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, in which the battery includes a first assembled battery and a second assembled battery, and the battery heating circuit includes a switch module, a heating module and a control module. The switch modules are respectively connected to the first assembled battery and the second assembled battery. The heating modules are respectively connected to the first assembled battery, the second assembled battery and the switch module. The control module is connected to the switch module and the heating module, and is used to control the switch module to switch the battery to a heating state, and is used to control the heating module so that the first assembled battery, the heating module and the second assembled battery form a circuit when the battery is in the heating state. Here, the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery. This can improve the heating speed of the battery.

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 technology]

[0002] As energy and environmental problems become more and more serious, the state provides strong support for new energy, and power battery technology becomes more and more mature, electric vehicles have become a new direction for the future development of the automobile industry. The driving range of electric vehicles has become an important factor influencing the popularity of electric vehicles. The battery, a key component, is the main power source of electric vehicles, so the stability and reliability of its product quality are very important.

[0003] However, in a low temperature environment, the use of the battery is somewhat limited. Specifically, the discharge capacity of the battery is severely attenuated in a low temperature environment, and the battery cannot be charged in a low temperature environment. Therefore, the battery needs to be heated to enable normal use of the battery.

[0004] In the prior art, the battery's external high voltage circuit is usually used to quickly switch the battery between charging and discharging to realize the heating process of the battery. In this method, the external high voltage circuit is usually provided with an energy storage unit to provide charging and discharging current. However, in practical application, the energy storage unit can only provide limited charging and discharging current, which results in a slow heating rate of the battery. Summary of the Invention

[0005] An object of the present application is to provide a battery heating circuit, a control method thereof, a battery, and an electric vehicle that can improve the heating rate of a battery. In order to achieve the above object, in a first aspect, the present application provides a battery heating circuit, in which the battery includes a first assembled battery and a second assembled battery, and the battery heating circuit includes a switch module, a heating module, and a control module. The switch module is connected to the first assembled battery and the second assembled battery, respectively, the heating module is connected to the first assembled battery, the second assembled battery, 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 to switch the battery to a heating state, and is used to control the heating module when the battery is in the heating state, so that the first assembled battery, the heating module, and the second assembled battery form a circuit. Here, the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery.

[0006] When the battery needs to be heated, the battery may first be switched to a heating state by the switch module to disassemble the first and second battery packs into two independent battery packs. Then, the first battery pack, the heating module, and the second battery pack form a circuit. In the circuit, the first battery pack can be discharged to the second battery pack by the heating module, and the second battery pack can be discharged to the first battery pack by the heating module, thereby realizing the heating of the first and second battery packs. Therefore, unlike the related art, there is no need for power supply by an external high-voltage circuit, that is, the current between the first and second battery packs is not limited to the energy storage unit, and thus the heating speed of the battery can be improved by controlling the current increase between the first and second battery packs. Then, the first and second battery packs can be heated simultaneously, which is also advantageous for improving the heating speed of the battery. In addition, since current flows only between the first and second assembled batteries, the connection wires between the electronic components are only present inside the batteries, whereas in the related art, a high-voltage circuit needs to be provided outside the batteries, and therefore the connection wires need to be connected from the external high-voltage circuit to the batteries. Generally, the connection wires connecting from the outside to the batteries are longer than the connection wires inside the batteries, i.e., compared to the related art solution of providing a high-voltage circuit outside the batteries, the connection wires required in the present application are short, which can reduce current loss in the connection wires and is advantageous for improving heating efficiency.

[0007] In an 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, a first end of the first branch is connected to the heating module, a second end of the first branch is connected to a first end of the second switch and the heating module, a connection point between the first battery pack and the first switch is connected to a second end of the second switch, and a connection point between the second battery pack and the first switch is connected to the heating module.

[0008] By controlling the first switch and the second switch to be on and off, in the normal state, the first assembled battery and the second assembled battery can be combined together for charging or discharging, and when the battery is switched to a heating state, the first assembled battery and the second assembled battery can be separated into two independent assembled batteries to enable charging and discharging between the two assembled batteries.

[0009] In an optional embodiment, the control module is further used to control the first switch to OFF and the second switch to ON to switch the battery to a heating state.

[0010] In a normal state, the first switch is on and the second switch is off, and the first assembled battery is connected in series with the second assembled battery, at which time the battery can be used to charge or discharge an external device. When it is necessary to heat the battery, the first switch is controlled to be off and the second switch is controlled to be on, and the first assembled battery and the second assembled battery are decomposed from being connected in series into two independent assembled batteries. At this time, the battery is in a heating state, and the charging and discharging process between the two assembled batteries realizes the heating process of the first assembled battery and the second assembled battery.

[0011] In an optional embodiment, the heating module includes a self-heating excitation unit including a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor. The first bridge arm is connected in parallel with the first capacitor to form a second branch, a first end of the second branch is connected to the switch module and the second assembled battery, the second bridge arm is connected in parallel with the second capacitor to form a third branch, a first end of the third branch is connected to the first assembled battery, a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between a midpoint of the first bridge arm and a midpoint of the second bridge arm. A control module is connected to the first bridge arm and the second bridge arm, respectively, and the control module is further used to control the first bridge arm and the second bridge arm when the battery is in a heating state to form a circuit in which the first assembled battery discharges to the second assembled battery and / or form a circuit in which the second assembled battery discharges to the first assembled battery, thereby heating the first assembled battery and the second assembled battery.

[0012] When the battery is heated, the first bridge arm and the second bridge arm may be controlled to form a circuit in which the first assembled battery discharges to the second assembled battery, or a circuit in which the second assembled battery discharges to the first assembled battery. On the one hand, by switching back and forth between the above two circuits, the electrical quantity of each assembled battery before and after heating can be kept consistent, which prevents the batteries from being damaged due to a large difference in the electrical quantity of different assembled batteries during normal use, protects the batteries, and is advantageous in extending the service life of the batteries. On the other hand, the two assembled batteries can be heated simultaneously, which obtains a high heating speed.

[0013] In an optional embodiment, the heating module further includes a pre-charge unit respectively connected to the first capacitor, the second capacitor, the first battery pack, and the second battery pack. The control module is connected to the pre-charge unit, and the control module is further used for controlling the pre-charge unit to a first operating state such that the first battery pack charges the first capacitor and / or the second battery pack charges the second capacitor. When 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 a second operating state to stop charging the first capacitor and the second capacitor.

[0014] By installing a pre-charging unit to pre-charge the first capacitor and the second capacitor, it is possible to avoid the first capacitor or electronic components such as the switch in the conduction circuit being destroyed or damaged due to the instantaneous current output by the first assembled battery being too large when the heating module is started, or the second capacitor or electronic components such as the switch in the conduction circuit being destroyed or damaged due to the instantaneous current output by the second assembled battery being too large, thereby improving the safety of the first capacitor, the second capacitor, and electronic components such as the switch in the conduction circuit, and extending the service life of the electronic components, which is favorable for improving the stability of the battery heating circuit.

[0015] In an optional embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor, the third switch is connected in series with the first resistor to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, and 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 assembled battery and the second assembled battery.

[0016] In this case, when the first capacitor and the second capacitor are charged, the first resistor can reduce the charging current, that is, the first resistor plays a role of current limiting, thereby preventing the first capacitor, the second capacitor, or electronic components such as the switch in the conductive circuit from being damaged by an excessive charging current, and playing a role of protecting the first capacitor and the second capacitor.

