Battery heating method, device and computer equipment

Abstract

The present application provides a battery heating method, apparatus, and computer device, applied to a motor control circuit. The motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, and a third bridge arm. The first end of the three-phase motor is connected to the first bridge arm, the second end of the three-phase motor is connected to the second bridge arm, and the third end of the three-phase motor is connected to the third bridge arm. The method includes: determining a target base voltage vector, which is used to control the upper bridge arm to be conductive and the lower bridge arm to be disconnected of the first, second, and third bridge arms; synthesizing a target voltage vector based on the target base voltage vector, a zero vector, and a target unit vector according to the driving state; and stimulating an alternating current in a battery pack based on the target voltage vector to heat the battery pack. This method can suppress motor noise and vibration while heating the battery pack.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a battery heating method, device and computer equipment. Background Art

[0002] With the development of technology in the field of electric vehicles, using the alternating current of the motor to stimulate the battery to generate heat has become a commonly used method for low-temperature heating of power batteries.

[0003] When the vehicle is not moving, the alternating current flowing through the battery energizes the motor, forcing the magnetic flux within the motor to move along a nearly straight path to prevent the rotor from generating torque. Traditional magnetic flux control requires a high frequency change to maintain a high amplitude of the alternating current. This high-frequency flux change can cause motor whistling and vibration.

[0004] It can be seen that the current low-temperature heating method of power batteries causes excessive motor noise and vibration. Summary of the Invention

[0005] Based on this, it is necessary to provide a battery heating method, device, computer equipment, computer-readable storage medium and computer program product that can suppress motor noise and vibration to address the above technical problems.

[0006] In a first aspect, the present application provides a battery heating method, which is applied to a motor control circuit, the motor control circuit including a three-phase motor, a first bridge arm, a second bridge arm, and a third bridge arm, wherein a first end of the three-phase motor is connected to the first bridge arm, a second end of the three-phase motor is connected to the second bridge arm, and a third end of the three-phase motor is connected to the third bridge arm, the first bridge arm is connected to a first battery pack, and the second bridge arm and the third bridge arm are respectively connected to the second battery pack. The method includes:

[0007] Determine a target basic voltage vector, where the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off;

[0008] synthesizing a target voltage vector based on the target base voltage vector, the zeroth vector, and the target unit vector according to the driving state;

[0009] An alternating current is excited in a battery pack based on the target voltage vector to heat the battery pack.

[0010] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the voltage between the second terminal and the third terminal of the three-phase motor is zero.

[0011] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the voltage between the first end and the second end of the three-phase motor and the voltage between the first end and the third end are both the voltage difference between the first battery group and the second battery group.

[0012] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the current of the first battery pack and the current of the second battery pack are both the same as the current of the first end of the three-phase motor.

[0013] In one embodiment, when the voltage difference between the first battery group and the second battery group is zero, the magnitude of the target base voltage vector is zero;

[0014] When the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the unit voltage vector corresponding to when the upper bridge arm of the first bridge arm is turned on, the lower bridge arm of the second bridge arm, and the lower bridge arm of the third bridge arm are turned on;

[0015] When the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage vector of the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the lower bridge arm of the first bridge arm, the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm being turned on.

[0016] In one embodiment, synthesizing the target voltage vector based on the target base voltage vector, the zeroth vector, and the target unit vector according to the motor state includes:

[0017] The two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector;

[0018] When the motor is in a stationary state, determining the action time of the target basic voltage vector based on the current frequency requirement;

[0019] The target voltage vector is synthesized according to the action time of the target basic voltage vector, the target basic voltage vector, a zeroth vector, and the target unit vector.

[0020] In one embodiment, synthesizing the target voltage vector based on the target base voltage vector, the zeroth vector, and the target unit vector according to the motor state includes:

[0021] The two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector;

[0022] When the motor is in a rotating state and the voltage difference between the first battery pack and the second battery pack is zero, the target basic voltage vector is used to replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector, and the target unit vector; or

[0023] When the voltage difference between the first battery pack and the second battery pack is not zero, the coaxial voltage vector of the target basic voltage vector is determined, the target basic voltage vector and the coaxial voltage vector are used to replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector.

[0024] In a second aspect, the present application provides a battery heating device, which is applied to a motor control circuit. The motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, and a third bridge arm. The first end of the three-phase motor is connected to the first bridge arm, the second end of the three-phase motor is connected to the second bridge arm, and the third end of the three-phase motor is connected to the third bridge arm. The first bridge arm is connected to a first battery pack, and the second bridge arm and the third bridge arm are respectively connected to the second battery pack. The device includes:

[0025] a basic vector determination module, configured to determine a target basic voltage vector, wherein the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off;

[0026] a target vector synthesis module, configured to synthesize a target voltage vector based on the target basic voltage vector, the zeroth vector, and the target unit vector according to a driving state;

[0027] A heating module is configured to excite an alternating current of a battery pack based on the target voltage vector to heat the battery pack.

