Control method and system for battery self-heating and vehicle

Abstract

The invention relates to a control method and system for battery self-heating and a vehicle, and the method comprises the steps: a receiving step: receiving a self-heating request sent by a VCU under the condition that a self-heating condition is satisfied, the self-heating request being used for requesting a motor to heat a battery; and a control step: in response to the received self-heating request, the at least two inverters control the heating state of one of the at least two motors respectively, so that the at least two motors alternately heat the battery at a first frequency. Therefore, the self-heating of the battery can be realized in a simple and convenient manner, and the temperature of the rotor of a single motor can be prevented from being too high.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicles, and particularly to a control method and system for battery self-heating and a vehicle. Background Art

[0002] The battery of a vehicle may not be able to discharge in a low-temperature environment, resulting in the inability to use the battery. Therefore, in a low-temperature environment, it is necessary to pre-heat the battery before using it.

[0003] Please refer to Figure 1 , the electric vehicle battery self-heating system of related art 1 includes a first battery 400, a second battery 500, a motor inductor 100, and a motor controller 1000. The motor controller 1000 includes an inverter 200 and a control unit 300. The inverter 200 includes a first switching tube K1, a second switching tube K2, a third switching tube K3, a fourth switching tube K4, a fifth switching tube K5, and a sixth switching tube K6. The control unit 300 controls the duty cycle of the switching tubes K1-K6 in the inverter 200 within a preset period to generate a pulsed current between the first battery 400 and the second battery 500, so as to charge the battery with a smaller voltage through the battery with a larger voltage among the first battery 400 and the second battery 500, thereby increasing the temperature of the first battery 400 and the second battery 500.

[0004] Therefore, related art 1 uses the inductance of a single motor winding and an inverter to generate a high-frequency pulsed current between the first battery and the second battery, thereby realizing battery self-heating.

[0005] However, when a single motor is used for battery heating, in order to obtain heating power, the pulsed current flowing through the motor winding will increase. If the motor works in the heating mode for heating the battery for a long time, the temperature of the rotor of the motor will increase significantly, as Figure 3 shown, this will cause the temperature of the rotor to be too high, resulting in demagnetization. Moreover, due to the continuous current of the motor, it is difficult to increase the heating power and heating rate.

[0006] Please refer to Figure 2 , the energy conversion device of related art 2 includes: a battery 104, a first bus capacitor C1, a first motor controller 111, a first motor 112, a second bus capacitor C2, a second motor controller 121, a second motor 122, a switch K1, a switch K2, a switch K3, and a resistor R, and also includes a control module (not shown), which is used to obtain the current heating power and the target heating power of the battery 104; adjust the phase difference between the first PWM control signal and the second PWM control signal according to the current heating power and the target heating power to adjust the ripple current flowing through the battery 104, and realize the adjustment of the heating power of the battery 104.

[0007] Therefore, the related art 2 utilizes the inductances of the first motor 112 and the first motor controller 111, as well as the inductances of the second motor 122 and the second motor controller 121, to generate high-frequency pulsed current to heat the battery 104. By adjusting the phase positions of the two PWM signals, it is ensured that the two phases of the currents flowing from the two motors to the battery are the same and the battery 104 is heated simultaneously via the two motors.

[0008] That is to say, when the two motors work simultaneously, the phase positions of the two PWMs can be adjusted. However, it is difficult to control the angles when the two motors stop, so it is difficult to make the two phases of the currents flowing from the two motors to the battery the same. If the two motors operate in the heating mode for a long time, the temperature rise of the rotor will also be relatively high, as Figure 3 shown, which will cause the temperature of the rotor to be too high and thus lead to demagnetization. Moreover, the control algorithm for achieving the same phase and simultaneous heating is relatively complex.

[0009] Therefore, the battery heating method in the prior art has problems of complex algorithm and too high temperature of the rotor of a single motor. Summary of the Invention

[0010] In view of this, the present disclosure proposes a control method, a system and a vehicle for battery self-heating, which can not only achieve battery self-heating in a simple manner, but also avoid too high temperature of the rotor of a single motor.

[0011] According to a first aspect of the present disclosure, there is provided a control method for battery self-heating, which is applied to a vehicle. The vehicle includes a vehicle control unit (VCU), at least two motors, at least two inverters and a battery. One of the at least two inverters is used to control one of the at least two motors. The control method includes: a receiving step of receiving a self-heating request sent by the VCU when the self-heating condition is satisfied, where the self-heating request is used to request the motor to heat the battery; a control step of, in response to receiving the self-heating request, controlling the heating states of one of the at least two motors by the at least two inverters respectively, so that the at least two motors alternately heat the battery at a first frequency.

[0012] In a possible implementation manner, before the control step, it further includes: in response to receiving the self-heating request, the at least two inverters determine a total heating time period for heating the battery according to a heating power corresponding to the heating amount carried by the self-heating request; the at least two inverters determine the first frequency according to the total heating time period and the number of the at least two motors.

[0013] In a possible implementation, after determining the first frequency, the method further includes: comparing, by the at least two inverters, the cooling time of the motors they control with the heating time corresponding to the first frequency; if the heating time exceeds the cooling time, re-determining the first frequency according to the cooling time; if the heating time does not exceed the cooling time, maintaining the first frequency.

