Battery heating circuit and control method thereof, battery and electric vehicle

Abstract

The present application provides a battery heating circuit and a control method thereof, a battery and an electric vehicle, wherein the battery includes a first battery group and a second battery group, and the battery heating circuit includes a switch module, a heating module and a control module. The switch module is connected to the first battery group and the second battery group, respectively. The heating module is connected to the first battery group, the second battery group and the switch module, respectively. The control module is connected to the switch module and the heating module, and the control module is used to control the switch module so that the battery switches to a heating state, and is used to control the heating module when the battery is in a heating state so that the first battery group, the heating module and the second battery group form a loop. The loop is used to transfer electricity between the first battery group and the second battery group to heat the first battery group and the second battery group. In the above manner, the heating rate of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery heating circuit and a control method thereof, a battery, and an electric vehicle. Background Art

[0002] With increasingly severe energy and environmental challenges, strong government support for new energy, and the maturing of power battery technology, electric vehicles have become a new development direction for the automotive industry. The range of electric vehicles has become a key factor influencing their widespread adoption. Batteries, as key components, are the primary power source for electric vehicles, and their stable and reliable product quality is crucial.

[0003] However, the use of batteries in low-temperature environments is subject to certain limitations. Specifically, the battery's discharge capacity will severely decline in low-temperature environments, and the battery cannot be charged in low-temperature environments. Therefore, in order to ensure normal use of the battery, it is necessary to be able to heat the battery.

[0004] In existing technologies, heating the battery typically requires the use of an external high-voltage circuit to rapidly cycle the battery between charge and discharge. This method typically incorporates an energy storage unit that provides charge and discharge currents. However, in practice, this energy storage unit can only provide a limited charge and discharge current, resulting in a slow battery heating rate. Summary of the Invention

[0005] The present application aims to provide a battery heating circuit and a control method thereof, a battery and an electric vehicle, which can improve the heating rate of the battery.

[0006] To achieve the above-mentioned objectives, in a first aspect, the present application provides a battery heating circuit. The battery includes a first battery pack and a second battery pack, and the battery heating circuit includes a switch module, a heating module, and a control module. The switch module is connected to the first battery pack and the second battery pack, respectively; the heating module is connected to the first battery pack, the second battery pack, and the switch module, respectively; and the control module is connected to the switch module and the heating module. The control module is used to control the switch module so that the battery switches to a heating state, and is used to control the heating module when the battery is in a heating state so that the first battery pack, the heating module, and the second battery pack form a loop. The loop is used to transfer electricity between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack.

[0007] When heating the battery is required, the switch module can first be used to switch the battery to the heating state, separating the first and second battery packs into two independent battery packs. The first battery pack, the heating module, and the second battery pack then form a circuit. Within this circuit, the first battery pack can discharge energy to the second battery pack via the heating module, and the second battery pack can also discharge energy to the first battery pack via the heating module, heating both the first and second battery packs. Therefore, there is no need for an external high-voltage power supply as in the related art. That is, the current between the first and second battery packs is not limited by the energy storage unit. This allows the current between the first and second battery packs to be increased, thereby increasing the battery heating rate. Furthermore, the first and second battery packs can be heated simultaneously, which also helps improve the battery heating rate. Furthermore, since current flows only between the first and second battery packs, the connecting wires between the electronic components are located only within the battery. In the related art, since a high-voltage circuit is required external to the battery, these connecting wires must be connected from the external high-voltage circuit to the battery. Generally speaking, the connecting wires from the outside to the battery are longer than the connecting wires inside the battery. That is, compared with the solution of setting up a high-voltage circuit outside the battery in the related art, the connecting wires required in this application are shorter, which can reduce the current loss in the connecting wires and help improve the heating efficiency.

[0008] In one optional embodiment, the switch module includes a first switch and a second switch. The first battery pack, the first switch, and the second battery pack are connected in series to form a first branch, the first end of the first branch is connected to the heating module, the second end of the first branch is connected to the first end of the second switch and the heating module, the connection point between the first battery pack and the first switch is connected to the second end of the second switch, and the connection point between the second battery pack and the first switch is connected to the heating module.

[0009] By controlling the closing or opening of the first switch and the second switch, it is possible to combine the first battery pack and the second battery pack into a whole for charging or discharging under normal circumstances, or to split the first battery pack and the second battery pack into two independent battery packs when the battery is switched to the heating state to realize charging and discharging between the two battery packs.

[0010] In an optional manner, the control module is further configured to: control the first switch to be opened, and control the second switch to be closed, so that the battery is switched to a heating state.

[0011] Under normal circumstances, the first switch is closed and the second switch is open, connecting the first and second battery packs in series. The batteries can now be used to charge or discharge external devices. When heating the batteries is required, the first switch is opened and the second switch is closed, separating the first and second battery packs from a series connection into two independent battery packs. At this point, the batteries are heated, and the charge and discharge process between the two battery packs can be used to heat the first and second battery packs.

[0012] In an optional embodiment, the heating module includes a self-heating excitation unit, which includes a first bridge arm, a second bridge arm, a first capacitor, a second capacitor and a first inductor. The first bridge arm and the first capacitor are connected in parallel to form a second branch, the first end of the second branch is connected to the switch module and the second battery pack, the second bridge arm and the second capacitor are connected in parallel to form a third branch, the first end of the third branch is connected to the first battery pack, the second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm. The control module is connected to the first bridge arm and the second bridge arm respectively, and the control module is also used to: when the battery is in a heating state, control the first bridge arm and the second bridge arm to form a circuit for the first battery pack to discharge to the second battery pack, and / or to form a circuit for the second battery pack to discharge to the first battery pack, so as to heat the first battery pack and the second battery pack.

[0013] When heating the batteries, the first and second bridge arms are controlled to form a circuit whereby the first battery pack discharges energy from the second battery pack, or vice versa. This switching between these two circuits ensures that the charge levels of each battery pack are consistent before and after heating, preventing damage to the batteries during normal use due to large differences in charge levels between battery packs. This helps protect the batteries and prolongs their service life. Furthermore, simultaneous heating of both battery packs is possible, achieving a higher heating rate.

[0014] In an optional embodiment, the heating module further includes a pre-charging unit, which is respectively connected to the first capacitor, the second capacitor, the second battery pack, and the second battery pack. The control module is connected to the pre-charging unit, and the control module is further used to: control the pre-charging unit to be in a first working state so that the first battery pack charges the first capacitor, and / or, the second battery pack charges the second capacitor. If the voltage across the first capacitor is not less than a first voltage threshold, and the voltage across the second capacitor is not less than a second voltage threshold, the pre-charging unit is controlled to be in a second working state to stop charging the first capacitor and the second capacitor.

[0015] By providing a pre-charging unit to pre-charge the first and second capacitors, it is possible to prevent the first capacitor or electronic components such as switches in the conduction loop from being damaged by breakdown due to excessive instantaneous current output by the first battery pack when the heating module is activated, or to prevent the second capacitor or electronic components such as switches in the conduction loop from being damaged by breakdown due to excessive instantaneous current output by the second battery pack. This improves the safety of the first and second capacitors, as well as the service life of these electronic components, and helps improve the stability of the battery heating circuit.

