Battery heating method of vehicle, battery heating system, vehicle and terminal device

Abstract

The application discloses a battery heating method, a battery heating system, a vehicle and a terminal device of the vehicle, the vehicle comprising a battery, a motor and an inverter, one end of the inverter being connected to a first end of the battery, the other end of the inverter being connected to a second end of the battery, the inverter comprising at least two-phase bridge arms, the motor comprising at least two-phase coils, the motor being connected to the inverter, each-phase coil being connected to a middle point between an upper bridge arm and a lower bridge arm of a corresponding one-phase bridge arm, and the method comprising: determining a target phase difference for controlling the at least two-phase bridge arms to be out of phase and to be turned on based on a heating requirement of the battery and a working state of the inverter; and controlling the at least two-phase bridge arms according to the target phase difference, so that the at least two-phase coils generate heat matching the heating requirement to heat the battery. By using the application, the heat generated by the motor during battery charging can be used to heat the battery, the circuit structure is simple, energy loss is small, and charging cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and in particular to a battery heating method of a vehicle, a battery heating system, a vehicle and a terminal device. BACKGROUND

[0002] With the development of the automobile industry, automobiles powered by power batteries are gradually becoming common. In the use of power battery automobiles, the power batteries need to be charged.

[0003] The present application relates to the technical field of power electronics, and in particular to a battery heating method of a vehicle, a battery heating system, a vehicle and a terminal device. SUMMARY

[0004] The present application provides a battery heating method of a vehicle, a battery heating system, a vehicle and a terminal device, which can utilize the heat generated by the motor during battery charging to heat the battery, has a simple circuit structure, low energy consumption and low charging cost.

[0005] The present application provides a battery heating method of a vehicle, a battery heating system, a vehicle and a terminal device, which can utilize the heat generated by the motor during battery charging to heat the battery, has a simple circuit structure, low energy consumption and low charging cost.

[0006] Based on the heating requirement of the battery and the working state of the inverter, a target phase difference for controlling the out-of-phase conduction of the at least two phase legs is determined.

[0007] The at least two phase legs are controlled according to the target phase difference, so that the at least two coils generate heat that matches the heating requirement and heats the battery.

[0008] In some possible implementations, the working state of the inverter includes the switching frequency of the at least two phase legs and the duty cycle corresponding to the at least two phase legs, and the duty cycle is used to represent the ratio of the conduction time of the phase leg to the switching period of the phase leg.

[0009] The target phase difference for controlling the out-of-phase conduction of the at least two phase legs is determined by the heating requirement of the battery, the switching frequency of the at least two phase legs and the duty cycle corresponding to the at least two phase legs.

[0010] In some possible implementation manners, the duty cycles corresponding to the at least two phase arms are determined according to a charging voltage required by the battery charging and an input voltage of the inverter.

[0011] In some possible implementation manners, before the target phase difference for controlling the at least two phase arms to conduct in a phase opposition manner is determined based on the heating requirement of the battery and the working state of the inverter, the method further includes:

[0012] controlling the at least two phase arms according to the duty cycles corresponding to the at least two phase arms and the initial phase difference for controlling the at least two phase arms to conduct in a phase opposition manner.

[0013] The initial phase difference is determined according to the heating requirement of the battery, a switching frequency of the at least two phase arms in the inverter, and the duty cycles corresponding to the at least two phase arms.

[0014] In some possible implementation manners, after the at least two phase arms are controlled according to the target phase difference to generate heat matching the heating requirement for heating the battery, the method further includes:

[0015] obtaining a relevant parameter when the battery is heated, to update the heating requirement of the battery, and re-executing the operation of determining the target phase difference for controlling the at least two phase arms to conduct in a phase opposition manner based on the heating requirement of the battery and the working state of the inverter.

[0016] In some possible implementation manners, after the at least two phase arms are controlled according to the target phase difference to generate heat matching the heating requirement for heating the battery, the method further includes:

[0017] obtaining a current flowing through the battery;

[0018] when the current exceeds a current threshold, updating the duty cycles corresponding to the at least two phase arms based on the current, and re-executing the operation of determining the target phase difference for controlling the at least two phase arms to conduct in a phase opposition manner based on the heating requirement of the battery, the switching frequency of the at least two phase arms, and the duty cycles corresponding to the at least two phase arms.

[0019] Another aspect of the embodiments of the present application provides a terminal device, including a processor, a memory, and a network interface.

[0020] The processor is connected to the memory and the network interface, the network interface is configured to provide a data communication function, the memory is configured to store program code, and the processor is configured to execute the program code to perform the battery heating method of the vehicle.

[0021] The vehicle battery heating system comprises a battery, a motor, an inverter and a heat transfer pipeline, one end of the inverter is connected to a first end of the battery, the other end of the inverter is connected to a second end of the battery, the inverter comprises at least two phase arms, the motor comprises at least two phase coils, the motor is connected to the inverter, each phase coil is connected to a middle point between an upper arm and a lower arm of a corresponding phase arm, one end of the heat transfer pipeline is connected to the motor, and the other end of the heat transfer pipeline is connected to the battery.

