Battery control system and vehicle

Abstract

The present disclosure relates to a battery control system and a vehicle, the battery control system comprising a charge-discharge port, a power battery pack, a multiphase bridge arm and a multiphase motor, wherein a first bus end of the multiphase bridge arm is connected with a positive electrode of the power battery pack, a second bus end of the multiphase bridge arm is respectively connected with a negative electrode of the power battery pack and a negative electrode of the charge-discharge port, the multiphase motor comprises a single set of windings or multiple sets of windings, a first end of the multiphase motor is connected with the multiphase bridge arm, and a second end of the multiphase motor is connected with a positive electrode of the charge-discharge port. The multiphase motor can form a circulating self-heating loop and a step-up charging loop with the charge-discharge port, the power battery pack and the multiphase bridge arm, so as to realize the cooperation of circulating self-heating and step-up charging and improve the heating and charging performance of the power battery pack.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of vehicle control, in particular, to a battery control system and a vehicle. BACKGROUND

[0002] Lithium ion batteries are relatively sensitive to low temperature. The internal resistance of lithium ion batteries increases sharply at low temperature, and the discharge capacity and charge-discharge performance are greatly limited, which leads to insufficient power performance of electric vehicles in low temperature environment and a significant reduction in driving range. In related technologies, a single-phase winding of a multi-phase motor on a vehicle is usually reused to charge or self-heat the power battery pack. However, related technologies do not consider how to use multiple coils of the multi-phase motor to further improve the heating and charge-discharge performance of the power battery pack. SUMMARY

[0003] The purpose of the present disclosure is to provide a battery control system and a vehicle. A first bus end of a multi-phase bridge arm is connected to a positive electrode of a power battery pack, and a second bus end of the multi-phase bridge arm is connected to negative electrodes of the power battery pack and a negative electrode of a charge-discharge port. A multi-phase motor includes a single set of windings or multiple sets of windings. A first end of the multi-phase motor is connected to the multi-phase bridge arm, and a second end of the multi-phase motor is connected to a positive electrode of the charge-discharge port. The multi-phase motor can form a circulating self-heating loop and a boost charging loop with the charge-discharge port, the power battery pack and the multi-phase bridge arm, thereby realizing the cooperation of circulating self-heating and boost charging and improving the heating and charge-discharge performance of the power battery pack.

[0004] To achieve the above purpose, the present disclosure provides a battery control system, comprising:

[0005] a charge-discharge port;

[0006] a power battery pack;

[0007] a multi-phase bridge arm, a first bus end of the multi-phase bridge arm being connected to a positive electrode of the power battery pack, and a second bus end of the multi-phase bridge arm being connected to negative electrodes of the power battery pack and a negative electrode of the charge-discharge port;

[0008] a multi-phase motor, the multi-phase motor including windings, the windings including a single set of windings or multiple sets of windings, a first end of the multi-phase motor being connected to the multi-phase bridge arm, and a second end of the multi-phase motor being connected to a positive electrode of the charge-discharge port;

[0009] the power battery pack, the multi-phase bridge arm and the multi-phase motor can form a circulating self-heating loop;

[0010] the charge-discharge port, the power battery pack, the multi-phase bridge arm and the multi-phase motor can form a boost charging loop.

[0011] Optionally, the multiphase motor comprises a plurality of pole pairs, each pole pair comprising three coil branches, the first ends of the coil branches of the same phase in the three coil branches of the plurality of pole pairs being connected together and connected to the midpoint of the corresponding bridge arm in the plurality of bridge arms, the second ends of the three coil branches of each pole pair being connected together to form a neutral point, the neutral points of the plurality of pole pairs being connected together and leading to an N line, and the N line being connected to the positive electrode of the charging and discharging port.

[0012] Optionally, the system further comprises:

[0013] a charging on-off switch unit configured to make the boost charging loop conductive or disconnected;

[0014] a circulating current self-heating on-off switch unit configured to make the circulating current self-heating loop conductive or disconnected.

[0015] Optionally, the system further comprises:

[0016] a controller connected to the plurality of bridge arms, the charging on-off switch unit and the circulating current self-heating on-off switch unit, respectively;

[0017] the controller is configured to control the plurality of bridge arms, the charging on-off switch unit and the circulating current self-heating on-off switch unit, so that at least one of the functions of the charging / discharging function, the circulating current self-heating function and the driving function is realized.

[0018] Optionally, the controller is configured to, when in a first state, control the plurality of bridge arms, the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the electric energy output by the power battery pack is output to the multiphase motor through the winding and the plurality of bridge arms to make the multiphase motor generate heat to heat the power battery pack, and so that the electric energy input by the charging and discharging port is input to the power battery pack to boost charge the power battery pack.

[0019] Optionally, the controller is configured to, when in a second state, control the plurality of bridge arms, the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the electric energy output by the power battery pack is output to the multiphase motor through the plurality of bridge arms and the winding to make the multiphase motor generate heat to heat the power battery pack, and so that the electric energy output by the power battery pack is output to the charging and discharging port to supply power to the load.

[0020] Optionally, the controller is configured to, when in the third state, control the multi-phase bridge arm and the circulating self-heating on-off switch unit, so that the power battery pack outputs electric energy to the multi-phase motor to make the multi-phase motor generate heat to heat the power battery pack, and so that the power battery pack outputs electric energy to the multi-phase motor to drive the vehicle.

[0021] Optionally, the controller is configured to, when in the fourth state, control the multi-phase bridge arm and the charging on-off switch unit, so that the power battery pack outputs electric energy to the charging and discharging port through the multi-phase bridge arm and the winding to supply power to the load, and so that the power battery pack outputs electric energy to the multi-phase motor to drive the vehicle.