[0016] In one optional embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor. The third switch and the first resistor are connected in series to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, a first end of the fourth branch is connected to the first capacitor and the second capacitor, and a second end of the fourth branch is connected to the first battery pack and the second battery pack.

[0017] When charging the first and second capacitors, the first resistor can reduce the charging current, i.e., the first resistor acts as a current limiter. This prevents damage to the first and second capacitors, or electronic components such as switches in the conduction loop, due to excessive charging current, thereby protecting the first and second capacitors.

[0018] In an optional manner, the control module is further configured to: control the third switch to be closed and the fourth switch to be opened to control the pre-charging unit to be in the first working state; and control the fourth switch to be closed and the third switch to be opened to control the pre-charging unit to be in the second working state.

[0019] When the third switch is closed and the fourth switch is open, the first resistor is added to the charging circuit between the first and second capacitors because the third switch is connected in series with the first resistor, acting as a current limiter. After the first and second capacitors are fully charged, the third switch is opened and the fourth switch is closed, disconnecting the circuit containing the first resistor. This prevents additional current loss caused by the first resistor during battery heating, helping to improve heating efficiency.

[0020] In one optional embodiment, the first end of the first branch and the second end of the first branch are both used to connect to an external device, wherein the external device includes a charging device and an electrical device. The control module is further configured to: if the temperature of the first battery pack is not less than a first temperature threshold and the temperature of the second battery pack is not less than a second temperature threshold, control the first switch to close and control the second switch and the fourth switch to open, so as to switch the battery to a use state. When the battery is in the use state, the battery is used to discharge the electrical device or to be charged by the charging device.

[0021] When the battery is heated, the first switch is closed and the second and fourth switches are opened, switching the battery to a usable state. In this state, the first and second battery packs are connected in series to form a single unit. The battery can then be used to discharge power to a device or be charged by a charger.

[0022] In an optional embodiment, the battery heating circuit further includes a first fuse module and a second fuse module. The first fuse module is connected to the first battery pack and the heating module respectively, and the second fuse module is connected to the second battery pack, the heating module, and the switch module respectively.

[0023] When the output current of the first battery pack is too high, the first fuse module can be blown, immediately disconnecting the circuit and thus protecting the electronic components in the circuit. Similarly, when the output current of the second battery pack is too high, the second fuse module can be blown, immediately disconnecting the circuit and thus protecting the electronic components in the circuit.

[0024] In a second aspect, the present application provides a method for controlling a battery heating circuit, wherein the battery includes a first battery pack and a second battery pack, and the battery heating circuit includes a switch module and a heating module, wherein the switch module is connected to the first battery pack and the second battery pack, respectively, and the heating module is connected to the first battery pack, the second battery pack, and the switch module, respectively. The method includes: controlling the switch module to switch the battery to a heating state. When the battery is in the heating state, controlling the heating module to form a loop with the first battery pack, the heating module, and the second battery pack. The loop is used to transfer electricity between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack.

[0025] In one optional embodiment, the switch module includes a first switch and a second switch. The first end of a first branch formed by the first battery pack, the first switch, and the second battery pack connected in series is connected to the heating module, the second end of the first branch is connected to the first end of the second switch and the heating module, and the connection point between the first battery pack and the first switch is connected to the second end of the second switch.

[0026] In an optional manner, controlling the switch module to switch the battery to a heating state includes: if a heating request signal is received, controlling the first switch to be opened, and controlling the second switch to be closed, to switch the battery to a heating state.

[0027] In an optional manner, the heating module is a self-heating excitation unit, and the self-heating excitation unit includes a first bridge arm, a second bridge arm, a first capacitor, a second capacitor and a first inductor. The first bridge arm and the first capacitor are connected in parallel to form a second branch, the first end of the second branch is connected to the first battery pack, the second bridge arm and the second capacitor are connected in parallel to form a third branch, the first end of the third branch is connected to the switch module and the second battery pack, the second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm. When the battery is in a heating state, controlling the heating module so that the first battery pack, the heating module and the second battery pack form a loop includes: controlling the first bridge arm and the second bridge arm to form a loop for the first battery pack to discharge to the second battery pack, and / or forming a loop for the second battery pack to discharge to the first battery pack.

[0028] In an optional embodiment, the heating module further includes a pre-charging unit, which is respectively connected to the first capacitor, the second capacitor, the second battery pack, and the second battery pack. The method further includes: controlling the pre-charging unit to be in a first working state so that the first battery pack charges the first capacitor, and / or, the second battery pack charges the second capacitor. If the voltage across the first capacitor is not less than a first voltage threshold, and the voltage across the second capacitor is not less than a second voltage threshold, controlling the pre-charging unit to be in a second working state to stop charging the first capacitor and the second capacitor.

[0029] In one optional embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor. The third switch and the first resistor are connected in series to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, a first end of the fourth branch is connected to the first capacitor and the second capacitor, and a second end of the fourth branch is connected to the first battery pack and the second battery pack.

[0030] In an optional manner, controlling the pre-charging unit to be in the first working state includes: controlling the third switch to be closed, and controlling the fourth switch to be open, so as to control the pre-charging unit to be in the first working state.

[0031] In an optional manner, controlling the pre-charging unit to be in the second working state includes: controlling the fourth switch to be closed; and controlling the third switch to be open, so as to control the pre-charging unit to be in the second working state.

[0032] In one optional embodiment, the first end of the first branch and the second end of the first branch are both used to connect to an external device, wherein the external device includes a charging device and an electrical device. The method further includes: if the temperature of the first battery pack is greater than a first temperature threshold and the temperature of the second battery pack is greater than a second temperature threshold, controlling the first switch to close and controlling the second switch to open to switch the battery to a use state. When the battery is in the use state, the battery is used to discharge the electrical device or to be charged by the charging device.

[0033] In a third aspect, the present application provides a battery, comprising: a first battery group and a second battery group, and a battery heating circuit as in the first aspect, wherein the battery heating circuit is connected to the first battery group and the second battery group, and the battery heating circuit is used to heat the first battery group and the second battery group.

[0034] In a fourth aspect, the present application provides an electric vehicle, comprising: a load and a battery as in the third aspect, wherein the battery is used to supply power to the load.

[0035] In a fifth aspect, the present application provides a computer-readable storage medium, comprising: storing computer-executable instructions, wherein the computer-executable instructions are configured as the method flow in the second aspect.

[0036] The beneficial effect of the embodiment of the present application is that the battery heating circuit provided in the present application switches the battery to a heating state through a switch module to separate the first battery group and the second battery group into two independent battery groups. Subsequently, the first battery group can discharge to the second battery group through the heating module, and the second battery group can also discharge to the first battery group through the heating module to achieve heating of the first battery group and the second battery group. Therefore, there is no need to use an external high-voltage circuit as in the related art, that is, the current between the first battery group and the second battery group is not limited by the energy storage unit, so that the heating rate of the battery can be increased by controlling the current between the first battery group and the second battery group. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0038] Figure 1 This is a schematic diagram of an application scenario disclosed in an embodiment of the present application;

[0039] Figure 2 It is a structural diagram of a battery heating circuit disclosed in one embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the circuit structure of a battery heating circuit disclosed in one embodiment of the present application;

[0041] Figure 4 is a flow chart of a control method for a battery heating circuit disclosed in one embodiment of the present application;

[0042] Figure 5 It is a structural schematic diagram of a control device for a battery heating circuit disclosed in one embodiment of the present application;

[0043] Figure 6 It is a structural schematic diagram of a control device for a battery heating circuit disclosed in another embodiment of the present application.

