Battery self-heating system and vehicle

Abstract

The present disclosure relates to a battery self-heating system and a vehicle, and relates to the field of automotive technology. The system includes: a first battery pack, a second battery pack, a first multi-phase inverter, a second multi-phase inverter, a first multi-phase inductor, and a second multi-phase inductor. The first battery pack, the first multi-phase inductor, the second multi-phase inductor, and the second battery pack are alternately charged and discharged by controlling the on-off states of the first multi-phase inverter and the second multi-phase inverter to achieve self-heating of the first battery pack and the second battery pack, and to achieve temperature increase of the first battery pack and the second battery pack during the charging and discharging process. In addition, both inductors participate in the charging, discharging, and heating processes, thereby achieving a better battery self-heating effect.

Description

Technical Field

[0001] The present disclosure relates to the field of automobile technology, and in particular, to a battery self-heating system and a vehicle. Background Art

[0002] In low-temperature environments, the power battery of an electric vehicle is too cold, and the activity of the active materials inside the battery decreases significantly. The internal resistance of the battery also increases as the temperature drops. Therefore, the charge and discharge performance of the battery decreases in low-temperature environments. To ensure the power of electric vehicles in low-temperature environments, the battery can be heated to increase the temperature of the battery body to ensure the battery power supply performance.

[0003] Existing methods for heating electric vehicle power batteries primarily include external heating and internal heating. External heating, which involves adding additional heating equipment to heat the battery, is costly and inefficient. Internal heating, on the other hand, relies on the battery's internal resistance to generate heat during cyclical charge and discharge. However, currently available battery self-heating technologies have limited heating power. Therefore, improving the heating capacity of electric vehicle batteries remains an urgent issue. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a battery self-heating system and a vehicle to solve the above-mentioned technical problems.

[0005] In order to achieve the above-mentioned objectives, the present disclosure provides a battery self-heating system, which is applied to a vehicle, comprising: a first battery pack, a second battery pack, a first multi-phase inverter, a second multi-phase inverter, a first multi-phase inductor and a second multi-phase inductor; wherein the first multi-phase inverter and the first battery pack are connected in parallel, the second multi-phase inverter and the second battery pack are connected in parallel, and the negative terminal of the first battery pack, the negative terminal of the first multi-phase inverter, the negative terminal of the second multi-phase inverter and the negative terminal of the second battery pack are connected; each phase of the first multi-phase inductor is connected one-to-one with each phase of the first multi-phase inverter, and each phase of the second multi-phase inductor is connected one-to-one with each phase of the second multi-phase inverter, and the first multi-phase inductor and the second multi-phase inductor are connected; the first multi-phase inverter and the second multi-phase inverter are used to control the alternating charging and discharging between the first battery pack, the first multi-phase inductor, the second multi-phase inductor and the second battery pack to achieve self-heating of the first battery pack and the second battery pack.

[0006] Optionally, the first multi-phase inverter and the second multi-phase inverter are used to control, by turning on and off the bridge arm switching tubes, that the first multi-phase inductor and the second multi-phase inductor charge the second battery pack after the first battery pack charges the first multi-phase inductor and the second multi-phase inductor, and to control that the first multi-phase inductor and the second multi-phase inductor charge the first battery pack after the second battery pack charges the first multi-phase inductor and the second multi-phase inductor.

[0007] Optionally, the first multi-phase inductor includes a first neutral line, the second multi-phase inductor includes a second neutral line, and the first neutral line and the second neutral line are connected.

[0008] Optionally, the vehicle includes a first drive motor and a second drive motor, the first multi-phase inductor is a multi-phase winding in the first drive motor, and the second multi-phase inductor is a multi-phase winding in the second drive motor.

[0009] Optionally, the battery self-heating system further includes: a first switch, one end of the first switch being connected to the first neutral line, and the other end of the first switch being connected to the second neutral line.

[0010] Optionally, the battery self-heating system also includes: a controller connected to the first switch; the controller is used to control the first switch to be closed when heating the first battery pack and the second battery pack; and to control the first switch to be opened when driving the first drive motor and the second drive motor.

[0011] Optionally, the positive terminal of the first battery pack, the positive terminal of the first multi-phase inverter, the positive terminal of the second multi-phase inverter and the positive terminal of the second battery pack are all connected to the positive main line, and the negative terminal of the first battery pack, the negative terminal of the first multi-phase inverter, the negative terminal of the second multi-phase inverter and the negative terminal of the second battery pack are all connected to the negative main line.

[0012] Optionally, the vehicle also includes: a third drive motor, a third multi-phase inverter connected to the third drive motor, and the third multi-phase inverter is connected in parallel with the first battery pack; the third drive motor is used to drive the vehicle when the first drive motor and the second drive motor are used for battery self-heating.

[0013] Optionally, the battery self-heating system also includes: a second switch, one end of the second switch is connected to the negative terminal of the first battery pack, and the other end is connected to the negative terminal of the first multi-phase inverter; a third switch, one end of the third switch is connected to the negative terminal of the second battery pack, and the other end is connected to the negative terminal of the second multi-phase inverter; a fourth switch, one end of the fourth switch is connected to the positive terminal of the first battery pack, and the other end is connected to the positive terminal of the third multi-phase inverter; a fifth switch, one end of the fifth switch is connected to the positive terminal of the first multi-phase inverter, and the other end is connected to the positive terminal of the second multi-phase inverter.

[0014] Optionally, the battery self-heating system also includes: a controller, which is connected to the first switch, the second switch, the third switch, the fourth switch and the fifth switch; the controller is used to, in a first state, control the first switch, the second switch and the fourth switch to be closed and control the third switch and the fifth switch to be disconnected, so as to control the first battery pack to charge the first multi-phase inductor and the second multi-phase inductor; in a second state, control the first switch, the third switch and the fourth switch to be closed and control the second switch and the fifth switch to be disconnected, so as to control the first multi-phase inductor and the second multi-phase inductor to charge the second battery pack; in a third state, control the first switch, the third switch and the fourth switch to be closed and control the second switch and the fifth switch to be disconnected, so as to control the second battery pack to charge the first multi-phase inductor and the second multi-phase inductor; in a fourth state, control the first switch, the second switch and the fourth switch to be closed and control the third switch and the fifth switch to be disconnected, so as to control the first multi-phase inductor and the second multi-phase inductor to charge the first battery pack.

