Battery heating system control method, battery heating system, and electric vehicle

Abstract

The present disclosure relates to a control method for a battery heating system, a battery heating system, and an electric vehicle, wherein the battery heating system includes a supercapacitor and a pulse control unit, and the control method includes the steps of: obtaining a temperature value and a SOC value of a power battery; and when the temperature value is lower than a predetermined temperature threshold and the SOC value is higher than a predetermined electrical quantity threshold, issuing a heating command to the pulse control unit, so that the pulse control unit controls a bidirectional energy flow between the power battery and the supercapacitor in the form of a pulse current according to the heating command, thereby heating the power battery.

Description

[Technical Field]

[0001] This disclosure claims priority to a Chinese patent application entitled "Control method for battery heating system and battery heating system for electric vehicle," filed on December 12, 2022, with patent application number 202211599149.7, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the technical field of power batteries, and in particular to a control method for a battery heating system, a battery heating system, and an electric vehicle. [Background technology]

[0003] With the rapid development of new energy electric vehicles, the problem of low-temperature range degradation specific to pure electric vehicles is gradually becoming more prominent.Statistical data shows that the range degradation of power batteries under low-temperature conditions is generally about 40%, which has a significant impact on users' actual vehicle usage experience.

[0004] To solve the problem of low-temperature range decay, three power battery heating methods have been proposed. These methods heat the power battery to improve its range. The three heating methods include external heating, internal heating, and internal-external combined heating.

[0005] Here, internal heating mainly utilizes the power battery to generate a pulse current to complete the heating process of the power battery, but when the power battery discharges, the electrical energy can usually only be dissipated in the form of heat, which leads to energy waste in the complete vehicle system. Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure aims to solve at least to some extent one of the technical problems in the related art, and therefore, one objective of the present disclosure is to provide a control method for a battery heating system, which can improve the utilization rate of electrical energy when heating the inside of a power battery, increase the cruising range of a completed vehicle under low-temperature conditions, and improve the user experience.

[0007] A second object of the present disclosure is to provide a battery heating system.

[0008] A third object of the present disclosure is to provide an electric vehicle. [Means for solving the problem]

[0009] To achieve the above object, a first embodiment of the present disclosure provides a control method for a battery heating system, the battery heating system including a supercapacitor and a pulse control unit, and the control method includes: The method includes the steps of obtaining a temperature value and a SOC value of a power battery; and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, issuing a heating command to the pulse control unit, so that the pulse control unit controls a bidirectional energy flow between the power battery and the supercapacitor in the form of a pulse current according to the heating command, thereby heating the power battery.

[0010] In the battery heating system control method of the embodiment of the present disclosure, when it is necessary to heat the power battery, the temperature value and SOC value of the power battery are first obtained, and when the temperature value is lower than a predetermined temperature threshold and the SOC value is higher than a predetermined electrical quantity threshold, a heating command is sent to the pulse control unit, and the pulse control unit can control a bidirectional energy flow between the power battery and the supercapacitor in the form of a pulse current according to the heating command. By heating the power battery, the electrical energy output by the power battery can be stored in the supercapacitor, thereby improving the electrical energy utilization rate, reducing energy waste in the vehicle system, and improving the cruising range of the vehicle under low temperature conditions, thereby improving the user experience.

[0011] In several possible ways, the energy flow between the power battery and the supercapacitor alternates.

[0012] In some possible modes, in each heating cycle, the pulse control unit controls the power battery to output a pulse current to the supercapacitor, and then controls the supercapacitor to output a pulse current to the power battery.

[0013] In some possible ways, the width and frequency of the pulse current are determined according to the temperature and SOC values ​​of the power battery.

[0014] In some possible implementations, when the temperature value is equal to or greater than a preset temperature threshold or the SOC value is equal to or less than a preset electrical quantity threshold, the method further includes sending a stop heating command to the pulse control unit, and controlling the power battery to stop heating by the pulse control unit.

[0015] In some possible implementations, the method further includes controlling the supercapacitor to supply power to on-board low-voltage electrical equipment after the power battery stops heating.

[0016] To achieve the above object, a second embodiment of the present disclosure provides a battery heating system, the system including a supercapacitor, a heating control unit, and a pulse control unit, wherein the heating control unit is used to obtain the temperature value and SOC value of a power battery, and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, issue a heating command; and the pulse control unit is used to control a bidirectional energy flow between the power battery and the supercapacitor in the form of a pulse current according to the heating command, thereby heating the power battery.