[0022] The heat transfer pipeline is used for transferring heat generated by the motor during operation to the battery to heat the battery.

[0023] The vehicle battery heating system is used to implement the vehicle battery heating method.

[0024] In some possible implementation manners, the vehicle battery heating system further comprises a direct current power supply, the direct current power supply is connected to the battery through the motor and the inverter.

[0025] The direct current power supply is used for supplying power to the motor and the inverter.

[0026] In some possible implementation manners, the vehicle battery heating system further comprises an inductor, the inductor is connected between the direct current power supply and the motor.

[0027] Another aspect of the embodiment of the application provides a vehicle, which comprises a load and the vehicle battery heating system.

[0028] In the application, the target phase difference for controlling the out-of-phase conduction of the at least two phase arms of the inverter can be determined according to the heating demand of the battery and the working state of the inverter, and the at least two phase arms of the inverter are controlled according to the target phase difference, so that the at least two phase coils of the motor generate heat matching the heating demand of the battery to heat the battery. Therefore, the vehicle battery heating method can utilize the heat generated by the motor during the battery charging process of the vehicle to heat the battery, the circuit structure is simple, the energy loss is small, and the charging cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings that can be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a structural schematic diagram of a battery heating system of a vehicle provided by an embodiment of the present application;

[0031] Figure 2 is a circuit schematic diagram of a battery heating system of a vehicle provided by an embodiment of the present application;

[0032] Figure 3 is a flow schematic diagram of a battery heating method of a vehicle provided by an embodiment of the present application;

[0033] Figure 4 is a three-phase control signal waveform schematic diagram provided by an embodiment of the present application;

[0034] Figure 5 is a current schematic diagram flowing through a three-phase inverter provided by an embodiment of the present application;

[0035] Figure 6 is a flow schematic diagram of another battery heating method of a vehicle provided by an embodiment of the present application;

[0036] Figure 7 is a structural schematic diagram of a vehicle provided by an embodiment of the present application;

[0037] Figure 8 is a structural schematic diagram of a terminal device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of the present application.

[0039] For the convenience of understanding, first, some nouns are simply explained as follows:

[0040] 1. Motor, also known as electric motor, is an alternating current motor driven by alternating current. If it is a three-phase alternating current motor, when three-phase stator windings (each phase is 120 degrees of electrical angle) of the motor are connected to three-phase alternating current, a rotating magnetic field will be generated, which cuts the rotor winding to generate electricity. The above three-phase alternating current motor can include three-phase synchronous motor and three-phase asynchronous motor.

[0041] 2、Inverter, is a high-power inverter power supply for electric power, if it is a three-phase inverter, its main function is to convert DC into three-phase AC, so as to control the operation of the motor. The basic components of inverter include semiconductor devices, drive circuit, filter, etc. Its working principle is to convert DC into AC by controlling the switching state of inverter bridge. Inverter can use CPU control, can output high quality, intelligent, can have the function of voltage stabilization, voltage rise.

[0042] 3、Drive control circuit, which can be used to control the operation of the inverter, including microprocessor, sensor and drive circuit, etc. Among them, microprocessor can detect voltage and current through sensor, and send corresponding control signal to adjust the working state of inverter.

[0043] Please refer to Figure 1 , Figure 1 is a structural diagram of the battery heating system of the vehicle provided by the embodiment of the application. The battery heating system of the vehicle includes a battery, a motor, an inverter and a heat transfer pipeline. In some possible embodiments, the heat transfer pipeline can be a motor oil cooling system or a motor rotor shaft water cooling system, or other devices that can dissipate heat from the motor rotor. For the sake of description, the motor oil cooling system is taken as an example for description. The motor includes at least two-phase coils, for example, a two-phase AC motor, a three-phase AC motor, etc. Taking a three-phase AC motor as an example, it can be a three-phase four-wire device, for example, a permanent magnet synchronous motor, an asynchronous motor, an electrically excited motor or other motors. For the sake of description, the embodiment of the application takes a three-phase AC motor as an example for description. It should be noted that the three-phase AC motor can include three-phase coils and a neutral line, and the neutral line (also referred to as neutral line N) can be led out from the midpoint of the three-phase coils. The neutral line can be connected in series between the switch and the inductor, thereby forming a connection circuit of the three-phase AC motor. The inverter includes at least two-phase bridge arms, that is, at least two-phase inverter, for example, a three-phase inverter, a four-phase inverter, etc. For the sake of description, the embodiment of the application takes a three-phase inverter as an example for description. In some possible embodiments, the battery heating system of the vehicle can include a drive control circuit, which can be connected to the battery, the inverter and the motor, thereby realizing the functions of detecting related parameters during battery heating, controlling the inverter and the motor, etc. The specific connection mode of the drive control circuit can be determined according to the actual application scenario, in addition, the functions of detecting related parameters during battery heating and controlling the inverter and the motor can also be realized by a controller or other devices, which are not limited in the application, and only the drive control circuit is taken as an example for description. In some possible embodiments, the battery heating system of the vehicle can also include a DC power supply. The DC power supply can be connected to the motor, and the voltage can be converted through the inverter connected to the motor, thereby charging the battery.