[0022] Optionally, the controller is configured to, when in the fifth state, control the multi-phase bridge arm and the charging on-off switch unit, so that the charging and discharging port inputs electric energy to the power battery pack through the winding and the multi-phase bridge arm to charge the power battery pack, and so that the charging and discharging port inputs electric energy to the multi-phase motor to drive the vehicle.

[0023] Optionally, the controller is configured to, when in the sixth state, control the multi-phase bridge arm, the circulating self-heating on-off switch unit and the charging on-off switch unit, so that the power battery pack outputs electric energy to the multi-phase motor to make the multi-phase motor generate heat to heat the power battery pack, and so that the charging and discharging port inputs electric energy to the power battery pack to boost charge the power battery pack, and so that the power battery pack outputs electric current or the charging and discharging port inputs electric current to the multi-phase motor to drive the vehicle.

[0024] Optionally, the controller is configured to, when in the seventh state, control the multi-phase bridge arm and the charging on-off switch unit, so that the charging and discharging port inputs electric energy to the multi-phase motor to make the multi-phase motor generate heat to heat the power battery pack.

[0025] Optionally, the power battery pack comprises a first battery group and a second battery group connected in series, and the N lines are further connected between the first battery group and the second battery group.

[0026] The power battery pack, the multi-phase bridge arm and the multi-phase motor can further constitute a self-heating loop.

[0027] The system further comprises a self-heating on-off switch unit configured to make the self-heating loop conductive or disconnected.

[0028] The controller is connected with the self-heating on-off switch unit, and the controller is configured to: in an eighth state, control the multi-phase bridge arm and the self-heating on-off switch unit, so that the first battery pack and the second battery pack are alternately charged and discharged to heat the power battery pack, or / and so that the power battery pack outputs electric energy to the multi-phase motor to drive the vehicle.

[0029] According to a second aspect of the embodiments of the present disclosure, a vehicle is provided, which comprises the battery control system provided in the first aspect of the embodiments of the present disclosure.

[0030] Through the above technical solution, the battery control system comprises a charging and discharging port, a power battery pack, a multi-phase bridge arm and a multi-phase motor, wherein the first bus end of the multi-phase bridge arm is connected with the positive electrode of the power battery pack, the second bus end of the multi-phase bridge arm is respectively connected with the negative electrode of the power battery pack, and the negative electrode of the charging and discharging port, the multi-phase motor comprises a single set of windings or multiple sets of windings, the first end of the multi-phase motor is connected with the multi-phase bridge arm, and the second end of the multi-phase motor is connected with the positive electrode of the charging and discharging port. The multi-phase motor can form a circulating self-heating loop and a step-up charging loop with the charging and discharging port, the power battery pack and the multi-phase bridge arm, so as to realize the cooperation of circulating self-heating and step-up charging, and improve the heating and charging performance of the power battery pack.

[0031] Other features and advantages of the present disclosure will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following specific embodiments to explain the present disclosure but do not constitute a limitation on the present disclosure. In the drawings:

[0033] Figure 1 is a schematic diagram of a battery control system according to an exemplary embodiment.

[0034] Figure 2 is a schematic diagram of another battery control system according to an exemplary embodiment.

[0035] Figure 3 is a schematic diagram of still another battery control system according to an exemplary embodiment.

[0036] Figure 4 is a schematic diagram of yet another battery control system according to an exemplary embodiment.

[0037] Figure 5 is a schematic diagram of the current flow direction in the first control phase of the cooperation of the circulating self-heating function and the step-up charging function according to an exemplary embodiment.

[0038] Figure 6is a current flow direction schematic diagram of a second control phase under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment.

[0039] Figure 7 is a current flow direction schematic diagram of a third control phase under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment.

[0040] Figure 8 is a current flow direction schematic diagram of a fourth control phase under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment.

[0041] BRIEF DESCRIPTION OF DRAWINGS

[0042] 1, charge-discharge port; 2, second battery pack; 3, first battery pack; 4, multiphase bridge arm; 5, multiphase motor. DETAILED DESCRIPTION

[0043] The specific embodiments of the present disclosure will be described in detail below 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 used to limit the present disclosure.

[0044] Lithium ion batteries are relatively sensitive to low temperatures. The internal resistance of lithium ion batteries increases sharply at low temperatures, and the discharge capacity and charge-discharge performance are greatly limited, resulting in insufficient power performance of electric vehicles in low temperature environments and a significant reduction in driving range. In related technologies, the single-phase winding of the multiphase motor on the vehicle is usually reused to charge or self-heat the power battery pack. The related technologies do not consider how to use multiple coils of the multiphase motor to further improve the heating and charge-discharge performance of the power battery pack.

[0045] To solve the above technical problems, the present disclosure provides a battery control system and a vehicle. The first bus end of the multiphase bridge arm is connected to the positive electrode of the power battery pack, the second bus end of the multiphase bridge arm is respectively connected to the negative electrode of the power battery pack, the negative electrode of the charge-discharge port is connected to the negative electrode of the power battery pack, the multiphase motor includes a single set of windings or multiple sets of windings, the first end of the multiphase motor is connected to the multiphase bridge arm, and the second end of the multiphase motor is connected to the positive electrode of the charge-discharge port. The multiphase motor can form a circulating current self-heating circuit and a boost charging circuit with the charge-discharge port, the power battery pack and the multiphase bridge arm. Current can flow into some of the bridge arms in the multiphase bridge arm and flow out of the remaining bridge arms, thereby realizing the cooperation of circulating current self-heating and boost charging and improving the heating and charge-discharge performance of the power battery pack.