[0028] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the voltage between the second terminal and the third terminal of the three-phase motor is zero.

[0029] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the voltage between the first end and the second end of the three-phase motor and the voltage between the first end and the third end are both the voltage difference between the first battery group and the second battery group.

[0030] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the current of the first battery pack and the current of the second battery pack are both the same as the current of the first end of the three-phase motor.

[0031] In one embodiment, when the voltage difference between the first battery group and the second battery group is zero, the amplitude of the target basic voltage vector is zero; when the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the upper bridge arm of the first bridge arm being turned on, the lower bridge arm of the second bridge arm and the lower bridge arm of the third bridge arm being turned on; when the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the lower bridge arm of the first bridge arm being turned on, the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm being turned on.

[0032] In one embodiment, the target vector synthesis module is further used to use two unit voltage vectors adjacent to the target voltage vector as the target unit vector; when the motor is in a stationary state, determine the action time of the target basic voltage vector based on the current frequency requirement; and synthesize the target voltage vector according to the action time of the target basic voltage vector, the target basic voltage vector, the zeroth vector and the target unit vector.

[0033] In one embodiment, the target vector synthesis module is further used to take two adjacent unit voltage vectors of the target voltage vector as the target unit vector; when the motor is in a rotating state, when the voltage difference between the first battery pack and the second battery pack is zero, the target basic voltage vector replaces the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector; or, when the voltage difference between the first battery pack and the second battery pack is not zero, determine the coaxial voltage vector of the target basic voltage vector, replace the zeroth vector with the target basic voltage vector and the coaxial voltage vector, and synthesize the target voltage vector by the target basic voltage vector, the new zeroth vector and the target unit vector.

[0034] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0035] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0036] In a fifth aspect, the present application further provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, it implements the steps in the above-mentioned method embodiments.

[0037] The battery heating method, apparatus, computer device, computer-readable storage medium, and computer program product described above determine a new target base voltage vector. This target base voltage vector controls the conduction of the upper arms of the first, second, and third bridge arms, and the disconnection of the lower arms. Based on the driving state, a target voltage vector is synthesized based on the target base voltage vector, the zeroth vector, and the target unit vector. This target voltage vector is used to stimulate an alternating current in the battery pack to heat the battery pack. Because the amplitude of the target base voltage vector is much smaller than that of other conventional vectors, increasing the duration of the target base voltage vector's action can reduce its amplitude, thereby reducing the amplitude of the flux change. This allows the flux to maintain the amplitude of the alternating current at a lower frequency, thereby achieving heating of the battery pack in an electric vehicle while suppressing motor noise and vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic structural diagram of a motor control circuit in one embodiment;

[0039] Figure 2 is a schematic flow chart of a battery heating method according to an embodiment;

[0040] Figure 3 Schematic diagram of a coordinate system of a motor control vector in one embodiment;

[0041] Figure 4 A schematic diagram of switch states and loop currents corresponding to a target basic voltage vector in one embodiment;

[0042] Figure 5 204 is a flow chart of step 204 in one embodiment;

[0043] Figure 6 Schematic diagram of flux change when the target base voltage vector does not participate in one embodiment;

[0044] Figure 7 Schematic diagram of flux change when the target base voltage vector is involved in one embodiment;

[0045] Figure 8 204 is a flow chart of step 204 in one embodiment;

[0046] Figure 9 is a schematic structural diagram of a battery heating device in one embodiment;

[0047] Figure 10 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0049] The battery heating method provided in the embodiment of the present application can be applied to Figure 1 Motor control circuit. Figure 1 As shown, the motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, and a third bridge arm. The first end A of the three-phase motor is connected to the first bridge arm, the second end B of the three-phase motor is connected to the second bridge arm, and the third end C of the three-phase motor is connected to the third bridge arm. Specifically, the first end A of the three-phase motor can be connected to the middle of the upper bridge arm and the lower bridge arm of the first bridge arm, the second end B of the three-phase motor can be connected to the middle of the upper bridge arm and the lower bridge arm of the second bridge arm, and the third end C of the three-phase motor can be connected to the middle of the upper bridge arm and the lower bridge arm of the third bridge arm. The battery pack includes a first battery pack E1 and a second battery pack E2 connected in parallel. The first bridge arm is connected to the first battery pack E1, and the second bridge arm and the third bridge arm are respectively connected to the second battery pack E2. The positive electrode of the first battery pack E1 is connected to the upper bridge arm of the first bridge arm, and the positive electrode of the second battery pack E2 is respectively connected to the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm.

