Battery self-heating system and vehicle

Abstract

The present disclosure relates to a battery self-heating system and a vehicle, and relates to the technical field of electric vehicles. When the vehicle is driven by a first electric drive module, in order to ensure the performance of the vehicle in a low-temperature environment, alternate charging and discharging of a first battery pack and a second battery pack are used, so that voltage fluctuations of the first battery pack and the second battery pack offset each other, so that the terminal voltage fluctuation of the power battery pack is small, which not only ensures the battery performance of the vehicle during the driving process, but also prevents the battery body from being damaged by the self-heating process of battery charging and discharging.

Description

Technical Field

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

[0002] In response to energy conservation and emission reduction, more and more electric vehicles are entering the public eye. When electric vehicles are in a low-temperature environment, the low temperature reduces the activity of the positive and negative electrode materials and the electrolyte in the battery, and its discharge performance will be greatly reduced. In order to ensure the power of electric vehicles in low-temperature environments, the batteries of electric vehicles can be heated to increase the temperature of the battery body to ensure the battery discharge performance. In related technologies, battery heating is achieved by alternating charge and discharge between the battery pack and the energy storage element, but in the current discharge process, the terminal voltage of the battery pack fluctuates greatly. Summary of the invention

[0003] The purpose of the present disclosure is to provide a battery self-heating system and a vehicle, aiming to solve the above-mentioned technical problems.

[0004] In order to achieve the above-mentioned objectives, the present disclosure provides, on the one hand, a battery self-heating system, which is applied to a vehicle, a power battery pack, and the power battery pack includes a first battery group and a second battery group connected in series; a first heating module, the first heating module is connected to the first battery group; a second heating module, the second heating module is connected to the second battery group; a first electric drive module, the first electric drive module is connected to the power battery pack; a controller, which is connected to the first heating module, the second heating module and the first electric drive module, and the controller is configured to: control the power battery pack to supply power to the first electric drive module to drive the vehicle, and in a first state, control the first heating module to store the electric energy released by the first battery group, and control the second heating module to release the stored energy to the second battery group, and in a second state, control the first heating module to release the stored energy to the first battery group, and control the second heating module to store the electric energy released by the second battery group, and the first state and the second state are executed alternately.

[0005] Optionally, the second electric drive module is multiplexed as the first heating module; and / or the third electric drive module is multiplexed as the second heating module.

[0006] Optionally, the first electric drive module includes a first electric control and a first motor, the first electric control is connected to the power battery pack, and each phase coil winding of the first motor is connected one-to-one with the center point of each phase bridge arm of the first electric control; the second electric drive module includes a second electric control, a second motor and a first capacitor, the first end of the first capacitor is connected to the first bus terminal of the second electric control, the second end of the first capacitor is connected to the second bus terminal of the second electric control, the center point of each phase bridge arm of the second electric control is connected one-to-one with each phase coil winding of the second motor, and the first N line of the second motor is connected to the The positive terminal of the first battery pack is connected, and the second bus terminal of the second electronic control is connected to the negative terminal of the first battery pack; the third electric drive module includes a third electronic control, a third motor and a second capacitor, the first end of the second capacitor is connected to the first bus terminal of the third electronic control, the second end of the second capacitor is connected to the second bus terminal of the third electronic control, the center point of each phase bridge arm of the third electronic control is connected one by one with each phase winding of the third motor, the second N line of the third motor is connected to the positive terminal of the second battery pack, and the second bus terminal of the third electronic control is connected to the negative terminal of the second battery pack.

[0007] Optionally, the system also includes: a controller, the second electronic control includes a first bridge arm, the second motor includes a first coil, and the third electronic control includes a second bridge arm; the third motor includes a second coil; the controller is configured to: within a first time period of a first preset state, control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, and control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned off, control the first battery group to discharge to store energy for the first coil, and control the second capacitor to discharge to charge the second battery group; within a second time period of the first preset state, control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned on, and control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned off, control the first battery group to discharge to store energy for the first capacitor, and control the second coil to discharge to charge the second battery group.

[0008] Optionally, the controller is also configured to: within a first time period of a second preset state, control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned on, and control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned off, control the first capacitor to discharge to charge the first battery group and the first coil, and control the second battery group to discharge to charge the second coil; within a second time period of the second preset state, control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, and control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned off, control the first coil to discharge to charge the first battery group, and control the first battery group and the second coil to discharge to charge the second capacitor.

[0009] Optionally, the system also includes: a switch module, the switch module is connected to the controller, and the controller is further configured to: control the on or off of the switch module to control the second electric drive module to enter the driving mode, and / or control the third electric drive module to enter the driving mode; or control the second electric drive module and the third electric drive module to enter the self-heating mode.

[0010] Optionally, the switch module includes: a first switch, which is a two-position switch, wherein the static contact of the first switch is connected to the negative terminal of the first battery pack, the first moving contact of the first switch is connected to the neutral point of the first coil, the second moving contact of the first switch is respectively connected to the first end of the first capacitor, the first bus terminal of the second electric control, the first end of the second capacitor and the first bus terminal of the third electric control; the static contact of the second switch is respectively connected to the second end of the first capacitor and the second bus terminal of the second electric control, the first moving contact of the second switch is respectively connected to the negative terminal of the first battery pack and the positive terminal of the second battery pack, and the second moving contact of the second switch is respectively connected to the negative terminal of the second battery pack, the second end of the second capacitor and the second bus terminal of the third electric control; the third switch is a two-position switch, wherein the first moving contact of the third switch is respectively connected to the second moving contact of the first switch and the neutral point of the first coil, the second moving contact of the third switch is respectively connected to the negative terminal of the first battery pack and the positive terminal of the second battery pack, and the static contact of the third switch is connected to the neutral point of the second coil.

[0011] Optionally, the controller is connected to the first switch, the second switch and the third switch respectively; the controller is configured to: control the connection between the static contact of the first switch and the first moving contact of the first switch to control the establishment of the connection between the first battery pack and the first motor, control the connection between the static contact of the second switch and the first moving contact of the second switch, and establish the connection between the first battery pack and the first capacitor and the first bridge arm, and control the connection between the static contact of the third switch and the second moving contact of the third switch to establish the connection between the second battery pack, the first battery pack and the second bridge arm, so as to realize self-heating of the first battery pack and the second battery pack.

[0012] Optionally, the controller is also configured to: control the static contact of the first switch to be connected to the second moving contact of the first switch, the static contact of the second switch to be connected to the second moving contact of the second switch, and the third switch to be disconnected, so as to control the first battery pack and the second battery pack to power the second motor and the third motor to drive the vehicle.