[0046] Figure 1 is a schematic diagram of a battery control system according to an example embodiment, as shown in Figure 1 the battery control system includes:

[0047] A charge-discharge port 1 is configured to output or input electric energy. For example, the charge-discharge port 1 can be connected to a discharge gun or other load to supply electric energy to the load. The charge-discharge port 1 can also be connected to a charging gun or charging device to receive electric energy to charge the power battery pack. The charging device can be a wireless charging device or a photovoltaic charging device.

[0048] A power battery pack can include a first battery group 3 and a second battery group 2 connected in series. Each battery group can include a plurality of battery cells or battery groups connected in series. The first battery group 3 and the second battery group 2 can include the same number of battery cells. The total number of battery cells in the power battery pack can be an even number.

[0049] A multiphase bridge arm 4 has a first common terminal connected to the positive electrode of the power battery pack and a second common terminal connected to the negative electrode of the power battery pack and the negative electrode of the charge-discharge port 1.

[0050] A multiphase motor 5 includes a winding that includes a single set of windings or multiple sets of windings. The first end of the multiphase motor is connected to the multiphase bridge arm 4, and the second end of the multiphase motor is connected to the positive electrode of the charge-discharge port 1. The multiphase motor 5 can be a three-phase motor, a six-phase motor, a nine-phase motor, a fifteen-phase motor, or the like.

[0051] Based on the battery control system of the embodiment, the power battery pack, the multiphase bridge arm 4, and the multiphase motor 5 can form a circulating self-heating loop. The circulating self-heating loop can generate heat through the consumption of the multiphase motor 5 to heat the power battery pack. For example, the heat generated by the consumption of the multiphase motor 5 can increase the temperature of the heat exchange medium of the heat exchange system of the vehicle. The high-temperature heat exchange medium can then heat the power battery pack to increase the temperature of the power battery pack, thereby improving the charging and discharging performance of the power battery pack.

[0052] The charge-discharge port 1, the power battery pack, the multiphase bridge arm 4, and the multiphase motor 5 can form a boost charging loop. The boost charging loop can achieve the boost charging or the step-down discharging of the power battery pack.

[0053] Based on the circulating self-heating loop and the boost charging loop, the current can flow into some bridge arms of the multiphase bridge arm 4 and flow out of the remaining bridge arms. This can achieve the cooperation of the circulating self-heating and the boost charging, thereby improving the heating and charging and discharging performance of the power battery pack.

[0054] In a possible implementation, the multiphase motor 5 includes a plurality of pole pairs, each pole pair includes three coil branches, the first ends of the coil branches of the same phase in the three coil branches of the plurality of pole pairs are connected together and connected to the midpoint of the corresponding bridge arm in the multiphase bridge arm 4, the second ends of the three coil branches of each pole pair are connected together to form a neutral point, the neutral points of the plurality of pole pairs are connected together and lead to an N line, and the N line is connected to the positive electrode of the charging and discharging port 1.

[0055] As shown in Figure 1 , the multiphase motor 5 can be a three-phase motor, the multiphase bridge arm 4 can be an ABC bridge arm, the multiphase motor 5 includes a plurality of pole pairs, each pole pair includes three coil branches, for example, the pole pair composed of the three coil branches A1, B1 and C1 in the figure, the pole pair composed of the three coil branches A2, B2 and C2, the pole pair composed of the three coil branches A3, B3 and C3, and the pole pair composed of the three coil branches A4, B4 and C4, the first ends of the coil branches of the same phase in the three coil branches of the plurality of pole pairs are connected together and connected to the midpoint of the corresponding bridge arm in the multiphase bridge arm 4, the second ends of the three coil branches of each pole pair are connected together to form a neutral point, the neutral points of the plurality of pole pairs are connected together and lead to an N line, as shown in Figure 1 , the neutral point n1n2n3n4 leads to the N line, and the N line is connected to the positive electrode of the charging and discharging port 1.

[0056] In the embodiment, each bridge arm corresponds to a plurality of coils in the multiphase motor, current can flow in from part of the bridge arms and their corresponding coils, and flow out from the remaining bridge arms and their corresponding coils, so that the cooperation of the circulating current self-heating loop and the boost charging loop can be realized to achieve the circulating current self-heating and boost charging, thereby improving the heating and charging and discharging performance of the power battery pack.

[0057] In a possible implementation, the battery control system further includes a charging on-off switch unit and a circulating current self-heating on-off switch unit, wherein the charging on-off switch unit is configured to make the boost charging loop conductive or disconnected, and in the case that the boost charging loop is conductive, the power battery pack can be boost charged through the boost charging loop or the power battery pack can be discharged to supply power to the load. The circulating current self-heating on-off switch unit is configured to make the circulating current self-heating loop conductive or disconnected, and in the case that the circulating current self-heating loop is conductive, the multiphase motor can generate heat to heat the power battery pack through the circulating current self-heating loop.

[0058] In a possible implementation, the battery control system further comprises a switch assembly, which can include a charging on-off switch unit and a circulating self-heating on-off switch unit, the power battery pack includes a first battery pack 3 and a second battery pack 2 connected in series, and the N line is further connected between the first battery pack 3 and the second battery pack 2. The switch assembly can specifically include a first switch, a second switch, a third switch, a fourth switch and a fifth switch, wherein the first switch is arranged on a connection line between the negative electrode of the second battery pack 2 and the second bus bar; the second switch is arranged on a connection line between the positive electrode of the first battery pack 3 and the first bus bar; the third switch is arranged on a connection line between the second bus bar and the negative electrode of the charging and discharging port 1; the fourth switch is arranged on a connection line between the N line and the positive electrode of the charging and discharging port 1; and the fifth switch is arranged on a connection line between the N line and the first battery pack 3 and the second battery pack 2. As shown in Figure 1 , the first switch can be K1, the second switch can be K2, the third switch can be K3, the fourth switch can be K4, and the fifth switch can be K5.