[0044] For ease of description, see Figure 2 , Figure 2 is a circuit schematic diagram of a battery heating system of a vehicle provided by an embodiment of the present application. As shown in Figure 2 , taking a three-phase alternating current motor as the motor and a three-phase inverter as the inverter as examples, one end of the inverter is connected to a first end of the battery, the other end of the inverter is connected to a second end of the battery, the motor is connected to the inverter, each phase coil is connected to a middle point between an upper bridge arm and a lower bridge arm of a corresponding phase bridge arm, one end of the heat transfer pipeline is connected to the motor, and the other end of the heat transfer pipeline is connected to the battery. In some possible embodiments, a drive control circuit is connected to the motor and the inverter. It can be understood that the battery heating system of the vehicle can be applied to an application scenario of heating the battery when the battery is charging, or can be applied to other application scenarios of heating by using heat generated when the three-phase alternating current motor works. For ease of description, the present application does not limit this, and only takes the heating application scenario of the battery charging as an example for description.

[0045] Please also refer to Figure 1The target phase difference for controlling the out-of-phase conduction of the bridge arms of the three-phase inverter is determined by the heating requirement of the battery and the working state of the three-phase inverter, wherein the working state of the three-phase inverter can include the switching frequency of the three-phase bridge arms and the duty cycle corresponding to the three-phase bridge arms. It should be noted that the duty cycle can be used to represent the ratio of the conduction time of the bridge arm to the switching period of the bridge arm. The drive control circuit can adjust the target phase difference for controlling the out-of-phase conduction of the three-phase bridge arms of the three-phase inverter according to the heating requirement of the battery, the switching frequency of the three-phase bridge arms and the duty cycle corresponding to the three-phase bridge arms. It should be noted that the drive control circuit can send a control signal to the inverter based on the target phase difference, thereby controlling the out-of-phase conduction of at least two phase bridge arms of the inverter. The control signal can be a three-phase control signal in the three-phase inverter. It can be understood that the heating requirement of the battery can be obtained according to the temperature detected by the battery during charging. The battery heating system of the vehicle heats the battery according to the heating requirement, and can heat the battery to a target temperature. The switching frequency of the three-phase bridge arms of the three-phase inverter can be obtained according to the device performance of the three-phase inverter. Different three-phase inverters can match different switching frequencies, and the present application does not limit the switching frequency, but the switching frequency should not exceed the maximum switching frequency of the three-phase inverter to avoid damaging the three-phase inverter. The duty cycle corresponding to the three-phase bridge arms can be calculated according to the charging voltage required by the battery during charging and the input voltage of the three-phase inverter, wherein the charging voltage can be a boost voltage. The drive control circuit can convert the input voltage to the charging voltage based on the duty cycle corresponding to the three-phase bridge arms. Further, the drive control circuit can adjust the target phase difference for controlling the out-of-phase conduction of the three-phase bridge arms by the heating requirement of the battery, the switching frequency of the three-phase bridge arms in the three-phase inverter and the duty cycle corresponding to the three-phase bridge arms, thereby adjusting the three-phase control signal. It can be understood that the target phase difference can be used to control the delay time of the three phases in the three-phase AC motor, so that the three phases can be output out of position.

[0046] In some possible embodiments, the drive control circuit can also be configured to control the three-phase inverter and the three-phase AC motor to adjust heat generated by the three-phase AC motor based on the adjusted three-phase control signal. Specifically, the three-phase control signal can control the three-phase AC motor to output pulse signals to the three-phase bridge arms of the three-phase inverter according to the target phase difference. Further, the drive control circuit can adjust the duty cycle of the pulse signals through the three-phase control signal, and thus realize a voltage conversion operation through the three-phase inverter and the three-phase AC motor. It should be noted that the duty cycle of the pulse signals is the same as the duty cycle value corresponding to the three-phase bridge arms. It can be understood that the voltage conversion operation can be a voltage increasing operation, a voltage decreasing operation, or a constant voltage operation, which should be determined according to an actual application scenario, and the present application does not make any limitation herein, and only the voltage increasing operation is taken as an example for illustration. During the process of increasing the voltage of the battery, the drive control circuit can control the switching frequency of the three-phase bridge arms and the duty cycle corresponding to the three-phase bridge arms to adjust the target phase difference of the out-of-phase phases, and thus adjust the air gap harmonic content of the three-phase AC motor, so as to adjust the heat generated by the motor rotor of the three-phase AC motor, that is, the heat generated by the three-phase AC motor during operation.

[0047] In some possible embodiments, as shown in Figure 2 the heat generated by the three-phase AC motor during operation can be transmitted to the battery through a heat transfer pipeline. Specifically, the heat transfer pipeline can absorb the heat of the three-phase AC motor, and transmit the heat to the battery to provide heat for the battery with a lower temperature. When the heat transfer pipeline passes through the three-phase AC motor again after cooling, the heat transfer pipeline can also absorb the heat of the three-phase AC motor with a higher temperature, and thus realize cyclic heat transfer.