[0017] In the battery heating system of the embodiment of the present disclosure, a heating control unit obtains the temperature value and SOC value of the power battery, and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, a heating command is sent, and a pulse control unit controls a bidirectional energy flow between the power battery and the supercapacitor in the form of a pulse current according to the heating command, thereby heating the power battery and storing the electrical energy output by the power battery in the supercapacitor, thereby improving the utilization rate of electrical energy, reducing the energy waste of the vehicle system, and improving the driving range of the vehicle under low temperature conditions, thereby improving the user experience.

[0018] To achieve the above object, a third embodiment of the present disclosure provides an electric vehicle, which includes the battery heating system provided by the second embodiment of the present disclosure.

[0019] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a structural schematic diagram of a battery heating system according to one embodiment of the present disclosure; FIG. [Figure 2] FIG. 2 is a flowchart of a method for controlling a battery heating system according to one embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram of a pulse current waveform according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a block diagram of a battery heating system according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021]

[0033] The following detailed description of the embodiments of the present disclosure will be given, and examples of the described embodiments are shown in the drawings, in which the same or similar reference numerals throughout refer to the same or similar elements, or elements having the same or similar functions. The embodiments described by referring to the following drawings are illustrative and are used only for the purpose of explaining the present disclosure, and should not be understood as limiting the present disclosure.

[0022] Hereinafter, a battery heating system control method, a battery heating system, and an electric vehicle according to embodiments of the present disclosure will be described with reference to the drawings.

[0023] 1 is a structural schematic diagram of a battery heating system according to one embodiment of the present disclosure. In order to facilitate understanding of the battery heating system, the battery heating system will first be specifically introduced below in combination with FIG. 1.

[0024] In this embodiment, the battery heating system includes a power battery, a pulse control unit, a supercapacitor, a heating control unit, and a thermal management controller. The heating control unit is connected to the power battery, the pulse control unit, the supercapacitor, and the thermal management controller, and the thermal management controller, the power battery, the pulse control unit, and the supercapacitor are sequentially connected. The supercapacitor is further connected to on-board low-voltage electrical equipment via a DC / DC converter.

[0025] Hereinafter, the control method for the battery heating system according to the embodiment of the present disclosure will be specifically introduced with reference to the structure of the battery heating system. FIG. 2 is a flowchart of the control method for the battery heating system according to one embodiment of the present disclosure. The control method for the battery heating system according to the embodiment of the present disclosure is executed by the heating control unit. As shown in FIG. 2, the method includes the following steps: Step S210: obtain the temperature value and SOC value of the power battery.

[0026] Specifically, after the completed vehicle is powered on, the power battery, the supercapacitor, the thermal management controller and the pulse control unit are first detected through the heating control unit to determine whether the power battery, the supercapacitor, the thermal management controller and the pulse control unit are in a normal state, where the normal state refers to a state in which no faults occur.

[0027] When it detects that the power battery, the supercapacitor, the thermal management controller, and the pulse control unit are all in a normal state, the heating control unit can send a request to the thermal management control and the power battery to heat up. After receiving the request to heat up, the thermal management controller can collect the temperature value of the power battery and send the temperature value to the heating control unit. In this embodiment, the power battery is provided with a temperature sensor, and the thermal management controller can be connected to the temperature sensor, and the thermal management controller can control the temperature sensor to collect the temperature value of the power battery.

[0028] After receiving the request of whether the power battery needs to be heated, the current SOC value (remaining battery capacity) can be sent to the heating control unit, so that the heating control unit can obtain the temperature value and SOC value of the power battery, and determine whether the power battery needs to be heated according to the temperature value and SOC value of the power battery.

[0029] Step S220: When the temperature value is lower than the preset temperature threshold and the SOC value is higher than the preset electrical quantity threshold, a heating command is sent to the pulse control unit, so that the pulse control unit controls the power battery and the supercapacitor to perform a bidirectional energy flow in the form of a pulse current according to the heating command, thereby heating the power battery.