[0015] Optionally, the battery self-heating system further includes: a third battery pack, a fourth battery pack, a fourth multi-phase inverter, a fifth multi-phase inverter, a third multi-phase inductor and a fourth multi-phase inductor; wherein, the fourth multi-phase inverter and the third battery pack are connected in parallel, the fifth multi-phase inverter and the fourth battery pack are connected in parallel, the negative terminal of the third battery pack, the negative terminal of the fourth multi-phase inverter, the negative terminal of the fifth multi-phase inverter and the negative terminal of the fourth battery pack are all connected to the negative main line, and the fourth multi-phase inverter and the fifth multi-phase inverter are connected; each phase of the third multi-phase inductor is connected one-to-one with each phase of the fourth multi-phase inverter, and the fourth multi-phase inductor is connected one-to-one with each phase of the fourth multi-phase inverter. Each phase of the inductor is connected one-to-one with each phase of the fifth multi-phase inverter, the negative terminal of the first battery pack is connected to the positive terminal of the third battery pack, and the negative terminal of the second battery pack is connected to the positive terminal of the fourth battery pack; the fourth multi-phase inverter and the fifth multi-phase inverter are used to control, through on-off state, that after the fourth battery pack charges the third multi-phase inductor and the fourth multi-phase inductor, the third multi-phase inductor and the fourth multi-phase inductor charge the third battery pack, and after the third battery pack charges the third multi-phase inductor and the fourth multi-phase inductor, the third multi-phase inductor and the fourth multi-phase inductor charge the fourth battery pack.

[0016] The present disclosure provides a vehicle including the above-mentioned battery self-heating system.

[0017] The present disclosure provides a battery self-heating system and a vehicle, wherein the battery self-heating system includes a first battery pack, a second battery pack, a first multi-phase inverter, a second multi-phase inverter, a first multi-phase inductor, and a second multi-phase inductor. The first multi-phase inverter and the first battery pack are connected in parallel, and the second multi-phase inverter and the second battery pack are connected in parallel. The negative terminal of the first battery pack, the negative terminal of the first multi-phase inverter, the negative terminal of the second multi-phase inverter, and the negative terminal of the second battery pack are all connected to the negative main line, and the first multi-phase inverter and the second multi-phase inverter are connected; the first multi-phase inductor Each phase of the inductor is connected one-to-one with each phase of the first multi-phase inverter, and each phase of the second multi-phase inductor is connected one-to-one with each phase of the second multi-phase inverter. The on-off states of the first multi-phase inverter and the second multi-phase inverter are used to control the alternating charging and discharging of the first battery pack, the first multi-phase inductor, the second multi-phase inductor, and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and to achieve temperature increase of the first battery pack and the second battery pack during the charging and discharging process. In addition, both inductors participate in the charging, discharging and heating process, so that the battery self-heating effect is better.

[0018] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0020] FIG1( a ) is a schematic diagram of an existing battery self-heating circuit.

[0021] FIG1( b ) is a schematic diagram of an existing battery self-heating circuit.

[0022] FIG1( c ) is a schematic diagram of an existing battery self-heating circuit.

[0023] Figure 2 This is a circuit diagram of a battery self-heating system provided by an embodiment of the present disclosure.

[0024] Figure 3 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0025] Figure 4 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0026] Figure 5 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0027] Figure 6 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0028] Figure 7 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0029] Figure 8 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0030] FIG9( a ) is a partial circuit diagram of a battery self-heating system provided by the present disclosure.

[0031] FIG9( b ) is a partial circuit diagram of the battery self-heating system provided by the present disclosure.

[0032] Figure 10 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0033] Figure 11 This is a circuit diagram of another battery self-heating system provided by an embodiment of the present disclosure.

[0034] Description of Reference Numerals

[0035] E1 first battery pack E2 second battery pack

[0036] E3 third battery pack E4 fourth battery pack

[0037] 10 first multi-phase inverter 20 second multi-phase inverter

[0038] 30 first multi-phase inductor 40 second multi-phase inductor

[0039] 50 third multi-phase inverter 60 third drive motor

[0040] 70 fourth multi-phase inverter 80 third multi-phase inductor

[0041] 90 fifth multi-phase inverter 100 fourth multi-phase inductor

[0042] K1 is the first switch, K2 is the second switch

[0043] K3 third switch K4 fourth switch

[0044] K5 fifth switch K6 sixth switch

[0045] K7 seventh switch K8 eighth switch

[0046] K9 ninth switch DETAILED DESCRIPTION

[0047] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0048] When electric vehicles are exposed to low temperatures, the activity of the active materials within the battery decreases significantly, reducing the battery's charge / discharge performance. To ensure the power of electric vehicles in low-temperature environments, the battery can be heated to increase the battery's body temperature and maintain its power supply performance.

[0049] Existing heating methods for electric vehicle power batteries mainly include external heating and internal heating. External heating involves adding additional heating equipment to heat the battery. This heating method is costly due to the additional heating equipment, and has low heating efficiency due to the rapid heat dissipation outside and the distance between the external temperature and the internal battery.

[0050] Another current heating method, internal heating, primarily utilizes the battery's cyclic charge and discharge cycles to generate heat through the battery's internal resistance. However, currently available battery self-heating technologies have limited heating power and generate little heat. According to Kirchhoff's first law, the sum of all currents entering a node equals the sum of all currents leaving the node. In current internal heating methods, the currents flowing through the motor's three phases at any given moment must have different directions to ensure that the sum of the incoming currents equals the sum of the outgoing currents. For example, at the neutral point n of the motor's three-phase winding, as shown in Figure 1(a), there is a single-phase input current Ia1 and a single-phase input current Ib1. As shown in Figure 1(b), there is a single-phase input current Ia1 and two-phase input currents Ib1 and Ib2. As shown in Figure 1(c), there are two-phase input currents Ia1 and Ia2, and a single-phase input current Ib1. In the solutions provided in Figures 1(1), 1(b) and 1(c), current flows through the motor to form a loop, but the current involved in heating is only one or two phases of the three-phase inductor, so that the current involved in heating is relatively small. The heat generated by charging and discharging with this small current is small, and the heating effect on the battery is poor.

[0051] In summary, how to improve the heating capacity of batteries in electric vehicles is still an urgent problem to be solved.

[0052] In order to improve the self-heating capability of the battery of a pure electric vehicle, the present disclosure proposes a battery self-heating system, which is applied to a vehicle, wherein the vehicle can be a pure electric vehicle or a hybrid vehicle including an electric vehicle. Figure 2 The battery self-heating system includes: a first battery pack E1, a second battery pack E2, a first multi-phase inverter 10, a second multi-phase inverter 20, a first multi-phase inductor 30 and a second multi-phase inductor 40.