[0017] In an optional aspect, the control module is further used to control the third switch to ON and the fourth switch to OFF to control the pre-charge unit to a first operating state, and to control the fourth switch to ON and the third switch to OFF to control the pre-charge unit to a second operating state.

[0018] When the third switch is turned on and the fourth switch is turned off, the third switch is connected in series with the first resistor, so that the first resistor is added to the charging circuit of the first capacitor and the second capacitor, and the first resistor serves the role of current limiting. After the charging of the first capacitor and the second capacitor is completed, the third switch is turned off and the fourth switch is turned on, so that the circuit in which the first resistor is located is turned off, thereby avoiding the extra loss of the first resistor in the current during the heating process of the battery, and helping to improve the heating efficiency.

[0019] In an optional embodiment, the first end of the first branch and the second end of the first branch are both used for connecting with an external device including a charging device and a power consuming device, and the control module is further used for controlling the first switch to be on and the second switch and the fourth switch to be off to switch the battery into a use state when the temperature of the first assembled battery is not lower than the first temperature threshold and the temperature of the second assembled battery is not lower than the second temperature threshold, where when the battery is in a use state, the battery is used for discharging to the power consuming device or is charged by the charging device.

[0020] When the heating of the battery is completed, the first switch is turned on and the second and fourth switches are turned off to switch the battery into a usage state, in which the first assembled battery is connected in series with and integrated into the second assembled battery, in which case the battery is used to discharge to a power consumption device or charged by a charging device.

[0021] In an optional embodiment, the battery heating circuit further includes a first fuse module and a second fuse module, the first fuse module being connected to the first assembled battery and the heating module, respectively, and the second fuse module being connected to the second assembled battery, the heating module, and the switch module, respectively.

[0022] When the output current of the first assembled battery is too large, the first fuse module melts and can turn off the circuit in a timely manner, thereby playing a role in protecting the electronic components in the circuit.Similarly, when the output current of the second assembled battery is too large, the second fuse module melts and can turn off the circuit in a timely manner, thereby playing a role in protecting the electronic components in the circuit.

[0023] In a second aspect, the present application provides a method for controlling a battery heating circuit, in which a battery includes a first battery pack and a second battery pack, and a battery heating circuit includes a switch module and a heating module, the switch module being connected to the first battery pack and the second battery pack respectively, and the heating module being 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, and controlling the heating module such that the first battery pack, the heating module and the second battery pack form a circuit when the battery is in the heating state, where the circuit 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.

[0024] In an optional embodiment, the switch module includes a first switch and a second switch, a first end of a first branch formed by connecting the first assembled battery, the first switch and the second assembled battery in series is connected to the heating module, a second end of the first branch is connected to the first end of the second switch and the heating module, and a connection point between the first assembled battery and the first switch is connected to the second end of the second switch.

[0025] In an optional aspect, controlling the switch module to switch the battery to a heating state includes, upon receiving a heating request signal, controlling the first switch to off and controlling the second switch to on to switch the battery to the heating state.

[0026] In an optional embodiment, the heating module includes a self-heating excitation unit including a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor. The first bridge arm is connected in parallel with the first capacitor to form a second branch, a first end of the second branch is connected to the first assembled battery, the second bridge arm is connected in parallel with the second capacitor to form a third branch, a first end of the third branch is connected to the switch module and the second assembled battery, a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between a midpoint of the first bridge arm and a midpoint of the second bridge arm. When the battery is in a heating state, controlling the heating module such that the first assembled battery, the heating module, and the second assembled battery form a circuit includes controlling the first bridge arm and the second bridge arm to form a circuit in which the first assembled battery discharges to the second assembled battery and / or to form a circuit in which the second assembled battery discharges to the first assembled battery.

[0027] In an optional aspect, the heating module further includes a pre-charge unit respectively connected to the first capacitor, the second capacitor, the first battery pack, and the second battery pack. The method further includes controlling the pre-charge unit to a first operating state such that the first battery pack charges the first capacitor and / or the second battery pack charges the second capacitor. When a voltage across the first capacitor is not less than a first voltage threshold and a voltage across the second capacitor is not less than a second voltage threshold, the pre-charge unit is controlled to a second operating state to stop charging the first capacitor and the second capacitor.

[0028] In an optional embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor, the third switch is connected in series with the first resistor to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, and 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 assembled battery and the second assembled battery.

[0029] In an optional aspect, controlling the pre-charge unit to a first operating state includes controlling a third switch to be on and a fourth switch to be off to control the pre-charge unit to the first operating state.

[0030] In an optional aspect, controlling the pre-charge unit to the second operating state includes controlling the fourth switch to be on and controlling the third switch to be off to control the pre-charge unit to the second operating state.

[0031] In an 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 including a charging device and a power consuming device. The method further includes controlling the first switch to ON and controlling the second switch to OFF when the temperature of the first assembled battery is greater than a first temperature threshold and the temperature of the second assembled battery is greater than a second temperature threshold, to switch the battery to a use state. Wherein, when the battery is in a use state, the battery is used to discharge to a power consuming device or is charged by a charging device.

[0032] In a third aspect, the present application provides a battery, the battery including a first assembled battery and a second assembled battery, and a battery heating circuit according to the first aspect, the battery heating circuit being connected to the first assembled battery and the second assembled battery, and the battery heating circuit being used to heat the first assembled battery and the second assembled battery.

[0033] In a fourth aspect, the present application provides an electric vehicle, the electric vehicle including a load and a battery according to the third aspect, the battery being used to provide power to the load.

[0034] In a fifth aspect, the present application provides a computer-readable storage medium having stored thereon computer-executable instructions configured as the steps of the method in the second aspect.

[0035] The beneficial effects of the embodiments of the present application are as follows: The battery heating circuit provided by the present application switches the battery to a heating state by a switch module, thereby decomposing the first and second battery packs into two independent battery packs. Then, the first battery pack can be discharged to the second battery pack by the heating module, and the second battery pack can also be discharged to the first battery pack by the heating module to realize heating of the first and second battery packs. Therefore, it is not necessary to use an external high-voltage circuit as in the related art, that is, the current between the first and second battery packs is not limited to the energy storage unit, so that the heating speed of the battery can be improved by controlling the current increase between the first and second battery packs. [Brief description of the drawings]

[0036] In order to more clearly explain the technical solutions of the embodiments of the present application, the following will briefly describe the drawings that need to be used in the embodiments of the present application. It is obvious that the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on the drawings without paying creative efforts. [Figure 1] FIG. 1 is a schematic diagram of an application scene disclosed in an embodiment of the present application; [Diagram 2] 1 is a schematic diagram of a battery heating circuit disclosed in one embodiment of the present application. [Diagram 3] FIG. 2 is a schematic circuit diagram of a battery heating circuit disclosed in an embodiment of the present application. [Figure 4] 4 is a flowchart of a control method for a battery heating circuit disclosed in an embodiment of the present application. [Diagram 5] FIG. 1 is a schematic diagram of a control device for a battery heating circuit disclosed in one embodiment of the present application. [Figure 6] FIG. 13 is a schematic diagram of a control device for a battery heating circuit disclosed in another embodiment of the present application.

[0037] In the drawing section, the drawings are not drawn to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Hereinafter, the embodiments of the present application will be described in more detail with reference to the drawings and examples. The detailed description of the following examples and the drawings are used to exemplarily explain the principles of the present application, but should not be used to limit the scope of the present application, i.e., the present application is not limited to the described examples.