[0048] In some possible embodiments, the drive control circuit can output the three-phase control signal with the duty cycle and the initial phase difference to the three-phase inverter, and thus control the three-phase inverter and the three-phase AC motor through the three-phase control signal. The initial phase difference can be determined according to the heating requirement of the battery, the switching frequency of the three-phase bridge arms in the three-phase inverter, and the duty cycle corresponding to the three-phase bridge arms, and can be used to control the initial value of the out-of-phase phases of the three-phase bridge arms, and thus control the initial lag time of the pulse signals of each phase output by the three-phase AC motor.

[0049] Please also refer to Figure 1In some possible implementation manners, the driving control circuit can acquire the related parameters of the battery during the battery heating process multiple times, and then update the heating demand of the battery. The related parameters can be temperature, heating time, etc., which are not limited in the present application. It can be understood that the heating demand of the battery changes as the heating operation proceeds, for example, when the temperature of the battery rises, the heating demand decreases, so the driving control circuit can detect the change of the heating demand of the battery, and after updating the heating demand, the operation of determining the target phase difference for controlling the out-of-phase conduction of the at least two phase legs based on the heating demand of the battery and the working state of the inverter is re-executed, and then the heating power of the three-phase AC motor can be adjusted based on the three-phase control signal, so as to avoid damage to the device caused by excessive heating temperature. Optionally, since the current size also generates heat, the driving control circuit can also detect the current size flowing through the battery, and when the current size exceeds the current threshold, the duty cycle corresponding to the three-phase bridge arm is updated based on the current size to obtain the control signal after the duty cycle is updated. Further, the driving control circuit can re-execute the operation of adjusting the target phase difference corresponding to the three-phase bridge arm of the three-phase inverter based on the heating demand of the battery, the switching frequency of the three-phase bridge arm and the duty cycle of the three-phase bridge arm, so as to adjust the heating power of the three-phase AC motor. It should be noted that the frequency of detecting the battery temperature or the current size by the driving control circuit can be determined according to the actual application scenario, for example, it can be set to detect once every certain period of time, such as once every minute, or it can be set to continuously detect, and when the heating demand of the battery changes or the current size exceeds the current threshold, the heating power of the three-phase AC motor is adjusted, which is not limited in the present application.

[0050] Please refer to Figure 2 In some possible implementation manners, the battery heating system of the vehicle can further include a direct-current power supply. The direct-current power supply can be a direct-current charging pile, a dry cell, a storage battery, a direct-current generator or the like, which can supply power to the battery heating system of the vehicle, which is not limited in the present application. For the convenience of description, only the direct-current charging pile is taken as an example to describe the direct-current power supply. The direct-current power supply can be connected with the three-phase AC motor, and then power supply for the working of the three-phase AC motor and the three-phase inverter is provided through the connection between the three-phase AC motor and the three-phase inverter. The three-phase AC motor and the three-phase inverter can perform voltage conversion according to the input voltage of the direct-current power supply, and then obtain the charging voltage required for battery charging to supply power to the battery.

[0051] Please refer to Figure 2In some possible implementation manners, the battery heating system of the vehicle can further include an inductor, and the inductor can be connected to the direct-current power supply and the three-phase alternating-current motor. It should be noted that the inductors in the three-phase coils of the three-phase alternating-current motor are connected in parallel, and the total inductance is small when the inductors are used in parallel, and the mutual inductance between the inductors can cause the total inductance to be small. Therefore, the inductance required by the battery heating system of the vehicle can be compensated by connecting an external inductor in series, so as to prevent the peak-to-peak values of the three-phase current and the charging current from being too large in the charging process due to insufficient inductance, and thus the stability of the system can be maintained. It can be understood that if the inductance of the three-phase alternating-current motor and other devices meets the inductance required by the battery heating system of the vehicle, the inductor can not be connected in series.

[0052] Further referring to Figure 2 In some possible implementation manners, the battery heating system of the vehicle can further include a switch, which can be connected in series between the direct-current power supply and the three-phase alternating-current motor, or connected in series between the positive electrode of the three-phase inverter and the positive electrode of the battery, or connected in series between the negative electrode of the three-phase inverter and the negative electrode of the battery, or connected in series between the three-phase inverter and the direct-current power supply. The present application does not limit the connection mode. The three-phase alternating-current motor can be connected to the switch through the neutral line, so that the connection between the neutral line and the direct-current power supply can be cut off by the switch in the case that charging is not required (for example, when the vehicle is normally running), and the charging connection can be cut off in the case that an abnormality or a fault occurs in the charging process, so as to ensure the safety of vehicle charging and the stability of the battery heating system of the vehicle.

[0053] Further referring to Figure 2 In some possible implementation manners, the battery heating system of the vehicle can further include a capacitor, which can be connected in parallel to the direct-current power supply or connected in parallel to the battery. The specific connection mode can be determined according to the actual application scenario, and the present application does not limit the connection mode.