[0053] The first multi-phase inverter 10 is connected in parallel with the first battery pack E1, that is, the two ports of the bridge arm of the first multi-phase inverter 10 are connected to the positive terminal and the negative terminal of the first battery pack E1 respectively. The second multi-phase inverter 20 is connected in parallel with the second battery pack E2, that is, the two ports of the bridge arm of the second multi-phase inverter 20 are connected to the positive terminal and the negative terminal of the second battery pack E2 respectively. The negative terminal of the first battery pack E1, the negative terminal of the first multi-phase inverter 10 (which can be understood as the first end on the lower bridge arm of the first multi-phase inverter), the negative terminal of the second multi-phase inverter 20 (which can be understood as the first end on the lower bridge arm of the second multi-phase inverter) and the negative terminal of the second battery pack E2 are all connected, and the first multi-phase inverter 10 and the second multi-phase inverter 20 are connected. Each phase of the first multi-phase inductor 30 is connected one-to-one with each phase of the first multi-phase inverter 10, as shown in FIG. Figure 2As shown, each phase inductance on the first multi-phase inductor 30 is connected to the midpoint of a phase bridge arm of the first multi-phase inverter 10, wherein the midpoint is located between the second end of the lower bridge arm and the second end of the upper bridge arm of the first multi-phase inverter, each phase of the second multi-phase inductor 40 is connected one-to-one with each phase of the second multi-phase inverter 20, and each phase inductance of the second multi-phase inductor 40 is connected to the midpoint of a phase bridge arm of the second multi-phase inverter 20, wherein the midpoint is located between the second end of the lower bridge arm and the second end of the upper bridge arm of the second multi-phase inverter.

[0054] The first multi-phase inverter 10 and the second multi-phase inverter 20 are used to control the alternating charging and discharging of the first battery pack E1, the first multi-phase inductor 30, the second multi-phase inductor 40, and the second battery pack E2 to achieve self-heating of the first battery pack E1 and the second battery pack E2. It is understood that the alternating charging and discharging can be understood as follows: after the first battery pack E1 charges the first multi-phase inductor 30 and the second multi-phase inductor 40, the first multi-phase inductor 30 and the second multi-phase inductor 40 charge the second battery pack E2; after the second battery pack E2 charges the first multi-phase inductor 30 and the second multi-phase inductor 40, the first multi-phase inductor 30 and the second multi-phase inductor 40 charge the first battery pack E1.

[0055] Optionally, the alternating charge and discharge described above can be achieved by controlling the on / off states of the first multiphase inverter 10 and the second multiphase inverter 20. The on / off state refers to the off or on state of the upper or lower arm switches in the multiphase inverter. The switches in the upper and lower arms of the same multiphase inverter are not off at the same time. For example, if the switch in the upper arm of the first multiphase inverter 10 is off, the switch in the lower arm of the first multiphase inverter 10 is off. It is understood that by controlling the on / off states of the switches in the first multiphase inverter 10 and the second multiphase inverter 20, the discharge of the first battery pack E1 is controlled, and current flows into the first and second multiphase inductors 30, 40, thereby charging the first and second multiphase inductors 30, 40 and storing electrical energy in the first and second multiphase inductors 30, 40. The first and second multiphase inductors 30, 40 release the stored electrical energy to charge the second battery pack E2. The second battery pack E2 charges the first and second multi-phase inductors 30 and 40. After charging, these inductors store electrical energy, which they then release to charge the first battery pack E1. Because battery packs have a certain internal resistance, the current flowing through this resistance during charging and discharging in the first and second battery packs E1 and E2 generates heat, causing the battery packs to heat up.

[0056] Optionally, the first multi-phase inductor 30 may be composed of multiple individual inductors, or may be the multi-phase inductor of the original first drive motor (e.g., the motor driving the wheels) on the vehicle, and the second multi-phase inductor 40 may be composed of multiple individual inductors, or may be the multi-phase inductor of the original second drive motor on the vehicle. Figure 2 The first multi-phase inductor and the second multi-phase inductor shown in FIG can both be three-phase inductors (which can be three-phase inductors in a three-phase motor). In this embodiment, it is not limited to Figure 2 As shown, the first multi-phase inductor and the second multi-phase inductor can also be six-phase inductors (which can be six-phase inductors in a six-phase motor), fifteen-phase inductors, etc.

[0057] It should be noted that when the first multi-phase inductor 30 is the first drive motor and the second multi-phase inductor 40 is the second drive motor, the first and second drive motors can perform the driving function when the vehicle does not require heating. When the vehicle requires heating but the first or second drive motor needs to perform the driving function, a motor selected from the idle motors can replace the idle motor for heating.

[0058] Since both inductors are involved in the charging, discharging and heating process, a large amount of heat is generated. In addition to increasing the temperature of the battery body, the heat generated by the battery pack during the charging and discharging process can also be extracted and transported to other battery packs or passenger compartments that are not in the above-mentioned battery self-heating system through a heat pump. In this way, the temperature of other battery packs or passenger compartments can be increased.

[0059] The battery self-heating system provided in this embodiment is applied to a vehicle. The battery self-heating system includes a first battery pack, a second battery pack, a first multi-phase inverter, a second multi-phase inverter, a first multi-phase inductor, and a second multi-phase inductor. The on-off state of the first multi-phase inverter and the second multi-phase inverter is used to control the alternating charging and discharging of the first battery pack, the first multi-phase inductor, the second multi-phase inductor, and the second battery pack to achieve self-heating of the first battery pack and the second battery pack, and to achieve temperature increase of the first battery pack and the second battery pack during the charging and discharging process. In addition, both inductors participate in the charging, discharging and heating process, so that the battery self-heating effect is better.

[0060] The first multiphase inverter 10 and the second multiphase inverter 20 are connected. In one embodiment, the first multiphase inverter 10 and the second multiphase inverter 20 are connected through a first multiphase inductor 30 and a second multiphase inductor 40. Specifically, the first multiphase inductor 30 includes a first neutral line (N line), and the second multiphase inductor 40 includes a second neutral line (N line), and the first neutral line and the second neutral line are connected. The first battery pack E1, the first multiphase inverter 10, the first multiphase inductor 30, the second multiphase inductor 20, and the second multiphase inductor 40 are sequentially connected to form the charge and discharge circuit of the first battery pack E1. The first multiphase inverter 10, the first multiphase inductor 30, the second multiphase inverter 20, the second multiphase inductor 40, and the second battery pack E2 are sequentially connected to form the charge and discharge circuit of the second battery pack.