[0050] The motor control circuit includes a battery pack. The upper bridge arm of the first bridge arm may include a switch V1, the lower bridge arm of the first bridge arm may include a switch V2, the upper bridge arm of the second bridge arm may include a switch V3, the lower bridge arm of the second bridge arm may include a switch V4, the upper bridge arm of the third bridge arm may include a switch V5, and the lower bridge arm of the third bridge arm may include a switch V7. The embodiment of the present application does not specifically limit the types of switches V1 to V6, as long as they can be turned on or off under control. Exemplarily, switches V1 to V6 can be MOS (MOSFET, Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) switches, IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), etc.

[0051] In one embodiment, Figure 2As shown, a battery heating method is provided, which is applied to Figure 1 The motor control circuit in FIG is taken as an example to illustrate the following steps:

[0052] Step 202 : determining a target basic voltage vector, where the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off.

[0053] The target basic voltage vector can represent the switching state of switches V1 to V6 in the motor control circuit. The target basic voltage vector U7 can be represented by binary (111), where 1 represents on and 0 represents off. (111) means that the upper bridge arm of the first bridge arm is on and the lower bridge arm is off, the upper bridge arm of the second bridge arm is on and the lower bridge arm is off, and the upper bridge arm of the third bridge arm is on and the lower bridge arm is off; that is, V1, V3, and V5 are on and V2, V4, and V6 are off.

[0054] Step 204 : synthesize a target voltage vector based on the target base voltage vector, the zeroth vector, and the target unit vector according to the motor state.

[0055] The motor control circuit can be applied to a driving object that requires a battery to provide driving power. The battery can provide power to the motor to rotate the motor, thereby causing the driving object to move. The motor state can include a rotating state and a stationary state. The zeroth vector U0 (000) is a voltage vector with an amplitude of 0. The target unit vector is two adjacent unit vectors from U0 to U6. The target unit vector can be determined based on the synthesis requirements of the target voltage vector. The target basic voltage vector is multiplied by the target basic voltage vector action time, the zeroth vector is multiplied by the action time of the zeroth vector, and the target unit vector is multiplied by the action time of the target unit vector, and then the target voltage vector is synthesized by adding them.

[0056] like Figure 3 As shown, the switch states corresponding to U0~U6 can be found in Figure 3 The binary identifier in the middle, for example, the zeroth vector U0 (000) is the origin, indicating that the upper bridge arm of the first bridge arm is turned off and the lower bridge arm is turned on, the upper bridge arm of the second bridge arm is turned off and the lower bridge arm is turned on, and the upper bridge arm of the third bridge arm is turned off and the lower bridge arm is turned on; that is, V1, V3, and V5 are turned off, and V2, V4, and V6 are turned on.

[0057] For example, the motor control circuit can be applied to an electric vehicle, and the driving state of the electric vehicle can be changed to a parking state or a driving state according to the state of the motor.

[0058] Step 206 : energize the alternating current of the battery pack based on the target voltage vector to heat the battery pack.

[0059] After the target voltage vector is determined, the target voltage vector is applied to the motor control circuit, and the alternating current flowing through the battery pack is the heating current, which heats the battery pack.

[0060] In the battery heating method provided in the embodiment of the present application, since the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery pack and the second battery pack, the amplitude of the traditional unit vector is proportional to the voltage of the first battery pack or the second battery pack, and the amplitude of the target basic voltage vector is much smaller than the amplitudes of other traditional vectors, the amplitude of the target basic voltage vector can be reduced by increasing the action time of the target basic voltage vector, thereby reducing the amplitude of the magnetic flux change, so that the magnetic flux can maintain the amplitude of the alternating current under lower frequency changes, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0061] In one embodiment, when the target basic voltage vector is applied to the motor control circuit, the voltage between the second terminal and the third terminal of the three-phase motor is zero.

[0062] Specifically, you can Figure 4 As shown in the figure, the bold line portion represents the current path. V3 and V5 are turned on, and the second terminal B and the third terminal C of the three-phase motor are connected to the positive terminal of the first battery pack E1. The voltage between the second terminal B and the third terminal C of the three-phase motor is 0.

[0063] In the disclosed embodiment, a target basic voltage vector is determined by voltage characteristics, so that the amplitude of the target basic voltage vector is much smaller than the amplitudes of other traditional vectors. The target voltage vector is then synthesized by the target basic voltage vector, so that the magnetic flux can maintain the amplitude of the alternating current under lower frequency changes, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0064] In one embodiment, Figure 1 As shown, when the target basic voltage vector acts on the motor control circuit, the voltage between the first and second ends and the voltage between the first and third ends of the three-phase motor are both the voltage difference between the first battery group and the second battery group.

