parameters, a target self-heating current is obtained; and based on the aforementioned battery equalization parameters, a target equalization current is obtained. A battery dynamic equalization device that drives the motor by 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 the actual phase current.

2. The aforementioned controller Based on the target drive current, the target self-heating current, the target equalization current, and the actual phase current, the first control signal for controlling the motor controller is adjusted to drive the motor and cause the first and second battery packs to self-heat and equalize. A battery dynamic equalization device according to claim 1, configured as described above.

3. The aforementioned controller The torque output of the motor, the rotational speed of the motor, the voltage of the power battery, and the electrical angle of the motor rotor are obtained. 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. A battery dynamic equalization device according to claim 2, configured as described above.

4. The target drive current is a combination of the d-axis target current and the q-axis target current, the actual phase current is a combination of the d-axis actual current and the q-axis actual current, and the controller is Closed-loop control is performed 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. Based on the d-axis target voltage, the q-axis target voltage, and the electrical angle of the motor's rotor, the differential mode voltages of each phase of the bridge arm are obtained. A battery dynamic equalization device according to claim 3, configured as described above.

5. The aforementioned controller Based on the target self-heating current and the target equalization current, a target heating equalization current is obtained. The actual phase current of the motor is obtained, Based on the target heating equalization current and the actual phase current, the common mode voltage is obtained. The first control signal of the motor controller is adjusted based on the differential mode voltage and the common mode voltage of each phase of the bridge arm. The battery dynamic equalization device according to claim 4, further configured as follows.

6. The aforementioned controller The battery equalization parameters and temperature requirement parameters of the power battery are collected, The target equalization current is obtained based on the battery equalization parameters, and the target self-heating current is obtained based on the temperature requirement parameters. A battery dynamic equalization device according to claim 2, configured as described above.

7. The battery dynamic equalization device according to claim 6, wherein the controller is configured to perform an integral calculation on the battery equalization parameter to obtain the target equalization current, the battery equalization parameter includes one of a discharge capacity difference, a voltage difference, and an instantaneous power difference, and 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 and the second battery pack, respectively.

8. The aforementioned battery equalization parameter is the difference in discharge capacity. The battery dynamic equalization device according to claim 7, wherein the controller is configured to collect the phase currents of the motor, calculate the neutral wire current of the motor based on the phase currents of the motor, and obtain the discharge capacity difference by integrating the neutral wire current.

9. The battery equalization parameter is the discharge capacity difference, The battery dynamic equalization device according to claim 7, wherein the controller is configured to collect the bus positive current and bus negative current of the power battery, perform an ampere-time integral on the bus positive current of the power battery to obtain the discharge capacity of the first battery pack, perform an ampere-time integral 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.

10. The battery equalization parameter is the discharge capacity difference, The battery dynamic equalization device according to claim 7, wherein the controller is configured to collect the positive bus current and the negative bus current of the motor controller, perform an ampere-time integral on the positive bus current to obtain the discharge capacity of the first battery pack, perform an ampere-time integral on the negative bus current 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.

11. The aforementioned battery equalization parameter is the voltage difference. The battery dynamic equalization device according to claim 7, wherein the controller is configured to collect the bus voltage of the motor controller and the voltage of the second battery pack, calculate the 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.

12. The battery equalization parameter is the instantaneous power difference, Battery dynamic equalization device according to claim 7, wherein the controller is configured to collect the bus positive current and bus negative current of the power battery, the voltage of the first battery pack, and the voltage of the second battery pack, to determine the instantaneous power of the first battery pack based on the bus positive current and the voltage of the first battery pack, to determine the instantaneous power of the second battery pack based on the bus negative current and the voltage of the second battery pack, and to determine the instantaneous power difference based on the instantaneous power of the first battery pack and the instantaneous power of the second battery pack.

13. The battery dynamic equalization device according to claim 6, wherein the controller is configured to acquire the required heating power based on the temperature requirement parameters, determine the amplitude and frequency of the neutral wire self-heating current based on the required heating power, and determine a target self-heating current based on the amplitude and frequency.

14. The aforementioned controller is defined by the following equation: In*=indc+ipk・sin(2・π・f・t) It is further configured to obtain the target heating equalization current by, The battery dynamic equalization device according to claim 13, 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.

15. Battery dynamic equalization device according to 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 detects that in a second default state the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack is greater than or equal to the default threshold.

16. A control method for a battery dynamic equalization device, wherein the battery dynamic equalization device comprises a power battery, a motor controller, a motor, and a controller, the power battery comprises a first battery pack and a second battery pack connected in series, a first node is provided between the first battery pack and the second battery pack, the first end of the motor controller is connected to the positive terminal of the first battery pack, the second end of the motor controller is connected to the negative terminal of the second battery pack, the first end of the motor is connected to the motor controller, the second end of the motor is connected to the first node, the controller is connected to the motor controller, and the method is applied to the controller. In the first default state, the motor controller is controlled to drive the motor, the first battery pack and the second battery pack are alternately charged and discharged to achieve self-heating of the first battery pack and the second battery pack, and the absolute value of the difference between the capacity of the first battery pack and the capacity of the second battery pack is set to less than a predetermined threshold. It is equipped with, It is, The motor controller comprises a first bridge arm with at least two phases, the first end of each phase of the first bridge arm being connected to the positive terminal of the first battery pack, the second end of each phase of the first bridge arm being connected to the negative terminal of the second battery pack, the motor comprises a first inductor with at least two phases, the first end of each phase of the first inductor being connected to the corresponding first bridge arm, the second end of each phase of the first inductor being connected to the first node, a neutral wire being drawn from the motor, and the neutral wire being connected to the first node, The aforementioned controller The battery equalization parameters, temperature requirement parameters, and drive requirement parameters of the aforementioned power battery are collected. Based on the aforementioned drive requirement parameters, a target drive current is obtained; based on the aforementioned temperature requirement parameters, a target self-heating current is obtained; and based on the aforementioned battery equalization parameters, a target equalization current is obtained. A control method for driving a motor by 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 the actual phase current.

17. A vehicle equipped with a battery dynamic equalization device according to any one of claims 1 to 15.

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