[0039] In the description of this application, it should be pointed out that unless otherwise stated, "multiple" means two or more, and the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", and "outer" does not indicate or imply that the indicated device or element must have a particular orientation or be configured and operated in a particular orientation, but is merely for ease of explanation and simplification of the description of this application and should not be understood as a limitation of this application. In addition, terms such as "first", "second", and "third" are used for explanatory purposes only and should not be understood as indicating or implying relative importance. "Perpendicular" is not perpendicular in the strict sense, but within the allowable margin of error. "Parallel" is not parallel in the strict sense, but within the allowable margin of error.

[0040] Any directional terms appearing in the following description are directions shown in the drawings, and are not intended to limit the specific structure of the present application. In the description of the present application, it should be further explained that unless otherwise clearly specified and limited, the terms "attached", "connected" and "connected" should be understood in a broad sense, for example, they may be fixedly connected, detachably connected, or integrally connected, and may be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0041] In recent years, the new energy automobile industry has experienced explosive growth. The battery is the core of the electric vehicle and is also the integration of automotive engineering and power engineering technology. Due to the electrochemical properties of the battery, the charge and discharge capacity of the battery is greatly limited in a low temperature environment, which greatly affects the experience of customers driving in winter. Therefore, in order to enable the battery to be used normally, it is necessary to heat the battery in a low temperature environment.

[0042] In the process of implementing this application, the inventors of this application find that currently, in the related art, a common solution for heating a battery is to use an external high-voltage circuit of the battery to quickly switch the battery between charging and discharging, and after a current flows through the battery, the battery's internal resistance characteristics will directly generate heat inside the battery to raise the temperature, thereby achieving the battery heating process.

[0043] However, in this solution, on the one hand, when the cells in the battery are in a parallel structure, the current flowing through the cells is a part of the total current flowing through the battery, and the current flowing through the cells is reduced, which reduces the heating efficiency of the cells, that is, the heating efficiency of the battery is also reduced. On the other hand, in order to realize the rapid switching between charging and discharging of the battery, an energy storage unit must be provided in the external high-voltage circuit. This energy storage unit may be a motor or a dedicated energy storage inductor. In order to achieve higher heating efficiency, the energy storage unit needs to provide a larger charging and discharging current. However, in practical use, if the energy storage unit is a motor, it is usually applied to electric vehicles, and in the motor design process, the main goal is to match the power of the entire vehicle, so the charging and discharging current that the motor can provide is limited. If the energy storage unit is an energy storage inductor, limiting factors such as volume, weight, etc. must be taken into account, so the charging and discharging current provided by the energy storage inductor is also limited. In this solution, it can be seen that the energy storage unit can only provide a limited charging and discharging current, which results in a slower heating speed of the battery.

[0044] Based on this, the applicant designs a battery heating circuit, which switches the battery to a heating state when the battery needs to be heated, and discharges the first assembled battery to the second assembled battery and / or the second assembled battery to the first assembled battery, thereby achieving the heating process of the battery. Therefore, there is no need to provide an external high voltage circuit as in the related art, and the current between the first assembled battery and the second assembled battery is not limited to the energy storage unit, so that the heating speed of the battery can be improved by controlling the increase in current between the first assembled battery and the second assembled battery. In this way, even if the insides of the first assembled battery and the second assembled battery are connected in parallel, the current flowing through the cell can be increased by controlling the increase in current between the first assembled battery and the second assembled battery, and thus the heating speed of the battery can be improved. In addition, because current flows only between the first and second assembled batteries, the connection wires between the electronic components are only present inside the batteries, whereas in the related art, the high-voltage circuit is provided outside the battery, and so the connection wires must be connected from the external high-voltage circuit to the battery, and typically the connection wires connecting from the outside to the battery are longer than the wires inside the battery. In other words, compared to the solution in the related art of providing a high-voltage circuit outside the battery, the connection wires required in the present application are short, which reduces current loss in the connection wires and is advantageous for improving heating efficiency.

[0045] The battery in the embodiment of the present application may be a lithium ion battery, a lithium metal battery, a lead acid battery, a nickel cadmium battery, a nickel hydrogen battery, a lithium sulfur battery, a lithium air battery, or a sodium ion battery, etc., and is not limited thereto. In terms of scale, each assembled battery in the battery in the embodiment of the present application may be a single cell, a battery module, or a battery pack, and is not limited thereto. In terms of application scenes, the battery may be applied in a power device such as an automobile or a steamship. For example, the battery may be applied to a power vehicle to power the motor of the power vehicle and serve as a power source for the electric vehicle. The battery may also supply power to other power consumption devices of the electric vehicle, such as an in-car air conditioner and an in-car player.

[0046] An embodiment of the present application provides a power consuming device including the battery of any one of the embodiments of the present application. The power consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, an electric bicycle, an electric vehicle, a ship, a spacecraft, etc., where the electric toy may include a stationary or mobile electric toy, such as a game console, an electric vehicle toy, an electric steamer toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0047] In order to facilitate understanding of the present application, we first introduce application scenarios to which the present application can be applied.

[0048] As shown in FIG. 1, FIG. 1 shows an application scene in which a battery 20 is heated by a battery heating circuit 10. Here, the battery heating circuit 10 is connected to the battery 20. The battery 20 includes N assembled batteries such as a first assembled battery, a second assembled battery, ... an Nth assembled battery as shown in FIG. 1, where N is a positive integer of 2 or more. The battery heating circuit 10 in the embodiment of the present application can simultaneously heat two of the assembled batteries at once. That is, the N battery sets can be divided into a plurality of sets, each of which has two assembled batteries, and the battery heating circuit 10 heats one of the assembled batteries each time. The embodiment of the present application does not limit how the N batteries are divided, nor does it limit the heating order of each set of assembled batteries.

[0049] The battery 20 may further be connected to a power system, which includes a motor, etc. The battery 20 may be connected to a drive circuit of the motor, and is used to provide power to the drive circuit of the motor so that a motor vehicle equipped with the battery 20 can run.

[0050] In one embodiment, a Battery Management System (BMS) of the battery 20 collects status information of the battery 20, 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 the status information. If it is determined that the battery 20 needs to be heated, the BMS may send a heating request to a Vehicle Control Unit (VCU). The VCU turns on the battery heating circuit 10 to heat the battery 20 according to the heating request sent from the BMS.

[0051] The present application does not limit the use scene of the battery heating circuit 10, and the battery heating circuit 10 in the embodiment of the present application can realize the heating process of the battery 20 in any necessary occasion.

[0052] Hereinafter, taking a battery 20 including a first assembled battery 21 and a second assembled battery 22 as an example, how the battery heating circuit 10 heats the batteries 20 simultaneously will be described.

[0053] Referring to Fig. 2, Fig. 2 is a schematic diagram of the connection between a battery heating circuit 10 and a battery 20 provided in an embodiment of the present application. As shown in Fig. 2, the battery heating circuit 10 includes a switch module 11, a heating module 12 and a control module 13. Here, the switch module 11 is connected to the first assembled battery 21 and the second assembled battery 22 respectively, the heating module 12 is connected to the first assembled battery 21, the second assembled battery 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.

[0054] Specifically, the control module 13 is used to control the switch module 11 to switch the battery 20 to a heating state, and to control the heating module 12 to make the first assembled battery 21, the heating module 12, and the second assembled battery 22 form a circuit when the battery 20 is in the heating state. Here, the circuit is for transferring electricity between the first assembled battery 21 and the second assembled battery 22 to heat the first assembled battery 21 and the second assembled battery 22.