[0014] In a possible implementation, before the control step, the method further includes: in response to receiving the self-heating request, determining, by the at least two inverters, the heating current of the motors they control when heating the battery according to the heating power corresponding to the heating amount carried by the self-heating request; correspondingly, the control step includes: in response to receiving the self-heating request, controlling, by the at least two inverters respectively, the heating states of one of the at least two motors, so that the at least two motors heat the battery alternately at the first frequency according to the heating current.

[0015] In a possible implementation, when the number of the at least two inverters and the number of the at least two motors are both N, the control step includes: a first heating sub-step, in response to receiving the self-heating request, the first one of the at least two inverters controls the first one of the at least two motors corresponding to the first inverter to heat the battery within a first heating time corresponding to the first frequency, during which, the other inverters except the first inverter respectively control the other motors except the first motor not to heat the battery within the first heating time; and so on, an Nth heating sub-step, after the (N - 1)th heating time, the Nth one of the at least two inverters controls the Nth one of the at least two motors corresponding to the Nth inverter to heat the battery within the Nth heating time, during which, the other inverters except the Nth inverter respectively control the other motors except the Nth motor not to heat the battery within the Nth heating time, repeating the first heating sub-step, …, the Nth heating sub-step until the battery is heated to the target temperature, where N is a positive integer greater than or equal to 2.

[0016] In a possible implementation, when N is equal to 2, the at least two inverters include a first inverter and a second inverter, the at least two motors include a first motor and a second motor, and the control steps include: in response to receiving the self-heating request, the first inverter controls the first motor to heat the battery within a first heating time, during which the second inverter controls the second motor not to heat the battery within the first heating time; after the first heating time, the second inverter controls the second motor to heat the battery within a second heating time, during which the first inverter controls the first motor not to heat the battery within the second heating time; after the second heating time, the first inverter controls the first motor to heat the battery within a third heating time, during which the second inverter controls the second motor not to heat the battery within the third heating time; after the third heating time, the second inverter controls the second motor to heat the battery within a fourth heating time, during which the first inverter controls the first motor not to heat the battery within the fourth heating time; and so on, heating the battery alternately via the first motor and the second motor until the battery is heated to the target temperature.

[0017] In a possible implementation, when N is equal to 3, the at least two inverters include a first inverter, a second inverter, and a third inverter, the at least two motors include a first motor, a second motor, and a third motor, and the control steps include: in response to receiving the self-heating request, the first inverter controls the first motor to heat the battery within a first heating time. During this period, the second inverter controls the second motor not to heat the battery within the first heating time, and the third inverter controls the third motor not to heat the battery within the first heating time; after the first heating time has elapsed, the second inverter controls the second motor to heat the battery within a second heating time. During this period, the first inverter controls the first motor not to heat the battery within the second heating time, and the third inverter controls the third motor not to heat the battery within the second heating time; after the second heating time has elapsed, the third inverter controls the third motor to heat the battery within a third heating time. During this period, the first inverter controls the first motor not to heat the battery within the third heating time, and the second inverter controls the second motor not to heat the battery within the third heating time; after the third heating time has elapsed, the first inverter controls the first motor to heat the battery within a fourth heating time. During this period, the second inverter controls the second motor not to heat the battery within the fourth heating time, and the third inverter controls the third motor not to heat the battery within the fourth heating time; after the fourth heating time has elapsed, the second inverter controls the second motor to heat the battery within a fifth heating time. During this period, the first inverter controls the first motor not to heat the battery within the fifth heating time, and the third inverter controls the third motor not to heat the battery within the fifth heating time; after the fifth heating time has elapsed, the third inverter controls the third motor to heat the battery within a sixth heating time. During this period, the first inverter controls the first motor not to heat the battery within the sixth heating time, and the second inverter controls the second motor not to heat the battery within the sixth heating time; thus, the battery is alternately heated by the first motor, the second motor, and the third motor until the battery is heated to the target temperature.

[0018] According to a second aspect of the present disclosure, there is provided a control system for battery self-heating, which is applied to a vehicle. The control system includes: a battery; a vehicle control unit (VCU) configured to send a self-heating request for requesting heating of the battery via a motor when the vehicle is in a stopped state and the temperature of the battery is lower than a threshold; at least two motors; and at least two inverters configured to execute the above control method.

[0019] In a possible implementation, a part of the at least two motors and their corresponding part of the inverters are arranged on the front axle of the vehicle, and the remaining motors of the at least two motors and their corresponding remaining inverters are arranged on the rear axle of the vehicle.

[0020] In a possible implementation, all of the at least two motors and all of the at least two inverters are arranged on the front axle of the vehicle.

[0021] In a possible implementation, all of the at least two motors and all of the at least two inverters are arranged on the rear axle of the vehicle.

[0022] According to a third aspect of the present disclosure, there is provided a vehicle, which includes the above control system.

[0023] According to the control method, system and vehicle for battery self-heating of the present disclosure, in response to receiving a self-heating request sent by the VCU of the vehicle, at least two inverters of the vehicle respectively control one of the at least two motors of the vehicle to alternately heat the battery of the vehicle at a first frequency. Thus, during the period when one motor heats the battery, other motors stop heating the battery. Therefore, not only can the self-heating of the battery be achieved in a simple manner, but also the temperature of the rotor of a single motor can be prevented from being too high.

[0024] Compared with related art 1 in which a single motor heats the battery of the vehicle, the present disclosure alternately heats the battery via at least two motors. Therefore, the long-term operation of a single motor can be avoided, so that the temperature of the rotor of the single motor can be prevented from being too high, and further the demagnetization of the rotor can be avoided.