[0065] Specifically, the motor control circuit may further include a switch, which is in an off state during the heating process, with a first end of the switch connected to the positive electrode of the first battery pack E1 and the upper bridge arm of the first bridge arm, and a second end of the switch connected to the positive electrode of the second battery pack E2 and the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm. Figure 4As shown in the figure, the bold line portion represents the current path. The second terminal B and the third terminal C of the three-phase motor are jointly connected to the positive terminal of the first battery pack E1. The first terminal A of the three-phase motor is connected to the positive terminal of the second battery pack E2. The voltage between the first terminal A and the second terminal B of the three-phase motor is the voltage difference between the first battery pack E1 and the second battery pack E2. The voltage between the first terminal A and the third terminal C of the three-phase motor is the voltage difference between the first battery pack E1 and the second battery pack E2.

[0066] In the disclosed embodiment, a target basic voltage vector is determined by voltage characteristics, and the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery pack and the second battery pack. The amplitude of a traditional unit vector is proportional to the voltage of the first battery pack or the second battery pack, so that the amplitude of the target basic voltage vector is much smaller than the amplitude of other traditional vectors. The target voltage vector is then synthesized by the target basic voltage vector, so that the magnetic flux can maintain the amplitude of the alternating current under lower frequency changes, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0067] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the current of the first battery pack and the current of the second battery pack are both the same as the current of the first terminal of the three-phase motor.

[0068] Specifically, the mapping relationship between the three-phase current of the motor and the current of the battery pack under different voltage control vectors can be referred to the following Table 1.

[0069] Table 1 Mapping relationship between motor three-phase current and battery pack current under different voltage control vectors

[0070]

[0071]

[0072] Among them, i dc,1 is the current of the first battery pack E1, i dc,2 is the current of the second battery pack E2, i a is the current output from the first terminal A of the three-phase motor, i b is the current output from the second terminal B of the three-phase motor, i c It is the current output from the third terminal C of the three-phase motor.

[0073] When the target basic voltage vector U7 acts on the motor control circuit, the current of the first battery group E1 is -i a , the current of the second battery pack E2 is i a , its magnitude is the same as the current i at the first terminal A of the three-phase motor a same.

[0074] In the disclosed embodiment, a target basic voltage vector is determined by current characteristics, so that the amplitude of the target basic voltage vector is much smaller than the amplitudes of other traditional vectors. The target voltage vector is then synthesized by the target basic voltage vector, so that the magnetic flux can maintain the amplitude of the alternating current under lower frequency changes, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0075] In one embodiment, when the voltage difference between the first battery group and the second battery group is zero, the amplitude of the target basic voltage vector is zero; when the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the corresponding unit voltage vector when the upper bridge arm of the first bridge arm is turned on, the lower bridge arm of the second bridge arm and the lower bridge arm of the third bridge arm are turned on; when the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the corresponding unit voltage vector when the lower bridge arm of the first bridge arm is turned on, the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm are turned on.

[0076] When the voltage difference between the first battery pack E1 and the second battery pack E2 is zero, the voltage between the first terminal A and the second terminal B of the three-phase motor is 0, and the voltage between the first terminal A and the third terminal C of the three-phase motor is 0. The amplitude of the target basic voltage vector is 0. Figure 3 U7 ’ As shown, when the voltage of the first battery pack E1 is higher than the voltage of the second battery pack E2, the target basic voltage vector U7 is a voltage vector whose amplitude is proportional to the voltage difference E1-E2 between the two battery packs, and the direction of the target basic voltage vector U7 is the same as the direction of the unit voltage vector U4. Figure 3 As shown in U7", when the voltage of the first battery pack E1 is lower than the voltage of the second battery pack E2, U7 is a voltage vector whose amplitude is proportional to the voltage difference E2-E1 between the two battery packs, and the direction of the target basic voltage vector U7 is the same as that of the unit voltage vector U3.

[0077] In the disclosed embodiment, the target basic voltage vector is determined by the voltage of the first battery pack E1 and the voltage of the second battery pack E2, so that the amplitude of the target basic voltage vector is much smaller than the amplitude of other traditional vectors, and then the target voltage vector is synthesized by the target basic voltage vector, so that the magnetic flux can maintain the amplitude of the alternating current under a lower frequency change, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0078] In one embodiment, Figure 5As shown, in step 204, according to the motor state, based on the target basic voltage vector, the zeroth vector and the target unit vector, synthesizing the target voltage vector may include:

[0079] Step 502: Take two unit voltage vectors adjacent to the target voltage vector as target unit vectors.