[0055] Here, the control module 13 may be a VCU or may be a control module relatively independent of the VCU, for example, a control module specially installed for the battery heating circuit 10, and the embodiments of the present application are not limited thereto.

[0056] In a normal state, the first assembled battery 21 and the second assembled battery 22 together form a battery 20, which can be used to discharge to an external power consuming device or to be charged by an external device. When it is necessary to heat the battery 20, the switch module 11 is controlled to switch the battery 20 to a heating state, and at this time, the first assembled battery 21 and the second assembled battery 22 are decomposed into two independent assembled batteries. That is, the heating state means that the battery 20 is in a heatable state, and at this time, the battery 20 cannot be used to discharge to an external power consuming device or to be charged by an external device.

[0057] Furthermore, the control of the heating module 12 can be continued so that the first assembled battery 21, the heating module 12, and the second assembled battery 22 form a circuit. In this circuit, the first assembled battery 21 can be discharged to the second assembled battery 22 by the heating module 12 and / or the second assembled battery 22 can be discharged to the first assembled battery 21 by the heating module 12.

[0058] According to Joule's law, when a current flows through a conductor (e.g. a resistor), heat is generated, and the amount of heat generated is proportional to the resistance of the conductor, proportional to the square of the current passing through the conductor, and proportional to the time the current is passed. Therefore, because there is internal resistance in both the first assembled battery 21 and the second assembled battery 22, heat is generated when a current flows through the first assembled battery 21 and the second assembled battery 22, and this realizes a heating process of the first assembled battery 21 and the second assembled battery 22.

[0059] In this embodiment, there is no need to provide an external high voltage circuit as in the related art, i.e., the current between the first assembled battery 21 and the second assembled battery 22 is not limited to the energy storage unit, so that the heating rate of the battery 20 can be improved by controlling the increase in current between the first assembled battery 21 and the second assembled battery 22.

[0060] Next, the first assembled battery 21 and the second assembled battery 22 can be heated simultaneously, which is also advantageous for improving the heating speed of the batteries.

[0061] In addition, since current flows only between the first assembled battery 21 and the second assembled battery 22, the connection wires between the electronic components are only present inside the battery, whereas in the related art, it is necessary to provide a high-voltage circuit outside the battery, and therefore it is also necessary to provide connection wires from the high-voltage circuit outside the battery to the battery. Obviously, compared to the solution in the related art of providing a high-voltage circuit outside the battery, the connection wires required in the present application are shorter and current loss in the connection wires can be reduced, which is advantageous for improving heating efficiency.

[0062] In one embodiment, as shown in Fig. 3, the switch module 11 includes a first switch K1 and a second switch K2. Here, the first assembled battery 21, the first switch K1, and the second assembled battery 22 are connected in series to form a first branch, a first end of the first branch (i.e., the positive electrode of the first assembled battery 21) is connected to the heating module 12, a second end of the first branch (i.e., the negative electrode of the second assembled battery 22) is connected to a first end of the second switch K2 and the heating module 12, a connection point between the first assembled battery 21 and the first switch K1 is connected to a second end of the second switch K2, and a connection point between the second assembled battery 22 and the first switch K1 is connected to the heating module 12. Here, the first switch K1 and the second switch K2 are also connected to the control module 13 (not shown in Fig. 3), i.e., the first switch K1 and the second switch K2 are controlled by the control module 13.

[0063] In this embodiment, the first assembled battery 21 and the second assembled battery 22 each include a plurality of cells connected in series. In other embodiments, the first assembled battery 21 and the second assembled battery 22 may include a plurality of cells connected in parallel, and the embodiments of the present application are not limited thereto.

[0064] In this embodiment, the control module 13 controls the on / off of the first switch K1 and the second switch K2, thereby enabling the first assembled battery 21 and the second assembled battery 22 to be combined together and charged or discharged under normal circumstances.

[0065] For example, in one embodiment, the control module 13 controls the first switch K1 to be on and the second switch K2 to be off, thereby connecting the first assembled battery 21 and the second assembled battery 22 in series and integrating them. At this time, the first end of the first branch is connected to an external device through port B+, and the second end of the first branch is connected to an external device through port B-, where the external device includes a charging device and a power consuming device. Then, the battery 20 can be discharged to the power consuming device through port B+ and port B-, or charged by the charging device.

[0066] On the other hand, it is also possible to disassemble the first assembled battery 21 and the second assembled battery 22 into two independent assembled batteries, and switch the battery 20 to a heating state so as to realize a charging / discharging process between the two assembled batteries.

[0067] For example, in one embodiment, the control module 13 controls the first switch K1 to be off and the second switch K2 to be on, thereby separating the first assembled battery 21 and the second assembled battery 22 from a series connection into two independent assembled batteries, and the battery 20 is switched to a heating state. At this time, the positive electrode of the first assembled battery 21 is connected to the positive electrode of the second assembled battery 22 by the heating module 12, and the negative electrode of the first assembled battery 21 is connected to the negative electrode of the second assembled battery 22. Then, by controlling the heating module 12, it is possible to realize the first assembled battery 21 discharging to the second assembled battery 22 (i.e., charging the second assembled battery 22) and the second assembled battery 22 discharging to the first assembled battery 21 (i.e., charging the first assembled battery 21), i.e., a charging / discharging process between the first assembled battery 21 and the second assembled battery 22 is realized, and a heating process of the first assembled battery 21 and the second assembled battery 22 is realized.

[0068] In the related art, the premise for realizing charging and discharging between two assembled batteries is that the two assembled batteries are connected in parallel. However, the voltage provided by the two assembled batteries connected in parallel is the voltage of a single assembled battery, and it is difficult to meet application scenarios that require high voltage. For the present application, this is only suitable for the case where the first assembled battery 21 and the second assembled battery 22 are connected in series. When the battery 20 needs to be heated, the first switch K1 and the second switch K2 can be controlled to disassemble the battery 20 into two independent assembled batteries, and the heating process of the battery 20 can be realized. When the battery 20 needs to supply power to an external device, the first switch K1 and the second switch K2 can be controlled to connect the first assembled battery 21 and the second assembled battery 22 in series together, thereby providing a high voltage to the external device, and thus satisfying application scenarios that require high voltage.

[0069] In one embodiment, the heating module 12 includes a self-heating excitation unit 121, which includes a first bridge arm 1211, a second bridge arm 1212, a first capacitor C1, a second capacitor C2, and a first inductor L1. Here, the first bridge arm 1211 is connected in parallel with the first capacitor C1 to form a second branch, a first end of the second branch is connected to the switch module 11 and the second assembled battery 22, the second bridge arm 1212 is connected in parallel with the second capacitor C2 to form a third branch, a first end of the third branch is connected to the first assembled battery 21, a 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.

[0070] The control module 13 is respectively connected to the first bridge arm 1211 and the second bridge arm 1212, and the control module is further used to control the first bridge arm 1211 and the second bridge arm 1212 when the battery 20 is in a heating state to form a circuit in which the first assembled battery 21 discharges to the second assembled battery 22 and / or to form a circuit in which the second assembled battery 22 discharges to the first assembled battery 21, thereby heating the first assembled battery 21 and the second assembled battery 22.