[0025] Compared with related art 2 which ensures the same phase of the currents flowing from two motors to the battery by adjusting the relative positions of two PWM signals and heats the vehicle battery via the two motors simultaneously, the present disclosure can heat the battery by controlling at least two motors to alternate at a first frequency, without achieving the same-phase and simultaneous-heating control in related art 2, nor making multiple motors heat the battery simultaneously as in related art 2. Therefore, the control algorithm of the present disclosure is relatively simple, and the present disclosure can avoid a motor running for a long time, thereby avoiding the overheating of the rotor of the motor, and further avoiding the demagnetization of the rotor.

[0026] Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are included in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the present disclosure and are used to explain the principles of the present disclosure.

[0028] Figure 1 is a schematic diagram of an electric vehicle self-heating system of related art 1.

[0029] Figure 2 is a circuit diagram of an energy conversion device of related art 2.

[0030] Figure 3 is a schematic diagram of the overheating of the rotor of a motor caused by heating the battery via a single motor.

[0031] Figure 4 is a flowchart of a control method for battery self-heating according to an embodiment of the present disclosure.

[0032] Figure 5 is a flowchart of a control method for battery self-heating according to an embodiment of the present disclosure.

[0033] Figure 6 is a schematic diagram of dual-motor alternating control according to an embodiment of the present disclosure.

[0034] Figure 7 is a block diagram of a control system for battery self-heating according to an embodiment of the present disclosure.

[0035] Figure 8 is a schematic diagram of the configuration of a dual-motor according to an embodiment of the present disclosure.

[0036] Figure 9 is a schematic diagram of the configuration of a dual-motor according to an embodiment of the present disclosure.

[0037] Figure 10It is a schematic diagram of the configuration of a dual-motor according to an embodiment of the present disclosure. Detailed implementation manners

[0038] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0039] The present disclosure provides a control method, system, and vehicle for battery self-heating. In response to receiving a self-heating request sent by the vehicle's VCU, at least two inverters of the vehicle respectively control one of at least two motors of the vehicle to alternately heat the vehicle's battery at a first frequency. Thus, during the period when one motor heats the battery, other motors stop heating the battery. Therefore, not only can the battery self-heating be achieved in a simple manner, but also the temperature of the rotor of a single motor can be prevented from being too high. In this way, the above technical problems to be solved by the present disclosure can be solved.

[0040] Based on the above concept, there is provided Figure 4 The flowchart of the control method for battery self-heating as shown. This control method can be applied to a vehicle, such as a new energy vehicle, including but not limited to an electric vehicle EV. The vehicle may include a vehicle control unit VCU, at least two motors, at least two inverters, and a battery. One of the at least two inverters is used to control one of the at least two motors. That is, each motor is controlled by a corresponding inverter. At least two motors and at least two inverters are used to drive the EV.

[0041] Please refer to Figure 4 , the control method of this embodiment may include the following steps:

[0042] In step S410 (corresponding to the receiving step), a self-heating request sent by the VCU when the self-heating condition is met is received. The self-heating request is used to request the motor to heat the battery.

[0043] In this embodiment, when the vehicle is in a stopped state and the temperature of the battery is lower than a threshold (such as -30 °C), the VCU sends a self-heating request for requesting to heat the battery via the motor to all inverters of the vehicle through the CAN bus. In a possible implementation manner, the self-heating request carries the heating amount required to raise the temperature of the battery to a target temperature (such as 20 °C). Accordingly, all inverters can receive this self-heating request.

[0044] In step S420 (corresponding to the control step), in response to receiving the self-heating request, the at least two inverters respectively control the heating states of one of the at least two motors to enable the at least two motors to alternately heat the battery at a first frequency.

[0045] In this embodiment, when each of at least two inverters receives a self-heating request sent by the VCU, each inverter controls its respective motor to be in a heating mode for heating the battery, and all the motors heat the battery alternately at a first frequency.

[0046] For example, assuming that the vehicle is equipped with 2 motors, within the time period T1 (T1 is equal to the reciprocal of the first frequency), the battery is heated via the first motor; within the time period T2 (T2 is equal to the reciprocal of the first frequency), the battery is heated via the second motor; within the time period T3 (T3 is equal to the reciprocal of the first frequency), the battery is heated via the first motor; within the time period T4 (T4 is equal to the reciprocal of the first frequency), the battery is heated via the second motor; within the time period T5 (T5 is equal to the reciprocal of the first frequency), the battery is heated via the first motor; within the time period T6 (T6 is equal to the reciprocal of the first frequency), the battery is heated via the second motor;...; and so on, until the battery is heated to the target temperature. Among them, within the time periods such as T1, T3, and T5 when the battery is heated via the first motor, the battery is not heated via the second motor; correspondingly, within the time periods such as T2, T4, and T6 when the battery is heated via the second motor, the battery is not heated via the first motor.

[0047] According to the control method for battery self-heating in this embodiment, in response to receiving a self-heating request sent by the VCU, at least two inverters respectively control one of at least two motors to heat the battery alternately at a first frequency. Thus, during the period when one motor heats the battery, other motors stop heating the battery. Therefore, at least two motors heat the battery independently of each other, and at least two motors alternately heat the battery and stop heating the battery. During the time period when heating the battery is stopped, the temperature of the rotor of this motor can be reduced. In this way, compared with Related Art 1 in which a single motor heats the battery and Related Art 2 in which two motors heat the battery simultaneously, this embodiment can effectively prevent the temperature of the rotor of this motor from being too high, thereby effectively avoiding rotor demagnetization.