[0061] Optionally, a first switch K1 may be provided between the first neutral line and the second neutral line to control the on / off of the line between the first multi-phase inductor 30 and the second multi-phase inductor 40. Figure 2 The midpoints of the multiple bridge arms of the first multiphase inverter 10 are connected to one end of each phase of the first multiphase inductor 30. The other ends of each phase of the first multiphase inductor 30 are interconnected to form a neutral point a. A first neutral line is drawn from neutral point a. Similarly, the midpoints of the multiple bridge arms of the second multiphase inverter 20 are connected to one end of each phase of the second multiphase inductor 40. The other ends of each phase of the second multiphase inductor 40 are interconnected to form a neutral point b. A second neutral line is drawn from neutral point b. The first neutral line and the second neutral line are connected via a first switch K1.

[0062] In another embodiment, the first multiphase inverter 10 and the second multiphase inverter 20 are connected via their respective positive terminals. For example, the positive terminal of the first battery pack E1, the positive terminal of the first multiphase inverter 10 (which can be understood as the first end of the upper bridge arm of the first multiphase inverter), the positive terminal of the second multiphase inverter 20 (which can be understood as the first end of the upper bridge arm of the second multiphase inverter), and the positive terminal of the second battery pack E2 are all connected to the positive main line, and the negative terminal of the first battery pack E1, the negative terminal of the first multiphase inverter 10, the negative terminal of the second multiphase inverter 20, and the negative terminal of the second battery pack E2 are all connected to the negative main line. The first battery pack E1, the first multiphase inverter 10, and the first multiphase inductor 30 are connected to form a charge and discharge circuit for the first battery pack, and the first battery pack E1, the second multiphase inverter 20, and the second multiphase inductor 40 form a charge and discharge circuit for the first battery pack E1. The second multi-phase inverter 20 and the second multi-phase inductor 40 and the second battery pack E2 form a charge and discharge loop of the second battery pack E2, and the first multi-phase inverter 10 and the first multi-phase inductor 30 and the second battery pack E2 form another charge and discharge loop of the second battery pack E2.

[0063] Optionally, in order to control the on / off of the line between the first multi-phase inverter 10 and the second multi-phase inverter 20, as shown in FIG. Figure 2 As shown, a fifth switch K5 is provided on the positive main line between the first multi-phase inverter 10 and the second multi-phase inverter 20 .

[0064] Optionally, the battery self-heating system proposed in this disclosure can achieve self-heating of the battery pack to maintain battery performance while the vehicle is running, ensuring that the battery pack provides continuous power for the vehicle. Figure 3 ,exist Figure 2 On the basis of , the battery self-heating system further includes: a third drive motor 60 and a third multi-phase inverter 50 connected to the third drive motor 60 , and the third multi-phase inverter 50 is connected in parallel with the first battery E1 pack.

[0065] The third drive motor 60 drives the vehicle during the discharge and charging processes of the first battery pack E1. The discharge process of the first battery pack E1 is the process of the first battery pack E1 charging the first multi-phase inductor 30 and the second multi-phase inductor 40. The charging process of the first battery pack E1 is the process of the first multi-phase inductor 30 and the second multi-phase inductor 40 charging the first battery pack E1.

[0066] It will be appreciated that the first battery pack E1, the third multi-phase inverter 50, and the third drive motor 60 form a circuit through which the first battery pack E1 supplies power to the third drive motor 60, enabling the third drive motor 60 to operate and drive the vehicle. Simultaneously, the first battery pack E1 charges the first and second multi-phase inductors 30 and 40, and the electrical energy stored in the first and second multi-phase inductors 30 and 40 charges the first battery pack E1. During the charging and discharging process, the first battery pack E1 generates self-heating. In cold environments, the heat generated by this self-heating maintains the battery performance of the first battery pack E1, ensuring that the first battery pack E1 can provide continuous and powerful power to the third drive motor 60.

[0067] Optionally, see Figure 4 The battery self-heating system further includes: a first switch K1, one end of the first switch K1 is connected to the first neutral line, and the other end is connected to the second neutral line.

[0068] The battery self-heating system further includes: a controller (in Figure 4 (not shown), the controller is connected to the first switch K1.

[0069] The controller is configured to control the first switch K1 to close when heating the first battery pack E1 and the second battery pack E2, and to control the first switch K1 to open when driving the first drive motor and / or the second drive motor. When vehicle heating is not required, the first drive motor and the second drive motor can perform driving functions. When vehicle heating is required but the first drive motor or the second drive motor needs to perform driving functions, a motor selected from idle motors can replace the aforementioned drive motor for heating.

[0070] See also Figure 4 The battery self-heating system further includes: a second switch K2, a third switch K3, a fourth switch K4 and a fifth switch K5.

[0071] Among them, one end of the second switch K2 is connected to the negative terminal of the first battery pack E1, and the other end is connected to the negative terminal of the first multi-phase inverter 10; one end of the third switch K3 is connected to the negative terminal of the second battery pack E2, and the other end is connected to the negative terminal of the second multi-phase inverter 20; one end of the fourth switch K4 is connected to the positive terminal of the first battery pack E1, and the other end is connected to the positive terminal of the third multi-phase inverter 50; the fifth switch K5, one end of the fifth switch K5 is connected to the positive terminal of the first multi-phase inverter 10 (i.e., the first end of the upper bridge arm), and the other end is connected to the positive terminal of the second multi-phase inverter 20 (i.e., the first end of the upper bridge arm).

[0072] Battery self-heating is achieved by adjusting the on / off states of the aforementioned switches. The controller is connected to the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, and the fifth switch K5. During the entire self-heating process, the controller controls the fifth switch K5 to be disconnected.

[0073] The controller is used to control the first switch K1, the second switch K2 and the fourth switch K4 to be closed and the third switch K3 to be opened in a first state, so as to control the first battery pack E1 to charge the first multi-phase inductor 30 and the second multi-phase inductor 40; and to control the first switch K1, the third switch K3 and the fourth switch K4 to be closed and the second switch K2 to be opened in a second state, so as to control the first multi-phase inductor 30 and the second multi-phase inductor 40 to charge the second battery pack E2.