[0071] In this embodiment, the first capacitor C1 is connected in parallel to the second assembled battery 22, and the second capacitor C2 is connected in parallel to the first assembled battery 21. Therefore, the first capacitor C1 and the second capacitor C2 can realize functions such as voltage stabilization, reduce voltage fluctuations in the second assembled battery 22 and the first assembled battery 21, and improve the voltage stability of the second assembled battery 22 and the first assembled battery 21.

[0072] Specifically, when the battery 20 is heated, the first bridge arm 1211 and the second bridge arm 1212 may be controlled to form a circuit in which the first assembled battery 21 discharges to the second assembled battery 22, or a circuit in which the second assembled battery 22 discharges to the first assembled battery 21. By switching back and forth between the above two circuits, it is possible to realize mutual flow of current between the first assembled battery 21 and the second assembled battery 22, that is, energy exchange between the first assembled battery 21 and the second assembled battery 22, and thereby it is possible to constantly maintain the same amount of electricity before and after heating of the first assembled battery 21 and the second assembled battery 22.

[0073] For example, in one embodiment, the battery state of charge (SOC) of the first assembled battery 21 before heating is 50%, and the SOC of the first assembled battery 21 after heating is completed is also 50% in order to maintain the same amount of electricity before and after heating of the first assembled battery 21. This prevents the battery 20 from being damaged due to the difference in the amount of electricity between different assembled batteries during normal use, protects the battery 20, and is advantageous in extending the service life of the battery 20.

[0074] Furthermore, in this embodiment, the first assembled battery 21 and the second assembled battery 22 can be heated simultaneously, which is advantageous in improving the heating speed of the batteries.

[0075] In one embodiment, the first bridge arm 1211 includes a switch transistor V1 and a switch transistor V2 connected in series, and the second bridge arm 1212 includes a switch transistor V3 and a switch transistor V4 connected in series.

[0076] In this embodiment, when the battery 20 is in a heating state, the control module 13 can control the switch transistor V3 and the switch transistor V2 to be simultaneously conductive, forming a circuit including the first assembled battery 21, the switch transistor V3, the first inductor L1, and the switch transistor V2, and the first assembled battery 21 is used to discharge to the first inductor L1 (the first inductor L1 plays the role of energy storage). Then, the control module 13 controls the switch transistor V3 and the switch transistor V1 to be simultaneously conductive, forming a circuit including the first assembled battery 21, the switch transistor V3, the first inductor L1, the switch transistor V1, and the second assembled battery 22, and the first assembled battery 21 and the first inductor L1 are used to discharge to the second assembled battery 22. By combining the above two processes, the entire process of the first assembled battery 21 discharging to the second assembled battery 22 is completed.

[0077] Alternatively, the control module 13 can control the switch transistor V1 and the switch transistor V4 to be simultaneously conductive, forming a circuit including the second assembled battery 22, the switch transistor V1, the first inductor L1, and the switch transistor V4, and the second assembled battery 22 is used to discharge to the first inductor L1. Next, the control module 13 controls the switch transistor V1 and the switch transistor V3 to be simultaneously conductive, forming a circuit including the second assembled battery 22, the switch transistor V1, the first inductor L1, the switch transistor V3, and the first assembled battery 21, and the second assembled battery 22 and the first inductor L1 are used to discharge to the first assembled battery 21. The combination of the above two processes completes the entire process of the second assembled battery 22 discharging to the first assembled battery 21.

[0078] It should be understood that in this embodiment, all switch transistors whose conduction is not controlled are in an off state. For example, when the control module 13 controls the switch transistor V3 and the switch transistor V2 to be simultaneously conductive, the switch transistor V1 and the switch transistor V4 are in an off state.

[0079] Meanwhile, in this embodiment, the first inductor L1 is only used for storing energy in the intermediate process, and the energy is mainly transferred between the first assembled battery 21 and the second assembled battery 22, so the above-mentioned function can be realized by selecting the first inductor L1 with a small inductance value. In the related art, when an energy storage inductor is installed in the external high-voltage circuit, the energy is mainly transferred between the energy storage inductor and the battery, and at this time, it is necessary to select an energy storage inductor with a large inductance value to provide a large charging / discharging current. Compared with the related art, it can be seen that the present application can select the first inductor L1 with a smaller inductance value so as to reduce the current lost in the first inductor L1 and have a higher heating efficiency.

[0080] In an embodiment, the heating module 12 further includes a pre-charge unit 122. The pre-charge unit 122 is respectively connected to the first capacitor C1, the second capacitor C2, the first assembled battery 21, and the second assembled battery 22. The control module 13 is connected to the pre-charge unit 122.

[0081] The control module 13 is further used to control the pre-charge unit 122 into a first working state, so that the first assembled battery 21 charges the first capacitor C1 and / or the second assembled battery 22 charges the second capacitor C2. When the voltage across the first capacitor C1 is not less than the first voltage threshold and the voltage across the second capacitor C2 is not less than the second voltage threshold, the control module 13 controls the pre-charge unit 122 into a second working state to stop charging the first capacitor C1 and the second capacitor C2.

[0082] Here, the first voltage threshold is the minimum voltage value that the voltage across the first capacitor C1 should reach, and the second voltage threshold is the minimum voltage value that the voltage across the second capacitor C2 should reach. In other words, when the heating module 12 is started up, the first capacitor C1 will not be destroyed by an overcurrent only if the voltage across the first capacitor C1 is equal to or greater than the first voltage threshold. Similarly, when the heating module 12 is started up, the second capacitor C2 will not be destroyed by an overcurrent only if the voltage across the second capacitor C2 is equal to or greater than the second voltage threshold.

[0083] Next, 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, and the embodiments of the present application are not limited thereto.

[0084] Specifically, the pre-charging of the first capacitor C1 and the second capacitor C2 can be realized by controlling the pre-charging unit 122 to a first working state, where, 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 pre-charging of both the first capacitor C1 and the second capacitor C2 is completed.

[0085] At the same time, the process of precharging the first capacitor C1 and the second capacitor C2 should be completed before controlling the heating module 12; in other words, only after the precharging of the first capacitor C1 and the second capacitor C2 is completed can the control module 13 control the heating module 12 to complete the heating process. When the heating module 12 is started, the instantaneous current output from the first assembled battery 21 becomes excessive, which can prevent the first capacitor C1 and electronic components such as the switch in the conductive circuit in which the first capacitor C1 is charged from being destroyed and damaged. Also, when the heating module 12 is started, the instantaneous current output from the second assembled battery 22 becomes excessive, which can prevent the second capacitor C2 and electronic components such as the switch in the conductive circuit in which the second capacitor C2 is charged from being destroyed and damaged. Therefore, the first capacitor C1 and the second capacitor C2 can be protected, which is advantageous for extending the service life of the first capacitor C1 and the second capacitor C2 and improving the stability of the battery heating circuit 10.

[0086] 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 is connected in series with the first resistor R1 to form a fourth branch, the fourth branch is connected in parallel with the fourth switch K4, and a first end of the fourth branch is connected to the first capacitor C1 and the second capacitor C2, and a second end of the fourth branch is connected to the first assembled battery 21 and the second assembled battery 22.

[0087] Here, the third switch K3 and the fourth switch K4 are further connected to a control module 13 that can control the third switch K3 and the fourth switch K4 to be on or off.