[0013] Optionally, the system also includes: a charging interface; the controller is further configured to: in a third preset state, control the conduction state of the first bridge arm and the second bridge arm so that the charging pile charges the first battery group and the second battery group through the charging interface.

[0014] Optionally, the controller is also configured to, within a first time period of a third preset state, control the upper bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, so as to control the current of the charging pile connected to the charging interface to charge the first battery group and the second battery group through the upper bridge arm of the first bridge arm and the first coil, and to charge the first battery group and the second battery group through the upper bridge arm of the second bridge arm and the second coil; within a second time period of the third preset state, control the lower bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned on, so as to discharge through the first coil and the second coil to charge the first battery group and the second battery group.

[0015] Optionally, the duration of the first time period of the third preset state is the first time period T1, the duration of the second time period of the third preset state is the second time period T2, the discharge voltage of the charging pile is the first voltage U1, and the discharge voltages of the second motor and the third motor are the second voltage U2, wherein the first time period T1, the second time period T2, the first voltage U1 and the second voltage U2 have the following relationship: U1*T1=U2*(T1+T2).

[0016] Optionally, the system also includes: a fourth switch; one end of the fourth switch is respectively connected to the second moving contact of the first switch, the positive terminal of the second capacitor and the positive terminal of the first bridge arm, and the other end of the fourth switch is used to be connected to the positive terminal of the DC charging port, and the controller is connected to the fourth switch; the controller is also configured to: control the static contact of the first switch to be connected to the second moving contact of the first switch, the static contact of the second switch to be connected to the second moving contact of the second switch, the third switch to be disconnected, and the fourth switch to be closed, so as to charge the first battery group and the second battery group through the charging pile.

[0017] Another aspect of the present disclosure provides a vehicle, comprising the above-mentioned battery self-heating system.

[0018] The present disclosure provides a battery self-heating system and a vehicle. When the vehicle is driven by a first electric drive module, in order to ensure the performance of the vehicle in a low-temperature environment, alternate charging and discharging of the first battery pack and the second battery pack are used. In this way, voltage fluctuations of the first battery pack and the second battery pack offset each other, so that the terminal voltage fluctuation of the power battery pack is relatively small. The present disclosure not only ensures the battery performance of the vehicle during driving, but also the small voltage fluctuation can prevent the battery body from being damaged by the self-heating process of battery charging and discharging.

[0019] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of a battery self-heating circuit in the prior art.

[0022] Figure 2 It is a schematic diagram of another battery self-heating circuit in the prior art.

[0023] Figure 3 is a circuit diagram of a battery self-heating system provided in an embodiment of the present disclosure.

[0024] Figure 4 is a circuit diagram of a battery self-heating system provided in an embodiment of the present disclosure.

[0025] Figure 5 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0026] Figure 6 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0027] Figure 7 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0028] Figure 8 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0029] Fig. 9 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0030] Fig.10 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0031] Fig.11 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0032] Fig.12 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0033] Fig.13 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0034] Fig.14 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0035] Fig.15 is a circuit diagram of another battery self-heating system provided in an embodiment of the present disclosure.

[0036] Description of Reference Numerals

[0037] E1 First battery pack E2 Second battery pack

[0038] K1 first switch K2 second switch

[0039] K3 third switch K4 fourth switch

[0040] C1 first capacitor C2 second capacitor

[0041] 1First heating module 2Second heating module

[0042] 3First electric drive module 11Second electric control

[0043] 12 Second motor 21 Third electronic control

[0044] 22 third motor 31 first electronic control

[0045] 32 First Motor 4 Charging Pile DETAILED DESCRIPTION

[0046] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0047] In response to energy conservation and emission reduction, more and more electric vehicles are being chosen by more users. In order to improve the driving performance of electric vehicles, multi-motor electric vehicles known for their strong power are gradually entering the public eye. Strong power requires good battery charging and discharging performance, but when electric vehicles are in a low temperature environment, especially below -10°C, the low temperature reduces the activity of the positive and negative electrode materials and the electrolyte in the battery, and its charging and discharging performance will drop significantly. In order to ensure the power of electric vehicles in low temperature environments, the battery of the electric vehicle can be heated to increase the temperature of the battery body to ensure the performance of the battery during discharge driving, or to ensure the battery charging and discharging performance.

[0048] At present, batteries can be heated by external heating and internal heating. Among them, external heating heats the battery by adding additional heating equipment. This heating method adds additional heating equipment, which leads to high costs. In addition, the external heat dissipation is fast and there is a certain distance between the external temperature and the internal battery, resulting in low heating efficiency. At present, another heating method, internal heating, mainly uses the battery cycle charge and discharge to generate heat by relying on the battery's own internal resistance. For example, Figure 1 Or the self-heating system shown in 2. Figure 1 Or in the self-heating system shown in 2, the battery pack is charged and discharged alternately with the motor windings and capacitors. When the battery pack discharges to the motor windings and capacitors, the battery pack voltage drops. When the motor windings and capacitors charge the battery pack, the battery pack voltage rises. In the above-mentioned buck and boost methods, the battery voltage fluctuates greatly, and this fluctuation may damage the battery and reduce the battery life. In addition, the battery voltage fluctuation ΔU=I*Rcell. When the total internal resistance Rcell of the battery remains unchanged, the greater the battery current, the greater the fluctuation of the battery voltage. The large voltage fluctuation causes the charging pile to be unable to track the battery voltage in real time during direct charging, resulting in a jump gun or charging failure. Or when the battery is discharged, large voltage fluctuations will harm the devices on the vehicle.

[0049] To solve the above problems, the present application provides a battery self-heating system, which is applied to vehicles. Figure 3 The battery self-heating system includes: a power battery pack, a first heating module 1, a second heating module 2, a first electric drive module 3 and a controller (not shown in the figure).

[0050] See also Figure 3 The power battery pack includes a first battery pack E1 and a second battery pack E2 connected in series.

[0051] The first heating module 1 is connected to the first battery group E1.

[0052] The second heating module 2 is connected to the second battery group E2.

[0053] The first electric drive module 3 is connected to the first battery pack E1 and the second battery pack E2 respectively.

[0054] The controller is connected to the first heating module 1, the second heating module 2 and the first electric drive module 3. The controller is configured to: control the power battery pack to supply power to the first electric drive module 3 to drive the vehicle, and in the first state, control the first heating module 1 to store the electric energy released by the first battery pack E1, and control the second heating module 2 to release the stored energy to the second battery pack E2, and in the second state, control the first heating module 1 to release the stored energy to the first battery pack E1, and control the second heating module 2 to store the electric energy released by the second battery pack E2, and the first state and the second state are executed alternately, that is, the first battery pack E1 and the second battery pack E2 are charged alternately. Two heating modules participate in the battery self-heating, which makes the heat of the battery self-heating twice as much as the original one, thereby improving the heating effect.