[0048] In this embodiment, at least two inverters configured in the vehicle are used to respectively control one of at least two motors, so that these motors heat the battery alternately at a first frequency. Therefore, compared with adjusting the phase positions of two PWM signals in Related Art 2, the control method principle of this embodiment is simple, without a complex control algorithm, and it is more convenient to implement battery heating.

[0049] Therefore, not only can the self-heating of the battery be achieved in a simple manner, but also the temperature of the rotor of a single motor can be prevented from being too high.

[0050] Moreover, by repeatedly using at least two motors to heat the battery, the heating cost of the vehicle can be reduced.

[0051] In addition, since the low temperature of the rotor of the motor increases, the heating current can be increased, thereby increasing the heating power and further reducing the heating time. This will give users a better experience.

[0052] In a possible implementation, please refer to Figure 5 and before step S420, it may further include:

[0053] In step S430, in response to receiving the self-heating request, the at least two inverters determine the total heating time period for heating the battery according to the heating power corresponding to the heating amount carried in the self-heating request. Then, the at least two inverters determine the first frequency according to the total heating time period and the number of motors of the at least two motors.

[0054] In this embodiment, the self-heating request carries the heating amount required to raise the temperature of the battery to the target temperature. When receiving this self-heating request, each inverter can calculate the corresponding heating power according to this heating amount, and calculate the total heating time period required to heat the battery to the target temperature according to this heating power. Any suitable method in the prior art can be used for the calculation, and this embodiment will not elaborate on it.

[0055] After calculating the total heating time period, the total heating time period can be equally divided for all motors, and the reciprocal of the unit time after equal division is used as the first frequency. For example, assuming that the vehicle is equipped with N motors, the unit time is the total heating time period / N, and correspondingly, the first frequency is N / the total heating time period.

[0056] In this way, each inverter can respectively control each motor to alternately heat the battery at the first frequency.

[0057] In a possible implementation, please refer to Figure 5 and after step S430, it may further include:

[0058] In step S440, the at least two inverters compare the cooling time of the controlled motors with the heating time corresponding to the first frequency.

[0059] In step S450, if the heating time exceeds the cooling time, step S460 is executed; otherwise, step S420 is executed.

[0060] In step S460, the first frequency is re-determined according to the cooling time.

[0061] In this embodiment, when determining the first frequency, the cooling time of the motor is also introduced. The heating time corresponding to the first frequency calculated according to the heating power can be compared with the cooling time of the motor, and whether to adjust the first frequency determined in step S430 can be controlled according to the comparison result.

[0062] If the heating time does not exceed the cooling time, the first frequency is maintained; if the heating time exceeds the cooling time, the reciprocal of the cooling time is used as the first frequency to further avoid the temperature of the rotor of the motor from being too high.

[0063] In a possible implementation manner, before step S420, it further includes: in response to receiving the self-heating request, the at least two inverters determine the heating current of the motor controlled by the inverter when heating the battery according to the heating power corresponding to the heating amount carried by the self-heating request. Correspondingly, step S420 may include: in response to receiving the self-heating request, the at least two inverters respectively control the heating states of one of the at least two motors, so that the at least two motors alternately heat the battery at the first frequency according to the heating current.

[0064] In this embodiment, the self-heating request carries the heating amount required to raise the temperature of the battery to the target temperature. When receiving this self-heating request, each inverter can calculate the corresponding heating power according to this heating amount, and calculate the heating current of each motor when heating the battery according to this heating power. Any suitable method in the prior art can be used for the calculation, and this embodiment will not elaborate on it.

[0065] In this way, each inverter can respectively control each motor to alternately heat the battery at the first frequency according to the heating current.

[0066] In a possible implementation, when the number of the at least two inverters and the number of the at least two motors are both N, step S420 may include: a first heating sub-step, in response to receiving the self-heating request, the first inverter among the at least two inverters controls the first motor corresponding to the first inverter among the at least two motors to heat the battery within a first heating time corresponding to the first frequency. During this period, the other inverters except the first inverter respectively control the other motors except the first motor not to heat the battery within the first heating time; and so on. The Nth heating sub-step, after the (N - 1)th heating time, the Nth inverter among the at least two inverters controls the Nth motor corresponding to the Nth inverter among the at least two motors to heat the battery within the Nth heating time. During this period, the other inverters except the Nth inverter respectively control the other motors except the Nth motor not to heat the battery within the Nth heating time. The first heating sub-step, …, the Nth heating sub-step are repeated until the battery is heated to the target temperature, where N is a positive integer greater than or equal to 2.

[0067] In this embodiment, the battery is heated alternately by N motors. For example, within a time period T1, the battery is heated by the first motor; within a time period T2, the battery is heated by the second motor; …; within a time period TN, the battery is heated by the Nth motor; within a time period T(N + 1), the battery is heated by the first motor; within a time period T(N + 2), the battery is heated by the second motor; …; within a time period T(N + N), the battery is heated by the Nth motor; …; and so on, until the battery is heated to the target temperature.