[0080] The two unit voltage vectors adjacent to the target voltage vector may be determined according to the synthesis requirement of the target voltage vector in an actual scenario.

[0081] For example, Figure 3 As shown, the target voltage vector U obj The two adjacent unit voltage vectors are U4 (100) and U6 (110), and the unit voltage vectors U4 (100) and U6 (110) are used as target unit vectors. Figure 3 Where α and β are the coordinate axes of the two-phase stationary coordinate system of the three-phase motor. The target voltage vector U obj In the direction of U4(100) and U6(110), it can be decomposed into T x and T y . T x is the action time of U4(100), T y is the action time of U6(110).

[0082] The change amplitude of the magnetic flux and the target voltage vector U obj The calculation of the change amplitude of the magnetic flux can satisfy the following formula (1).

[0083] △Ψa=U obj *T formula (1)

[0084] Among them, △Ψa is the amplitude of flux change, T is the vector control period, T is a fixed value, which is the operating period of switches V1~V6. That is, when the target voltage vector U obj As the amplitude of increases, the change amplitude of flux linkage △Ψa also increases; when the target voltage vector U obj The amplitude of decreases, and the amplitude of change of magnetic flux △Ψa also decreases.

[0085] The flux change when the basic voltage vector U7 is not used is as follows Figure 6 As shown. Where Ψ1 and Ψ2 are respectively the positive amplitude limit and the reverse amplitude limit that the motor flux can reach when the motor rotor is in the current position due to the winding current limit. Each change in the direction of the flux is half a cycle. The larger the flux change amplitude △Ψa, the more times the flux changes in one cycle, that is, the faster the flux change frequency, which will cause the motor to whistle and vibrate. The flux change when using the target basic voltage vector U7 is as follows Figure 7As shown in the figure, the flux change amplitude △Ψb is small, and the number of flux changes in one cycle is reduced, that is, the flux change frequency is slow, which enables the flux to maintain the amplitude of the alternating current at a lower frequency change, thereby suppressing motor noise and vibration.

[0086] Step 504 : When the motor is in a stationary state, determine the action time of the target basic voltage vector based on the current frequency requirement.

[0087] Specifically, the motor is in a stationary state, meaning the three-phase motor's speed is zero. Taking the motor control circuit used in an electric vehicle as an example, when the motor is stationary, the electric vehicle can be parked. The control system can be controlled based on the alternating current of the battery pack, and the flux variation of the three-phase motor can be adjusted within a certain range. The current frequency requirement is the frequency requirement of the heating current, which is also the frequency requirement of the alternating current flowing through the battery pack. After determining the frequency requirement of the heating current, the amplitude and action time of the required target voltage vector can be determined. The target base voltage vector, the zeroth vector, and the action time of the target unit vector required to synthesize the target voltage vector can then be calculated. The heating current frequency requirement can be reflected in the frequency requirement of the flux variation. When the required flux variation frequency is low, the action time of the target base voltage vector U7 can be increased. When the required flux variation frequency is high, the action time of the target base voltage vector U7 can be reduced, while the action time of the target unit vector can be increased. The target base voltage vector U7 can provide an alternating current (the current at the third terminal A of the three-phase motor) with a small amplitude to the battery pack.

[0088] Taking the target unit vectors U4 (100) and U6 (110) as an example, if the frequency of the flux change is small, the amplitude of the synthesized target voltage vector needs to be small, and the T vector in the direction of U4 (100) and U6 (110) is decomposed. x and T y Small, that is, the action time of the target unit vector is reduced, the time for the target unit vector to provide alternating current to the battery pack to heat the battery pack is reduced, and the heating effect is worse. However, the amplitude of the target basic voltage vector U7 is much smaller than the amplitude of U4 (100). For example, if the action time T of U4 (100) is x If the target basic voltage vector U7 is reduced by 1ms, the action time of the target basic voltage vector U7 will be increased by 1ms accordingly. The amplitude of the synthesized target voltage vector will be reduced, and the frequency of the flux change will be reduced. However, the total time for the excitation alternating current to cause the battery pack to generate heat will not change, and the heating effect will not change. If the frequency of the flux change is maintained unchanged, the amplitude of the synthesized target voltage vector needs to remain unchanged. At this time, the action time T of U4 (100) is xTo reduce it by 1ms, the action time of the target basic voltage vector U7 needs to be increased by 10ms accordingly. The total time for the battery pack to generate heat by stimulating the alternating current is greatly increased, thereby improving the heating effect.