[0044] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0045] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0046] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0047] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0048] In recent years, the new energy vehicle industry has experienced explosive growth. Batteries are the core of electric vehicles and represent a fusion of automotive and power engineering technologies. However, due to their electrochemical characteristics, their charge and discharge capabilities are significantly limited in low-temperature environments, severely impacting the customer experience in winter. Therefore, to ensure proper battery operation in low-temperature environments, heating is necessary.

[0049] During the development of this application, the inventors discovered that, in current technology, a common approach to heating batteries involves utilizing a high-voltage circuit external to the battery to rapidly switch between charging and discharging. Subsequently, when current flows through the battery, due to its inherent internal resistance, the battery directly generates heat and heats up, thereby achieving the battery heating process.

[0050] However, in this solution, when the battery cells are connected in parallel, the current flowing through the cells is only a fraction of the total current flowing through the battery, resulting in a reduced current flowing through the cells and reduced heating efficiency. Furthermore, to enable rapid switching between charging and discharging of the battery, the external high-voltage circuit must include an energy storage unit, which can be a motor or a dedicated energy storage inductor. To achieve higher heating efficiency, the energy storage unit needs to provide a higher charge and discharge current. However, in actual use, if the energy storage unit is a motor, as is often the case in electric vehicles, the motor design process must primarily focus on matching the overall vehicle power, limiting the charge and discharge current that the motor can provide. If the energy storage unit is an energy storage inductor, factors such as volume and weight must be considered, also limiting the charge and discharge current provided by the inductor. Therefore, in this solution, the energy storage unit can only provide a limited charge and discharge current, resulting in a slower battery heating rate.

[0051] Based on this, the applicant has designed a battery heating circuit, which switches the battery to a heating state when it is necessary to heat the battery, so as to discharge the battery from the first battery pack to the second battery pack, and / or the second battery pack to the first battery pack, to achieve the battery heating process. Therefore, there is no need to set up an external high-voltage circuit as in the related art, and the current between the first battery pack and the second battery pack is not limited by the energy storage unit, so that the heating rate of the battery can be increased by controlling the current between the first battery pack and the second battery pack. It can be seen that even if the first battery pack and the second battery pack have parallel cells inside, the current between the first battery pack and the second battery pack can be increased to increase the current flowing through the cells, thereby improving the heating rate of the battery. In addition, the current only flows between the first battery pack and the second battery pack, so the connecting wires between the electronic components only exist inside the battery. In the related art, since the high-voltage circuit is set outside the battery, its connecting wires need to be connected from the external high-voltage circuit to the battery. Generally speaking, the connecting wires connected from the outside to the battery are longer than the connecting wires inside the battery. That is, compared with the solution of setting a high-voltage circuit outside the battery in the related art, the connecting wires required in the present application are shorter, which can reduce the current loss on the connecting wires and help improve the heating efficiency.

[0052] The battery in the embodiment of the present application can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cathode battery, a nickel-metal hydride battery, a lithium-sulfur battery, a lithium-air battery or a sodium-ion battery, etc., which are not limited here. In terms of scale, each battery pack in the battery in the embodiment of the present application can be a single cell, or a battery module or a battery pack, which are not limited here. In terms of application scenarios, the battery can be used in power devices such as automobiles and ships. For example, it can be used in power vehicles to power the motor of the power vehicle and serve as a power source for electric vehicles. The battery can also power other electrical devices in electric vehicles, such as in-car air conditioners, car players, etc.

[0053] The embodiments of the present application provide an electrical device comprising the battery of any of the embodiments of the present application. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric vehicle, a ship, a spacecraft, and the like. The electric toy may include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0054] In order to facilitate understanding of this application, we first introduce an application scenario in which this application can be applied.

[0055] like Figure 1 As shown, Figure 1 The application scenario of heating the battery 20 by the battery heating circuit 10 is shown. The battery heating circuit 10 is connected to the battery 20. The battery 20 includes N battery packs, where N is a positive integer greater than or equal to 2, for example Figure 1 The first battery pack, the second battery pack, ... the Nth battery pack, etc. are shown in FIG. The battery heating circuit 10 in the embodiment of the present application can heat two of the battery packs simultaneously at a time. In other words, the N batteries can be divided into multiple groups, each with two battery packs, and the battery heating circuit 10 heats one of the battery packs at a time. The embodiment of the present application does not limit how the N batteries are grouped, nor does it limit the order in which the battery packs are heated.

[0056] In addition, the battery 20 can also be connected to a power system including a motor, etc. The battery 20 can be connected to a drive circuit of the motor to provide power to the drive circuit of the motor, thereby allowing the power vehicle equipped with the battery 20 to travel.

[0057] In one embodiment, the battery management system (BMS) of the battery 20 collects battery 20 status information, such as battery temperature, state of charge (SOC), voltage signal, current signal, etc., and determines whether the battery 20 needs to be heated based on this status information. When it is determined that the battery 20 needs to be heated, the BMS can send a heating request to the vehicle control unit (VCU). Based on the heating request sent by the BMS, the VCU activates the battery heating circuit 10 to heat the battery 20.

[0058] The present application does not limit the usage scenario of the battery heating circuit 10 . The battery heating circuit 10 of the embodiment of the present application can realize the heating process of the battery 20 under any necessary circumstances.

[0059] Hereinafter, taking the battery 20 including the first battery group 21 and the second battery group 22 as an example, how the battery heating circuit 10 heats the battery 20 simultaneously is described.

[0060] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of the connection between the battery heating circuit 10 and the battery 20 provided in the embodiment of the present application. Figure 2 As shown, the battery heating circuit 10 includes a switch module 11, a heating module 12, and a control module 13. The switch module 11 is connected to the first battery pack 21 and the second battery pack 22, respectively; the heating module 12 is connected to the first battery pack 21, the second battery pack 22, and the switch module 11, respectively; and the control module 13 is connected to the switch module 11 and the heating module 12, respectively.

[0061] Specifically, the control module 13 is configured to control the switch module 11 to switch the battery 20 to a heating state, and, when the battery 20 is in the heating state, control the heating module 12 to form a circuit with the first battery pack 21, the heating module 12, and the second battery pack 22. This circuit is configured to transfer power between the first battery pack 21 and the second battery pack 22 to heat the first battery pack 21 and the second battery pack 22.

[0062] The control module 13 may be a VCU, or a control module relatively independent of the VCU, for example, a control module specially provided for the battery heating circuit 10 , which is not limited in the embodiment of the present application.