[0055] The battery self-heating system provided in this embodiment uses the alternating charge and discharge of the first battery pack and the second battery pack to ensure the performance of the vehicle in a low temperature environment when the vehicle is driven by the first electric drive module. In this way, the voltage fluctuations of the first battery pack and the second battery pack offset each other, so that the terminal voltage fluctuation of the power battery pack is small, which not only ensures the battery performance of the vehicle during the driving process, but also prevents the battery body from being damaged by the self-heating process of battery charging and discharging. Also, when the vehicle is charging, the small voltage fluctuation avoids the charging failure caused by the jumping of the charging pile.

[0056] As for the heating module in the above embodiment, as an implementation mode, the heating module is a separately arranged heating module, that is, a separate first heating module and a second self-heating module are arranged in the battery self-heating system for heating the battery.

[0057] As another embodiment, the heating module is a reused component of the vehicle itself, and when the second electric drive module and the third electric drive module do not need to be driven, the two electric drive modules can be reused as the heating module. For example, the second electric drive module is reused as the first heating module; and / or the third electric drive module is reused as the second heating module.

[0058] For example, see Figure 4The first electric drive module 3 includes a first electric control 31 and a first motor 32. The first electric control 31 is connected to the power battery pack. Figure 4 As shown, the upper bridge arm of the first electronic control 31 is connected to the positive terminal of the first battery pack E1, the lower bridge arm of the first electronic control 31 is connected to the negative terminal of the second battery pack E2, and each phase coil winding of the first motor 32 is connected one by one to the center point of each phase bridge arm of the first electronic control.

[0059] The second electric drive module includes a second electric control 11, a second motor 12 and a first capacitor C1, wherein a first end of the first capacitor C1 is connected to a first bus terminal of the second electric control 11, a second end of the first capacitor C1 is connected to a second bus terminal of the second electric control 11, a center point of each phase bridge arm of the second electric control 11 is connected one-to-one with each phase coil winding of the second motor 12, a first N line of the second motor 12 is connected to a positive terminal of the first battery pack E1, and a second bus terminal of the second electric control 11 is connected to a negative terminal of the first battery pack E1;

[0060] The third electric drive module includes a third electric control 21, a third motor 22 and a second capacitor C2, the first end of the second capacitor C2 is connected to the first bus terminal of the third electric control 21, the second end of the second capacitor C2 is connected to the second bus terminal of the third electric control 21, the center point of each phase bridge arm of the third electric control 21 is connected one by one with each phase winding of the third motor 22, the second N line of the third motor 22 is connected to the positive terminal of the second battery pack E2, and the second bus terminal of the third electric control 21 is connected to the negative terminal of the second battery pack E2.

[0061] Optionally, the second electric control 11 and the third electric control 21 may be three-phase inverter bridges, six-phase inverter bridges, etc. Correspondingly, the second motor 12 and the third motor 22 may be three-phase motors, six-phase motors, etc.

[0062] In this embodiment, the second electric drive module and the third electric drive module of the vehicle itself are reused for heating, and there is no need to set up additional heating modules, thereby reducing the cost of battery self-heating.

[0063] In the second electric drive module and the third electric drive module Figure 4As shown, the self-heating of the battery can be controlled in the following manner. For example, the controller controls the on and off states of the second electronic control 11 and the third electronic control 21 to control that when the first battery pack E1 discharges to charge the first capacitor C1 or the second motor 12, the second capacitor C2 or the third motor 22 discharges to charge the second battery pack E2; when the first capacitor C1 or the second motor 12 discharges to charge the first battery pack E1, the second battery pack E2 discharges to charge the second capacitor C2 or the third motor 22, so that the first battery pack E1 and the second battery pack E2 are heated during the charging and discharging process to achieve multi-motor oscillation heating.

[0064] The on-off state refers to the off or off state of the switch tube of the upper bridge arm or the lower bridge arm in the electric control. At most, only one of the upper bridge arm and the lower bridge arm of the same electric control is turned on. For example, if the switch tube of the upper bridge arm of the second electric control 11 is turned off, the switch tube of the lower bridge arm of the second electric control 11 is turned off. The first battery group E1 and the second battery group E2 are alternately discharged through the on-off state of the second electric control 11, so that the total voltage fluctuation is small, reducing damage to the battery cells of the battery group.

[0065] The battery pack of the vehicle can be divided into a first battery pack E1 and a second battery pack E2, and the internal resistance Rcell of the battery pack is also divided into the internal resistance Rcell1 of the first battery pack E1 and the internal resistance Rcell2 of the second battery pack E2. In this embodiment, the second battery pack is charged and boosted and the first battery pack is discharged and reduced, or the first battery pack is discharged and boosted and the second battery pack is discharged and reduced, so that the total voltage fluctuation of the battery pack is small. Optionally, the discharge voltage of the first battery pack E1 drops ΔU1=I1*Rcell1, and the charging voltage of the second battery pack E2 rises ΔU2=I2*Rcell2, so that the total voltage fluctuation of the battery pack ΔU=ΔU1+ΔU2=0, where I1 is the current of the first battery pack and I2 is the current of the second battery pack. Or the charging voltage of the first battery pack E1 rises, and the discharge voltage of the second battery pack E2 drops, so that the total voltage fluctuation of the battery pack is 0.

[0066] Optionally, when the cells of the battery pack are equally divided into two battery groups, that is, the internal resistance Rcell1 of the first battery group E1 and the internal resistance Rcell2 of the second battery group E2 are the same, that is, Rcell1=Rcell2, as long as I1=I2 is ensured, the total voltage fluctuation of the battery pack can be achieved to be 0.

[0067] When the cells of the battery pack are not evenly divided, that is, the internal resistance Rcell1 of the first battery group E1 and the internal resistance Rcell2 of the second battery group E2 are different, it is sufficient to ensure that the voltage reduction of the first battery group and the voltage increase of the second battery group are the same, or the voltage increase of the first battery group and the voltage reduction of the second battery group are the same, that is, I1*Rcell1=I2*Rcell2.

[0068] That is, the ratio of the self-heating current of the first battery pack E1 and the second battery pack E2 is controlled to be I1 / I2=Rcell2 / Rcell1. Assuming that the internal resistance of all cells is the same, I1 / I2=Rcell2 / Rcell1=N2 / N1. Among them, N1 is the number of cells included in the first battery pack E1, N2 is the number of cells included in the second battery pack E2, Rcell1 is the total internal resistance of the first battery pack E1, and Rcell2 is the total internal resistance of the second battery pack E2.