[0054] In the present application, the target phase difference for controlling the out-of-phase conduction of the at least two-phase bridge arms of the inverter can be determined according to the heating requirement of the battery and the working state of the inverter, and the at least two-phase bridge arms of the inverter can be controlled according to the target phase difference, so that the at least two-phase coils of the motor generate heat matching the heating requirement of the battery to heat the battery. Therefore, the battery heating method of the vehicle can utilize the heat generated by the motor in the battery charging process of the vehicle to heat the battery, and the circuit structure is simple, the energy loss is small, and the charging cost is low.

[0055] Further referring to Figure 3 , Figure 3 is a flowchart of the battery heating method of the vehicle provided in the embodiments of the present application. The battery heating method of the vehicle provided in the present application can be applied to the battery heating system of the vehicleFigure 1 and Figure 2 The battery heating system of the vehicle in the corresponding embodiment can include a battery, a motor, an inverter, and a heat transfer pipeline, and in some possible implementation manners, the battery heating system of the vehicle can further include a drive control circuit for detecting relevant parameters in the battery charging process and controlling the motor and the inverter to work. For ease of description, the following will take the drive control circuit as the execution subject, the three-phase alternating current motor as the motor, and the three-phase inverter as the inverter as examples for description. As shown in Figure 3 The battery heating method of the vehicle provided in the application can include the following steps:

[0056] Step S101, determining a target phase difference for controlling the out-of-phase conduction of the at least two phase arms based on the heating requirement of the battery and the working state of the inverter.

[0057] In some possible implementation manners, the drive control circuit can determine the target phase difference for controlling the out-of-phase conduction of the at least two phase arms of the inverter according to the heating requirement of the battery and the working state of the inverter. Taking the three-phase inverter as an example, the working state of the three-phase inverter can be determined by the switching frequency of each phase arm in the three-phase inverter and the duty cycle corresponding to the three-phase arms, and the target phase difference for controlling the out-of-phase conduction of the three-phase arms can be determined by the heating requirement of the battery, the switching frequency of the three-phase arms in the three-phase inverter, and the duty cycle corresponding to the three-phase arms. Specifically, the drive control circuit can detect the temperature of the battery to obtain the heating requirement of the battery, and then adjust the target phase difference for controlling the out-of-phase conduction of the three-phase arms by the heating requirement, the switching frequency of the three-phase arms in the three-phase inverter, and the duty cycle corresponding to the three-phase arms, to determine the target phase difference that can adapt to the battery, the three-phase alternating current motor, and the three-phase inverter. The three-phase control signal is transmitted by the drive control circuit to the three-phase inverter, and can be used as a control signal for indicating the working of the three-phase inverter and the three-phase alternating current motor. It can be understood that the control signal for the three-phase inverter is the three-phase control signal, and if the control signal is for a two-phase inverter, it should be a two-phase control signal. The control signal should be determined according to the number of phase arms of the inverter selected in the actual application scenario.

[0058] For ease of understanding, the battery heating method flow of the vehicle in the embodiments of the application is described in detail. Please refer to Figure 6 , Figure 6 is another battery heating method flow of the vehicle provided in the embodiments of the application. As shown in Figure 6As shown, in the actual application debugging stage of the battery heating system, the drive control circuit can determine the switching frequency of the three-phase inverter according to the device parameters of the three-phase inverter, and obtain the heating demand of the battery. Then, the step of determining the period value can be performed, that is, the period value of the pulse signal flowing through the three-phase inverter is calculated through the switching frequency. Then, the drive control circuit can perform the operation of determining the duty cycle, that is: the drive control circuit can calculate the conduction time required for converting the input voltage into the charging voltage according to the input voltage of the three-phase inverter and the required charging voltage of the battery, and calculate the ratio of the conduction time to the period value to obtain the duty cycle. The waveform diagram of the three-phase control signal can be seen together Figure 4 , Figure 4 is a three-phase control signal waveform diagram provided by the embodiment of the application. As shown in Figure 4 , the three-phase control signal realizes delayed input of different phase bridge arms of the three-phase inverter according to the target phase difference, for example, the first waveform from left to right is the waveform of the three-phase control signal input to the first three-phase bridge arm of the three-phase inverter, the second waveform is the waveform of the three-phase control signal input to the second three-phase bridge arm of the three-phase inverter, the third waveform is the waveform of the three-phase control signal input to the third three-phase bridge arm of the three-phase inverter, and the fourth waveform is the waveform of the three-phase control signal input to the first three-phase bridge arm of the three-phase inverter in the second period, and so on. Among them, the first waveform, the second waveform and the third waveform can be the first period, the fourth waveform, the fifth waveform and the sixth waveform can be the second period, and so on, which will not be repeated here.

[0059] Further, the drive control circuit can obtain the target phase difference of the three-phase bridge arm mis-phase conduction based on the heating demand, the switching frequency and the duty cycle.