[0030] After receiving the temperature value and SOC value of the power battery, the heating control unit determines whether to send a heating command according to the temperature value and SOC value of the power battery. Specifically, when the heating control unit determines that the temperature value of the power battery is lower than a preset threshold, it indicates that the temperature of the power battery is low, which may affect the driving range of the power battery. When the heating control unit determines that the SOC value of the power battery is higher than a preset threshold, it indicates that the remaining battery power of the power battery is sufficient to meet the required electrical energy for the heating process. Therefore, when the temperature is lower than a preset temperature threshold and the SOC value is higher than a preset electrical energy threshold, it determines that the power battery needs to be heated and that the remaining battery power of the power battery is sufficient to meet the required electrical energy for heating. At this time, the heating control unit can send a heating command to the pulse control unit.

[0031] The preset temperature threshold and the preset electricity threshold may be set manually according to actual needs, and are not specifically limited herein.

[0032] For example, if the preset temperature threshold is set to 15°C and the preset power amount threshold is set to 10% of the total power amount of the power battery, the temperature value of the power battery received by the heating control unit is 10°C and the SOC value of the power battery is 12%, and the heating control unit can send a heating command to the pulse control unit to heat the power battery.

[0033] After the pulse control unit receives the heating command, the pulse control unit controls the power battery to charge and discharge, and the supercapacitor to charge and discharge according to the heating command, and the current output or input from the power battery is a pulse current, and similarly, the current output or input from the supercapacitor is also a pulse current, thereby realizing two-way energy flow and thus realizing heating of the power battery.

[0034] In some implementations, the width and frequency of the pulse current are determined according to the temperature and SOC of the power battery. Specifically, the heating control unit can send the temperature and SOC to the pulse control unit. After receiving a heating command, the pulse control unit can first determine the frequency and width of the pulse current according to the temperature and SOC, and then send the frequency and width of the pulse current to the power battery. The manner of determining the frequency and width of the pulse current according to the temperature and SOC can be to provide a correspondence table of temperature, SOC, frequency, and width, and query the required frequency and width of the pulse current corresponding to the current temperature and SOC according to the correspondence table.

[0035] After the power battery receives the frequency and width value, it can output a corresponding pulse current according to the frequency and width value. Similarly, the supercapacitor outputs a pulse current to the power battery, and the pulse control unit adjusts the frequency and width value of the pulse current output by the supercapacitor so that the frequency and width value of the pulse current received by the power battery is the same as the frequency and width value it outputs.

[0036] In some implementations, energy flows alternately between the power battery and the supercapacitor. Specifically, the power battery can be controlled to output a pulsed current to the supercapacitor first, and then the supercapacitor can be controlled to output a pulsed current to the power battery. Alternatively, the supercapacitor can be controlled to output a pulsed current to the power battery, and then the power battery can be controlled to output a pulsed current to the supercapacitor. This allows for alternate energy flows between the power battery and the supercapacitor. This configuration is used to heat the power battery, and the electrical energy output by the power battery flows repeatedly between the power battery and the supercapacitor to heat the power battery. This configuration can effectively reduce electrical energy consumption and improve energy utilization.

[0037] In some implementations, during each heating cycle, the pulse control unit controls the power battery to output a pulse current to the supercapacitor, and then controls the supercapacitor to output a pulse current to the power battery. Specifically, the heating cycle can be defined as the process in which the power battery outputs a pulse current to the supercapacitor and the supercapacitor outputs a pulse current to the power battery. When the pulse control unit receives a heating command, and the power battery receives the frequency and width values ​​transmitted by the pulse control unit, the power battery first outputs a pulse current with the corresponding frequency and width value. The pulse current flows through the pulse control unit to the supercapacitor, thereby discharging the power battery. After half of the heating cycle, the pulse control unit adjusts the direction of the pulse current so that the supercapacitor outputs a pulse current. When the pulse current passes through the pulse control unit, the pulse control unit can adjust the frequency and width values ​​of the pulse current, so that the adjusted pulse current flows to the power battery, thereby discharging the supercapacitor.

[0038] Furthermore, when the above method is used to heat the power battery, there is no need to store electricity in the supercapacitor in advance, and the power battery can be heated via the internal electricity of the power battery.

[0039] In some embodiments, the pulse current is a rectangular pulse current. Figure 3 is a schematic diagram of a pulse current waveform according to an embodiment of the present disclosure. As shown in Figure 3, Figure 3a shows the pulse current waveform output by the power battery, and Figure 3b shows the pulse current waveform output by the supercapacitor.