[0069] Optionally, in addition to being divided into the above two groups, the cells of the battery pack can also be divided into three, four or even more groups (n groups), and accordingly, there are n motors and electronic controls matching each motor to match the n battery packs. In order to ensure the stability of the total voltage of the battery pack, by controlling the action of the bridge arm of the electronic control, assuming that the number of cells contained in the n battery packs is N1, N2, N3...Nn, respectively, the self-heating current of the n battery packs should satisfy the following relationship: I1 / I2 / I3 / ... / In=Nn / ... / N3 / N2 / N1.

[0070] Optionally, when there are m motors and an electronic control matching each of the m motors connected in parallel to the same battery pack, the sum of the currents flowing through each of the m electronic controls is controlled to be equal to the current of the battery pack, wherein the currents of each electronic control of the battery pack are not equal.

[0071] Optionally, the battery self-heating system further includes: a controller (not shown in the figure). The second electric control 11 includes a first bridge arm, the second motor 12 includes a first coil, the third electric control 21 includes a second bridge arm; and the third motor 22 includes a second coil.

[0072] The controller is configured to: in a first time period of a first preset state, control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, and control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned off, control the first battery pack E1 to discharge to store energy for the first coil, and control the second capacitor C2 to discharge to charge the second battery pack E2. The first preset state is the state in which the first battery pack E1 is discharged.

[0073] The controller is used to, in a first preset state, control the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on, so as to control the first battery pack E1 to discharge to charge the second motor 12, and control the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, so as to control the second capacitor C2 to discharge to charge the second battery pack E2 and the first coil (i.e., the coil of the second motor 12).

[0074] Taking the first motor, the second motor and the third motor as three-phase motors as an example, the battery self-heating system is as follows Figure 5 As shown. Figure 5 There are two circuits in it, one of which is a power battery pack composed of the first battery pack E1 and the second battery pack E2 connected in series to supply power to the third motor, and the arrow indicates the direction of the driving current. The other circuit is used for self-heating to ensure the discharge performance of the battery pack during driving.

[0075] This embodiment Figure 5 The battery self-heating process of another circuit in the circuit is described separately, please refer to Figure 6 , in the first time period under the first preset state, the controller controls the lower bridge arm of the second electric control 11 to be turned on, and the current flows out from the positive terminal of the first battery pack E1, and the current flows through the second motor 12 and the lower bridge arm of the second electric control 11 in turn back to the negative terminal of the first battery pack E1, forming a discharge circuit of the first battery pack E1, in which the first battery pack E1 is discharged to charge the winding of the second motor 12. At the same time, the controller controls the upper bridge arm of the third electric control 21 to be turned on, and the current flows out from the first end of the second capacitor C2, flows through the upper bridge arm of the third electric control 21 and the third motor 22 in turn into the positive terminal of the second battery pack E2, charges the second battery pack E2, and then flows back from the negative terminal of the second battery pack E2 to the second end of the second capacitor C2, forming a discharge circuit of the second capacitor C2, in which the second capacitor C2 is discharged to charge the second battery pack E2 and the third motor 22.

[0076] The controller is configured to: within a second time period of a first preset state, control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned on, and control the lower bridge arm of the first bridge arm and the upper bridge arm to be turned off, control the first battery pack E1 to discharge to store energy in the first capacitor C1, and control the second coil to discharge to charge the second battery pack E2.

[0077] See also Figure 7In the second time period of the first preset state, the controller controls the upper bridge arm of the second electronic control 11 to be turned on (the power switch device VT in the upper bridge arm can be closed, or the power switch device VT in the upper bridge arm can be disconnected, and the current flows through the diode VD), and the current flows out from the positive terminal of the first battery pack E1, flows through the first coil of the second motor 12, the upper bridge arm of the first bridge arm (that is, the bridge arm of the second electronic control 11) and the first capacitor C1 in turn, and then flows back to the negative terminal of the first battery pack E1 to form a loop. In the first time period of the first preset state, the first coil of the second motor 12 stores electrical energy after being charged. Therefore, in this loop, the first battery pack E1 and the first coil of the second motor 12 are discharged to charge the first capacitor C1. At the same time, the controller controls the lower bridge arm of the second bridge arm to be turned on. In the first preset state, the second coil of the third motor 22 is charged and stores electrical energy. Due to the freewheeling characteristics of the second coil of the third motor 22, the second coil of the third motor 22 is discharged, and the current flows out through the midpoint n2 of the second coil, flows into the positive terminal of the second battery pack E2, and charges the second battery pack E2. Then, the current flows out from the negative terminal of the second battery pack E2, flows into the lower bridge arm of the second bridge arm (that is, the bridge arm of the third electronic control 21), and then returns to the second coil of the third motor 22. In this loop, the second coil of the third motor 22 is discharged to charge the second battery pack E2.

[0078] Optionally, the controller is also configured to: within a first time period of a second preset state, control the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm to be turned on, and control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned off, control the first capacitor to discharge to charge the first battery pack and the first coil, and control the second battery pack to discharge to charge the second coil; wherein the second preset state is the state of the second battery pack discharging.

[0079] See also Figure 8, within the first time period of the second preset state, the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) is controlled to be turned on, and the current flows out from the first end of the first capacitor C1, and flows through the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) and the first coil of the second motor 12 in sequence, and then flows into the positive terminal of the first battery pack E1, after charging the first battery pack E1, and then flows out from the negative terminal of the first battery pack E1, and flows back to the second end of the first capacitor C1 to form a loop. Since the first capacitor C1 is charged and stored with electrical energy in the second time period of the first preset state, in this loop, the first capacitor C1 is discharged to charge the first battery pack E1 and the first coil of the second motor 12. At the same time, the controller controls the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, and the current flows out from the positive pole of the second battery group E2, flows through the second coil of the third motor 22 and the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) in sequence, and then flows back to the negative pole of the second battery group E2, forming a loop. In this loop, the second battery group E2 discharges to charge the second coil of the third motor 22.

[0080] The controller is configured to: within a second time period in a second preset state, control the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, and control the upper bridge arm of the first bridge arm and the lower bridge arm to be turned off, control the first coil to discharge to charge the first battery pack, and control the first battery pack and the second coil to discharge to charge the second capacitor.