[0074] The controller is also used to control the first switch K1, the third switch K3 and the fourth switch K4 to be closed and the third switch K2 to be opened in the third state, so as to control the second battery pack E2 to charge the first multi-phase inductor 30 and the second multi-phase inductor 40; and to control the first switch K1, the second switch K2 and the fourth switch K4 to be closed and the third switch K3 to be opened in the fourth state, so as to control the first multi-phase inductor 30 and the second multi-phase inductor 40 to charge the first battery pack E1.

[0075] The charging and discharging of the first battery pack E1 and the second battery pack E2 are achieved through the first to fourth states.

[0076] See also Figure 5 In the first state, the controller controls the first switch K1, the second switch K2, and the fourth switch K4 to close, and controls the third switch K3 and the fifth switch K5 to open. Simultaneously, the controller controls the switches of the upper arm of the first multiphase inverter 10 to close, and the switches of the lower arm of the second multiphase inverter 20 to close. The second switch K2 connects the negative terminal of the first battery pack E1 to the negative terminal of the first multiphase inverter 10, and the first switch K1 connects the first multiphase inductor 30 to the second multiphase inductor 40. Current flows from the positive terminal of the first battery pack E1 through the upper arm of the first multiphase inverter 10, the first multiphase inductor 30, the first switch K1, the second multiphase inductor 40, and the lower arm of the second multiphase inverter 20, before returning to the negative terminal of the first battery pack E1, forming a loop. In this loop, the first battery pack E1 discharges, charging the first multiphase inductor 30 and the second multiphase inductor 40.

[0077] See also Figure 6In the second state, the controller controls the first switch K1, the third switch K3, and the fourth switch K4 to be closed, and controls the second switch K2 and the fifth switch K5 to be open. At the same time, the controller controls the switches of the lower bridge arm of the first multi-phase inverter 10 to be closed, and controls the switches of the upper bridge arm of the second multi-phase inverter 20 to be closed. The third switch K3 connects the negative terminal of the second battery pack E2 to the negative terminal of the second multi-phase inverter 20. The first switch K1 connects the first multi-phase inductor 30 and the second multi-phase inductor 40. In the first state, the first multi-phase inductor 30 and the second multi-phase inductor 40 store electrical energy. Due to the freewheeling characteristics of the first and second multi-phase inductors 30 and 40, the first and second multi-phase inductors 30 and 40 are connected via the first switch K1. The two multi-phase inductors freewheel together, and current flows through the upper bridge arm of the second multi-phase inverter 20 into the positive terminal of the second battery pack E2, charging the second battery pack E2. The charging current then flows out of the negative terminal of the second battery pack E2, passes through the third switch K3 and the lower bridge arm of the first multi-phase inverter 10, and flows back to the first multi-phase inductor 30, forming a freewheeling loop. In this freewheeling loop, the first and second multi-phase inductors 30 and 40 discharge to charge the second battery pack E2.

[0078] See also Figure 7 In the third state, the controller controls the first switch K1, the third switch K3, and the fourth switch K4 to close, and controls the second switch K2 and the fifth switch K5 to open. Simultaneously, the controller controls the switches of the lower arm of the first multiphase inverter 10 to close, and the switches of the upper arm of the second multiphase inverter 20 to close. The second switch K2 connects the negative terminal of the first battery pack E1 to the negative terminal of the first multiphase inverter 10, and the first switch K1 connects the first multiphase inductor 30 to the second multiphase inductor 40. The current of the second battery pack E2 flows from the positive terminal, passes through the upper arm of the second multiphase inverter 20, the second multiphase inductor 40, the first switch K1, the first multiphase inductor 30, the lower arm of the first multiphase inverter 10, and returns to the negative terminal of the second battery pack E2, forming a loop. In this loop, the discharge of the second battery pack E2 charges the first multiphase inductor 30 and the second multiphase inductor 40.

[0079] See also Figure 8In the fourth state, the controller controls the first switch K1, the second switch K2, and the fourth switch K4 to be closed, and controls the third switch K3 and the fifth switch K5 to be open. Simultaneously, the controller controls the switch of the upper arm of the first multi-phase inductor 30 to be closed, and controls the switch of the lower arm of the second multi-phase inductor 40 to be closed. The second switch K2 connects the negative terminal of the first battery pack E1 and the negative terminal of the first multi-phase inverter 10. The first switch K1 connects the first multi-phase inductor 30 and the second multi-phase inductor 40. The first multi-phase inductor 30 and the second multi-phase inductor 40 store electrical energy in the third state. The first multi-phase inductor 30 and the second multi-phase inductor 40 are connected via the first switch K1. The two multi-phase inductors continue to flow together. The current flows through the upper bridge arm of the first multi-phase inverter 10 and flows into the positive terminal of the first battery pack E1 to charge the first battery pack E1. The current then flows out through the negative terminal of the first battery pack E1 and passes through the second switch K2 and the lower bridge arm of the second multi-phase inverter 20 in sequence to return to the two multi-phase inductors, forming a freewheeling loop. In this freewheeling loop, the first multi-phase inductor 30 and the second multi-phase inductor 40 discharge to charge the first battery pack E1.

[0080] The first multi-phase inductor 30 and the second multi-phase inductor 40 are charged through the battery pack, and then the battery pack is charged by relying on the freewheeling characteristics of the first multi-phase inductor 30 and the second multi-phase inductor 40 to realize the charging and discharging of the battery pack, so that the temperature of the battery pack rises.

[0081] exist Figure 5-Figure 8 When the controller is in any of the above states and performs battery self-heating, the controller controls the switch tube on the upper bridge arm of the third multi-phase inverter 50 to be closed, so that current flows out from the positive terminal of the first battery pack E1, passes through the fourth switch K4 and the upper bridge arm of the third multi-phase inverter 50 in sequence, and then enters the third drive motor 60. The current flows from the third drive motor 60 through the second switch K2 and returns to the negative terminal of the first battery pack E1, forming a power supply circuit for the first battery pack E1, the third multi-phase inverter 50 and the third drive motor 60. The third drive motor 60 is powered by this power supply circuit, so that the third drive motor 60 drives the vehicle.

[0082] It should be noted that the switching tubes of the upper and lower bridge arms of the same inverter cannot be closed at the same time. Therefore, when the switching tube of the upper bridge arm is closed, the switching tube of the lower bridge arm is disconnected, or when the switching tube of the lower bridge arm is closed, the switching tube of the upper bridge arm is disconnected. For example, when the switching tube of the upper bridge arm of the first multi-phase inverter 10 is closed, it should be considered that the switching tube of the lower bridge arm of the first multi-phase inverter 10 is disconnected.