[0059] The charging on-off switch unit can include the first switch, the second switch, the third switch and the fourth switch, and the circulating self-heating on-off switch unit can include the first switch and the second switch.

[0060] The power battery pack, the multi-phase bridge arm 4 and the multi-phase motor 5 can further constitute a self-heating loop; the system further comprises a self-heating on-off switch unit, which is configured to make the self-heating loop conductive or disconnected. The self-heating on-off switch unit can include a first switch unit, a second switch unit and a fifth switch unit.

[0061] Figure 2 is a schematic diagram of another battery control system according to an exemplary embodiment, Figure 3 is a schematic diagram of still another battery control system according to an exemplary embodiment, Figure 4 is a schematic diagram of still another battery control system according to an exemplary embodiment, as shown in Figure 2 , the switch K5 can be replaced by two bridge arm switches to enable fast on-off. As shown in Figure 3 and Figure 4 , the multi-phase bridge arm 4 can be a six-phase bridge arm, including an A bridge arm, a B bridge arm, a C bridge arm, a U bridge arm, a V bridge arm and a W bridge arm.

[0062] In a possible implementation, the battery control system further comprises a controller, which can be an MCU (Microcontroller Unit), and the controller is connected with the multi-phase bridge arm 4, the charging on-off switch unit and the circulating self-heating on-off switch unit respectively;

[0063] The controller is configured to control the multiphase bridge arm 4, the charging on-off switch unit and the circulating current self-heating on-off switch unit, so that at least one of the functions of the circulating current self-heating function, the boost charging function and the driving function is realized. That is, by controlling the controller to control the multiphase bridge arm 4, the charging on-off switch unit and the circulating current self-heating on-off switch unit, the cooperation of the circulating current self-heating function and the boost charging function, the cooperation of the circulating current self-heating function and the step-down discharging function, the cooperation of the driving function and the circulating current self-heating function, the cooperation of the driving function and the step-down discharging function, the cooperation of the driving function and the boost charging function, the cooperation of the circulating current self-heating function, the boost charging function and the driving function, and the circulating current self-heating function of the charging and discharging port 1 can be realized.

[0064] In one possible implementation, for the cooperation of the circulating current self-heating function and the boost charging function, the controller is configured to control the multiphase bridge arm 4, the circulating current self-heating on-off switch unit and the charging on-off switch unit when in the first state, so that the power battery pack outputs the electric energy to the multiphase motor 5 to make the multiphase motor 5 generate heat to heat the power battery pack, and the charging and discharging port 1 inputs the electric energy to the power battery pack to charge the power battery pack. The first state can be a mode of cooperation of the circulating current self-heating function and the boost charging function.

[0065] For example, the circulating current self-heating circuit can be controlled to realize the circulating current self-heating function, and the boost charging circuit can be controlled to realize the boost charging function. The control mode can be to sequentially execute the first control stage, the second control stage, the third control stage and the fourth control stage to realize the cooperation of the circulating current self-heating function and the boost charging function.

[0066] Figure 5 is a current flow direction schematic diagram of the first control stage under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment, Figure 6 is a current flow direction schematic diagram of the second control stage under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment, Figure 7 is a current flow direction schematic diagram of the third control stage under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment, Figure 8 is a current flow direction schematic diagram of the fourth control stage under the cooperation of the circulating current self-heating function and the boost charging function according to an example embodiment, wherein is used to indicate the current flow direction of the circulating current self-heating function, and is used to indicate the current flow direction of the charging and discharging function.

[0067] As Figure 5As shown, the first control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arm of the A bridge arm to be connected, the lower bridge arm to be disconnected, and control the upper bridge arms of the B bridge arm and the C bridge arm to be disconnected, the lower bridge arms to be connected, so as to make the power battery pack and the charging and discharging port 1 deliver electric energy to charge the single set of windings, and make the single set of windings generate heat for heating the power battery pack.

[0068] As shown, Figure 6 the second control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the lower bridge arm of the A bridge arm to be connected, the upper bridge arm to be disconnected, and control the lower bridge arms of the B bridge arm and the C bridge arm to be disconnected, the upper bridge arms to be connected, so as to make the multi-phase motor and the charging and discharging port 1 boost charge the power battery pack, and make the multi-phase motor generate heat for heating the power battery pack.

[0069] As shown, Figure 7 the third control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arms of the B bridge arm and the C bridge arm to be connected, the lower bridge arms to be disconnected, and control the upper bridge arm of the A bridge arm to be disconnected, the lower bridge arm to be connected, so as to make the power battery pack and the charging and discharging port 1 deliver electric energy to charge the multi-phase motor, and make the multi-phase motor generate heat for heating the power battery pack.

[0070] As shown, Figure 8 the fourth control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arm of the A bridge arm to be connected, the lower bridge arm to be disconnected, and control the upper bridge arms of the B bridge arm and the C bridge arm to be disconnected, the lower bridge arms to be connected, so as to make the multi-phase motor and the charging and discharging port 1 boost charge the power battery pack, and make the multi-phase motor generate heat for heating the power battery pack.

[0071] In the embodiment, the circulating current self-heating function can be realized by controlling the circulating current self-heating loop, and the boost charging function can be realized by controlling the boost charging loop, so as to realize the cooperation of the circulating current self-heating function and the boost charging function. In order to improve the temperature of the power battery pack, so that the power battery pack also has good charge and discharge performance in low temperature environment.