[0089] Step 506 : synthesize the target voltage vector according to the action time of the target basic voltage vector, the target basic voltage vector, the zeroth vector, and the target unit vector.

[0090] The target voltage vector is synthesized by multiplying the target basic voltage vector by the action time of the target basic voltage vector, multiplying the zeroth vector by the action time of the zeroth vector, and multiplying the target unit vector by the action time of the target unit vector.

[0091] In this disclosed embodiment, when the motor is stationary, the duration of the target base voltage vector can be controlled based on the current flux variation frequency requirement, satisfying both low-frequency and high-frequency application scenarios. Furthermore, the synthesized target voltage vector can provide an alternating current to the battery pack at a relatively low amplitude. This ensures that the amplitude of the alternating current is maintained at a relatively low flux variation frequency, reducing motor noise and vibration.

[0092] In one embodiment, Figure 8 As shown, in step 204, according to the motor state, based on the target basic voltage vector, the zeroth vector and the target unit vector, synthesizing the target voltage vector may include:

[0093] Step 802: Take two unit voltage vectors adjacent to the target voltage vector as target unit vectors.

[0094] The two unit voltage vectors adjacent to the target voltage vector may be determined according to the synthesis requirement of the target voltage vector in an actual scenario.

[0095] Step 804, when the motor is in a rotating state and the voltage difference between the first battery pack and the second battery pack is zero, the target basic voltage vector replaces the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector; or, when the voltage difference between the first battery pack and the second battery pack is not zero, the coaxial voltage vector of the target basic voltage vector is determined, the target basic voltage vector and the coaxial voltage vector replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector.

[0096] Specifically, when the motor is in a rotating state, the electric vehicle can be in a driving state. When the three-phase motor has speed (frequency of flux change) and torque (amplitude of flux change) requirements, the control system can control the flux according to the operating requirements of the three-phase motor, and the alternating current of the battery pack can be adjusted.

[0097] When the speed and torque of the three-phase motor are determined, that is, when the flux change process is determined, if the voltage difference between the first battery pack E1 and the second battery pack E2 is zero, the target basic voltage vector U7 is a zero vector. The target basic voltage vector can be synthesized by using the target basic voltage vector U7 instead of the zeroth vector. In this case, the new zeroth vector is the target basic voltage vector U7. The target voltage vector can be synthesized by multiplying the target basic voltage vector by the target basic voltage vector action time, multiplying the target basic voltage vector by the action time of the original zeroth vector, and multiplying the target unit vector by the action time of the target unit vector.

[0098] Alternatively, if the voltage difference between the first battery pack E1 and the second battery pack E2 is not zero, the coaxial voltage vector of the target basic voltage vector U7 is determined. The coaxial voltage vector is a voltage vector in the same direction or opposite direction of the target basic voltage vector in the two-phase stationary coordinate system. Figure 3 As shown, the coaxial voltage vectors of the target basic voltage vector U7 are voltage vectors U3 (011) and U4 (100). That is, the target basic voltage vector U7, the coaxial voltage vector U3 (011) and the coaxial voltage vector U4 (100) can be used to replace the zero vector. At this time, the new zero vector is the combined vector of the target basic voltage vector U7, the coaxial voltage vector U3 (011) and the coaxial voltage vector U4 (100). The target basic voltage vector U7 is multiplied by the action time of the target basic voltage vector U7, the combined vector of the target basic voltage vector U7, the coaxial voltage vector U3 (011) and the coaxial voltage vector U4 (100) is multiplied by the action time of the original zero vector, and the target unit vector is multiplied by the action time of the target unit vector, and then added to synthesize the target voltage vector.

[0099] In the disclosed embodiment, the target base voltage vector U7 and / or the coaxial voltage vector are used to replace the original zeroth vector. The original zeroth vector U0(000) does not generate an alternating current in the battery pack. Compared to the zeroth vector U0(000), the target base voltage vector U7 generates an alternating current in the battery pack. In this case, the alternating current on the power supply side increases. When the electric vehicle is driving, the motor excites the alternating current to heat the battery, thereby increasing the amplitude of the alternating current in the battery.

[0100] The battery heating method provided in this application is based on the motor control circuit of two battery packs, proposes a new basic voltage vector, and develops a magnetic flux synthesis method based on the basic voltage vector, so that the magnetic flux can maintain the amplitude of the alternating current under lower frequency changes. It can work normally when the voltages of the two battery packs are the same or different, realizes low-frequency changes in the magnetic flux, and greatly reduces the noise and vibration of the motor.

[0101] It should be understood that, although the steps in the flowcharts of the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts of the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0102] Based on the same inventive concept, embodiments of the present application also provide a battery heating device for implementing the aforementioned battery heating method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more battery heating device embodiments provided below can be found in the aforementioned limitations of the battery heating method and will not be further elaborated here.