[0040] Specifically, after the pulse control unit, power battery, and supercapacitor receive a heating command, the pulse control unit determines the frequency and width of the pulse current according to the temperature and SOC values ​​and sends the frequency and width to the power battery. The power battery outputs a rectangular pulse current with the corresponding frequency and width. After half a cycle, the pulse control unit controls and adjusts the direction of the pulse current, so that the supercapacitor outputs a rectangular pulse current to the power battery. The pulse control unit can also adjust the frequency and width of the rectangular pulse current output by the supercapacitor. After one cycle, the pulse control unit adjusts the direction of the rectangular pulse current, so that the power battery outputs a rectangular pulse current to the supercapacitor. The above process is repeated to complete the heating of the power battery.

[0041] In some implementations, when the temperature value is equal to or greater than a preset temperature threshold or the SOC value is equal to or less than a preset electrical quantity threshold, the control method further includes sending a stop heating command to the pulse control unit, and controlling the power battery to stop heating by the pulse control unit.

[0042] Specifically, during the process of heating the power battery, the thermal management controller can collect the temperature value of the power battery in real time and transmit the temperature value to the heating control unit. Similarly, the power battery can transmit its current SOC value to the heating control unit in real time. When the heating control unit detects that the temperature value is above a preset temperature threshold or the SOC value is below a preset electrical quantity threshold, the heating control unit transmits a stop heating command to the pulse control unit. After receiving the stop heating command, the pulse control unit controls the power battery and the supercapacitor to stop outputting pulse current, thereby stopping heating of the power battery.

[0043] When the heating control unit detects that the temperature value is equal to or greater than the preset temperature threshold, it indicates that the current temperature value of the power battery has reached the required temperature value, and when the SOC value is equal to or less than the preset power threshold, it indicates that the remaining battery power of the power battery can no longer support the heating process of the power battery. Therefore, in both cases, it is necessary to stop heating the power battery.

[0044] In some implementations, the method further includes controlling the supercapacitor to supply power to onboard low-voltage electrical equipment after the power battery stops heating. Specifically, after the power battery stops heating, the electrical energy discharged and output by the power battery can be stored in the supercapacitor. The electrical energy stored in the supercapacitor can be converted to 12V low voltage using a DC / DC converter and output to the onboard low-voltage electrical equipment, thereby enabling the supercapacitor to supply power to the onboard low-voltage electrical equipment, thereby improving the utilization rate of electrical energy and reducing energy waste in the entire vehicle system.

[0045] In order to understand the control method of the battery heating system, a specific example of the control method of the battery heating system will be introduced below.

[0046] After the vehicle is powered on, the heating control unit first detects whether the power battery, super capacitor, thermal management controller and pulse control unit are in normal operation. If all of the above devices are in normal operation, the heating control unit can send a request to the thermal management controller and the power battery to heat up.

[0047] After receiving the request for heating, the thermal management control device can collect the temperature value of the power battery and send the temperature value to the heating control unit. After receiving the request for heating, the power battery can send the current SOC to the heating control unit. When the temperature value is less than the preset temperature threshold and the SOC value is greater than the preset electrical quantity threshold, the heating control unit sends a heating command to the pulse control unit.

[0048] After receiving the heating command, the pulse control unit determines the frequency and width of the pulse current according to the temperature and SOC values, and sends the frequency and width values ​​to the power battery. After receiving the frequency and width values, the power battery outputs a rectangular pulse current of the corresponding frequency and width value, which flows to the supercapacitor through the pulse control unit to complete the discharge of the power battery. After a half cycle, the pulse control unit adjusts the direction of the pulse current, so that the supercapacitor outputs a rectangular pulse current to the power battery.

[0049] When the heating control unit detects that the current temperature value of the power battery is higher than the preset temperature threshold or the SOC value is lower than the preset electrical quantity threshold, it sends a stop heating command to the pulse control unit, thereby controlling the pulse control unit to stop heating the power battery.

[0050] After the heating of the power battery is stopped, the electric energy stored in the super capacitor is converted to 12V low voltage using a DC / DC converter, and the electric energy is output to the on-board low-voltage electrical equipment, thereby supplying power to the on-board low-voltage electrical equipment.

[0051] This controls the pulse control unit to control the bidirectional flow of energy between the power battery and the supercapacitor, realizing the heating of the power battery and storing the excess electrical energy output by the supercapacitor during heating. The stored electrical energy can then be supplied to on-board low-voltage electrical equipment, reducing the electrical energy consumption during the heating process of the power battery and improving the utilization rate of electrical energy. This reduces the energy waste of the entire vehicle system and improves the driving range of the entire vehicle under low-temperature conditions, thereby improving the user experience.