[0072] The control method of the embodiment is only one possible embodiment. For the plurality of windings corresponding to the multi-phase bridge arms 4 and the multi-phase motor, in the four control stages of the embodiment, the current can flow into any bridge arm and the winding corresponding thereto, and flow out from the remaining bridge arms and the windings corresponding thereto. For example, in the first control stage, the current can flow into the A bridge arm and the B bridge arm, and flow out from the C bridge arm, and the corresponding adjustment in other control stages can be made, which is also applicable to motors with more than three phases.

[0073] In a possible implementation, for the cooperation of the circulating current self-heating function and the step-down discharging function, the controller is configured to: when in the second state, control the multi-phase bridge arm 4, the circulating current self-heating on-off switch unit, and the charging on-off switch unit, so that the power battery pack outputs the electric energy to the multi-phase motor to make the multi-phase motor generate heat to heat the power battery pack, and outputs the electric energy to the charging and discharging port 1 to supply power to the load. The second state can be a mode in which the circulating current self-heating function and the step-down discharging function cooperate.

[0074] For example, the circulating current self-heating circuit can be controlled to implement the circulating current self-heating function, and the step-up charging circuit can be controlled to implement the step-down discharging function. The control manner can be: sequentially performing a first control phase, a second control phase, a third control phase, and a fourth control phase to realize the cooperation of the circulating current self-heating function and the step-down discharging function.

[0075] The first control phase can be: controlling the first switch, the second switch, the third switch, and the fourth switch to be closed, controlling other switches in the switch assembly to be turned off, controlling the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and controlling the upper bridge arms of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arms to be connected, so that the power battery pack charges the multi-phase motor while delivering electric energy to the charging and discharging port 1 to supply power to the load at a low voltage, and the multi-phase motor generates heat to heat the power battery pack.

[0076] The second control phase can be: controlling the first switch, the second switch, the third switch, and the fourth switch to be closed, controlling other switches in the switch assembly to be turned off, controlling the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and controlling the upper bridge arms of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arms to be connected, so that the multi-phase motor charges the power battery pack, the multi-phase motor delivers electric energy to the charging and discharging port 1 to supply power to the load at a low voltage, and the multi-phase motor generates heat to heat the power battery pack.

[0077] The third control phase can be: controlling the first switch, the second switch, the third switch, and the fourth switch to be closed, controlling other switches in the switch assembly to be turned off, controlling the upper bridge arms of the B bridge arm and the C bridge arm to be connected and the lower bridge arms to be disconnected, and controlling the upper bridge arm of the A bridge arm to be disconnected and the lower bridge arm to be connected, so that the power battery pack charges the multi-phase motor while delivering electric energy to the charging and discharging port 1 to supply power to the load at a low voltage, and the multi-phase motor generates heat to heat the power battery pack.

[0078] The fourth control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and control the upper bridge arm of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arm to be connected, so that the multi-phase motor charges the power battery pack, the multi-phase motor delivers electric energy to the charging and discharging port 1 to supply power to the load at a reduced voltage, and the multi-phase motor generates heat to heat the power battery pack.

[0079] In the embodiment, the circulating current self-heating circuit is controlled to realize the circulating current self-heating function, and the boost charging circuit is controlled to realize the step-down discharging function, so as to realize the cooperation of the circulating current self-heating function and the step-down discharging function. In this way, the temperature of the power battery pack is raised, so that the power battery pack has good charging and discharging performance in a low-temperature environment.

[0080] In a possible embodiment, for the cooperation of the driving function and the circulating current self-heating function, the controller is configured to: when in the third state, control the multi-phase bridge arm 4 and the circulating current self-heating on-off switch unit, so that the electric energy output by the power battery pack is output to the multi-phase motor to make the multi-phase motor generate heat to heat the power battery pack, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle. The third state can be a mode of cooperation of the driving function and the circulating current self-heating function.

[0081] For example, the circulating current self-heating circuit can be controlled to realize the circulating current self-heating function and the driving function. The control mode can be: sequentially executing the first control stage, the second control stage, the third control stage and the fourth control stage to realize the cooperation of the circulating current self-heating function and the driving function.

[0082] The first control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and control the upper bridge arm of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arm to be connected, so that the power battery pack and the charging and discharging port 1 deliver electric energy to the multi-phase motor to charge the multi-phase motor, the multi-phase motor generates heat to heat the power battery pack, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0083] The second control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the lower bridge arm of the A bridge arm to be connected and the upper bridge arm to be disconnected, and control the lower bridge arm of the B bridge arm and the C bridge arm to be disconnected and the upper bridge arm to be connected, so that the multi-phase motor and the charging and discharging port 1 boost charge the power battery pack, the multi-phase motor generates heat to heat the power battery pack, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0084] The third control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the B bridge arm and the C bridge arm to be connected and the lower bridge arm to be disconnected, control the upper bridge arm of the A bridge arm to be disconnected and the lower bridge arm to be connected, so that the power battery pack and the charging and discharging port 1 deliver electric energy to charge the multi-phase motor, the multi-phase motor generates heat to heat the power battery pack, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0085] The fourth control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and control the upper bridge arm of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arm to be connected, so that the multi-phase motor and the charging and discharging port 1 boost charge the power battery pack, the multi-phase motor generates heat to heat the power battery pack, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0086] In the embodiment, the controllable circulating current self-heating circuit can realize the circulating current self-heating function and the driving function, so as to realize the cooperation of the circulating current self-heating function and the boost charging function. The boost charging function can be wireless charging or photovoltaic charging, so as to improve the endurance mileage of the vehicle.

[0087] In a possible implementation, for the cooperation of the driving function and the step-down discharging function, the controller is configured to: when in the fourth state, control the multi-phase bridge arm 4 and the charging and discharging switch unit, so that the electric energy output by the power battery pack is output to the charging and discharging port 1 to supply power to the load, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle. The fourth state can be a mode of cooperation of the driving function and the step-down discharging function.