[0088] In this embodiment, when the first capacitor C1 and the second capacitor C2 are precharged, the first resistor R1 must be connected to the charging circuit, and serves to limit the current. This can prevent the charging current from becoming excessive the moment the first assembled battery 21 starts charging, which would destroy the first capacitor C1 and electronic components such as the switches in the conductive circuit. This can also prevent the charging current from becoming excessive the moment the second assembled battery 22 starts charging, which would destroy the second capacitor C2 and electronic components such as the switches in the conductive circuit. This is advantageous in improving the safety of electronic components such as the first capacitor C1 and the second capacitor C2, and in extending the service life of electronic components such as the first capacitor C1 and the second capacitor C2.

[0089] When the pre-charging of the first capacitor C1 and the second capacitor C2 is completed, the circuit where the first resistor R1 is located is cut off to prevent the first resistor R1 from causing unnecessary current loss in the process of heating the first assembled battery 21 and the second assembled battery 22, which helps to maintain high heating efficiency.

[0090] In one embodiment, the control module 13 is further used to control the third switch K3 to be on and the fourth switch K4 to be off to control the pre-charge unit 122 to a first working state, and to control the fourth switch K4 to be on and the third switch K3 to be off to control the pre-charge unit 122 to a second working state.

[0091] When the third switch K3 is turned on and the fourth switch K4 is turned off, the charging circuit for the first capacitor C1 is the second assembled battery 22, the first capacitor C1, and the first resistor R1, and the charging circuit for the second capacitor C2 is the first assembled battery 21, the second capacitor C2, and the first resistor R1. In this case, it can be seen that the first resistor R1 is added to the charging circuits for the first capacitor C1 and the second capacitor C2, and electronic components such as the first capacitor C1, the second capacitor C2, and the switches in the conductive circuit (e.g., the third switch K3) are prevented from being destroyed by an overcurrent.

[0092] After the first capacitor C1 and the second capacitor C2 are pre-charged, the fourth switch K4 is turned on first, and then the third switch K3 is turned off, so that the circuit where the first resistor R1 is located is cut off, and thus, in the heating process of the first assembled battery 21 and the second assembled battery 22, no current flows through the first resistor R1, which can avoid the first resistor R1 from causing extra current loss, and helps to improve the heating efficiency.

[0093] In one embodiment, after heating the first assembled battery 21 and the second assembled battery 22, the control module 13 is further used to switch the battery 20 to a usage state by controlling the first switch K1 to be on and the second switch K2 and the fourth switch K4 to be off when the temperature of the first assembled battery 21 is not lower than the first temperature threshold and the temperature of the second assembled battery 22 is not lower than the second temperature threshold.

[0094] Here, when the battery 20 is in use, the battery 20 can be used to discharge to a power consuming device via port B+ and port B-, or can be charged by a charging device via port B+ and port B-.

[0095] Here, the first temperature threshold is the minimum temperature value that the temperature of the first assembled battery 21 should reach, and the second temperature threshold is the minimum temperature value that the temperature of the second assembled battery 22 should reach. In other words, when the temperature of the first assembled battery 21 is equal to or higher than the first temperature threshold, heating of the first assembled battery 21 has already been completed. When the temperature of the second assembled battery 22 is equal to or higher than the second temperature threshold, heating of the second assembled battery 22 has already been completed.

[0096] Next, the first temperature threshold and the second temperature threshold can be set according to actual applications, and the first temperature threshold and the second voltage threshold can be the same or different, and the embodiments of the present application are not limited thereto.

[0097] When both the first assembled battery 21 and the second assembled battery 22 have completed heating, the first switch K1 is turned on and the second switch K2 and the fourth switch K4 are turned off, thereby switching the battery 20 from a heating state to a usage state. In the usage state, the first assembled battery 21 and the second assembled battery 22 are connected in series and integrated, and at this time, the battery 20 can be used to discharge to a power consumption device or charged by a charging device.

[0098] 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 assembled battery 21 and the heating module 12, respectively, and the second fuse module 15 is connected to the second assembled battery 22, the switch module 11, and the heating module 12, respectively.

[0099] In this embodiment, if the output current of the first assembled battery 21 is too large, the first fuse module 14 can melt and therefore cut off the circuit at the appropriate time, thereby playing a role in protecting each electronic component in the battery heating circuit 10. Similarly, if the output current of the second assembled battery 22 is too large, the second fuse module 15 can melt and therefore cut off the circuit at the appropriate time, thereby playing a role in protecting each electronic component in the battery heating circuit 10.

[0100] In one embodiment, the first fuse module 14 and the second fuse module 15 both include a fuse, which melts when the output current of the first assembled battery 21 or the second assembled battery 22 becomes excessive, thereby protecting the first assembled battery 21 and the second assembled battery 22.

[0101] In one embodiment, the battery heating circuit 10 and the battery 20 shown in Fig. 3 can be applied to an electric vehicle, where the battery 20 can be used to provide power to power consuming devices of the electric vehicle, such as an in-car air conditioner, a motor, etc.

[0102] During normal operation, i.e., when the battery 20 is in use, the BMS in the electric vehicle controls the first switch K1 to be on and the second switch K2, the third switch K3, and the fourth switch K4 to be off. At this time, the first assembled battery 21 is connected in series together with the second assembled battery 22, and can provide power to power consuming devices such as an air conditioner in the electric vehicle through port B+ and port B-, or can be charged by a charging device such as a charging station.

[0103] When the battery 20 needs to be heated, the BMS first controls the first switch K1 to be turned off and the second switch K2 to be turned on to switch the battery 20 into a heating state. Next, the BMS controls the third switch K3 to be turned on and keeps the fourth switch K4 off to realize a pre-charging process of the first capacitor C1 and the second capacitor C2.

[0104] After the pre-charging of the first capacitor C1 and the second capacitor C2 is completed, the third switch K3 is turned off and the fourth switch K4 is turned on. At this time, the BMS starts to control each switch transistor in the self-heating excitation unit 121 to be turned on or off, so as to form a circuit in which the first assembled battery 21 discharges to the second assembled battery 22 and / or form a circuit in which the second assembled battery 22 discharges to the first assembled battery 21, thereby completing the heating process of the first assembled battery 21 and the second assembled battery 22.

[0105] Then, when heating of the first assembled battery 21 and the second assembled battery 22 is completed, the BMS controls the first switch K1 to be on and the second switch K2, the third switch K3 and the fourth switch K4 to be off, thereby switching the battery 20 back to a usage state.

[0106] Referring to Fig. 4, Fig. 4 is a flow chart of a method for controlling a battery heating circuit provided by an embodiment of the present application. Here, the battery includes a first assembled battery and a second assembled battery, and the structure of the battery heating circuit can refer to the above detailed description of Fig. 2 and Fig. 3. It will not be repeated here. As shown in Fig. 4, the method for controlling the battery heating circuit includes the following steps:

[0107] 41, Control the switch module to switch the battery to a heating state.

[0108] 42. Control the heating module so that the first assembled battery, the heating module, and the second assembled battery form a circuit when the battery is in a heating state, where the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery.

[0109] Based on the above technical solution, the first and second battery packs can be decomposed into two independent battery packs by controlling the switch module, and the first battery pack is discharged to the second battery pack by the heating module, and / or the second battery pack is discharged to the first battery pack by the heating module, thereby realizing heating of the first and second battery packs. Therefore, there is no need to provide an external high-voltage circuit as in the related art, and obviously, the current between the first and second battery packs is not limited to the energy storage unit, so that the heating speed of the battery can be improved by controlling the current increase between the first and second battery packs. In addition, the first and second battery packs can be heated simultaneously during the charging and discharging process between the two batteries, and the heating efficiency can also be improved.