[0068] Among them, within time periods such as T1 and T(N + 1) when the battery is heated by the first motor, the battery is not heated by the other motors except the first motor; correspondingly, within time periods such as T2 and T(N + 2) when the battery is heated by the second motor, the battery is not heated by the other motors except the second motor, and so on. Within time periods such as TN and T(N + N) when the battery is heated by the Nth motor, the battery is not heated by the other motors except the Nth motor.

[0069] In a possible implementation, when N is equal to 2, the at least two inverters include a first inverter and a second inverter, and the at least two motors include a first motor and a second motor. Step S420 may include:

[0070] In response to receiving the self-heating request, the first inverter controls the first motor to heat the battery within the first heating time. During this period, the second inverter controls the second motor not to heat the battery within the first heating time;

[0071] After the first heating time has elapsed, the second inverter controls the second motor to heat the battery within the second heating time. During this period, the first inverter controls the first motor not to heat the battery within the second heating time;

[0072] After the second heating time has elapsed, the first inverter controls the first motor to heat the battery within the third heating time. During this period, the second inverter controls the second motor not to heat the battery within the third heating time;

[0073] After the third heating time has elapsed, the second inverter controls the second motor to heat the battery within the fourth heating time. During this period, the first inverter controls the first motor not to heat the battery within the fourth heating time; and so on, the battery is heated alternately by the first motor and the second motor until the battery is heated to the target temperature.

[0074] Please refer to Figure 6 , the total heating time is 20 minutes, and the single heating time is 2 minutes. The vehicle is equipped with two motors, motor A serving as the first motor and motor B serving as the second motor. In response to receiving the self-heating request, under the control of two inverters corresponding to motor A and motor B, within the first 2 minutes, the battery is heated via motor A; within the second 2 minutes, the battery is heated via motor B; within the third 2 minutes, the battery is heated via motor A; within the fourth 2 minutes, the battery is heated via motor B; within the fifth 2 minutes, the battery is heated via motor A; within the sixth 2 minutes, the battery is heated via motor B; within the seventh 2 minutes, the battery is heated via motor A; within the eighth 2 minutes, the battery is heated via motor B; within the ninth 2 minutes, the battery is heated via motor A; within the tenth 2 minutes, the battery is heated via motor B. In this way, the heating time of both motor A and motor B is shortened from 20 minutes to 10 minutes, and the heating stops for 2 minutes every 2 minutes of heating.

[0075] Within the first two - minute period, the temperature of the rotor of motor A gradually rises as the heating time elapses. Within the second two - minute period, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the third two - minute period, the temperature of the rotor of motor A gradually rises as the heating time elapses. Within the fourth two - minute period, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the fifth two - minute period, the temperature of the rotor of motor A gradually rises as the heating time elapses. Within the sixth two - minute period, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the seventh two - minute period, the temperature of the rotor of motor A gradually rises as the heating time elapses. Within the eighth two - minute period, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the ninth two - minute period, the temperature of the rotor of motor A gradually rises as the heating time elapses. Within the tenth two - minute period, the temperature of the rotor of motor A gradually decreases as the heating time increases. The temperature curve of the rotor of motor B is similar to that of motor A and will not be elaborated here.

[0076] Every time motor A performs a two - minute heating process, it stops heating for two minutes. During these two minutes, the temperature of the rotor of motor A can drop to the temperature before the heating process. In this way, the temperature of the rotor of motor A can be effectively prevented from being too high. Similarly, the temperature of the rotor of motor B can also be effectively prevented from being too high.

[0077] In this embodiment, both motor A and motor B can independently implement the battery self - heating function. Motor A and motor B alternate between working and stopping. Both motor A and motor B can fully provide the heating power required by the battery. During the period when one of motor A and motor B stops heating, the temperature of the rotor of the motor that stops heating can decrease. This can effectively protect the rotor of the motor from having too high a temperature.

[0078] In a possible implementation, when N equals 3, the at least two inverters include the first inverter, the second inverter, and the third inverter, and the at least two motors include the first motor, the second motor, and the third motor. Step S420 may include:

[0079] In response to receiving the self - heating request, the first inverter controls the first motor to heat the battery within the first heating time. During this period, the second inverter controls the second motor not to heat the battery within the first heating time, and the third inverter controls the third motor not to heat the battery within the first heating time;

[0080] After the first heating time has elapsed, the second inverter controls the second motor to heat the battery during a second such heating time, during which the first inverter controls the first motor not to heat the battery during the second heating time, and the third inverter controls the third motor not to heat the battery during the second heating time;

[0081] After the second heating time has elapsed, the third inverter controls the third motor to heat the battery during a third such heating time, during which the first inverter controls the first motor not to heat the battery during the third heating time, and the second inverter controls the second motor not to heat the battery during the third heating time;

[0082] After the third heating time has elapsed, the first inverter controls the first motor to heat the battery during a fourth such heating time, during which the second inverter controls the second motor not to heat the battery during the fourth heating time, and the third inverter controls the third motor not to heat the battery during the fourth heating time;

[0083] After the fourth heating time has elapsed, the second inverter controls the second motor to heat the battery during a fifth such heating time, during which the first inverter controls the first motor not to heat the battery during the fifth heating time, and the third inverter controls the third motor not to heat the battery during the fifth heating time;

[0084] After the fifth heating time has elapsed, the third inverter controls the third motor to heat the battery during a sixth such heating time, during which the first inverter controls the first motor not to heat the battery during the sixth heating time, and the second inverter controls the second motor not to heat the battery during the sixth heating time;

[0085] In this way, the battery is alternately heated by the first motor, the second motor, and the third motor until the battery is heated to the target temperature.