[0052] FIG. 4 is a block diagram of a battery heating system according to another embodiment of the present disclosure.

[0053] As shown in FIG. 4, the battery heating system 400 includes a supercapacitor 410, a heating control unit 420, and a pulse control unit 430. The heating control unit 420 is used to obtain the temperature value and SOC value of the power battery, and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, it issues a heating command. The pulse control unit 430 controls the two-way energy flow between the power battery and the supercapacitor 410 in the form of a pulse current according to the heating command, thereby heating the power battery.

[0054] Thus, the heating control unit 420 obtains the temperature value and SOC value of the power battery, and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, it issues a heating command, and the pulse control unit 430 controls the power battery and the supercapacitor 410 to perform a bidirectional energy flow in the form of a pulse current according to the heating command. By heating the power battery, the electrical energy output by the power battery can be stored in the supercapacitor 410, improving the utilization rate of electrical energy, reducing energy waste in the vehicle system, and improving the driving range of the vehicle under low temperature conditions, thereby improving the user experience.

[0055] In some implementations, energy flows alternately between the power battery and the supercapacitor 410.

[0056] In some implementations, during each heating cycle, the pulse control unit 430 controls the power battery to output a pulse current to the supercapacitor 410, and then controls the supercapacitor 410 to output a pulse current to the power battery.

[0057] In some implementations, the pulse control unit 430 is used to determine the width and frequency of the pulse current according to the temperature and SOC values ​​of the power battery.

[0058] In some implementations, the heating control unit 420 is further used to send a stop heating command to the pulse control unit 430 when the temperature value is equal to or greater than a preset temperature threshold or the SOC value is equal to or less than a preset electrical quantity threshold, so that the pulse control unit 430 controls the power battery to stop heating.

[0059] In some implementations, the heating control unit 420 is further used to control the supercapacitor 410 to power the on-board low-voltage electrical equipment after the power battery stops heating.

[0060] For the sake of simplicity and ease of explanation, those skilled in the art can clearly understand that the specific work steps of the described modules can refer to the corresponding steps in the method embodiments, and therefore, they will be omitted here.

[0061] To realize the above embodiment, the present disclosure further provides an electric vehicle, which includes the battery heating system provided in the above embodiment.

[0062] It should be noted that other configurations and operations of the electric vehicle according to the embodiment of the present disclosure are well known to those skilled in the art and will not be described here to reduce redundancy.

[0063] It should be noted that the logic and / or steps depicted in flowcharts or otherwise described herein may be viewed, for example, as an executable sequential listing of instructions for implementing logical functions, and may be tangibly embodied in any computer-readable medium for use with an instruction-executing system, apparatus, or device (including, for example, a computer-based system, a processor-based system, or a system that retrieves and executes instructions from other instruction-executing systems, apparatus, or devices), or for use in conjunction with such instruction-executing systems, apparatus, or devices. For purposes of this specification, a "computer-readable medium" may include any program capable of containing, storing, communicating, propagating, or transmitting an instruction-executing system, apparatus, or device, or a device for use in conjunction with such an instruction-executing system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include electrical connections having one or more wires (electronic devices), portable computer disk enclosures (magnetic devices), random access memory (RAM), read-only memory (ROM), programmable-erasable read-only memory (EPROM or flash memory), fiber optic devices, and portable CD-ROMs (CD-ROMs). It may also be a computer readable medium, such as paper or other suitable medium onto which the program may be printed, since the program may be obtained in electronic form, for example by optically scanning the paper or other medium and editing, interpreting or otherwise processing as needed in an appropriate manner, and then stored in computer memory.

[0064] It should be noted that each part of the present disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the above-described implementation, several steps or methods can be implemented in software or firmware stored in a memory and executed by an appropriate instruction execution system. For example, when implemented in hardware, as with other implementations, it can be implemented in any one or combination of discrete logic circuits having logic circuits for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc., as are known in the art.

[0065] In the description herein, reference to the reference terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific feature, structure, material, or characteristic described in the relevant embodiment or example is included in at least one embodiment or example of the present disclosure. In the description herein, the exemplary use of the term does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0066] In the description of the present disclosure, the orientations or positional relationships indicated by terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial direction," "radial direction," and "circumferential direction" are orientations or positional relationships shown based on the drawings, and are intended merely to facilitate and simplify the description of the present disclosure. They do not indicate or imply that the indicated devices or elements have a specific orientation or should be configured or operated in a specific orientation, and therefore should not be understood as limiting the present disclosure.