[0110] In one embodiment, the switch module includes a first switch and a second switch, a first end of a first branch formed by serially connecting the first assembled battery, the first switch and the second assembled battery is connected to the heating module, a second end of the first branch is connected to the first end of the second switch and the heating module, and a connection point between the first assembled battery and the first switch is connected to the second end of the second switch.

[0111] In one embodiment, controlling the switch module to switch the battery to a heating state includes, upon receiving a heating request signal, controlling a first switch to off and controlling a second switch to on to switch the battery to the heating state.

[0112] Here, the heating request signal may be a signal given manually by a user, for example, by pressing a button to output a heating request signal. The heating request signal may also be a signal given by a control module, for example, a heating request signal given when the control module detects that the temperature of the battery is too low. The embodiments of the present application are not limited thereto.

[0113] In one embodiment, the heating module includes a self-heating excitation unit, including a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor, the first bridge arm is connected in parallel with the first capacitor to form a second branch, a first end of the second branch is connected to the first assembled battery, the second bridge arm is connected in parallel with the second capacitor to form a third branch, a first end of the third branch is connected to the switch module and the second assembled battery, a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between a midpoint of the first bridge arm and a midpoint of the second bridge arm.

[0114] When the batteries are in a heating state, controlling the heating module so that the first assembled battery, the heating module, and the second assembled battery form a circuit includes controlling the first bridge arm and the second bridge arm to form a circuit in which the first assembled battery discharges to the second assembled battery and / or to form a circuit in which the second assembled battery discharges to the first assembled battery.

[0115] In one embodiment, the heating module further includes a pre-charge unit respectively connected to the first capacitor, the second capacitor, the first assembled battery, and the second assembled battery.

[0116] The method for controlling a battery heating circuit further includes controlling a pre-charge unit to a first operating state so that the first assembled battery charges the first capacitor and / or the second assembled battery charges the second capacitor, and controlling the pre-charge unit to a second operating state to stop charging the first capacitor and the second capacitor when the voltage across the first capacitor is not less than the first voltage threshold and the voltage across the second capacitor is not less than the second voltage threshold.

[0117] In one embodiment, the pre-charge unit includes a third switch, a fourth switch, and a first resistor, the third switch is connected in series with the first resistor to form a fourth branch, the fourth branch is connected in parallel with the fourth switch, and 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 assembled battery and the second assembled battery.

[0118] In one embodiment, controlling the pre-charge unit to the first operating state includes controlling the third switch to be on and controlling the fourth switch to be off to control the pre-charge unit to the first operating state.

[0119] In one embodiment, controlling the pre-charge unit to the second operating state includes controlling the fourth switch to be on and controlling the third switch to be off to control the pre-charge unit to the second operating state.

[0120] In one embodiment, the first end of the first branch and the second end of the first branch are both used for connecting to external devices, including a charging device and a power consuming device.

[0121] The method for controlling the battery heating circuit further includes, when the temperature of the first assembled battery is not lower than the first temperature threshold and the temperature of the second assembled battery is not lower than the second temperature threshold, controlling the first switch to be on and the second switch to be off to switch the battery into a use state, where when the battery is in a use state, the battery is used to discharge to a power consumption device or is charged by a charging device.

[0122] It should be understood that the specific control of the battery heating circuit in the method embodiment and the resulting beneficial effects may be referred to the corresponding descriptions of the apparatus embodiments described above, and will not be repeated here for the sake of brevity.

[0123] 5, a schematic diagram of a control device 50 of a battery heating circuit provided by an embodiment of the present application is shown. As shown in FIG. 5, the control device 50 of the battery heating circuit includes a state switching unit 51 and a heating unit 52.

[0124] The state switching unit 51 is used to control the switch module to switch the battery into a heating state.

[0125] The heating unit 52 is used to control the heating module so that the first assembled battery, the heating module and the second assembled battery form a circuit when the batteries are in a heating state, where the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery.

[0126] The above product can implement the method provided in the embodiment of the present application as shown in Figure 4, and has the corresponding functional modules for implementing the method and beneficial effects. For technical details not described in detail in this embodiment, please refer to the method provided in the embodiment of the present application.

[0127] Referring to Fig. 6, a schematic configuration diagram of a control device 60 of a battery heating circuit provided by an embodiment of the present application is shown. As shown in Fig. 6, the control device 60 of the battery heating circuit includes one or more processors 61 and a memory 62. Note that Fig. 6 takes one processor 61 as an example.

[0128] The processor 61 and the memory 62 may be connected by a bus or other method, and FIG. 6 illustrates a connection by a bus.

[0129] The memory 62, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs and modules, such as program instructions / modules (e.g., each unit shown in FIG. 5) corresponding to the control method of the battery heating circuit in the embodiments of the present application. The processor 61 executes the non-volatile software programs, instructions and modules stored in the memory 62 to perform various functional applications and data processing of the control device 60 of the battery heating circuit, i.e., to realize the control method of the battery heating circuit in the above-mentioned method embodiments and the functions of each unit in the above-mentioned device embodiments.

[0130] Memory 62 may include high speed random access memory and may further include non-volatile memory, such as, for example, at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, memory 62 may optionally include memory located remotely relative to processor 61, and these remote memories may be connected to processor 61 by a network. Examples of such networks include, but are not limited to, the Internet, a corporate intranet, a local area network, a mobile communication network, and combinations thereof.

[0131] The program instructions / modules, when stored in the memory 62 and executed by the one or more processors 61, perform the method for controlling a battery heating circuit in any of the above-mentioned method embodiments, for example, each step shown in Figure 4 above. The functions of each unit shown in Figure 5 can also be realized.

[0132] An embodiment of the present application further provides a battery, including a first assembled battery, a second assembled battery, and the battery heating circuit of any of the above embodiments, where the battery heating circuit is used to heat the first assembled battery and the second assembled battery.

[0133] Additionally, an embodiment of the present application further provides an electric vehicle including a load and the battery of any of the above embodiments for providing power to the load.

[0134] An embodiment of the present application further provides a non-volatile computer storage medium having computer-executable instructions stored therein, which, when executed by one or more processors, can cause the one or more processors to execute the control method for the battery heating circuit in any of the above-mentioned method embodiments. For example, each step shown in Fig. 4 described above can be executed. Also, the functions of each unit shown in Fig. 5 can be realized.

[0135] The above-mentioned device or equipment embodiments are merely illustrative, in which the unit modules described as separate parts may or may not be physically separate, and the parts shown as module units may or may not be physical units, i.e., they may be located in one place or distributed among multiple network module units. According to actual requirements, some or all of those modules may be selected to achieve the objectives of the solution of the embodiment.

[0136] From the above description of the embodiments, it is obvious to those skilled in the art that each embodiment can be realized by software and a general-purpose hardware platform, and of course can be realized by hardware. Based on this understanding, the essential or related technical part of the above technical solution can be embodied as a software product, and the computer software product can be stored in a computer-readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes some instructions for making a computer device (such as a personal computer, a server, or a network device) execute the method described in various embodiments or a part of the embodiments.

[0137] Although the present application has been described with reference to preferred embodiments, various improvements can be made thereto without departing from the scope of the present application, and the elements herein can be replaced with equivalents. In particular, as long as there is no structural contradiction, any of the technical features mentioned in each embodiment can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions included in the claims.