[0083] exist Figure 5-Figure 8In the embodiment, the inductors in the first multiphase inductor 30 and the second multiphase inductor 40 are both star-connected, and the currents of each phase in the multiphase inductor converge at the neutral point and are drawn out from the neutral line. As shown in FIG9(a), the three-phase currents Ia1, Ia2, and Ia3 in the first multiphase inductor 30 converge onto the first neutral line to obtain current Ib2. Similarly, as shown in FIG9(b), the three-phase currents Ia1, Ia2, and Ia3 in the second multiphase inductor 40 converge onto the second neutral line to obtain current Ib2. In this embodiment, as shown by the directions of the phase currents in the multiphase inductors in FIG9(a) and FIG9(b), the heating currents of each phase in the multiphase inductor flow in the same direction. Ignoring the asymmetry of the inductor windings of the multiphase inductor, the currents of each phase in the multiphase inductor are equal in magnitude, and the resulting electromagnetic force is approximately zero, thereby achieving zero torque output and ensuring that the multiphase inductor is stationary during the heating process. Moreover, compared with the methods in Figures 1(a), 1(b) and 1(c), the current obtained through the multi-phase inductor in the embodiment of the present disclosure is larger, which can better exert the maximum overcurrent capacity of the bridge arm of the multi-phase inverter, ensuring a larger heating current in the charging and discharging circuit. The larger heating current can improve the heating effect.

[0084] Optionally, in Figure 5-Figure 8 In the embodiment, when the vehicle is traveling, the second switch K2, the third switch K3, the first switch K1 and the fifth switch K5 are closed, and the first switch K1 is controlled to be open, so that the first battery pack E1 and the second battery pack E2 can simultaneously power the third drive motor 60.

[0085] There may be more than two battery packs in a vehicle, see Figure 10 The battery self-heating system further includes a third battery pack E3, a fourth battery pack E4, a fourth multi-phase inverter 70, a fifth multi-phase inverter 90, a third multi-phase inductor 80, and a fourth multi-phase inductor 100. The fourth multi-phase inverter 70 is connected in parallel to the third battery pack E3, the fifth multi-phase inverter 70 is connected in parallel to the fourth battery pack E4, the negative terminal of the third battery pack E3, the negative terminal of the fourth multi-phase inverter 70, the negative terminal of the fifth multi-phase inverter 90, and the negative terminal of the fourth battery pack E4 are all connected to the negative main line, and the fourth multi-phase inverter 70 and the fifth multi-phase inverter 90 are connected to each other. Each phase of the third multi-phase inductor 80 is connected one-to-one to each phase of the fourth multi-phase inverter 70, each phase of the fourth multi-phase inductor 100 is connected one-to-one to each phase of the fifth multi-phase inverter 90, the negative terminal of the first battery pack E1 is connected to the positive terminal of the third battery pack E3, and the negative terminal of the second battery pack E2 is connected to the positive terminal of the fourth battery pack E4.

[0086] The fourth multi-phase inverter 70 and the fifth multi-phase inverter 90 are used to control the on-off state so that after the fourth battery pack E4 charges the third multi-phase inductor 80 and the fourth multi-phase inductor 100, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 charge the third battery pack E3; after the third battery pack E3 charges the third multi-phase inductor 80 and the fourth multi-phase inductor 100, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 charge the fourth battery pack E4. After the above-mentioned charging and discharging, the battery body temperature of the third battery pack E3 and the fourth battery pack E4 rises.

[0087] Optionally, see Figure 10 The battery self-heating system further includes a sixth switch K6, a seventh switch K7, an eighth switch K8 and a ninth switch K9, wherein the sixth switch K6 and the seventh switch K7 are both transfer switches, and the sixth switch K6 is provided on the connection line between the first battery pack E1 and the first multi-phase inverter 10, as shown in FIG. Figure 10 As shown, the contact m1 and the contact m2 of the sixth switch K6 are connected, and a path is established between the negative terminal of the first battery pack E1 and the negative terminal of the first multi-phase inverter 10 through the sixth switch K6. The seventh switch K7 is set on the connection line between the third battery pack E3 and the fourth multi-phase inverter 70, as shown in FIG. Figure 10 As shown, the contact m3 and the contact m4 in the seventh switch K7 are connected, and a path is established between the positive terminal of the third battery pack E3 and the positive terminal of the fourth multi-phase inverter 70 through the seventh switch K7. The eighth switch K8 is set on the line connecting the fourth multi-phase inverter 70 and the fifth multi-phase inverter 90.

[0088] See also Figure 10 The battery self-heating system also includes a first switch K1 and a fifth switch K5. The first switch K1 is set on the line connecting the first multi-phase inductor 30 and the second multi-phase inductor 40, and the fifth switch K5 is set on the line connecting the first multi-phase inverter 10 and the second multi-phase inverter 20.

[0089] The controller is connected to the first switch K1, the fifth switch K5, the sixth switch K6, the seventh switch K7, the eighth switch K8 and the ninth switch K9. Figure 10 The switches and multi-phase inverters in the circuit are used to control the charging and discharging in the circuit. This can be done as follows:

[0090] In the first state, the controller closes the first switch K1 and the sixth switch K6, opens the fifth switch K5, closes the switches of the upper arm of the first multi-phase inverter 10, and closes the switches of the lower arm of the second multi-phase inverter 20. The first switch K1 connects the first multi-phase inductor 30 and the second multi-phase inductor 40, and the sixth switch K6 connects the negative terminal of the first battery pack E1 to the negative terminal of the first multi-phase inverter 10. Current flows from the positive terminal of the first battery pack E1 through the upper arm of the first multi-phase inverter 10, the first multi-phase inductor 30, the first switch K1, the second multi-phase inductor 40, and the lower arm of the second multi-phase inverter 20, before returning to the negative terminal of the first battery pack E1, forming a loop. In this loop, the first battery pack E1 discharges, charging the first multi-phase inductor 30 and the second multi-phase inductor 40. At the same time, the controller turns on m3 and m4 of the seventh switch K7 and closes the ninth switch K9, closing the switches of the upper arm of the fifth multiphase inverter 90 and the lower arm of the fourth multiphase inverter 70. The closing of the ninth switch K9 connects the third multiphase inductor 80 and the fourth multiphase inductor 100. Current flows from the positive terminal of the fourth battery pack E4, sequentially passing through the upper arm of the fifth multiphase inverter 90, the fourth multiphase inductor 100, the third multiphase inductor 80, and the lower arm of the fourth multiphase inverter 70, before returning from the lower arm of the fourth multiphase inverter 70 to the negative terminal of the fourth battery pack E4. In this loop, the fourth battery pack E4 discharges to charge the third multiphase inductor 80 and the fourth multiphase inductor 100.