[0081] See also Fig. 9 In the second time period of the second preset state, the controller controls the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on. In the first time period of the second preset state, the first coil of the second motor 12 is charged and stores electric energy. Due to the freewheeling performance of the motor winding of the first coil of the second motor 12, the current flows out from the first coil of the second motor 12 and flows into the positive terminal of the first battery pack E1 to charge the first battery pack E1. Then, the current flows out from the negative terminal of the first battery pack E1, flows through the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11), and flows back to the first coil of the second motor 12 to form a loop. In this loop, the first coil of the second motor 12 discharges to charge the first battery pack E1. At the same time, the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) is controlled to be turned on, and the current flows out through the second battery group E2, flows through the second coil of the third motor 22, the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) and the second capacitor C2 in turn, and then flows back to the negative end of the second battery group E2. Since the second coil of the third motor 22 has been charged and stored with electrical energy in the first time period of the second preset state, in this circuit, the second battery group E2 and the second coil of the third motor 22 are discharged to charge the second capacitor C2.

[0082] from Figure 6-Figure 9 It can be seen from the self-heating process shown that in the above four time periods, the charge and discharge states of the first battery E1 and the second battery E2 are always opposite. When the first battery E1 is discharging, the second battery E2 is charging, and when the second battery E2 is discharging, the first battery E1 is charging. Therefore, in the self-heating system disclosed in this embodiment, the voltage changes of the first battery E1 and the second battery E2 are always offset each other, thereby achieving overall stability of the terminal voltage of the power battery pack.

[0083] Figure 6-Figure 9 It can be used for self-heating of the battery before the vehicle is driven. The battery pack after shock heating has good discharge performance, which is convenient for vehicle starting. After the vehicle is started, in addition to the battery self-heating discharge, the energy generated by the operation of other electrical components in the vehicle can be used to heat the battery pack to ensure the performance of the battery pack during the formation process. Figure 6-Figure 9 It can also be used to heat the vehicle before or during charging. The battery pack after vibration heating has good charging performance, which is convenient for charging the battery pack. During the charging process, the battery pack will self-heat to ensure that the charging process goes smoothly.

[0084] Optionally, the system also includes: a switch module, the switch module is connected to the controller, and the controller is further configured to: control the on or off of the switch module to control the second electric drive module to enter the driving mode, and / or control the third electric drive module to enter the driving mode; or control the second electric drive module and the third electric drive module to enter the self-heating mode.

[0085] For example, taking the first motor and the second motor as three-phase motors, see Fig.10 The battery self-heating system further includes a first switch K1, a second switch K2 and a third switch K3, wherein the first switch K1 and the second switch K2 are both double-position switches, and the third switch K3 can be Fig.10 The two-position switch shown can also be a single-pole switch.

[0086] The first switch K1 is a two-position switch, wherein the static contact a of the first switch K1 is connected to the negative terminal of the first battery pack E1, the first moving contact b of the first switch K1 is connected to the neutral point n1 of the first coil, and the second moving contact c of the first switch K1 is respectively connected to the first end of the first capacitor C1, the first bus terminal of the second electric control 11, the first end of the second capacitor C2, and the first bus terminal of the third electric control 21;

[0087] The second switch K2 is a two-position switch, wherein the static contact a of the second switch K2 is respectively connected to the second end of the first capacitor C1 and the second bus terminal of the second electric control 11, the first moving contact b of the second switch K2 is respectively connected to the negative terminal of the first battery pack E1 and the positive terminal of the second battery pack E2, and the second moving contact c of the second switch K2 is respectively connected to the negative terminal of the second battery pack E2, the second end of the second capacitor C2 and the second bus terminal of the third electric control 21;

[0088] The third switch K3 is a double-position switch. The first moving contact b of the third switch K3 is respectively connected to the second moving contact b of the first switch K1 and the neutral point of the first coil, the second moving contact c of the third switch K3 is respectively connected to the negative terminal of the first battery pack E1 and the positive terminal of the second battery pack E2, and the static contact c of the third switch K3 is connected to the neutral point of the second coil.

[0089] Optionally, the controller is connected to the first switch K1 , the second switch K2 and the third switch K3 respectively.

[0090] Optionally, in this embodiment, the first switch K1, the second switch K2 and the third switch K3 are used to establish the connection between the various components of the circuit, so the first switch K1, the second switch K2 and the third switch K3 are not limited to the above-mentioned two-position switches, and can also be unit switches, three-position switches, etc., as long as the above-mentioned connection can be established. For example, the first switch K1 can include two unit switches, and the two unit switches are used to establish the connection between the positive terminal of the first battery pack E1 and the first end of the first capacitor C1, and the connection between the positive terminal of the first battery pack E1 and the second motor 12. Similarly, the second switch K2 can also include two unit switches, and the two unit switches can establish the connection between the negative terminal of the first battery pack E1 and the second end of the first capacitor C1, and the connection between the negative terminal of the second battery pack E2 and the second end of the first capacitor C1.

[0091] In the scenario of oscillating heating, Fig.10 As shown, the controller is configured to: control the connection between the static contact a of the first switch K1 and the first moving contact b of the first switch K1 to control the establishment of the connection between the first battery group E1 and the second motor 12, control the connection between the static contact a of the second switch K2 and the first moving contact b of the second switch K2, and establish the connection between the first battery group E1 and the first capacitor C1 and the first bridge arm, and control the connection between the static contact a of the third switch K3 and the second moving contact c of the third switch K3 to establish the connection between the second battery group E2, the first battery group E1 and the second bridge arm, so as to realize self-heating of the first battery group E1 and the second battery group E2.

[0092] During the first time period under the first preset state, the controller controls the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on, and the current flows out from the positive terminal of the first battery group E1. The current flows through the ab contacts of the first switch K1 in sequence through the first coil of the second motor 12, the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11), and the two ab contacts of the second switch K2 and returns to the negative terminal of the first battery group E1, forming a discharge circuit of the first battery group E1, in which the first battery group E1 discharges to charge the winding of the first coil of the second motor 12. At the same time, the controller controls the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, and the current flows out from the first end of the second capacitor C2, and flows through the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21), the second coil of the third motor 22 and the ac contact of the third switch K3 in turn, and flows into the positive end of the second battery group E2 to charge the second battery group E2, and then flows back from the negative end of the second battery group E2 to the second end of the second capacitor C2, forming a discharge circuit of the second capacitor C2, in which the second capacitor C2 discharges to charge the second battery group E2 and the second coil of the third motor 22.

[0093] The controller is also used to control the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on during a second time period under the first preset state, so as to control the first battery pack E1 and the first coil of the second motor 12 to discharge to charge the first capacitor C1, and to control the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, so as to control the second coil of the third motor 22 to discharge to charge the second battery pack E2.