[0103] In one embodiment, Figure 9 As shown, the present application provides a battery heating device 900, which is applied to a motor control circuit. The motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, and a third bridge arm. The first end of the three-phase motor is connected to the first bridge arm, the second end of the three-phase motor is connected to the second bridge arm, and the third end of the three-phase motor is connected to the third bridge arm. The first bridge arm is connected to the first battery pack, and the second and third bridge arms are respectively connected to the second battery pack. The battery heating device 900 includes:

[0104] A basic vector determination module 902 is used to determine a target basic voltage vector, where the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off;

[0105] A target vector synthesis module 904 is configured to synthesize a target voltage vector based on a target base voltage vector, a zeroth vector, and a target unit vector according to a motor state;

[0106] The heating module 906 is configured to stimulate an alternating current of the battery pack based on the target voltage vector to heat the battery pack.

[0107] The battery heating device provided in the embodiment of the present application has a target base voltage vector whose amplitude is much smaller than the amplitudes of other traditional vectors. Therefore, increasing the action time of the target base voltage vector can reduce the amplitude of the target voltage vector, thereby reducing the amplitude of the flux change. This allows the flux to maintain the amplitude of the alternating current at a lower frequency, thereby achieving heating of the battery pack in the electric vehicle while suppressing motor noise and vibration.

[0108] In one embodiment, when the target basic voltage vector is applied to the motor control circuit, the voltage between the second terminal and the third terminal of the three-phase motor is zero.

[0109] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the voltage between the first and second terminals and the voltage between the first and third terminals of the three-phase motor are both the voltage difference between the first battery group and the second battery group.

[0110] In one embodiment, when the target basic voltage vector acts on the motor control circuit, the current of the first battery pack and the current of the second battery pack are both the same as the current of the first terminal of the three-phase motor.

[0111] In one embodiment, when the voltage difference between the first battery group and the second battery group is zero, the amplitude of the target basic voltage vector is zero; when the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the corresponding unit voltage vector when the upper bridge arm of the first bridge arm is turned on, the lower bridge arm of the second bridge arm and the lower bridge arm of the third bridge arm are turned on; when the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the corresponding unit voltage vector when the lower bridge arm of the first bridge arm is turned on, the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm are turned on.

[0112] In one embodiment, the target vector synthesis module 904 is further used to use two unit voltage vectors adjacent to the target voltage vector as the target unit vector; when the motor is in a stationary state, based on the current frequency requirement, determine the action time of the target basic voltage vector; and synthesize the target voltage vector according to the action time of the target basic voltage vector, the target basic voltage vector, the zeroth vector and the target unit vector.

[0113] In one embodiment, the target vector synthesis module 904 is also used to take two unit voltage vectors adjacent to the target voltage vector as the target unit vector; when the motor is in a rotating state, when the voltage difference between the first battery pack and the second battery pack is zero, the target basic voltage vector replaces the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector; or, when the voltage difference between the first battery pack and the second battery pack is not zero, the coaxial voltage vector of the target basic voltage vector is determined, the target basic voltage vector and the coaxial voltage vector replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector.

[0114] Each module in the battery heating device described above may be implemented in whole or in part through software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a computer device memory in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0115] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 10 As shown. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, it implements a battery heating method.

[0116] Those skilled in the art will understand that Figure 10 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0117] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0118] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0119] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0120] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0121] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A battery heating method, characterized in that: Applied to a motor control circuit, the motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, a third bridge arm, a battery pack, and a switching switch, the battery pack includes a first battery pack and a second battery pack connected in parallel, the first end of the three-phase motor is connected to the first bridge arm, the second end of the three-phase motor is connected to the second bridge arm, the third end of the three-phase motor is connected to the third bridge arm, the first bridge arm is connected to the first battery pack, and the second bridge arm and the third bridge arm are respectively connected to the second battery pack; the motor state of the three-phase motor includes a rotating state and a stationary state; wherein, during the heating process, the switching switch is in an off state, the first end of the switching switch is respectively connected to the positive electrode of the first battery pack and the upper bridge arm of the first bridge arm, the second end of the switching switch is respectively connected to the positive electrode of the second battery pack and the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm, and the method includes: Determine a target basic voltage vector, where the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off; synthesizing a target voltage vector based on the target base voltage vector, the zeroth vector, and the target unit vector according to the motor state; wherein two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector, and the zeroth vector indicates that the upper bridge arm of the first bridge arm is turned off and the lower bridge arm is turned on, the upper bridge arm of the second bridge arm is turned off and the lower bridge arm is turned on, and the upper bridge arm of the third bridge arm is turned off and the lower bridge arm is turned on; exciting an alternating current of a battery pack based on the target voltage vector to heat the battery pack; When the voltage difference between the first battery group and the second battery group is zero, the magnitude of the target basic voltage vector is zero; When the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the upper bridge arm of the first bridge arm being turned on and the lower bridge arm of the second bridge arm and the lower bridge arm of the third bridge arm being turned on; When the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the lower arm of the first bridge arm being turned on, the upper arm of the second bridge arm and the upper arm of the third bridge arm being turned on.