[0060] It should be noted that in some possible embodiments, before charging and heating the battery, the parameters of the drive control circuit can be determined first. Please refer to Figure 6 , as shown in Figure 6 , in the parameter determination stage, after ensuring that the lines between the devices of the drive control circuit are normally connected (this operation can also be referred to as device connection), the drive control circuit can perform the operation of determining the device parameters. Specifically, the drive control circuit can perform the operation of determining the ripple current threshold, that is, according to the parameters of the devices connected to the drive control circuit, the ripple current threshold of the system is determined, and the ripple current threshold can also be referred to as the index value S. The ripple current threshold is to prevent the ripple current in the circuit from being too large and burning electronic devices such as capacitors. Further, the drive control circuit can perform the operation of determining the highest switching frequency, that is, according to the device parameters of the three-phase inverter, the highest switching frequency of the three-phase inverter is determined to prevent damage to the three-phase inverter due to the switching frequency being too large.

[0061] In some possible implementations, the drive control circuit can further calculate or simulate the three-phase inductance values of the motor rotor of the three-phase AC motor at different angles according to the device parameters of the three-phase AC motor, through a three-phase AC motor model, and the like, and then can establish an inductance model of the three-phase AC motor (this operation can also be referred to as establishing the inductance model). Further, the drive control circuit can further establish a simulation model of the battery heating system including the battery, the inductance model of the three-phase AC motor, the three-phase inverter, the inductance, the direct-current power supply, and the drive control circuit according to the inductance model, and then can calculate or simulate the ripple current value through the simulation model of the battery heating system. If the simulated ripple current value exceeds the ripple current threshold, the simulated inductance value is reduced to simulate again until the inductance value suitable for the actual application scenario is determined (this operation can also be referred to as determining the inductance value).

[0062] Further, in some possible implementations, the drive control circuit can further perform the operation of establishing a motor rotor heating simulation model, that is, establishing a motor rotor heating simulation model of the three-phase AC motor, and then can calculate or simulate the motor rotor heating power at different target phase differences through the heating simulation model (this operation can also be referred to as simulating the heating power). According to the data of the motor rotor heating power, the drive control circuit can use different motor rotor heating powers at different temperatures of the battery, and then can adjust the heating temperature.

[0063] In step S102, the at least two bridge arms are controlled according to the target phase difference, so that the at least two coils generate heat matching the heating demand to heat the battery.

[0064] In some possible implementations, taking the three-phase inverter and the three-phase AC motor as an example, the drive control circuit can control the three-phase inverter to work according to the adjusted three-phase control signal, for example, can control the conduction or turn-off of the upper bridge arm and the lower bridge arm of the three-phase inverter, and then make the three-phase coil of the three-phase AC motor generate heat matching the battery heating demand to heat the battery. Please see Figure 5 , Figure 5 is a schematic diagram of the current flowing through the three-phase inverter provided by the embodiment of the present application. As shown in Figure 5 , the current flowing through the three-phase inverter increases when the lower bridge arm of the three-phase inverter is turned on, showing an upward trend; when the lower bridge arm of the three-phase inverter is turned off, the current decreases, showing a downward trend; with the periodic conduction and turn-off of the lower bridge arm of the three-phase inverter, the overall shows a periodic fluctuation. It can be understood that the three-phase control signal can control the phase difference between the three phases, that is, as shown in Figure 5The first, second, and third bridge arm currents shown correspond to three phases, and the current diagrams for these three phases are staggered. It should be noted that the current flowing through the three-phase inverter affects the heat generated by the vehicle's battery heating system. Therefore, the drive control circuit can update the battery's heating requirements by detecting the current magnitude, and then adjust the heat generated by the vehicle's battery heating system to heat the battery based on the updated heating requirements.

[0065] For better understanding, please refer to [link / reference]. Figure 6 ,like Figure 6 In the practical application debugging phase shown, the drive control circuit can execute the step of controlling the motor to generate heat, and transfer the heat to the battery through the heat transfer pipe, thereby achieving the effect of heating the battery. The drive control circuit can also perform real-time detection operations (such as temperature detection and current detection) during battery charging until charging is completed.

[0066] Specifically, in some feasible implementations, the drive control circuit can control the operation of the three-phase AC motor through the three-phase control signal. Specifically, the drive control circuit can obtain the duty cycle corresponding to the three-phase bridge arm of the three-phase inverter. The duty cycle is determined by the input voltage of the three-phase AC motor and the charging voltage required by the battery, and can be applied to the three-phase control signal transmitted to the three-phase inverter. Further, the drive control circuit can also obtain the initial phase difference (also called the initial value of the phase difference) for controlling the staggered phase conduction of the three-phase bridge arm. The initial phase difference can be determined by the switching frequency of the three-phase bridge arm in the three-phase inverter, the duty cycle corresponding to the three-phase bridge arm, and the heating requirements of the battery. It should be noted that the three-phase phases controlled by the initial phase difference are sequentially delayed. The initial phase difference can be set to one-third of the period to make the three-phase control signal uniformly distributed. Other non-uniform initial phase differences can also be set; this application does not limit this. The drive control circuit outputs a three-phase control signal that indicates the duty cycle and the initial phase difference to the three-phase inverter. Through the connection between the three-phase inverter and the three-phase AC motor, the air gap harmonic content of the three-phase AC motor can be adjusted to change the rotor speed of the three-phase AC motor, thereby adjusting the heat generated by the battery heating system of the vehicle.