[0094] During the second time period under the first preset state, the controller controls the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on (the power switching device VT in the upper bridge arm can be closed, or the power switching device VT in the upper bridge arm can be disconnected, and the current flows through the diode VD), and the current flows out from the positive terminal of the first battery pack E1, and flows through the ab contact of the first switch K1, the first coil of the second motor 12, the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) and the first capacitor C1 in turn, and then flows back to the negative terminal of the first battery pack E1 through the ab contact of the second switch K2 to form a loop. In the first preset state, the first coil of the second motor 12 stores electrical energy after being charged. Therefore, in this loop, the first battery pack E1 and the first coil of the second motor 12 discharge to charge the first capacitor C1. At the same time, the controller controls the lower bridge arm of the second bridge arm to be turned on. Within the first time period under the first preset state, the second coil of the third motor 22 is charged and stores electrical energy. Due to the freewheeling characteristics of the second coil, the second coil of the third motor 22 is discharged. The current flows out through the midpoint n2 of the second coil of the third motor 22, flows into the positive terminal of the second battery pack E2 through the ac contact of the third switch K3, and charges the second battery pack E2. Then, the current flows out from the negative terminal of the second battery pack E2, flows into the lower bridge arm of the second bridge arm (that is, the bridge arm of the third electronic control 21), and then returns to the second coil of the third motor 22. In this loop, the second coil of the third motor 22 is discharged to charge the second battery pack E2.

[0095] The controller is also used to control the upper bridge arm of the first and second bridge arms to be turned on within a first time period under a second preset state, so as to control the first capacitor C1 to discharge to charge the first coil of the second motor 12 and the first battery pack E1, and to control the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, so as to control the second battery pack E2 to discharge to charge the second coil of the third motor 22.

[0096] During the first time period under the second preset state, the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) is controlled to be turned on, and current flows out from the first end of the first capacitor C1, and flows through the upper bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11), the first coil of the second motor 12, and the ab contacts of the first switch K1 in sequence, and then flows into the positive terminal of the first battery group E1 to charge the first battery group E1, and then flows out from the negative terminal of the first battery group E1, and flows back to the second end of the first capacitor C1 through the ab contacts of the second switch K2 to form a loop. Since the first capacitor C1 is charged and stores electrical energy during the second time period under the first preset state, in this loop, the first capacitor C1 discharges to charge the first battery group E1 and the first coil of the second motor 12. At the same time, the controller controls the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) to be turned on, and the current flows out from the positive pole of the second battery group E2, flows through the ac contact of the third switch K3, the second coil of the third motor 22 and the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) in sequence, and then flows back to the negative pole of the second battery group E2, forming a loop, in which the second battery group E2 discharges to charge the second coil of the third motor 22.

[0097] The controller is also used to control the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on during a second time period under a second preset state, so as to control the first coil of the second motor 12 to discharge to charge the first battery pack E1, and to control the upper bridge arm of the second bridge arm to be turned on, so as to control the second coil of the second battery pack E2 and the third motor 22 to discharge to charge the second capacitor.

[0098] During the second time period under the second preset state, the controller controls the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) to be turned on. In the third preset state, the first coil of the second motor 12 is charged and stores electrical energy. Due to the freewheeling performance of the motor winding of the first coil of the second motor 12, current flows out from the first coil of the second motor 12, flows into the positive terminal of the first battery pack E1 through the ab contact of the first switch K1, and charges the first battery pack E1. Current then flows out from the negative terminal of the first battery pack E1, flows through the ab contact of the second switch K2 and the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electronic control 11) in turn, and flows back to the first coil of the second motor 12, forming a loop. In this loop, the first coil of the second motor 12 discharges to charge the first battery pack E1. At the same time, the lower bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) is controlled to be turned on, and the current flows out through the second battery pack E2. After flowing through the second coil of the third motor 22, the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electronic control 21) and the second capacitor C2 in sequence through the ac contact of the third switch K3, it flows back to the negative end of the second battery pack E2. Since the second coil of the third motor 22 has been charged and stored with electrical energy in the first time period under the second preset state, in this circuit, the second battery pack E2 and the second coil of the third motor 22 are discharged to charge the second capacitor C2.

[0099] Optionally, the controller is also configured to: control the static contact a of the first switch K1 to be connected to the second moving contact c of the first switch K1, the static contact a of the second switch K2 to be connected to the second moving contact c of the second switch K2, and the third switch K3 to be disconnected, so as to control the first battery pack E1 and the second battery pack E2 to supply power to the second motor and the third motor to drive the vehicle.

[0100] Optionally, the system further comprises: a charging interface (not shown in the figure); the charging interface is used to connect to a charging pile. When charging is required, the charging pile is plugged into the charging interface.

[0101] The controller is further configured to: in a third preset state, control the conduction state of the first bridge arm and the second bridge arm, so that the charging pile charges the first battery pack E1 and the second battery pack E2 through the charging interface.

[0102] Optionally, the controller is also used to control the upper arm of the first bridge arm and the upper arm of the second bridge arm to be turned on within a first time period of a third preset state, so as to control the current of the charging pile connected to the charging interface to charge the first battery group E1 and the second battery group E2 through the upper arm of the first bridge arm and the first coil, and to charge the first battery group E1 and the second battery group E2 through the upper arm of the second bridge arm and the second coil.

[0103] See also Fig.13 , within the first time period of the third preset state, the controller controls the upper bridge arm of the first bridge arm (i.e. the bridge arm of the second electric control 11) and the upper bridge arm of the second bridge arm (i.e. the bridge arm of the third electric control 21) to be turned on, and the current flows out from the positive end of the DC charging pile, passes through the fourth switch K4, and one path of the current flows through the upper bridge arm of the first bridge arm (i.e. the bridge arm of the second electric control 11), the first coil of the second motor 12 and the ab contacts of the first switch K1 in sequence and flows into the positive end of the first battery pack E1 to charge the first battery pack E1, and then flows from the negative end of the first battery pack E1 to the positive end of the second battery pack E2 to charge the second battery pack E2, and the current flows back from the negative end of the second battery pack E2 to the negative end of the charging pile 4. Another current from the positive end of the charging pile 4 passes through the fourth switch K4 and flows through the upper bridge arm of the second bridge arm (i.e., the bridge arm of the third electric control 21), the second coil of the third motor 22, the ab contact of the third switch K3, and the ab contact of the first switch K1, and then flows into the positive end of the first battery pack E1 to charge the first battery pack E1, and then flows from the negative end of the first battery pack E1 to the positive end of the second battery pack E2 to charge the second battery pack E2, and the current flows back from the negative end of the second battery pack E2 to the negative end of the charging pile 4. In this embodiment, the first battery pack E1 and the second battery pack E2 are directly charged through the charging pile 4.