[0088] For example, the controllable boost charging circuit can realize the step-down discharging function and the driving function. The control mode can be: sequentially executing the first control stage and the second control stage to realize a mode of cooperation of the driving function and the step-down discharging function.

[0089] The first control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the multi-phase bridge arm 4 to be connected and the lower bridge arm to be disconnected, so that the power battery pack charges the multi-phase motor at the same time as delivering electric energy to the charging and discharging port 1 to supply step-down power to the load, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0090] The second control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the lower bridge arm of the A bridge arm to be connected and the upper bridge arm to be disconnected, and control the lower bridge arm of the B bridge arm and the C bridge arm to be disconnected and the upper bridge arm to be connected, so that the multi-phase motor delivers electric energy to the charge-discharge port 1 to supply power to the load in a step-down manner, and the electric energy output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle.

[0091] In the embodiment, the boost charging circuit can be controlled to realize the step-down discharging function and the driving function, so as to realize a cooperative mode of the driving function and the step-down discharging function. In this way, the power demand of the user in the vehicle can be met when the vehicle is in a driving working condition, for example, the notebook computer, the tablet computer or the mobile phone of the user in the vehicle is powered.

[0092] In a possible embodiment, for the cooperation of the driving function and the boost charging function, the controller is configured to, when in the fifth state, control the multi-phase bridge arm 4 and the charge-discharge switch unit, so that the electric energy input by the charge-discharge port 1 is input to the power battery pack to charge the power battery pack, and the electric energy input by the charge-discharge port 1 is input to the multi-phase motor 5 to drive the vehicle. The fifth state can be the cooperative mode of the driving function and the boost charging function.

[0093] For example, the boost charging circuit can be controlled to realize the boost charging function and the driving function. The control mode can be to sequentially execute the first control stage and the second control stage to realize the cooperation of the driving function and the boost charging function.

[0094] The first control stage can be to control the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, and control the lower bridge arm of the multi-phase bridge arm 4 to be connected and the upper bridge arm to be disconnected, so that the electric energy input by the charge-discharge port 1 charges the multi-phase motor 5, and the electric energy input by the charge-discharge port 1 is input to the multi-phase motor 5 to drive the vehicle.

[0095] The second control stage can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm of the multi-phase bridge arm 4 to be connected and the lower bridge arm to be disconnected, so that the charge-discharge port 1 and the multi-phase motor 5 simultaneously charge the power battery pack, and the electric energy input by the charge-discharge port 1 is output to the multi-phase motor 5 to drive the vehicle.

[0096] In the embodiment, the boost charging circuit can be controlled to realize the boost charging function and the driving function, so as to realize the cooperation of the driving function and the boost charging function. The charging mode corresponding to the boost charging function can be wireless charging or photovoltaic charging. For example, for wireless charging, a wireless coil charging device can be laid on the road, and the vehicle can be charged wirelessly while driving. Two vehicles in driving can also charge and discharge wirelessly to each other for vehicle rescue. For photovoltaic charging, a photovoltaic power generation device can be arranged on the vehicle, and the electric energy generated by the power generation device is used to boost charge the power battery pack through the first set of windings, so as to improve the endurance mileage of the vehicle.

[0097] In a possible implementation, for the cooperation of the circulating current self-heating function and the boost charging function and the driving function, the controller is configured to: when in the sixth state, control the multi-phase bridge arm 4, the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the electric energy output by the power battery pack is output to the multi-phase motor 5 to make the multi-phase motor 5 generate heat to heat the power battery pack, and the electric energy input by the charging and discharging port 1 is input to the power battery pack to boost charge the power battery pack, and the current output by the power battery pack or the current input by the charging and discharging port 1 is transmitted to the multi-phase motor 5 to drive the vehicle. The sixth state can be a mode of cooperation of the circulating current self-heating function and the boost charging function and the driving function.

[0098] For example, the circulating current self-heating circuit can be controlled to realize the circulating current self-heating function, the boost charging circuit can be controlled to realize the boost charging function, and the driving function can be realized through the circulating current self-heating circuit or the boost charging circuit. The control mode can be: sequentially executing the first control phase, the second control phase, the third control phase and the fourth control phase to realize the cooperation of the circulating current self-heating function and the boost charging function and the driving function.

[0099] The first control phase can be to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, and control the upper bridge arm of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arm to be connected, so that the power battery pack and the charging and discharging port 1 transmit electric energy to charge the multi-phase motor 5, the multi-phase motor 5 generates heat to heat the power battery pack, and the current output by the power battery pack or the current input by the charging and discharging port 1 is transmitted to the multi-phase motor 5 to drive the vehicle.

[0100] The second control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the lower bridge arm of the A bridge arm to be connected and the upper bridge arm to be disconnected, control the lower bridge arm of the B bridge arm and the C bridge arm to be disconnected and the upper bridge arm to be connected, so that the multi-phase motor 5 and the charge-discharge port 1 perform boost charging on the power battery pack, the multi-phase motor 5 generates heat for heating the power battery pack, and the current output by the power battery pack or the current input by the charge-discharge port 1 is transmitted to the multi-phase motor 5 to drive the vehicle.

[0101] The third control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arm of the B bridge arm and the C bridge arm to be connected and the lower bridge arm to be disconnected, control the upper bridge arm of the A bridge arm to be disconnected and the lower bridge arm to be connected, so that the power battery pack and the charge-discharge port 1 transmit electric energy to charge the multi-phase motor 5, the multi-phase motor 5 generates heat for heating the power battery pack, and the current output by the power battery pack or the current input by the charge-discharge port 1 is transmitted to the multi-phase motor 5 to drive the vehicle.