[0091] In the second state, the controller controls the fifth switch K5 to close, any two contacts of the sixth switch K6 are not connected, controls the switch tube of the upper bridge arm of the first multi-phase inverter 10 to close, controls the switch tube of the lower bridge arm of the second multi-phase inverter 20 to close, and connects the first multi-phase inverter 10 and the second multi-phase inverter 20 through the fifth switch K5. In the first state, the first and second multiphase inductors 30 and 40 are charged and store electrical energy. Due to the freewheeling characteristics of the first and second multiphase inductors 30 and 40, they discharge together. Current flows sequentially through the second multiphase inductor 40, the lower arm of the second multiphase inverter 20, the negative electrode of the second battery pack E2, the positive electrode of the second battery pack E2, the fifth switch, the upper arm of the first multiphase inverter 10, and back to the first multiphase inductor 30. In this loop, the first and second multiphase inductors 30 and 40 discharge to charge the second battery pack E2. Simultaneously, the controller turns on m3 and m4 of the seventh switch K7, closes the eighth and ninth switches K8 and K9, closes the switches of the upper arm of the fifth multiphase inverter 90, and closes the switches of the lower arm of the fourth multiphase inverter 70. Since in the previous state, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 store electrical energy after being charged, due to the freewheeling characteristics of the third multi-phase inductor 80 and the fourth multi-phase inductor 100, the third multi-phase inductor 80 and the fourth multi-phase inverter 70 discharge together, and the current flows through the upper bridge arm of the fifth multi-phase inverter 90, the eighth switch K8, the positive terminal of the third battery pack E3, the negative terminal of the third battery pack E3 and the lower bridge arm of the fourth multi-phase inverter 70 in sequence, and then returns to the third multi-phase inductor 80. In this loop, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 discharge to charge the third battery pack E3.

[0092] In the third state, the controller closes the first switch K1, opens the fifth switch K5, disconnects any two contacts of the sixth switch K6, closes the switches of the upper arm of the second multi-phase inverter 20, and closes the switches of the lower arm of the first multi-phase inverter 10. Current flows from the positive electrode of the second battery pack E2, sequentially through the upper arm of the second multi-phase inverter 20, the second multi-phase inductor 40, the first switch K1, the first multi-phase inductor 30, and the lower arm of the first multi-phase inverter 10, before returning to the negative electrode of the second battery pack E2. In this loop, the discharge of the second battery pack E2 charges the first and second multi-phase inductors 30 and 40. Simultaneously, the controller connects m3 and m4 of the seventh switch K7, closes the ninth switch K9, opens the eighth switch K8, closes the switches of the upper arm of the fourth multi-phase inverter 70, and closes the switches of the lower arm of the fifth multi-phase inverter 90. The current flows out of the positive terminal of the third battery pack E3, flows through the seventh switch K7, the upper bridge arm of the fourth multi-phase inverter 70, the third multi-phase inductor 80, the ninth switch K9, the fourth multi-phase inductor 100, the lower bridge arm of the fifth multi-phase inverter 90, and then returns to the negative terminal of the third battery pack E3. In this loop, the third battery pack E3 discharges to charge the third multi-phase inductor 80 and the fourth multi-phase inductor 100.

[0093] In the fourth state, the controller controls the first switch K1 and the sixth switch K6 to close, controls the fifth switch K5 to open, controls the switches of the upper arm of the first multi-phase inverter 10 to close, and controls the switches of the lower arm of the second multi-phase inverter 20 to close. After being charged in the third state, the first multi-phase inductor 30 and the second multi-phase inductor 40 store electrical energy. Due to the freewheeling characteristics of the first multi-phase inductor 30 and the second multi-phase inductor 40, the first multi-phase inductor 30 and the second multi-phase inductor 40 discharge together. The current flows sequentially through the upper arm of the first multi-phase inverter 10, the positive terminal of the first battery pack E1, the negative terminal of the first battery pack E1, the sixth switch K6, the lower arm of the second multi-phase inverter 20, and then returns to the second multi-phase inductor 40. In this loop, the first multi-phase inductor 30 and the second multi-phase inductor 40 discharge to charge the first battery pack E1. At the same time, the controller controls the eighth switch K8 and the ninth switch K9 to close, disconnects any two contacts of the seventh switch K7, closes the switches of the upper arm of the fourth multi-phase inverter 70, and closes the switches of the lower arm of the fifth multi-phase inverter 90. After being charged in the third state, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 store electrical energy. Due to the freewheeling characteristics of the third multi-phase inductor 80 and the fourth multi-phase inductor 100, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 discharge together. The current sequentially flows through the upper arm of the fourth multi-phase inverter 70, the eighth switch K8, the positive terminal of the fourth battery pack E4, the negative terminal of the fourth battery pack E4, the lower arm of the fifth multi-phase inverter 90, and then flows back to the fourth multi-phase inductor 100. In this loop, the third multi-phase inductor 80 and the fourth multi-phase inductor 100 discharge to charge the fourth battery pack E4.

[0094] exist Figure 10 In the above four states of the battery self-heating system, the charging and discharging of the first battery pack E1, the second battery pack E2, the third battery pack E3 and the fourth battery pack E4 are realized, and the temperature of the battery pack body is increased. Moreover, when the first battery pack is discharged, the fourth battery pack is discharged, and when the second battery pack is discharged, the third battery pack is discharged, thereby avoiding the simultaneous discharge of the battery packs on the same side (such as avoiding the simultaneous discharge of the first battery pack and the third battery pack, or the simultaneous discharge of the second battery pack and the fourth battery pack), which causes the occurrence of voltage peaks, thereby preventing the voltage peaks from damaging the battery cells of the battery packs.

[0095] Optionally, the first multi-phase inverter, the second multi-phase inverter, the first multi-phase inductor and the second multi-phase inductor may be six-phase in addition to the three-phase shown above, such as Figure 11 As shown, when the battery self-heats, the working principle is the same as above. Figure 5-Figure 8 The principle is the same and will not be repeated here.

[0096] Optionally, the present disclosure further provides a vehicle, comprising the above-mentioned battery self-heating system, which heats and raises the temperature of the battery in the vehicle to ensure the performance of the battery in a low-temperature environment.