[0063] Under normal circumstances, the first battery pack 21 and the second battery pack 22 form a battery 20 as a whole, which is used for discharging to external electrical devices or for charging via external devices. When the battery 20 needs to be heated, the switch module 11 is controlled to switch the battery 20 to a heating state. At this time, the first battery pack 21 and the second battery pack 22 are separated into two independent battery packs. In other words, the heating state means that the battery 20 is in a state that can be heated, and at this time, the battery 20 can neither be used to discharge to external electrical devices nor be used to charge via external devices.

[0064] Then, the heating module 12 can be further controlled to form a loop among the first battery pack 21, the heating module 12, and the second battery pack 22. In this loop, the first battery pack 21 can discharge to the second battery pack 22 through the heating module 12, and / or the second battery pack 22 can discharge to the first battery pack 21 through the heating module 12.

[0065] According to Joule's law, when current flows through a conductor (such as a resistor), heat is generated. This heat is proportional to the conductor's resistance, the square of the current flowing through the conductor, and the duration of the current flow. Therefore, because both the first battery pack 21 and the second battery pack 22 have internal resistance, heat is generated when current flows through them, thereby heating the first battery pack 21 and the second battery pack 22.

[0066] In this embodiment, there is no need to set up an external high-voltage circuit as in the related art, that is, the current between the first battery group 21 and the second battery group 22 is not limited by the energy storage unit, so that the heating rate of the battery 20 can be increased by controlling the current between the first battery group 21 and the second battery group 22.

[0067] Secondly, the first battery group 21 and the second battery group 22 can be heated at the same time, which is also beneficial to improving the heating rate of the batteries.

[0068] In addition, the current only flows between the first battery group 21 and the second battery group 22, so the connecting wires between the electronic components only exist inside the battery. In the related art, since it is necessary to set up an external high-voltage circuit in the battery, it is also necessary to set up connecting wires from the high-voltage circuit outside the battery to the battery. It can be seen that compared with the solution of setting up a high-voltage circuit outside the battery in the related art, the connecting wires required in the present application are shorter, which can reduce the current loss in the connecting wires and is conducive to improving the heating efficiency.

[0069] In one embodiment, if Figure 3As shown, the switch module 11 includes a first switch K1 and a second switch K2. The first battery pack 21, the first switch K1, and the second battery pack 22 are connected in series to form a first branch. The first end of the first branch (i.e., the positive electrode of the first battery pack 21) is connected to the heating module 12, and the second end of the first branch (i.e., the negative electrode of the second battery pack 2) is connected to the first end of the second switch K2 and the heating module 12. The connection point between the first battery pack 21 and the first switch K1 is connected to the second end of the second switch K2, and the connection point between the second battery pack 22 and the first switch K1 is connected to the heating module 12. The first switch K1 and the second switch K2 are also connected to the control module 13 ( Figure 3 ), that is, the first switch K1 and the second switch K2 are controlled by the control module 13.

[0070] It should be understood that in this embodiment, the first battery pack 21 and the second battery pack 22 each include a plurality of battery cells connected in series. In other embodiments, the first battery pack 21 and the second battery pack 22 may also include a plurality of battery cells connected in parallel, and this embodiment of the application is not limited thereto.

[0071] In this embodiment, the control module 13 controls the closing or opening of the first switch K1 and the second switch K2 to, on the one hand, realize that under normal circumstances, the first battery pack 21 and the second battery pack 22 are combined into a whole for charging or discharging.

[0072] For example, in one embodiment, the control module 13 controls the first switch K1 to close and the second switch K2 to open, thereby connecting the first battery pack 21 and the second battery pack 22 in series to form a single unit. In this case, if the first end of the first branch is connected to an external device via port B+, and the second end of the first branch is connected to an external device via port B-, where the external device includes a charging device and a power-consuming device, the battery 20 can discharge to the power-consuming device via ports B+ and B-, or be charged by the charging device.

[0073] On the other hand, it is also possible to switch the battery 20 to a heating state, that is, to split the first battery group 21 and the second battery group 22 into two independent battery groups, so as to realize the charging and discharging process between the two battery groups.

[0074] For example, in one embodiment, the control module 13 controls the first switch K1 to open and the second switch K2 to close, thereby separating the first battery pack 21 and the second battery pack 22 from a series connection into two independent battery packs, and the battery 20 is switched to a heating state. At this time, the positive electrode of the first battery pack 21 is connected to the positive electrode of the second battery pack 22 through the heating module 12, and the negative electrode of the first battery pack 21 is connected to the negative electrode of the second battery pack 22. By controlling the heating module 12, the first battery pack 21 can discharge to the second battery pack 22 (i.e., the second battery pack 22 charges), and the second battery pack 22 can discharge to the first battery pack 21 (i.e., the first battery pack 21 charges), thus achieving a charge and discharge process between the first battery pack 21 and the second battery pack 22, thereby achieving a heating process for the first battery pack 21 and the second battery pack 22.

[0075] It should be noted that in the related art, the premise for realizing charging and discharging between two battery packs is that the two battery packs are connected in parallel. However, the voltage provided by the two parallel battery packs is the voltage of a single battery pack, which is difficult to meet the application scenarios with high voltage requirements. For the present application, it is only applicable to the case where the first battery pack 21 and the second battery pack 22 are connected in series. Not only can it be achieved that when the battery 20 needs to be heated, the battery 20 can be split into two independent battery packs by controlling the first switch K1 and the second switch K2 to realize the heating process of the battery 20; it can also be achieved that when the battery 20 needs to power an external device, the first battery pack 21 and the second battery pack 22 are connected in series as a whole by controlling the first switch K1 and the second switch K2 to provide a higher voltage to the external device, thereby meeting the application scenarios with high voltage requirements.

[0076] In one embodiment, the heating module 12 includes a self-heating excitation unit 121, wherein the self-heating excitation unit 121 includes a first bridge arm 1211, a second bridge arm 1212, a first capacitor C1, a second capacitor C2, and a first inductor L1. The first bridge arm 1211 and the first capacitor C1 are connected in parallel to form a second branch, the first end of the second branch is connected to the switch module 11 and the second battery pack 22, the second bridge arm 1212 and the second capacitor C2 are connected in parallel to form a third branch, the first end of the third branch is connected to the first battery pack 21, the second end of the second branch is connected to the second end of the third branch, and the first inductor L1 is connected between the midpoint M1 of the first bridge arm 1211 and the midpoint M2 of the second bridge arm 1212.

[0077] The control module 13 is connected to the first bridge arm 1211 and the second bridge arm 1212 respectively. The control module is also used to: when the battery 20 is in a heating state, control the first bridge arm 1211 and the second bridge arm 1212 to form a circuit for discharging the first battery group 21 to the second battery group 22, and / or to form a circuit for discharging the second battery group 22 to the first battery group 21, so as to heat the first battery group 21 and the second battery group 22.

[0078] In this embodiment, since the first capacitor C1 is connected in parallel with the second battery group 22, and the second capacitor C2 is connected in parallel with the first battery group 21, the first capacitor C1 and the second capacitor C2 can achieve functions such as voltage stabilization, reduce voltage fluctuations of the second battery group 22 and the first battery group 21, and improve the voltage stability of the second battery group 22 and the first battery group 21.