2. The method according to claim 1, characterized in that When the target basic voltage vector acts on the motor control circuit, the voltage between the second end and the third end of the three-phase motor is zero.

3. The method according to claim 2, characterized in that When the target basic voltage vector acts on the motor control circuit, the voltage between the first end and the second end of the three-phase motor and the voltage between the first end and the third end are both the voltage difference between the first battery group and the second battery group.

4. The method according to claim 3, characterized in that When the target basic voltage vector acts on the motor control circuit, the current of the first battery pack and the current of the second battery pack are both the same as the current of the first end of the three-phase motor.

5. The method according to claim 1, characterized in that The step of synthesizing a target voltage vector based on the target basic voltage vector, the zeroth vector, and the target unit vector according to the motor state includes: The two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector; When the motor is in a stationary state, determining the action time of the target basic voltage vector based on the current frequency requirement; The target voltage vector is synthesized according to the action time of the target basic voltage vector, the target basic voltage vector, a zeroth vector, and the target unit vector.

6. The method according to claim 1, wherein The step of synthesizing a target voltage vector based on the target basic voltage vector, the zeroth vector, and the target unit vector according to the motor state includes: The two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector; When the motor is in a rotating state and the voltage difference between the first battery pack and the second battery pack is zero, the target basic voltage vector is used to replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector, and the target unit vector; or When the voltage difference between the first battery pack and the second battery pack is not zero, the coaxial voltage vector of the target basic voltage vector is determined, the target basic voltage vector and the coaxial voltage vector are used to replace the zeroth vector, and the target voltage vector is synthesized by the target basic voltage vector, the new zeroth vector and the target unit vector.

7. A battery heating device, characterized in that: Applied to a motor control circuit, the motor control circuit includes a three-phase motor, a first bridge arm, a second bridge arm, a third bridge arm, a battery pack, and a switching switch, the battery pack includes a first battery pack and a second battery pack connected in parallel, the first end of the three-phase motor is connected to the first bridge arm, the second end of the three-phase motor is connected to the second bridge arm, the third end of the three-phase motor is connected to the third bridge arm, the first bridge arm is connected to the first battery pack, and the second bridge arm and the third bridge arm are respectively connected to the second battery pack; wherein, during the heating process, the switching switch is in an off state, the first end of the switching switch is respectively connected to the positive electrode of the first battery pack and the upper bridge arm of the first bridge arm, the second end of the switching switch is respectively connected to the positive electrode of the second battery pack and the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm, the device includes: a basic vector determination module, configured to determine a target basic voltage vector, wherein the target basic voltage vector is used to control the upper bridge arms of the first bridge arm, the second bridge arm, and the third bridge arm to be turned on and the lower bridge arms to be turned off; a target vector synthesis module, configured to synthesize a target voltage vector based on the target base voltage vector, a zeroth vector, and a target unit vector according to a driving state; wherein two unit voltage vectors adjacent to the target voltage vector are used as the target unit vector, and the zeroth vector indicates that the upper bridge arm of the first bridge arm is turned off and the lower bridge arm is turned on, the upper bridge arm of the second bridge arm is turned off and the lower bridge arm is turned on, and the upper bridge arm of the third bridge arm is turned off and the lower bridge arm is turned on; A heating module, used to stimulate the alternating current of the battery group based on the target voltage vector to heat the battery group; when the voltage difference between the first battery group and the second battery group is zero, the amplitude of the target basic voltage vector is zero; when the voltage of the first battery group is higher than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the first battery group and the second battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the upper bridge arm of the first bridge arm being turned on, the lower bridge arm of the second bridge arm and the lower bridge arm of the third bridge arm being turned on; when the voltage of the first battery group is lower than the voltage of the second battery group, the amplitude of the target basic voltage vector is proportional to the voltage difference between the second battery group and the first battery group, and the direction is the same as the direction of the unit voltage vector corresponding to the lower bridge arm of the first bridge arm being turned on, the upper bridge arm of the second bridge arm and the upper bridge arm of the third bridge arm being turned on.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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