[0067] Additionally, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to specify the number of technical features being indicated. Thus, a feature qualified as "first" or "second" may indicate or imply the inclusion of at least one of that feature. In the description of this disclosure, "plurality" means at least two, e.g., two, three, etc., unless otherwise clearly and specifically limited.

[0068] In this disclosure, unless otherwise expressly specified or limited, the terms "attached," "coupled," "connected," "fixed," etc. should be interpreted broadly, and may refer to, for example, a fixed connection, a detachable connection, or integration, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, an internal communication between two components, or an interactive relationship between two components. Those skilled in the art can understand the specific meanings of the above terms in this disclosure according to specific circumstances.

[0069] In this disclosure, unless otherwise expressly specified and limited, when a first feature is "above" or "below" a second feature, it may mean that the first feature and the second feature are in direct contact or indirect contact via an intermediate medium. Furthermore, when a first feature is "above," "upper," or "on top" of a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or that the first feature is at a higher horizontal height than the second feature. When a first feature is "below," "below," or "on the bottom" of a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or that the first feature is at a lower horizontal height than the second feature.

[0070] Although the above has already shown and described examples of the present disclosure, the above examples are merely illustrative and should not be construed as limitations on the present disclosure. Those skilled in the art may make changes, modifications, substitutions, and variations to the above examples within the scope of the present disclosure.

Claims

1. A control method for a battery heating system, the battery heating system including a super capacitor and a pulse control unit, the control method comprising: obtaining a temperature value and an SOC value of the power battery; When the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, the pulse control unit issues a heating command to the pulse control unit, so that the pulse control unit controls a bidirectional energy flow between the power battery and the super capacitor in the form of a pulse current according to the heating command, thereby heating the power battery.

2. The method for controlling a battery heating system according to claim 1 , wherein the energy flow between the power battery and the super capacitor is alternated.

3. 3. The method for controlling a battery heating system according to claim 2, wherein in each heating cycle, the pulse control unit controls the power battery to output a pulse current to the super capacitor, and then controls the super capacitor to output a pulse current to the power battery.

4. 4. The method for controlling a battery heating system according to claim 1, wherein the width and frequency of the pulse current are determined according to the temperature and SOC values ​​of the power battery.

5. When the temperature value is equal to or greater than a predetermined temperature threshold or the SOC value is equal to or less than a predetermined electrical quantity threshold, the method includes: A control method for a battery heating system described in any one of claims 1 to 4, further comprising a step of sending a stop heating command to the pulse control unit and controlling the power battery to stop heating by the pulse control unit.

6. After the power battery stops heating, the method includes: The method for controlling a battery heating system according to claim 5, further comprising the step of controlling the super capacitor to supply electricity to on-board low-voltage electrical equipment.

7. 1. A battery heating system, comprising: a super capacitor, a heating control unit, and a pulse control unit; The heating control unit is used to obtain a temperature value and an SOC value of the power battery, and when the temperature value is lower than a preset temperature threshold and the SOC value is higher than a preset electrical quantity threshold, issue a heating command; A battery heating system, wherein the pulse control unit controls a bidirectional energy flow between the power battery and the super capacitor in the form of a pulse current according to the heating command, and is used to heat the power battery.

8. The battery heating system of claim 7, wherein energy flow between the power battery and the super capacitor alternates.

9. 9. The battery heating system of claim 8, wherein in each heating cycle, the pulse control unit controls the power battery to output a pulse current to the super capacitor, and then controls the super capacitor to output a pulse current to the power battery.

10. The battery heating system according to any one of claims 7 to 9, wherein the pulse control unit is further used for determining the width value and frequency of the pulse current according to the temperature value and SOC value of the power battery.

11. The battery heating system according to any one of claims 7 to 10, wherein the heating control unit is further used to send a stop heating command to the pulse control unit when the temperature value is equal to or greater than a preset temperature threshold or the SOC value is equal to or less than a preset electrical quantity threshold, and to control the power battery to stop heating by the pulse control unit.

12. 12. The battery heating system according to claim 11, wherein the heating control unit is further used to control the super capacitor to supply power to on-board low-voltage electrical equipment after the power battery stops heating.

13. An electric vehicle comprising a battery heating system according to any one of claims 7 to 12.

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