[0079] Specifically, when heating the battery 20, by controlling the first bridge arm 1211 and the second bridge arm 1212, a circuit can be formed in which the first battery group 21 discharges to the second battery group 22, and a circuit can also be formed in which the second battery group 22 discharges to the first battery group 21. By switching back and forth between the two circuits, current can flow between the first battery group 21 and the second battery group 22, that is, energy exchange is achieved between the first battery group 21 and the second battery group 22, so that the charge level of the first battery group 21 before and after heating is always consistent, and the charge level of the second battery group 22 before and after heating is always consistent.

[0080] For example, in one embodiment, if the state of charge (SOC) of the first battery pack 21 before heating is 50%, the SOC of the first battery pack 21 after heating is also 50%, thereby maintaining the same charge level before and after heating. This prevents damage to the battery 20 due to large differences in charge levels between different battery packs during normal use, protects the battery 20, and helps extend the service life of the battery 20.

[0081] In addition, in this embodiment, the first battery group 21 and the second battery group 22 can be heated simultaneously, which is beneficial to improving the heating rate of the batteries.

[0082] In one embodiment, the first bridge arm 1211 includes a switch tube V1 and a switch tube V2 connected in series, and the second bridge arm 1212 includes a switch tube V3 and a switch tube V4 connected in series.

[0083] In this embodiment, when the battery 20 is in the heating state, the control module 12 can control the switch V3 and the switch V2 to be turned on simultaneously, forming a circuit including the first battery pack 21, the switch V3, the first inductor L1, and the switch V2, for the first battery pack 21 to discharge into the first inductor L1 (the first inductor L1 serves as an energy storage device). Subsequently, the control module 12 controls the switch V3 and the switch V1 to be turned on simultaneously, forming a circuit including the first battery pack 21, the switch V3, the first inductor L1, the switch V1, and the second battery pack 22, for the first battery pack 21 and the first inductor L1 to discharge into the second battery pack 22. The combination of the above two processes completes the entire process of discharging from the first battery pack 21 to the second battery pack 22.

[0084] Alternatively, the control module 12 can control the switching transistors V1 and V4 to be turned on simultaneously, forming a loop including the second battery pack 22, the switching transistor V1, the first inductor L1, and the switching transistor V4, for the second battery pack 22 to discharge into the first inductor L1. Subsequently, the control module 12 controls the switching transistors V1 and V3 to be turned on simultaneously, forming a loop including the second battery pack 22, the switching transistor V1, the first inductor L1, the switching transistor V3, and the first battery pack 21, for the second battery pack 22 and the first inductor L1 to discharge into the first battery pack 21. The combination of the above two processes completes the entire process of the second battery pack 22 discharging into the first battery pack 21.

[0085] It is understandable that in this embodiment, the switches that are not controlled to be turned on are all in the off state. For example, when the control module 12 controls the switches V3 and V2 to be turned on at the same time, the switches V1 and V4 are in the off state.

[0086] At the same time, in this embodiment, the first inductor L1 is only used to store energy during the intermediate process, and the energy transfer is mainly between the first battery pack 21 and the second battery pack 22. Therefore, the above function can be achieved by selecting a first inductor L1 with a smaller inductance value. In the related art, if an energy storage inductor is set in the external high-voltage circuit, the energy transfer is mainly between the energy storage inductor and the battery. At this time, an energy storage inductor with a larger inductance value needs to be selected to provide a larger charge and discharge current. It can be seen that compared with the related art, the present application can select a first inductor L1 with a smaller inductance value to reduce the current lost in the first inductor L1, which has a higher heating efficiency.

[0087] In one embodiment, the heating module 12 further includes a pre-charging unit 122. The pre-charging unit 122 is respectively connected to the first capacitor C1, the second capacitor C2, the first battery pack 21, and the second battery pack 22. The control module 13 is connected to the pre-charging unit 122.

[0088] The control module 13 is further configured to control the pre-charging unit 122 to operate in a first operating state, so that the first battery pack 21 charges the first capacitor C1 and / or the second battery pack 22 charges the second capacitor C2. If the voltage across the first capacitor C1 is not less than a first voltage threshold, and the voltage across the second capacitor C2 is not less than a second voltage threshold, the pre-charging unit 122 is controlled to operate in a second operating state, so as to stop charging the first capacitor C1 and the second capacitor C2.

[0089] The first voltage threshold can be the minimum voltage value that the voltage across the first capacitor C1 should reach, and the second voltage threshold can be the minimum voltage value that the voltage across the second capacitor C2 should reach. In other words, when the heating module 12 is started, only when the voltage across the first capacitor C1 is greater than or equal to the first voltage threshold will the first capacitor C1 not break down due to excessive current. Similarly, when the heating module 12 is started, only when the voltage across the second capacitor C2 is greater than or equal to the second voltage threshold will the second capacitor C2 not break down due to excessive current.

[0090] Secondly, the first voltage threshold and the second voltage threshold can be set according to actual application conditions, and the first voltage threshold and the second voltage threshold can be the same or different, which is not limited in the embodiment of the present application.

[0091] Specifically, by controlling the pre-charging unit 122 to be in the first working state, the first capacitor C1 and the second capacitor C2 can be pre-charged. When the voltage across the first capacitor C1 is not less than a first voltage threshold, and the voltage across the second capacitor C2 is not less than a second voltage threshold, it is determined that the first capacitor C1 and the second capacitor C2 have been pre-charged.

[0092] At the same time, the process of pre-charging the first capacitor C1 and the second capacitor C2 should be set to be completed before controlling the heating module 12. In other words, only after the pre-charging of the first capacitor C1 and the second capacitor C2 is completed, can the heating module 12 be controlled by the control module 13 to complete the heating process. This can prevent the instantaneous current output by the first battery pack 21 from being too large when the heating module 12 is started, causing the first capacitor C1 or electronic components such as switches in the conduction loop to be broken down and damaged, wherein the conduction loop refers to the circuit for charging the first capacitor C1. It can also prevent the instantaneous current output by the second battery pack 22 from being too large when the heating module 12 is started, causing the second capacitor C2 or electronic components such as switches in the conduction loop to be broken down and damaged, wherein the conduction loop refers to the circuit for charging the second capacitor C2. Thereby, it can protect the first capacitor C1 and the second capacitor C2, thereby extending the service life of the first capacitor C1 and the second capacitor C2, which is beneficial to improving the stability of the battery heating circuit 10.

[0093] In one embodiment, the pre-charge unit 122 includes a third switch K3, a fourth switch K4, and a first resistor R1. The third switch K3 and the first resistor R1 are connected in series to form a fourth branch. The fourth branch is connected in parallel with the fourth switch K4. The first end of the fourth branch is connected to the first capacitor C1 and the second capacitor C2, and the second end of the fourth branch is connected to the first battery pack 21 and the second battery pack 22.

[0094] The third switch K3 and the fourth switch K4 are further connected to the control module 13 , and the control module 13 can control the closing or opening of the third switch K3 and the fourth switch K4 .