Claims

1. A heating circuit for a battery, the battery including a first assembled battery and a second assembled battery, the heating circuit for the battery comprising: a switch module connected to the first assembled battery and the second assembled battery, a heating module connected to the first assembled battery, the second assembled battery, and the switch module, respectively; a control module connected to the switch module and the heating module, the control module being used to control the switch module to switch the battery to a heating state, and controlling the heating module so that the first assembled battery, the heating module and the second assembled battery form a circuit when the battery is in the heating state; the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery; the switch module includes a first switch and a second switch; a battery heating circuit, wherein the first assembled battery, the first switch and the second assembled battery are connected in series to form a first branch, a first end of the first branch is connected to the heating module, a second end of the first branch is connected to a first end of the second switch and the heating module, a connection point between the first assembled battery and the first switch is connected to a second end of the second switch, and a connection point between the second assembled battery and the first switch is connected to the heating module.

2. The control module further comprises:

2. The battery heating circuit of claim 1, used to control the first switch to be off and the second switch to be on to switch the battery to a heating state.

3. The heating module includes a self-heating excitation unit including a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor; the first bridge arm is connected in parallel to the first capacitor to form a second branch, a first end of the second branch is connected to the switch module and the second assembled battery, the second bridge arm is connected in parallel to the second capacitor to form a third branch, a first end of the third branch is connected to the first assembled battery, a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between a midpoint of the first bridge arm and a midpoint of the second bridge arm, 2. The battery heating circuit of claim 1, wherein the control module is connected to the first bridge arm and the second bridge arm, respectively, and the control module is further used to control the first bridge arm and the second bridge arm when the battery is in a heating state, to form a circuit in which the first assembled battery discharges to the second assembled battery and / or to form a circuit in which the second assembled battery discharges to the first assembled battery, thereby heating the first assembled battery and the second assembled battery.

4. The heating module further includes a pre-charge unit, the pre-charge unit being respectively connected to the first capacitor, the second capacitor, the first assembled battery and the second assembled battery; The control module is connected to the pre-charge unit, and the control module further controls the pre-charge unit to a first operating state so that the first assembled battery charges the first capacitor and / or the second assembled battery charges the second capacitor; 4. The battery heating circuit of claim 3, further comprising: when 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 a second operating state to stop charging the first capacitor and the second capacitor.

5. the precharge unit includes a third switch, a fourth switch, and a first resistor; 5. The battery heating circuit of claim 4, wherein the third switch is connected in series with the first resistor 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 assembled battery and the second assembled battery.

6. The control module further comprises: Controlling the third switch to be on and the fourth switch to be off to control the precharge unit to be in a first working state; 6. The battery heating circuit as claimed in claim 5, which is used to control the fourth switch to be on and the third switch to be off to control the pre-charge unit to a second working state.

7. The first end of the first branch and the second end of the first branch are both used for connecting to an external device, where the external device includes a charging device and a power consuming device, and the control module further comprises: when the temperature of the first assembled battery is not lower than a first temperature threshold and the temperature of the second assembled battery is not lower than a second temperature threshold, the first switch is controlled to be on and the second switch and the fourth switch are controlled to be off to switch the battery into a usage state; 7. The battery heating circuit according to claim 5 or 6, wherein, when the battery is in a use state, the battery is used to discharge to the power consuming device or is charged by the charging device.

8. the heating circuit of the battery further includes a first fuse module and a second fuse module; 2. The battery heating circuit of claim 1, wherein the first fuse module is connected to the first assembled battery and the heating module, and the second fuse module is connected to the second assembled battery, the heating module, and the switch module, respectively.

9. A method for controlling a heating circuit of a battery, the battery including a first assembled battery and a second assembled battery, the heating circuit of the battery including a switch module and a heating module, the switch module being connected to the first assembled battery and the second assembled battery, respectively, and the heating module being connected to the first assembled battery, the second assembled battery, and the switch module, respectively; The control method includes: controlling the switch module to switch the battery to a heating state; and controlling the heating module so that the first assembled battery, the heating module, and the second assembled battery form a circuit when the battery is in a heating state; the circuit is used to transfer electricity between the first assembled battery and the second assembled battery to heat the first assembled battery and the second assembled battery; the switch module includes a first switch and a second switch; A method for controlling a battery heating circuit, wherein a first end of a first branch formed by connecting the first assembled battery, the first switch, and the second assembled battery in series is connected to the heating module, a second end of the first branch is connected to a first end of the second switch and the heating module, and a connection point between the first assembled battery and the first switch is connected to the second end of the second switch.

10. controlling the switch module to switch the battery to a heating state comprises:

10. The method of claim 9, further comprising: upon receiving a heating request signal, controlling the first switch to be OFF and controlling the second switch to be ON to switch the battery to a heating state.

11. The heating module includes a self-heating excitation unit including a first bridge arm, a second bridge arm, a first capacitor, a second capacitor, and a first inductor; the first bridge arm is connected in parallel to the first capacitor to form a second branch, a first end of the second branch is connected to the switch module and the second assembled battery, the second bridge arm is connected in parallel to the second capacitor to form a third branch, a first end of the third branch is connected to the first assembled battery, a second end of the second branch is connected to the second end of the third branch, and the first inductor is connected between a midpoint of the first bridge arm and a midpoint of the second bridge arm, controlling the heating module so that the first assembled battery, the heating module, and the second assembled battery form a circuit when the battery is in a heating state; 10. The control method according to claim 9, further comprising controlling the first bridge arm and the second bridge arm to form a circuit in which the first assembled battery discharges to the second assembled battery and / or to form a circuit in which the second assembled battery discharges to the first assembled battery.

12. The heating module further includes a pre-charge unit, the pre-charge unit being respectively connected to the first capacitor, the second capacitor, the first assembled battery and the second assembled battery; The method comprises: Controlling the pre-charge unit to a first operating state so that the first assembled battery charges the first capacitor and / or the second assembled battery charges the second capacitor; 12. The control method of claim 11, further comprising: when 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-charge unit to a second operating state to stop charging the first capacitor and the second capacitor.

13. the precharge unit includes a third switch, a fourth switch, and a first resistor; 13. The control method according to claim 12, wherein the third switch is connected in series with the first resistor 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 assembled battery and the second assembled battery.

14. controlling the precharge unit to a first operating state includes:

14. The control method according to claim 13, further comprising: controlling the third switch to be on and the fourth switch to be off to control the pre-charge unit to a first working state.

15. controlling the precharge unit to a second operating state includes: controlling the fourth switch to be on; The control method according to claim 14 , further comprising: controlling the third switch to be off to control the pre-charge unit to a second operating state.

16. a first end of the first branch and a second end of the first branch are both used for connecting to an external device, where the external device includes a charging device and a power consuming device; The method comprises: when a temperature of the first assembled battery is not lower than a first temperature threshold and a temperature of the second assembled battery is not lower than a second temperature threshold, controlling the first switch to be on and the second switch to be off to switch the battery to a usage state; A control method according to any one of claims 9 to 15, wherein when the battery is in a use state, the battery is used to discharge to the power consumption device or is charged by the charging device.

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

18. 20. An electric vehicle comprising: a load; and a battery according to claim 17, the battery being adapted to provide power to the load.

19. A computer readable storage medium having stored thereon computer executable instructions configured as a sequence of the method according to any one of claims 9 to 16.

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