[0086] For example, assume that the total heating time is 24 minutes and the single heating time is 2 minutes. The vehicle is equipped with three motors, namely motor A, motor B, and motor C, which are used as the first motor, the second motor, and the third motor respectively. In response to receiving a self-heating request, under the control of three inverters corresponding to motor A, motor B, and motor C, within the first 2 minutes, the battery is heated via motor A; within the second 2 minutes, the battery is heated via motor B; within the third 2 minutes, the battery is heated via motor C; within the fourth 2 minutes, the battery is heated via motor A; within the fifth 2 minutes, the battery is heated via motor B; within the sixth 2 minutes, the battery is heated via motor C; within the seventh 2 minutes, the battery is heated via motor A; within the eighth 2 minutes, the battery is heated via motor B; within the ninth 2 minutes, the battery is heated via motor C; within the tenth 2 minutes, the battery is heated via motor A; within the eleventh 2 minutes, the battery is heated via motor B; within the twelfth 2 minutes, the battery is heated via motor C. In this way, the heating time of both motor A and motor B is shortened from 22 minutes to 8 minutes. For every 2 minutes of heating, the heating stops for 4 minutes.

[0087] Within the first 2 minutes, the temperature of the rotor of motor A gradually increases as the heating time elapses. Within the second and third 2-minute periods, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the fourth 2 minutes, the temperature of the rotor of motor A gradually increases as the heating time elapses. Within the fifth and sixth 2-minute periods, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the seventh 2 minutes, the temperature of the rotor of motor A gradually increases as the heating time elapses. Within the eighth and ninth 2-minute periods, the temperature of the rotor of motor A gradually decreases as the heating time increases. Within the tenth 2 minutes, the temperature of the rotor of motor A gradually increases as the heating time elapses. Within the eleventh and twelfth 2-minute periods, the temperature of the rotor of motor A gradually decreases as the heating time increases. The temperature curves of the rotors of motor B and motor C are similar to that of motor A and will not be elaborated here.

[0088] For every 2 minutes of heating operation performed by motor A, the heating stops for 4 minutes. During these 4 minutes, the temperature of the rotor of motor A can be decreased to the temperature before the heating operation. In this way, the temperature of the rotor of motor A can be effectively prevented from being too high. Similarly, the temperature of the rotors of motor B and motor C can also be effectively prevented from being too high.

[0089] In this embodiment, motors A, B, and C can each independently achieve the function of battery self-heating. Motors A, B, and C alternate between working and stopping. Motors A, B, and C can all fully provide the heating power required by the battery. During the period when one of motors A, B, and C stops heating, the temperature of the rotor of the motor that stops heating can decrease. This can effectively protect the rotor of the motor from overheating.

[0090] Figure 7 FIG. is a block diagram of a control system for battery self-heating according to an exemplary embodiment. This embodiment provides a control system for battery self-heating. The control system can be applied to a vehicle, which can be, for example, a new energy vehicle.

[0091] Please refer to Figure 7 , the control system may include: a battery 720; a vehicle control unit VCU 710, configured to send a self-heating request for requesting heating of the battery via a motor when the vehicle is in a stopped state and the temperature of the battery is lower than a threshold; at least two motors 740; at least two inverters 730 for: receiving the self-heating request sent by the VCU when the self-heating condition is met, the self-heating request being used to request heating of the battery via a motor; in response to receiving the self-heating request, the at least two inverters respectively control the heating state of one of the at least two motors to cause the at least two motors to alternately heat the battery at a first frequency.

[0092] In a possible implementation, the at least two inverters 730 are configured to: in response to receiving the self-heating request, the at least two inverters determine a total heating time period for heating the battery according to a heating power corresponding to the heating amount carried by the self-heating request; the at least two inverters determine the first frequency according to the total heating time period and the number of motors of the at least two motors.

[0093] In a possible implementation, the at least two inverters 730 are configured to: compare the cooling time of the controlled motor with the heating time corresponding to the first frequency; if the heating time exceeds the cooling time, re-determine the first frequency according to the cooling time; if the heating time does not exceed the cooling time, maintain the first frequency.

[0094] In a possible implementation, at least two inverters 730 are configured to: in response to receiving the self-heating request, determine, according to the heating power corresponding to the heating amount carried by the self-heating request, the heating current of the motor controlled by the inverter when heating the battery; in response to receiving the self-heating request, respectively control the heating states of one motor in the at least two motors, so that the at least two motors alternately heat the battery at the first frequency according to the heating current.

[0095] In a possible implementation, when the number of the at least two inverters and the number of the at least two motors are both N, at least two inverters 730 are configured to perform the following steps: a first heating sub-step, in response to receiving the self-heating request, the first inverter in the at least two inverters controls the first motor corresponding to the first inverter in the at least two motors to heat the battery within a first heating time corresponding to the first frequency, during which, other inverters except the first inverter respectively control other motors except the first motor not to heat the battery within the first heating time; and so on, an Nth heating sub-step, after the (N - 1)th heating time, the Nth inverter in the at least two inverters controls the Nth motor corresponding to the Nth inverter in the at least two motors to heat the battery within the Nth heating time, during which, other inverters except the Nth inverter respectively control other motors except the Nth motor not to heat the battery within the Nth heating time, and repeat the first heating sub-step, …, the Nth heating sub-step until the battery is heated to a target temperature, where N is a positive integer greater than or equal to 2.