[0095] In this embodiment, if the first capacitor C1 and the second capacitor C2 are to be precharged, the first resistor R1 needs to be connected to the charging circuit to provide current limiting. This prevents the first battery pack 21 from being overcharged at the moment of charging, which could cause the first capacitor C1 or electronic components such as switches in the conduction circuit to break down. It also prevents the second battery pack 22 from being overcharged at the moment of charging, which could cause the second capacitor C2 or electronic components such as switches in the conduction circuit to break down. This is beneficial for improving the safety of electronic components such as the first capacitor C1 and the second capacitor C2, and extending the service life of electronic components such as the first capacitor C1 and the second capacitor C2.

[0096] If the first capacitor C1 and the second capacitor C2 have been pre-charged, the circuit where the first resistor R1 is located should be disconnected to avoid additional current loss caused by the first resistor R1 during the heating process of the first battery pack 21 and the second battery pack 22, which helps to maintain a high heating efficiency.

[0097] In one embodiment, the control module 13 is further configured to: control the third switch K3 to be closed and the fourth switch K4 to be opened, so as to control the pre-charging unit 122 to be in the first working state; and control the fourth switch K4 to be closed and the third switch K3 to be opened, so as to control the pre-charging unit 122 to be in the second working state.

[0098] When the third switch K3 is closed and the fourth switch K4 is open, the charging circuit for the first capacitor C1 is: the second battery pack 22, the first capacitor C1, and the first resistor R1; the charging circuit for the second capacitor C2 is: the first battery pack 21, the second capacitor C2, and the first resistor R1. It can be seen that in this case, the first resistor R1 is added to the charging circuit of the first capacitor C1 and the second capacitor C2 to prevent the first capacitor C1, the second capacitor C2, and the switches in the conductive circuit (such as the third switch K3) from breaking down due to excessive current.

[0099] After the first capacitor C1 and the second capacitor C2 are precharged, the fourth switch K4 is closed first. After the fourth switch K4 is closed, the third switch K3 is opened. The loop of the first resistor R1 is disconnected, so that during the heating process of the first battery pack 21 and the second battery pack 22, current does not flow through the first resistor R1. This can avoid additional current loss caused by the first resistor R1 and help improve heating efficiency.

[0100] In one embodiment, after heating the first battery pack 21 and the second battery pack 22, the control module 13 is further configured to: if the temperature of the first battery pack 21 is not less than a first temperature threshold, and the temperature of the second battery pack 22 is not less than a second temperature threshold, control the first switch K1 to close, and control the second switch K2 and the fourth switch K4 to open, so that the battery 20 is switched to a use state.

[0101] When the battery 20 is in use, the battery 20 is used to discharge the power to the power-consuming device through the port B+ and the port B−, or to be charged by the charging device through the port B+ and the port B−.

[0102] The first temperature threshold may be the minimum temperature value that the first battery pack 21 must reach, and the second temperature threshold may be the minimum temperature value that the second battery pack 22 must reach. In other words, when the temperature of the first battery pack 21 is greater than or equal to the first temperature threshold, the first battery pack 21 has been heated; when the temperature of the second battery pack 22 is greater than or equal to the second temperature threshold, the second battery pack 22 has been heated.

[0103] Secondly, the first temperature threshold and the second voltage threshold can be set according to actual application conditions, and the first temperature threshold and the second voltage threshold can be the same or different, which is not limited in the embodiment of the present application.

[0104] When both the first and second battery packs 21, 22 have completed heating, the first switch K1 is closed, and the second and fourth switches K2, K4 are opened, switching the battery 20 from the heating state to the operational state. In the operational state, the first and second battery packs 21, 22 are connected in series to form a single unit. At this point, the battery 20 can be used to discharge power to a device or be charged by a charging device.

[0105] In one embodiment, the battery heating circuit 10 further includes a first fuse module 14 and a second fuse module 15. The first fuse module 14 is connected to the first battery pack 21 and the heating module 12, respectively. The second fuse module 15 is connected to the second battery pack 22, the switch module 11, and the heating module 12, respectively.

[0106] In this embodiment, when the output current of the first battery pack 21 is too high, the first fuse module 14 can be fused, immediately disconnecting the circuit and thus protecting the electronic components in the battery heating circuit 10. Similarly, when the output current of the second battery pack 22 is too high, the second fuse module 15 can be fused, immediately disconnecting the circuit and thus protecting the electronic components in the battery heating circuit 10.

[0107] In one embodiment, the first fuse module 14 and the second fuse module 15 both include fuses that blow when the output current of the first battery pack 21 or the second battery pack 22 is too large, thereby protecting the first battery pack 21 and the second battery pack 22 .

[0108] In one embodiment, Figure 3 The battery heating circuit 10 and the battery 20 shown are applied in an electric vehicle, wherein the battery 20 can be used to power electrical components in the electric vehicle, such as the air conditioner and the motor in the vehicle.

[0109] Under normal circumstances, when the battery 20 is in use, the electric vehicle's BMS controls the first switch K1 to close and the second, third, and fourth switches K2, K3, and K4 to open. At this point, the first and second battery packs 21 and 22 are connected in series and function as a single unit. These units can power electrical components such as the air conditioner in the electric vehicle through ports B+ and B-, or be charged by charging equipment such as a charging station.

[0110] When heating the battery 20 is required, the BMS first controls the first switch K1 to open and the second switch K2 to close, switching the battery 20 to the heating state. The BMS then controls the third switch K3 to close and the fourth switch K4 to open, precharging the first and second capacitors C1 and C2.

[0111] After the first capacitor C1 and the second capacitor C2 are precharged, the third switch K3 is opened and the fourth switch K4 is closed. At this point, the BMS can start controlling the switching transistors in the self-heating excitation unit 121 to turn on or off, forming a circuit for the first battery pack 21 to discharge to the second battery pack 22, and / or forming a circuit for the second battery pack 22 to discharge to the first battery pack 21, thereby completing the heating process of the first battery pack 21 and the second battery pack 22.

[0112] Then, after the first battery pack 21 and the second battery pack 22 are heated, the BMS controls the first switch K1 to close, and controls the second switch K2, the third switch K3 and the fourth switch K4 to open, switching the battery 20 back to the use state.

[0113] See also Figure 4 , Figure 4Flowchart of the control method of the battery heating circuit provided in the embodiment of the present application. The battery includes a first battery pack and a second battery pack, and the structure of the battery heating circuit can refer to the above Figure 2 and Figure 3 The detailed description of is omitted here. Figure 4 As shown, the control method of the battery heating circuit includes the following steps:

[0114] 41: Control the switch module to switch the battery to the heating state.

[0115] 42: When the battery is in a heating state, control the heating module so that the first battery pack, the heating module, and the second battery pack form a loop, wherein the loop is used to transfer electricity between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack.

[0116] Based on the above technical solution, the first battery group and the second battery group can be separated into two independent battery groups by controlling the switch module, so that the first battery group discharges to the second battery group through the heating module, and / or the second battery group discharges to the first battery group through the heating module, thereby heating the first battery group and the second battery group. There is no need to set up an external high-voltage circuit as in the related art. It can be seen that the current between the first battery group and the second battery group is not limited by the energy storage unit, and the current between the first battery group and the second battery group can be increased by controlling the current between the first battery group and the second battery group to increase the heating rate of the battery. In addition, the first battery group and the second battery group can be heated simultaneously during the charge and discharge process between the two battery groups, which can also improve the heating efficiency.