[0097] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0098] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction.

[0099] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A battery self-heating system, characterized in that: Applied to a vehicle, comprising: a first battery pack, a second battery pack, a first multi-phase inverter, a second multi-phase inverter, a first multi-phase inductor, and a second multi-phase inductor; wherein the first multi-phase inverter and the first battery pack are connected in parallel, the second multi-phase inverter and the second battery pack are connected in parallel, and the negative terminal of the first battery pack, the negative terminal of the first multi-phase inverter, the negative terminal of the second multi-phase inverter, and the negative terminal of the second battery pack are connected; Each phase of the first multi-phase inductor is connected to each phase of the first multi-phase inverter in a one-to-one manner, each phase of the second multi-phase inductor is connected to each phase of the second multi-phase inverter in a one-to-one manner, and the first multi-phase inductor and the second multi-phase inductor are connected; The first multi-phase inverter and the second multi-phase inverter are used to control the alternating charging and discharging of the first battery pack, the first multi-phase inductor, the second multi-phase inductor, and the second battery pack to achieve self-heating of the first battery pack and the second battery pack; The vehicle includes a first drive motor, a second drive motor, a third drive motor, and a third multi-phase inverter connected to the third drive motor, the first multi-phase inductor is a multi-phase winding in the first drive motor, the second multi-phase inductor is a multi-phase winding in the second drive motor; the third multi-phase inverter is connected in parallel with the first battery pack; The third drive motor is used to drive the vehicle when the first drive motor and the second drive motor are used for battery self-heating.

2. The battery self-heating system according to claim 1, characterized in that: The first multi-phase inverter and the second multi-phase inverter are used to control, by turning on and off the bridge arm switching tubes, that the first multi-phase inductor and the second multi-phase inductor charge the second battery pack after the first battery pack charges the first multi-phase inductor and the second multi-phase inductor, and to control that the first multi-phase inductor and the second multi-phase inductor charge the first battery pack after the second battery pack charges the first multi-phase inductor and the second multi-phase inductor.

3. The battery self-heating system according to claim 1, characterized in that: The first multi-phase inductor includes a first neutral line, and the second multi-phase inductor includes a second neutral line, and the first neutral line and the second neutral line are connected.

4. The battery self-heating system according to claim 3, characterized in that: The battery self-heating system further includes: A first switch, wherein one end of the first switch is connected to the first neutral line, and the other end of the first switch is connected to the second neutral line.

5. The battery self-heating system according to claim 4, characterized in that: The battery self-heating system further includes: a controller connected to the first switch; The controller is configured to control the first switch to be closed when heating the first battery pack and the second battery pack; and to control the first switch to be opened when driving the first drive motor and the second drive motor.

6. The battery self-heating system according to claim 4, characterized in that: The positive terminal of the first battery pack, the positive terminal of the first multi-phase inverter, the positive terminal of the second multi-phase inverter and the positive terminal of the second battery pack are all connected to the positive main line, and the negative terminal of the first battery pack, the negative terminal of the first multi-phase inverter, the negative terminal of the second multi-phase inverter and the negative terminal of the second battery pack are all connected to the negative main line.

7. The battery self-heating system according to claim 6, characterized in that: The battery self-heating system further includes: a second switch, one end of the second switch being connected to the negative terminal of the first battery pack, and the other end of the second switch being connected to the negative terminal of the first multi-phase inverter; a third switch, one end of the third switch being connected to the negative terminal of the second battery pack, and the other end of the third switch being connected to the negative terminal of the second multi-phase inverter; a fourth switch, one end of the fourth switch being connected to the positive terminal of the first battery pack, and the other end being connected to the positive terminal of the third multi-phase inverter; A fifth switch, one end of the fifth switch is connected to the positive terminal of the first multi-phase inverter, and the other end of the fifth switch is connected to the positive terminal of the second multi-phase inverter.

8. The battery self-heating system according to claim 7, characterized in that: The battery self-heating system further includes: a controller connected to the first switch, the second switch, the third switch, the fourth switch, and the fifth switch; The controller is configured to, in a first state, control the first switch, the second switch, and the fourth switch to be closed and control the third switch and the fifth switch to be open, so as to control the first battery pack to charge the first multi-phase inductor and the second multi-phase inductor; In a second state, the first switch, the third switch, and the fourth switch are controlled to be closed, and the second switch and the fifth switch are controlled to be open, so as to control the first multi-phase inductor and the second multi-phase inductor to charge the second battery pack; In a third state, the first switch, the third switch, and the fourth switch are controlled to be closed, and the second switch and the fifth switch are controlled to be open, so as to control the second battery pack to charge the first multi-phase inductor and the second multi-phase inductor; In a fourth state, the first switch, the second switch, and the fourth switch are controlled to be closed, and the third switch and the fifth switch are controlled to be open, so as to control the first multi-phase inductor and the second multi-phase inductor to charge the first battery pack.

9. The battery self-heating system according to claim 1, characterized in that: The battery self-heating system further includes: a third battery pack, a fourth battery pack, a fourth multi-phase inverter, a fifth multi-phase inverter, a third multi-phase inductor, and a fourth multi-phase inductor; The fourth multi-phase inverter and the third battery pack are connected in parallel, the fifth multi-phase inverter and the fourth battery pack are connected in parallel, the negative terminal of the third battery pack, the negative terminal of the fourth multi-phase inverter, the negative terminal of the fifth multi-phase inverter, and the negative terminal of the fourth battery pack are all connected to the negative main line, and the fourth multi-phase inverter and the fifth multi-phase inverter are connected to each other; Each phase of the third multi-phase inductor is connected one-to-one to each phase of the fourth multi-phase inverter, each phase of the fourth multi-phase inductor is connected one-to-one to each phase of the fifth multi-phase inverter, the negative terminal of the first battery pack is connected to the positive terminal of the third battery pack, and the negative terminal of the second battery pack is connected to the positive terminal of the fourth battery pack; The fourth multi-phase inverter and the fifth multi-phase inverter are used to control, through on-off states, after the fourth battery pack charges the third multi-phase inductor and the fourth multi-phase inductor, the third multi-phase inductor and the fourth multi-phase inductor charge the third battery pack, and after the third battery pack charges the third multi-phase inductor and the fourth multi-phase inductor, the third multi-phase inductor and the fourth multi-phase inductor charge the fourth battery pack.

10. A vehicle, characterized in that: A battery self-heating system comprising the battery self-heating system according to any one of claims 1 to 9.

Images