[0104] Optionally, when the voltage of the charging pile 4 is higher than the voltage of the battery pack, the vehicle is charged using the charging pile 4, and the on and off of the electrical components in the battery self-heating system can be controlled to control the DC charging pile to step down and charge. Fig.13 Based on the combination Fig.14 , after the first time period of the third preset state, within the second time period of the third preset state, the lower bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned on, so as to charge the first battery pack E2 and the second battery pack E2 by discharging through the first coil and the second coil.

[0105] See also Fig.14In the second time period of the third preset state, the controller controls the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electric control 11) and the lower bridge arm of the second bridge arm to be turned on. In the first time period of the third preset state, the first coil of the second motor 12 and the second coil of the third motor 22 are charged and store electrical energy. Due to the freewheeling characteristics of the motor winding in the motor, the first coil of the second motor 12 is discharged, and the current flows out from the midpoint of the first coil, flows into the positive terminal of the first battery pack E1 through the ab contact of the first switch K1, and charges the first battery pack E1. Then, the current flows from the negative terminal of the first battery pack E1 into the positive terminal of the second battery pack E2, and charges the second battery pack E2. The current flows out from the negative terminal of the second battery pack E2, passes through the ac contact of the second switch K2, flows through the lower bridge arm of the first bridge arm (i.e., the bridge arm of the second electric control 11), and flows back to the first coil of the second motor 12. And the second coil of the third motor 22 is discharged, the current flows out from the midpoint of the second coil of the third motor 22, passes through the ab contact of the third switch K3 and the ab contact of the first switch K1, flows into the positive terminal of the first battery pack E1, charges the first battery pack E1, and then flows from the negative terminal of the first battery pack E1 into the positive terminal of the second battery pack E2, charges the second battery pack E2, and the current flows out from the negative terminal of the second battery pack E2, passes through the lower bridge arm of the second bridge arm and flows back to the second coil of the third motor 22. The first coil of the second motor 12 and the second coil of the third motor 22 are discharged to charge the first battery pack E1 and the second battery pack E2. In this embodiment, the first battery pack E1 and the second battery pack E2 are charged alternately in two time periods of the third preset state, so as to realize the step-down charging of the DC charging pile.

[0106] Optionally, the duration of the first time period of the third preset state is the first time period T1, the duration of the second time period of the third preset state is the second time period T2, the discharge voltage of the charging pile is the first voltage U1, and the discharge voltages of the second motor and the third motor are the second voltage U2, wherein the first time period T1, the second time period T2, the first voltage U1 and the second voltage U2 have the following relationship: U1*T1=U2*(T1+T2). The ratio of U1 to U2 can be adjusted by controlling the time proportion of T1 and T2, so as to control the charging voltage.

[0107] It should be noted that the conduction of the above-mentioned bridge arm can be that the entire bridge arm is turned on, or that part of the bridge arm is turned on. For example, taking the first bridge arm as a three-phase bridge arm, the partial conduction can be that any one phase of the three-phase bridge arm is turned on, or any two phases of the three-phase bridge arm are turned on.

[0108] Optionally, when the vehicle is charged through a DC charging station, it can also be self-heated through the battery self-heating system to ensure battery performance and improve the charging rate in low temperature environments. Fig.12, the system also includes: a fourth switch K4.

[0109] One end of the fourth switch K4 is respectively connected to the second moving contact c of the first switch K1, the first end of the second capacitor C1 and the positive end of the first bridge arm, the other end of the fourth switch K4 is used to be connected to the positive end of the DC charging port, and the controller is connected to the fourth switch K4.

[0110] The controller is also configured to: control the static contact a of the first switch K1 to be connected to the second moving contact c of the first switch K1, the static contact a of the second switch K2 to be connected to the second moving contact c of the second switch K2, the third switch K3 to be disconnected, and the fourth switch K4 to be closed, so as to charge the first battery pack E1 and the second battery pack E2 through the charging pile.

[0111] Optionally, in addition to the above Fig.13 and Fig.14 In addition to the charging methods shown, you can also Fig.15 The first battery pack E1 and the second battery pack E2 are charged in the manner shown in FIG. Fig.15 The controller is also used to control the static contact a of the first switch K1 to be connected to the second moving contact c of the first switch K1, the static contact a of the second switch K2 to be connected to the second moving contact c of the second switch K2, the third switch K3 to be disconnected, and the fourth switch K4 to be closed, so as to control the charging pile 4 to charge the first battery pack E1 and the second battery pack E2. Fig.15 , the current flows out from the positive terminal of the charging pile 4, flows into the positive terminal of the first battery pack E1 through the ac contact of the first switch K1, charges the first battery pack E1, and then flows from the negative terminal of the first battery pack E1 to the positive terminal of the second battery pack E2, charges the second battery pack E2, and the current flows back from the negative terminal of the second battery pack E2 to the negative terminal of the charging pile 4. The current of the charging pile 4 does not pass through the capacitor, the electric control and the motor, and directly charges the battery pack. At the same time, multiple motors are used for self-heating, the heating current is large, and the self-heating efficiency is improved.

[0112] Optionally, during the battery self-heating process, in addition to the above Figure 4-Figure 10 In addition to the two motors involved in oscillation heating, there can also be 3 motors, 4 motors or more motors.

[0113] Optionally, the present disclosure further provides a vehicle, comprising the above-mentioned battery self-heating system, and when the vehicle is driving, the battery in the vehicle is heated and heated by the battery self-heating system to ensure the performance of the battery in a low temperature environment.

[0114] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations. In addition, the various different embodiments of the present disclosure can also be combined arbitrarily, as long as they do not violate the ideas 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, the system comprises: A power battery pack, the power battery pack comprising a first battery group and a second battery group connected in series; a first heating module, wherein the first heating module is connected to the first battery pack; a second heating module, wherein the second heating module is connected to the second battery pack; A first electric drive module, wherein the first electric drive module is connected to the power battery pack; A controller is connected to the first heating module, the second heating module and the first electric drive module, and the controller is configured to: control the power battery pack to supply power to the first electric drive module to drive the vehicle, and in a first state, control the first heating module to store the electric energy released by the first battery pack, and control the second heating module to release the stored energy to the second battery pack; in a second state, control the first heating module to release the stored energy to the first battery pack, and control the second heating module to store the electric energy released by the second battery pack, and the first state and the second state are executed alternately.

2. The system according to claim 1, characterized in that Reusing the second electric drive module as the first heating module; And / or, the third electric drive module is reused as the second heating module.