[0102] The fourth control stage is to control the first switch, the second switch, the third switch and the fourth switch to be closed, control other switches in the switch assembly to be opened, control the upper bridge arm of the A bridge arm to be connected and the lower bridge arm to be disconnected, control the upper bridge arm of the B bridge arm and the C bridge arm to be disconnected and the lower bridge arm to be connected, so that the multi-phase motor 5 and the charge-discharge port 1 perform boost charging on the power battery pack, the multi-phase motor 5 generates heat for heating the power battery pack, and the current output by the power battery pack or the current input by the charge-discharge port 1 is transmitted to the multi-phase motor 5 to drive the vehicle.

[0103] In the embodiment, the circulating current self-heating circuit can be controlled to realize the circulating current self-heating function, the boost charging circuit can be controlled to realize the boost charging function, and the driving function can be realized through the circulating current self-heating circuit or the boost charging circuit, so as to realize the cooperation of the circulating current self-heating function, the boost charging function and the driving function. Thus, the circulating current self-heating can be performed during the driving of the vehicle, the charging and discharging performance of the battery is improved, and the electricity demand of the user in the vehicle is met.

[0104] In a possible implementation, for the circulating current self-heating function of the power taking of the charge-discharge port 1, the controller is configured to: when in the seventh state, control the multi-phase bridge arm 4 and the charge-disconnection switch unit, so that the power input by the charge-discharge port 1 is input to the multi-phase motor 5, to make the multi-phase motor 5 generate heat to heat the power battery pack. The seventh state can be a mode of the circulating current self-heating function of the power taking of the charge-discharge port 1. In the case that the temperature is extremely low, for example, in the case that the temperature is less than a preset temperature, for example, in the case that the temperature is less than -30°C, the self-heating function of the battery pack, the circulating current self-heating function and the charging / discharging function cannot be performed. The mode of the circulating current self-heating function of the power taking of the charge-discharge port 1 can be performed first. The power is taken from the charge-discharge port 1 and delivered to the multi-phase motor 5, so that the multi-phase motor 5 generates heat to heat the power battery pack. In the case that the temperature of the power battery pack is greater than -30°C, at least one of the self-heating function of the battery pack, the circulating current self-heating function and the charging / discharging function is performed again.

[0105] For example, the boost charging circuit can be controlled to implement the circulating current self-heating function of the power taking of the charge-discharge port 1. The control mode is: the third switch and the fourth switch are controlled to be closed, the other switches in the switch assembly are controlled to be open, the lower bridge arm of the multi-phase bridge arm 4 is controlled to be connected, and the upper bridge arm of the multi-phase bridge arm 4 is controlled to be disconnected, so that the power input by the charge-discharge port 1 is delivered to the multi-phase motor 5, and the multi-phase motor 5 generates heat to heat the power battery pack.

[0106] In a possible implementation, the controller is further connected with the self-heating disconnection switch unit, and the controller is configured to: in the eighth state, control the multi-phase bridge arm 4 and the self-heating disconnection switch unit, so that the first battery pack 3 and the second battery pack 2 are alternately charged and discharged to heat the power battery pack, and the power output by the power battery pack is output to the multi-phase motor 5 to drive the vehicle. The eighth state can be a mode of the cooperation of the driving function and the self-heating function. The self-heating of the power battery pack is achieved by the alternating charging and discharging of the first battery pack 3 and the second battery pack 2.

[0107] For example, the self-heating circuit can be controlled to implement the self-heating function and the driving function. The control mode can be: the first control stage, the second control stage, the third control stage and the fourth control stage are sequentially executed to implement the cooperation of the self-heating function and the driving function.

[0108] The first control stage can be: the first switch and the fifth switch are controlled to be closed, the other switches in the switch assembly are controlled to be open, the lower bridge arm of the multi-phase bridge arm 4 is controlled to be connected, and the upper bridge arm of the multi-phase bridge arm 4 is controlled to be disconnected, so that the first battery pack 3 charges the multi-phase motor 5, and the current output by the power battery pack is delivered to the multi-phase motor 5 to drive the vehicle.

[0109] The second control stage is to control the second switch and the fifth switch to be closed, control other switches in the switch assembly to be turned off, control the lower bridge arm in the multi-phase bridge arm 4 to be turned off, control the upper bridge arm in the multi-phase bridge arm 4 to be connected, so that the multi-phase motor 5 charges the second battery pack 2, and the current output by the power battery pack is delivered to the multi-phase motor 5 to drive the vehicle.

[0110] The third control stage is to control the first switch and the fifth switch to be closed, control other switches in the switch assembly to be turned off, control the lower bridge arm in the multi-phase bridge arm 4 to be turned off, control the upper bridge arm in the multi-phase bridge arm 4 to be connected, so that the second battery pack 2 charges the multi-phase motor 5, and the current output by the power battery pack is delivered to the multi-phase motor 5 to drive the vehicle.

[0111] The fourth control stage is to control the first switch and the fifth switch to be closed, control other switches in the switch assembly to be turned off, control the upper bridge arm in the multi-phase bridge arm 4 to be connected, control the lower bridge arm in the multi-phase bridge arm 4 to be turned off, so that the multi-phase motor 5 charges the first battery pack 3, and the current output by the power battery pack is delivered to the multi-phase motor 5 to drive the vehicle.