[0117] In one embodiment, the switch module includes a first switch and a second switch. The first end of a first branch formed by the first battery pack, the first switch, and the second battery pack connected in series is connected to the heating module. The second end of the first branch is connected to the first end of the second switch and the heating module. The connection point between the first battery pack and the first switch is connected to the second end of the second switch.

[0118] In one embodiment, controlling the switch module to switch the battery to a heating state includes: if a heating request signal is received, controlling the first switch to be opened and controlling the second switch to be closed to switch the battery to the heating state.

[0119] The heating request signal may be a manually-generated signal, such as a user pressing a button to generate a heating request signal. The heating request signal may also be a signal generated by a control module, such as a control module generating a heating request signal when it detects that the battery temperature is too low. This embodiment of the present application is not limited thereto.

[0120] In one embodiment, the heating module includes a self-heating excitation unit, which includes a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor. The first bridge arm and the first capacitor are connected in parallel to form a second branch, the first end of the second branch is connected to the first battery pack, the second bridge arm and the second capacitor are connected in parallel to form a third branch, the first end of the third branch is connected to the switch module and the second battery pack, the second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm.

[0121] When the battery is in a heating state, the heating module is controlled to form a loop among the first battery group, the heating module, and the second battery group, including: controlling the first bridge arm and the second bridge arm to form a loop for discharging from the first battery group to the second battery group, and / or forming a loop for discharging from the second battery group to the first battery group.

[0122] In one embodiment, the heating module further includes a pre-charging unit, which is respectively connected to the first capacitor, the second capacitor, the first battery pack, and the second battery pack.

[0123] The control method of the battery heating circuit further includes: controlling the pre-charging unit to be in a first operating state to enable the first battery pack to charge the first capacitor and / or the second battery pack to charge the second capacitor. If the voltage across the first capacitor is not less than a first voltage threshold and the voltage across the second capacitor is not less than a second voltage threshold, controlling the pre-charging unit to be in a second operating state to stop charging the first and second capacitors.

[0124] In one embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor. The third switch and the first resistor are connected in series to form a fourth branch. The fourth branch is connected in parallel with the fourth switch. A first end of the fourth branch is connected to the first capacitor and the second capacitor, and a second end of the fourth branch is connected to the first battery pack and the second battery pack.

[0125] In one embodiment, controlling the pre-charging unit to be in the first working state includes: controlling the third switch to be closed, and controlling the fourth switch to be open, so as to control the pre-charging unit to be in the first working state.

[0126] In one embodiment, controlling the pre-charging unit to be in the second working state includes: controlling the fourth switch to be closed and controlling the third switch to be open, so as to control the pre-charging unit to be in the second working state.

[0127] In one embodiment, the first end of the first branch and the second end of the first branch are both used to connect to an external device, wherein the external device includes a charging device and a power-consuming device.

[0128] The battery heating circuit control method further includes: if the temperature of the first battery pack is not less than a first temperature threshold and the temperature of the second battery pack is not less than a second temperature threshold, controlling the first switch to close and the second switch to open to switch the battery to a use state. When the battery is in the use state, the battery is used to discharge to an electrical device or to be charged by a charging device.

[0129] It should be understood that the specific control of the battery heating circuit and the beneficial effects produced in the method embodiment can refer to the corresponding description in the above device embodiment, and for the sake of brevity, they are not repeated here.

[0130] See Figure 5 , which shows a schematic structural diagram of a control device 50 for a battery heating circuit provided by an embodiment of the present application. Figure 5 As shown, the control device 50 of the battery heating circuit includes a state switching unit 51 and a heating unit 52 .

[0131] The state switching unit 51 is used to control the switch module to switch the battery to the heating state.

[0132] The heating unit 52 is configured to control the heating module when the battery is in the heating state, so that the first battery pack, the heating module, and the second battery pack form a circuit. The circuit is configured to transfer power between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack.

[0133] The above products can be executed Figure 4 The method provided in the embodiment of the present application shown has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided in the embodiment of the present application.

[0134] See Figure 6 , which shows a schematic structural diagram of a control device 60 for a battery heating circuit provided by an embodiment of the present application. Figure 6 As shown, the control device 60 of the battery heating circuit includes one or more processors 61 and a memory 62. Figure 6 A processor 61 is taken as an example.

[0135] The processor 61 and the memory 62 may be connected via a bus or other means. Figure 6 The bus connection is taken as an example.

[0136] The memory 62 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as the program instructions / modules corresponding to the control method of the battery heating circuit in the embodiment of the present application (for example, the attached Figure 5The processor 61 executes the non-volatile software programs, instructions, and modules stored in the memory 62 to execute various functional applications and data processing of the battery heating circuit control device 60, that is, to implement the battery heating circuit control method in the above-mentioned method embodiment and the functions of the various units in the above-mentioned device embodiment.

[0137] The memory 62 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device. In some embodiments, the memory 62 may optionally include a memory remotely located relative to the processor 61, and such remote memory may be connected to the processor 61 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0138] The program instructions / modules are stored in the memory 62 and, when executed by the one or more processors 61, execute the control method of the battery heating circuit in any of the above method embodiments, for example, executing the above described Figure 4 The steps shown in the figure can also be implemented in the following Figure 5 The functions of each unit described.

[0139] The present application also provides a battery comprising a first battery pack, a second battery pack, and a battery heating circuit as described in any of the above embodiments, wherein the battery heating circuit is configured to heat the first battery pack and the second battery pack.

[0140] An embodiment of the present application further provides an electric vehicle, comprising a load and the battery according to any one of the above embodiments, wherein the battery is used to power the load.

[0141] The present application also provides a non-volatile computer storage medium that stores computer executable instructions. The computer executable instructions are executed by one or more processors, which can enable the one or more processors to execute the battery heating circuit control method in any of the above method embodiments. For example, executing the above described Figure 4 The steps shown in the figure can also be implemented in the following Figure 5 The functions of each unit are shown.

[0142] The above-described device or apparatus embodiments are merely illustrative. The unit modules described as separate components may or may not be physically separate, and the components shown as module units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network module units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment.

[0143] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiment.

[0144] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery heating circuit, wherein: The battery includes a first battery pack and a second battery pack, and the battery heating circuit includes: a switch module, wherein the switch module is connected to the first battery pack and the second battery pack respectively; a heating module, the heating module being connected to the first battery pack, the second battery pack, and the switch module, respectively; a control module, the control module being connected to the switch module and the heating module, the control module being configured to control the switch module to switch the battery to a heating state, and, when the battery is in the heating state, to control the heating module so that the first battery pack, the heating module, and the second battery pack form a loop; wherein the loop is configured to transfer power between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack; The heating module includes a self-heating excitation unit and a pre-charging unit, the self-heating excitation unit includes a first bridge arm, a second bridge arm, a first capacitor, a second capacitor and a first inductor; the pre-charging unit is respectively connected to the first capacitor, the second capacitor, the first battery pack and the second battery pack; The first bridge arm and the first capacitor are connected in parallel to form a second branch, a first end of the second branch is connected to the switch module and the second battery pack, the second bridge arm and the second capacitor are connected in parallel to form a third branch, a first end of the third branch is connected to the first battery pack, and a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm; The control module is connected to the pre-charging unit, and the control module is further used to: control the pre-charging unit to be in a first working state, so that the first battery pack charges the first capacitor, and / or the second battery pack charges the second capacitor; If the voltage across the first capacitor is not less than a first voltage threshold, and the voltage across the second capacitor is not less than a second voltage threshold, the pre-charge unit is controlled to be in a second working state to stop charging the first capacitor and the second capacitor.