[0096] In a possible implementation, when N is equal to 2, the at least two inverters include a first inverter and a second inverter, the at least two motors include a first motor and a second motor, and the at least two inverters 730 are configured to: in response to receiving the self-heating request, the first inverter controls the first motor to heat the battery within a first heating time, during which the second inverter controls the second motor not to heat the battery within the first heating time; after the first heating time has elapsed, the second inverter controls the second motor to heat the battery within a second heating time, during which the first inverter controls the first motor not to heat the battery within the second heating time; after the second heating time has elapsed, the first inverter controls the first motor to heat the battery within a third heating time, during which the second inverter controls the second motor not to heat the battery within the third heating time; after the third heating time has elapsed, the second inverter controls the second motor to heat the battery within a fourth heating time, during which the first inverter controls the first motor not to heat the battery within the fourth heating time; and so on, heating the battery alternately via the first motor and the second motor until the battery is heated to the target temperature.

[0097] In a possible implementation, when N is equal to 3, the at least two inverters include a first inverter, a second inverter, and a third inverter, and the at least two motors include a first motor, a second motor, and a third motor. The at least two inverters 730 are configured to: in response to receiving the self-heating request, the first inverter controls the first motor to heat the battery within a first heating time. During this period, the second inverter controls the second motor not to heat the battery within the first heating time, and the third inverter controls the third motor not to heat the battery within the first heating time; after the first heating time has elapsed, the second inverter controls the second motor to heat the battery within a second heating time. During this period, the first inverter controls the first motor not to heat the battery within the second heating time, and the third inverter controls the third motor not to heat the battery within the second heating time; after the second heating time has elapsed, the third inverter controls the third motor to heat the battery within a third heating time. During this period, the first inverter controls the first motor not to heat the battery within the third heating time, and the second inverter controls the second motor not to heat the battery within the third heating time; after the third heating time has elapsed, the first inverter controls the first motor to heat the battery within a fourth heating time. During this period, the second inverter controls the second motor not to heat the battery within the fourth heating time, and the third inverter controls the third motor not to heat the battery within the fourth heating time; after the fourth heating time has elapsed, the second inverter controls the second motor to heat the battery within a fifth heating time. During this period, the first inverter controls the first motor not to heat the battery within the fifth heating time, and the third inverter controls the third motor not to heat the battery within the fifth heating time; after the fifth heating time has elapsed, the third inverter controls the third motor to heat the battery within a sixth heating time. During this period, the first inverter controls the first motor not to heat the battery within the sixth heating time, and the second inverter controls the second motor not to heat the battery within the sixth heating time; thus, the battery is alternately heated by the first motor, the second motor, and the third motor until the battery is heated to the target temperature.

[0098] In a possible implementation, a part of the at least two motors and their corresponding part of the inverters are arranged on the front axle of the vehicle, and the remaining motors of the at least two motors and their corresponding remaining inverters are arranged on the rear axle of the vehicle.

[0099] For example, assume that the vehicle is equipped with two motors, motor A and motor B, two inverters, inverter A and inverter B, and two gearboxes, gearbox A and gearbox B. Then, as Figure 8 shown, motor A, inverter A, and gearbox A are arranged on the front axle of the vehicle, and motor B, inverter B, and gearbox B are arranged on the rear axle of the vehicle.

[0100] In a possible implementation, all of the at least two motors and all of the at least two inverters are arranged on the front axle of the vehicle.

[0101] For example, assume that the vehicle is equipped with two motors, motor A and motor B, two inverters, inverter A and inverter B, and two gearboxes, gearbox A and gearbox B. Then, as Figure 9 shown, motor A, inverter A, gearbox A, motor B, inverter B, and gearbox B are all arranged on the front axle of the vehicle.

[0102] In a possible implementation, all of the at least two motors and all of the at least two inverters are arranged on the rear axle of the vehicle.

[0103] For example, assume that the vehicle is equipped with two motors, motor A and motor B, two inverters, inverter A and inverter B, and two gearboxes, gearbox A and gearbox B. Then, as Figure 9 shown, motor A, inverter A, gearbox A, motor B, inverter B, and gearbox B are all arranged on the rear axle of the vehicle.

[0104] This embodiment further provides a vehicle, which includes the above control system.

[0105] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0106] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A control method for battery self-heating, applied to a vehicle, characterized in that, the vehicle includes a vehicle control unit (VCU), at least two motors, at least two inverters, and a battery, and one of the at least two inverters is used to control one of the at least two motors, the control method includes: a receiving step of receiving a self-heating request sent by the VCU when the self-heating condition is met, where the self-heating request is used to request the motor to heat the battery; a control step of, in response to receiving the self-heating request, controlling the heating states of one motor in each of the at least two motors by the at least two inverters respectively, so that the at least two motors alternately heat the battery at a first frequency.

2. The control method according to claim 1, wherein Before the control step, it further includes: in response to receiving the self-heating request, the at least two inverters determine a total heating time period for heating the battery according to a heating power corresponding to the heating amount carried in the self-heating request; the at least two inverters determine the first frequency according to the total heating time period and the number of motors of the at least two motors.