[0067] In some feasible implementations, the battery heating system of the aforementioned vehicle can transfer the heat generated by the three-phase AC motor during operation to the battery via the aforementioned heat transfer pipes or other equipment to heat the battery. Specifically, the heat generated by the rotation of the motor rotor during operation can be absorbed by a motor oil cooling system or a motor rotor shaft water cooling system, and the heat can be transferred to the battery at a lower temperature as it flows through the battery.

[0068] Optionally, in some possible embodiments, the drive control circuit can detect the battery temperature to adjust the heating power of the three-phase alternating current motor. Specifically, after the heat transfer pipeline heats the battery, the drive control circuit can detect the temperature of the battery in real time, and then update the heating requirement of the battery. It can be understood that the heating requirement changes with the charging and heating process of the battery, and therefore the battery needs to be detected and the heating requirement needs to be updated to prevent the temperature from being too high. The drive control circuit can adjust the target phase difference according to the updated heating requirement, and then update the three-phase control signal. The three-phase alternating current motor and the three-phase inverter can update the working state according to the updated three-phase control signal, for example, change the speed of the motor rotor, and then the heating power of the three-phase alternating current motor can be adjusted. For example, when the drive control circuit detects that the temperature of the battery exceeds a temperature threshold, for example, the temperature threshold is 40 degrees Celsius, the speed of the motor rotor of the three-phase alternating current motor is reduced through the three-phase control signal, and then the heating power of the three-phase alternating current motor is reduced, and the heat transferred by the heat transfer pipeline is reduced, thereby preventing the temperature of the battery from being too high.

[0069] Optionally, in some possible embodiments, the drive control circuit can also detect the current flowing through the battery, and when the current size exceeds a current threshold, update the duty cycle corresponding to the three-phase bridge arm based on the current size to obtain an updated three-phase control signal, and adjust the target phase difference of the three-phase bridge arm based on the updated three-phase control signal, to adjust the heating power of the three-phase alternating current motor based on the target phase difference. It can be understood that during the charging process of the battery, the current fluctuates, and the user can set the current threshold according to the actual application scenario. When the current size exceeds the current threshold, it indicates that the current flowing through the battery is too large, which may damage the devices in the circuit at a high temperature. The drive control circuit can update the duty cycle according to the current size, and then adjust the target phase difference of the controllable three-phase bridge arm according to the updated duty cycle, and then update the three-phase control signal to adjust the heating power of the three-phase alternating current motor.

[0070] Optionally, in some possible embodiments, the drive control circuit can also reduce the duty cycle after the battery is fully charged, and then reduce the current flowing through the battery to 0. Further, in some possible embodiments, the drive control circuit can also disconnect the switch after the battery is fully charged, so that the battery heating system circuit of the vehicle to which the battery heating method is applicable is disconnected.

[0071] The application also provides a vehicle, please see Figure 7 , Figure 7 is a structural schematic diagram of a vehicle provided by an embodiment of the application. As shown inFigure 7 As shown, the vehicle includes a load and, as Figure 1 and Figure 2 The battery heating system of the vehicle described in the corresponding embodiment includes a motor, an inverter, a battery, a DC power supply, and an inductor. Please refer to the above description for details. Figure 1 and Figure 2 The descriptions in the corresponding embodiments will not be repeated here. In some feasible embodiments, the vehicle's battery heating system may further include a drive control circuit, which can be used for the interaction and functional implementation between the various devices included in the vehicle's battery heating system. Alternatively, the drive control circuit may also be other devices that can be used for the interaction and functional implementation between the various devices included in the vehicle's battery heating system, and this application does not limit this. It is understood that the vehicle can heat the battery during charging using the vehicle's battery heating system, thereby providing driving power to the load through the battery.

[0072] In this application, a target phase difference for controlling the phase-shifted conduction of at least two phase bridge arms of the inverter can be determined based on the battery's heating requirements and the inverter's operating state. Then, at least two phase bridge arms of the inverter are controlled according to the target phase difference, so that at least two phase coils of the motor generate heat matching the battery's heating requirements for battery heating. Therefore, the above-described vehicle battery heating method utilizes the heat generated by the motor during battery charging to heat the battery, resulting in a simple circuit structure, low energy loss, and low charging cost.

[0073] Please see Figure 8 This is a schematic diagram of the structure of the terminal device provided in an embodiment of this application. Figure 8As shown, the terminal device 1000 may include a processor 1001, a network interface 1004, and a memory 1005. Furthermore, the terminal device 1000 may also include a user interface 1003 and at least one communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 includes random access memory (RAM) and non-volatile memory (NVM), such as erasable programmable read-only memory (EPROM). The memory 1005 may also optionally be at least one storage device located remotely from the processor 1001. Figure 8 As shown, the memory 1005, which is a computer-readable storage medium, may include an operating system, a network communication module, a user interface module, and a device control application.

[0074] In such Figure 8 In the terminal device 1000 shown, the network interface 1004 provides network communication functionality; the user interface 1003 is mainly used to provide an input interface for the user; and the processor 1001 can be used to call the device control application stored in the memory 1005 to achieve:

[0075] Based on the heating requirements of the battery and the operating state of the inverter, a target phase difference for controlling the phase-shifted conduction of at least two phase bridge arms is determined.