2. The battery heating circuit according to claim 1, wherein: The switch module includes a first switch and a second switch; The first battery pack, the first switch, and the second battery pack are connected in series to form a first branch, the first end of the first branch is connected to the heating module, the second end of the first branch is connected to the first end of the second switch and the heating module, the connection point between the first battery pack and the first switch is connected to the second end of the second switch, and the connection point between the second battery pack and the first switch is connected to the heating module.

3. The battery heating circuit according to claim 2, wherein: The control module is further configured to: The first switch is controlled to be opened, and the second switch is controlled to be closed, so that the battery is switched to a heating state.

4. The battery heating circuit according to claim 1, The control module is connected to the first bridge arm and the second bridge arm respectively, and the control module is also used to: when the battery is in a heating state, control the first bridge arm and the second bridge arm to form a circuit for the first battery group to discharge to the second battery group, and / or to form a circuit for the second battery group to discharge to the first battery group, so as to heat the first battery group and the second battery group.

5. The battery heating circuit according to claim 1, wherein: The pre-charge unit includes a third switch, a fourth switch and a first resistor; The third switch and the first resistor are connected in series to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, and the first end of the fourth branch is connected to the first capacitor and the second capacitor, and the second end of the fourth branch is connected to the first battery pack and the second battery pack.

6. The battery heating circuit according to claim 5, wherein: The control module is further configured to: controlling the third switch to be closed and controlling the fourth switch to be open, so as to control the pre-charging unit to be in a first working state; The fourth switch is controlled to be closed, and the third switch is controlled to be open, so as to control the pre-charging unit to be in the second working state.

7. The battery heating circuit according to any one of claims 2 to 3, wherein: The first end of the first branch and the second end of the first branch are both used to connect to an external device, wherein the external device includes a charging device and an electric device, and the control module is further used to: If the temperature of the first battery pack is not less than a first temperature threshold, and the temperature of the second battery pack is not less than a second temperature threshold, controlling the first switch to be closed, and controlling the second switch and the fourth switch to be opened, so that the battery is switched to a use state; Wherein, when the battery is in use, the battery is used to discharge the electrical device or to be charged by the charging device.

8. The battery heating circuit according to claim 1, wherein: The battery heating circuit further includes a first fuse module and a second fuse module; The first fuse module is connected to the first battery pack and the heating module respectively, and the second fuse module is connected to the second battery pack, the heating module and the switch module respectively.

9. A method for controlling a battery heating circuit, wherein: The battery includes a first battery group and a second battery group, and the battery heating circuit includes a switch module and a heating module, the switch module is connected to the first battery group and the second battery group respectively, and the heating module is connected to the first battery group, the second battery group and the switch module respectively; The heating module includes a self-heating excitation unit and a pre-charging unit, the self-heating excitation unit includes a first bridge arm, a second bridge arm, a first capacitor, a second capacitor and a first inductor; the pre-charging unit is respectively connected to the first capacitor, the second capacitor, the first battery pack and the second battery pack; The first bridge arm and the first capacitor are connected in parallel to form a second branch, a first end of the second branch is connected to the switch module and the second battery pack, the second bridge arm and the second capacitor are connected in parallel to form a third branch, a first end of the third branch is connected to the first battery pack, and a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between the midpoint of the first bridge arm and the midpoint of the second bridge arm; The method comprises: controlling the switch module to switch the battery to a heating state; When the battery is in a heating state, controlling the heating module so that the first battery pack, the heating module, and the second battery pack form a loop; wherein the loop is used to transfer electricity between the first battery pack and the second battery pack to heat the first battery pack and the second battery pack; controlling the pre-charging unit to be in a first working state so that the first battery pack charges the first capacitor, and / or the second battery pack charges the second capacitor; If the voltage across the first capacitor is not less than a first voltage threshold, and the voltage across the second capacitor is not less than a second voltage threshold, the pre-charge unit is controlled to be in a second working state to stop charging the first capacitor and the second capacitor.

10. The method according to claim 9, wherein: The switch module includes a first switch and a second switch; The first end of the first branch formed by the first battery pack, the first switch and the second battery pack in series is connected to the heating module, the second end of the first branch is connected to the first end of the second switch and the heating module, and the connection point between the first battery pack and the first switch is connected to the second end of the second switch.

11. The method according to claim 10, wherein: The controlling the switch module to switch the battery to a heating state includes: If a heating request signal is received, the first switch is controlled to be opened, and the second switch is controlled to be closed, so that the battery is switched to a heating state.

12. The method according to claim 9, wherein When the battery is in a heating state, controlling the heating module so that the first battery pack, the heating module, and the second battery pack form a loop includes: The first bridge arm and the second bridge arm are controlled to form a circuit for discharging the first battery group to the second battery group, and / or to form a circuit for discharging the second battery group to the first battery group.

13. The method according to claim 9, wherein: The pre-charge unit includes a third switch, a fourth switch and a first resistor; The third switch and the first resistor are connected in series to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, and the first end of the fourth branch is connected to the first capacitor and the second capacitor, and the second end of the fourth branch is connected to the first battery pack and the second battery pack.

14. The method according to claim 13, wherein: The controlling the pre-charging unit to be in the first working state includes: The third switch is controlled to be closed, and the fourth switch is controlled to be opened, so as to control the pre-charging unit to be in the first working state.

15. The method according to claim 13, wherein The controlling the pre-charging unit to be in the second working state includes: controlling the fourth switch to be closed; The third switch is controlled to be disconnected to control the pre-charging unit to be in the second working state.

16. The method according to any one of claims 10 to 11, wherein: The first end of the first branch and the second end of the first branch are both used to connect to external devices, wherein the external devices include charging devices and power-consuming devices; The method further comprises: If the temperature of the first battery pack is not less than a first temperature threshold, and the temperature of the second battery pack is not less than a second temperature threshold, controlling the first switch to be closed and controlling the second switch to be open, so that the battery is switched to a use state; Wherein, when the battery is in use, the battery is used to discharge the electrical device or to be charged by the charging device.

17. A battery comprising: a first battery pack and a second battery pack; The battery heating circuit according to any one of claims 1 to 8, wherein the battery heating circuit is connected to the first battery pack and the second battery pack, and is configured to heat the first battery pack and the second battery pack.

18. An electric vehicle comprising: A load and a battery as claimed in claim 17, wherein the battery is used to power the load.

19. A computer-readable storage medium comprising: Computer-executable instructions are stored, and the computer-executable instructions are configured as the method according to any one of claims 9 to 16.

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