3. The control method according to claim 2, wherein After determining the first frequency, it further includes: the at least two inverters compare the cooling time of the motors they control with the heating time corresponding to the first frequency; if the heating time exceeds the cooling time, the first frequency is re-determined according to the cooling time; if the heating time does not exceed the cooling time, the first frequency is maintained.

4. The control method according to claim 1, characterized in that, Before the control step, it further includes: in response to receiving the self-heating request, the at least two inverters determine a heating current when the motors they control heat the battery according to a heating power corresponding to the heating amount carried in the self-heating request, correspondingly, the control step includes: in response to receiving the self-heating request, the at least two inverters control the heating states of one motor in each of the at least two motors respectively, so that the at least two motors alternately heat the battery at the first frequency according to the heating current.

5. The control method according to any one of claims 1-4, characterized in that, when the number of both the at least two inverters and the at least two motors is N, the control step includes: a first heating sub-step of, in response to receiving the self-heating request, the first inverter among the at least two inverters controlling the first motor corresponding to the first inverter among the at least two motors to heat the battery within a first heating time corresponding to the first frequency, during which, other inverters except the first inverter respectively control other motors except the first motor not to heat the battery within the first heating time; and so on, The Nth heating sub-step, after the (N - 1)th heating time, the Nth inverter among the at least two inverters controls the Nth motor corresponding to the Nth inverter among the at least two motors to heat the battery within the Nth heating time. During this period, the other inverters except the Nth inverter respectively control the other motors except the Nth motor not to heat the battery within the Nth heating time. Repeat the 1st heating sub-step, …, the Nth heating sub-step until the battery is heated to the target temperature. Wherein, N is a positive integer greater than or equal to 2.

6. The control method according to claim 5, wherein When N is equal to 2, the at least two inverters include a 1st inverter and a 2nd inverter, the at least two motors include a 1st motor and a 2nd motor, and the control step includes: In response to receiving the self-heating request, the 1st inverter controls the 1st motor to heat the battery within the 1st heating time. During this period, the 2nd inverter controls the 2nd motor not to heat the battery within the 1st heating time. After the 1st heating time, the 2nd inverter controls the 2nd motor to heat the battery within the 2nd heating time. During this period, the 1st inverter controls the 1st motor not to heat the battery within the 2nd heating time. After the 2nd heating time, the 1st inverter controls the 1st motor to heat the battery within the 3rd heating time. During this period, the 2nd inverter controls the 2nd motor not to heat the battery within the 3rd heating time. After the 3rd heating time, the 2nd inverter controls the 2nd motor to heat the battery within the 4th heating time. During this period, the 1st inverter controls the 1st motor not to heat the battery within the 4th heating time. In this way, the battery is alternately heated by the 1st motor and the 2nd motor until the battery is heated to the target temperature.

7. The control method according to claim 5, characterized in that When N is equal to 3, the at least two inverters include a 1st inverter, a 2nd inverter and a 3rd inverter, the at least two motors include a 1st motor, a 2nd motor and a 3rd motor, and the control step includes: In response to receiving the self-heating request, the 1st inverter controls the 1st motor to heat the battery within the 1st heating time. During this period, the 2nd inverter controls the 2nd motor not to heat the battery within the 1st heating time, and the 3rd inverter controls the 3rd motor not to heat the battery within the 1st heating time. After the first heating time has elapsed, the second inverter controls the second motor to heat the battery during the second heating time. During this period, the first inverter controls the first motor not to heat the battery during the second heating time, and the third inverter controls the third motor not to heat the battery during the second heating time; After the second heating time has elapsed, the third inverter controls the third motor to heat the battery during the third heating time. During this period, the first inverter controls the first motor not to heat the battery during the third heating time, and the second inverter controls the second motor not to heat the battery during the third heating time; After the third heating time has elapsed, the first inverter controls the first motor to heat the battery during the fourth heating time. During this period, the second inverter controls the second motor not to heat the battery during the fourth heating time, and the third inverter controls the third motor not to heat the battery during the fourth heating time; After the fourth heating time has elapsed, the second inverter controls the second motor to heat the battery during the fifth heating time. During this period, the first inverter controls the first motor not to heat the battery during the fifth heating time, and the third inverter controls the third motor not to heat the battery during the fifth heating time; After the fifth heating time has elapsed, the third inverter controls the third motor to heat the battery during the sixth heating time. During this period, the first inverter controls the first motor not to heat the battery during the sixth heating time, and the second inverter controls the second motor not to heat the battery during the sixth heating time; In this way, the battery is alternately heated by the first motor, the second motor, and the third motor until the battery is heated to the target temperature.

8. A control system for battery self-heating, applied to a vehicle, characterized in that: The control system includes: A battery; A vehicle control unit VCU for sending a self-heating request for requesting a motor to heat the battery when the vehicle is in a stopped state and the temperature of the battery is lower than a threshold; At least two motors; At least two inverters for performing the control method according to any one of claims 1-7.

9. The control system according to claim 8, wherein A part of the at least two motors and their corresponding part of the inverters are arranged on the front axle of the vehicle, and the remaining motors of the at least two motors and their corresponding remaining inverters are arranged on the rear axle of the vehicle; Or All of the at least two motors and all of the at least two inverters are arranged on the front axle of the vehicle; or All of the at least two motors and all of the at least two inverters are arranged on the rear axle of the vehicle.

10. A vehicle, comprising the control system according to claim 8 or 9.

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