3. The system according to claim 2, characterized in that The first electric drive module includes a first electric control and a first motor, the first electric control is connected to the power battery pack, and each phase coil winding of the first motor is connected one by one to the center point of each phase bridge arm of the first electric control; The second electric drive module includes a second electric control, a second motor and a first capacitor, wherein the first end of the first capacitor is connected to the first bus terminal of the second electric control, the second end of the first capacitor is connected to the second bus terminal of the second electric control, the center point of each phase bridge arm of the second electric control is connected one by one with each phase coil winding of the second motor, the first N line of the second motor is connected to the positive terminal of the first battery pack, and the second bus terminal of the second electric control is connected to the negative terminal of the first battery pack; The third electric drive module includes a third electronic control, a third motor and a second capacitor. The first end of the second capacitor is connected to the first bus terminal of the third electronic control, the second end of the second capacitor is connected to the second bus terminal of the third electronic control, the center point of each phase bridge arm of the third electronic control is connected one by one with each phase winding of the third motor, the second N line of the third motor is connected to the positive terminal of the second battery pack, and the second bus terminal of the third electronic control is connected to the negative terminal of the second battery pack.

4. The system according to claim 3, characterized in that The second electric control includes a first bridge arm, the second motor includes a first coil, the third electric control includes a second bridge arm; the third motor includes a second coil; The controller is configured to: In a first time period of a first preset state, the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm are controlled to be turned on, and the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned off, the first battery pack is controlled to discharge to store energy for the first coil, and the second capacitor is controlled to discharge to charge the second battery pack; During the second time period of the first preset state, the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned on, and the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm are controlled to be turned off, the first battery pack is controlled to discharge to store energy in the first capacitor, and the second coil is controlled to discharge to charge the second battery pack.

5. The system according to claim 4, characterized in that The controller is also configured to: In a first time period of a second preset state, the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned on, and the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm are controlled to be turned off, the first capacitor is controlled to discharge to charge the first battery pack and the first coil, and the second battery pack is controlled to discharge to charge the second coil; During a second time period of a second preset state, the lower bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm are controlled to be turned on, and the upper bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned off, the first coil is controlled to discharge to charge the first battery pack, and the first battery pack and the second coil are controlled to discharge to charge the second capacitor.

6. The system according to claim 4, characterized in that The system further comprises: A switch module, the switch module is connected to the controller, and the controller is further configured to: control the switch module to be turned on or off, so as to control the second electric drive module to enter the driving mode, and / or control the third electric drive module to enter the driving mode; Alternatively, the second electric drive module and the third electric drive module are controlled to enter a self-heating mode.

7. The system according to claim 6, characterized in that The switch module comprises: The first switch is a two-position switch, wherein the static contact of the first switch is connected to the negative terminal of the first battery pack, the first moving contact of the first switch is connected to the neutral point of the first coil, and the second moving contact of the first switch is respectively connected to the first end of the first capacitor, the first bus terminal of the second electric control, the first end of the second capacitor, and the first bus terminal of the third electric control; The second switch is a two-position switch, wherein the static contact of the second switch is respectively connected to the second end of the first capacitor and the second bus terminal of the second electric control, the first moving contact of the second switch is respectively connected to the negative terminal of the first battery pack and the positive terminal of the second battery pack, and the second moving contact of the second switch is respectively connected to the negative terminal of the second battery pack, the second end of the second capacitor and the second bus terminal of the third electric control; The third switch is a double-position switch, wherein the first moving contact of the third switch is respectively connected to the second moving contact of the first switch and the neutral point of the first coil, the second moving contact of the third switch is respectively connected to the negative terminal of the first battery pack and the positive terminal of the second battery pack, and the static contact of the third switch is connected to the neutral point of the second coil.

8. The system according to claim 7, characterized in that The controller is connected to the first switch, the second switch and the third switch respectively; The controller is configured to: Control the connection between the static contact of the first switch and the first moving contact of the first switch to establish the connection between the first battery pack and the second motor, control the connection between the static contact of the second switch and the first moving contact of the second switch, and establish the connection between the first battery pack and the first capacitor and the first bridge arm, and control the connection between the static contact of the third switch and the second moving contact of the third switch to establish the connection between the second battery pack, the first battery pack and the second bridge arm, so as to realize self-heating of the first battery pack and the second battery pack.

9. The system according to claim 8, characterized in that The controller is also configured to: Control the static contact of the first switch to be connected with the second moving contact of the first switch, the static contact of the second switch to be connected with the second moving contact of the second switch, and the third switch to be disconnected, so as to control the first battery pack and the second battery pack to supply power to the second motor and the third motor to drive the vehicle.

10. The system according to claim 9, characterized in that The system further comprises: a charging interface; The controller is also configured to: In a third preset state, the conduction states of the first bridge arm and the second bridge arm are controlled so that the charging pile charges the first battery group and the second battery group through the charging interface.

11. The system according to claim 10, characterized in that The controller is further configured to, within a first time period of a third preset state, control the upper bridge arm of the first bridge arm and the upper bridge arm of the second bridge arm to be turned on, so as to control the current of the charging pile connected to the charging interface to charge the first battery pack and the second battery pack through the upper bridge arm of the first bridge arm and the first coil, and to charge the first battery pack and the second battery pack through the upper bridge arm of the second bridge arm and the second coil; In a second time period of the third preset state, the lower bridge arm of the first bridge arm and the lower bridge arm of the second bridge arm are controlled to be turned on, so as to charge the first battery pack and the second battery pack by discharging through the first coil and the second coil.

12. The system according to claim 11, characterized in that The duration of the first time period of the third preset state is the first time period T1, the duration of the second time period of the third preset state is the second time period T2, the discharge voltage of the charging pile is the first voltage U1, and the discharge voltages of the second motor and the third motor are the second voltage U2, wherein the first time period T1, the second time period T2, the first voltage U1 and the second voltage U2 have the following relationship: U1*T1=U2*(T1+T2).

13. The system according to claim 7, characterized in that The system further comprises: a fourth switch; One end of the fourth switch is respectively connected to the second moving contact of the first switch, the positive terminal of the second capacitor and the positive terminal of the first bridge arm, the other end of the fourth switch is used to be connected to the positive terminal of the DC charging port, and the controller is connected to the fourth switch; The controller is also configured to: Control the static contact of the first switch to be connected with the second moving contact of the first switch, the static contact of the second switch to be connected with the second moving contact of the second switch, the third switch to be opened, and the fourth switch to be closed, so as to charge the first battery pack and the second battery pack through the charging pile.

14. A vehicle, characterized in that: A battery self-heating system comprising any one of claims 1-13.

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