[0076] The at least two phase arms are controlled according to the target phase difference so that the at least two phase coils generate heat that matches the heating requirement to heat the battery.

[0077] It should be understood that the terminal device 1000 described in the embodiments of this application can execute the foregoing text. Figure 3 and Figure 6The description of the battery heating method for the vehicle in any of the corresponding embodiments will not be repeated here. In addition, the description of the beneficial effects of using the same method will also not be repeated. Those skilled in the art can realize that the system and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in the above description in general terms. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. The above disclosure is only for the preferred embodiments of the present application, and of course cannot limit the scope of the present application, so equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.

Claims

1. A method for heating a vehicle battery, characterized in that, The vehicle includes a battery, a motor, and an inverter. One end of the inverter is connected to a first terminal of the battery, and the other end of the inverter is connected to a second terminal of the battery. The inverter includes at least two phase arms, and the motor includes at least two phase coils. The motor is connected to the inverter, and each phase coil is connected to the midpoint between the upper and lower arms of the corresponding phase arm. The method includes: Based on the heating requirements of the battery and the operating state of the inverter, a target phase difference for controlling the phase shift of each phase bridge arm is determined. The phase arms are controlled according to the target phase difference so that the at least two phase coils generate heat that matches the heating requirement to heat the battery.

2. The battery heating method for a vehicle according to claim 1, characterized in that, The operating state of the inverter includes the switching frequency of the at least two phase bridge arms and the duty cycle corresponding to the at least two phase bridge arms. The duty cycle is used to represent the ratio of the conduction time of the bridge arm to the switching cycle of the bridge arm. The target phase difference used to control the phase shift of each phase arm is determined by the heating requirements of the battery, the switching frequency of the at least two phase arms, and the duty cycle of the at least two phase arms.

3. The battery heating method for a vehicle according to claim 2, characterized in that, The duty cycle corresponding to the at least two phase arms is determined by the charging voltage required for battery charging and the input voltage of the inverter.

4. The battery heating method for a vehicle according to claim 3, characterized in that, Before determining the target phase difference for controlling the phase shift of each phase bridge arm based on the heating requirements of the battery and the operating state of the inverter, the method further includes: The at least two phase arms are controlled according to the duty cycle corresponding to the at least two phase arms and the initial phase difference used to control the phase-off conduction of the at least two phase arms; The initial phase difference is determined by the heating requirements of the battery, the switching frequency of at least two phase arms in the inverter, and the duty cycle of the at least two phase arms.

5. The battery heating method for a vehicle according to any one of claims 1-4, characterized in that, After controlling each phase arm according to the target phase difference to generate heat matching the heating demand for heating the battery by the at least two phase coils, the method further includes: The relevant parameters during battery heating are obtained to update the battery heating requirements, and the operation based on the battery heating requirements and the inverter operating state is re-executed to determine the target phase difference for controlling the phase shift of each phase bridge arm.

6. The battery heating method for a vehicle according to any one of claims 2-4, characterized in that, After controlling each phase arm according to the target phase difference to generate heat matching the heating demand for heating the battery by the at least two phase coils, the method further includes: Obtain the magnitude of the current flowing through the battery; When the current exceeds the current threshold, the duty cycle of each phase bridge arm is updated based on the current, and the operation of determining the target phase difference for controlling the phase-shifted conduction of each phase bridge arm is re-executed based on the heating requirements of the battery, the switching frequency of at least two phase bridge arms, and the duty cycle of at least two phase bridge arms.

7. A terminal device, characterized in that, include: Processor, memory, and network interface; The processor is connected to the memory and the network interface, wherein the network interface is used to provide data communication functions, the memory is used to store program code, and the processor is used to execute the program code to perform the method according to any one of claims 1-6.

8. A battery heating system for a vehicle, characterized in that, The vehicle's battery heating system includes a battery, a motor, an inverter, and a heat transfer pipe. One end of the inverter is connected to the first end of the battery, and the other end of the inverter is connected to the second end of the battery. The inverter includes at least two phase arms, and the motor includes at least two phase coils. The motor is connected to the inverter, and each phase coil is connected to the midpoint between the upper and lower arms of the corresponding phase arm. One end of the heat transfer pipe is connected to the motor, and the other end of the heat transfer pipe is connected to the battery. The heat transfer pipe is used to transfer the heat generated by the motor during operation to the battery to heat the battery; The vehicle's battery heating system is used to implement the method as described in any one of claims 1-6.

9. The battery heating system for a vehicle according to claim 8, characterized in that, The vehicle's battery heating system also includes a DC power supply, which is connected to the battery via the motor and the inverter; The DC power supply is used to power the motor and the inverter.

10. The battery heating system for a vehicle according to any one of claims 9, characterized in that, The vehicle's battery heating system also includes an inductor connected between the DC power supply and the motor.

11. A vehicle, characterized in that, The vehicle includes a load and a battery heating system as described in any one of claims 8-10.

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