[0112] In a possible implementation, the controller can control the multi-phase bridge arm 4, the charging on-off switch unit, the circulating current self-heating on-off switch unit, and the self-heating on-off switch unit through control instructions to realize the cooperation of the circulating current self-heating function and the boost charging function, the cooperation of the circulating current self-heating function and the step-down discharging function, the cooperation of the driving function and the circulating current self-heating function, the cooperation of the driving function and the step-down discharging function, the cooperation of the driving function and the boost charging function, the cooperation of the circulating current self-heating function, the boost charging function, and the driving function, the circulating current self-heating function of the power charging port 1, and the cooperation of the driving function and the self-heating function.

[0113] The control instructions can include switch control instructions and bridge arm control instructions, the switch control instructions are used to control the charging on-off switch unit, the self-heating on-off switch unit, and the circulating current self-heating on-off switch unit, and the bridge arm control instructions are used to control the multi-phase bridge arm 4. The bridge arm control instructions can include the duty ratio of each phase bridge arm, and the corresponding function is realized through the control of the common-mode voltage, regardless of the circulating current self-heating, the self-heating, the boost charging, or the step-down discharging. The driving function is controlled through the differential-mode voltage of the bridge arm, the control voltage of each phase bridge arm is obtained by adding the common-mode voltage and the differential-mode voltage, the duty ratio is output through the modulation of the bridge arm, and each function is independently controlled to realize the corresponding function.

[0114] In a low-temperature environment, during the process of boosting charging or step-down discharging, the multi-phase motor 5 stores and releases energy to the charging and discharging port 1 to charge the power battery pack. After the driving controller receives the heating request of the power battery pack, the power battery pack is discharged by controlling the motor inductance and motor resistance energy consumption, and the power battery pack is charged by controlling the energy storage and release of the multi-phase motor 5 of the motor, realizing high-frequency charging and discharging of the power battery pack, realizing self-heating of the power battery pack, relying on the impedance of the battery cell itself to generate heat, and also relying on the heat pump system refrigerant to directly heat and absorb the heat generated by the multi-phase motor 5 to circulate and self-heat the power battery, and to heat the passenger compartment, improving the charging and discharging performance of the power battery in a low-temperature environment, improving the charging power and discharging power, and at the same time shortening the low-temperature charging time and improving the user experience.

[0115] Among them, the power battery pack is connected in parallel with a capacitor C1 at both ends, and the charging and discharging port is connected in parallel with a capacitor C2 at both ends, wherein the number of bridge arms can be configured according to the number of phases of the motor; assuming that the motor is an M-phase N-wire motor, the current on the M-phase is measured, and the current on the N-wire of the motor can be indirectly determined according to the measured current. The following is an example: if the motor is a three-phase four-wire motor, the physical specifications are as follows: the direction of the current flowing into the motor is positive, and satisfies ia+ib+ic+in=0, ia, ib, ic, in can be installed in any at least three wires, and the current ia, ib, ic is preferably collected, and the current in on the N-wire is calculated by in=-ia-ib-ic.

[0116] If the motor is a six-phase seven-wire motor, the physical specifications are as follows: the direction of the current flowing into the motor is positive, and satisfies ia+ib+ic+iu+iv+iw+in=0, ia, ib, ic, iu, iv, iw, in can be installed in any at least six wires, and the current ia, ib, ic, iu, iv, iw is preferably collected, and the current in on the N-wire is calculated by in=-ia-ib-ic-iu-iv-iw.

[0117] Un1 is the voltage on the capacitor C2, Udc is the voltage on the bus capacitor C1, and idc is the total current from the battery end to the motor controller, that is, the total current flowing through K2. The duty cycle here refers to the duty cycle of the upper bridge arm, and the duty cycles of the upper and lower bridge arms are complementary, and a certain dead time is reserved according to the characteristics of the power device.

[0118] For boosting charging, step-down discharging and circulating self-heating:

[0119] The control system receives the boosting charging and discharging instruction, the battery circulating self-heating current amplitude instruction, and the circulating self-heating current frequency instruction:

[0120] ① Circulation self-heating function: the instruction solving module obtains the circulation self-heating power instruction:

[0121] According to the temperature of the current battery cell and the circulation self-heating power, the given circulation self-heating current amplitude ipk_x, the heating current frequency f_x, the amplitude of the circulation self-heating current and the frequency of the circulation self-heating current corresponding to the circulation self-heating power of the cell at different temperatures can be obtained. The circulation self-heating power can be calibrated on a bench first, and generally obtained by using a lookup table or a linear fitting method. The circulation self-heating reactive direct current component indc_x, the control target d-q coordinate system is obtained: id_x*=indc_x+ipk_x*sin(2pi*f_x*t) or id_x*=indc_x+ipk_x*cos(2pi*f_x*t), iq_x*=0 or iq_x*=a small value, the meshing gear gap, to prevent the motor rotor from shaking, after the solving process, the target id_x* and iq_x* are obtained, and the current vector on the dq axis is closed-loop controlled according to the vector control method of the motor. Among them, indc_x is a preset value [0, 70) A, iq_x* is a preset value [0, 10) A, the deviation jitter problem of the zero crossing point is solved, and at least one of the two is set, which will generate a force to press the gap between the rotor and the transmission, so that it will not shake.

[0122] The sampled p_x phase current values i1_x, i2_x,..., ip_x are converted to iα_x, iβ_x in the αβ coordinate system through Clark coordinate transformation, and are converted to the direct-axis current id_x and the quadrature-axis current iq_x in the dq coordinate system through Park coordinate transformation.

[0123] The difference between the current given target value id_x* and id_x is outputted as the Ud_x target value after PID control, and the difference between the current given target value iq_x* and iq_x is outputted as the Uq_x target value after PID control.

[0124] Ud_x, Uq_x are converted to Uα_x, Uβ_x through inverse Park transformation, Uα_x, Uβ_x are converted to U1_x, U2_x,..., Up_x through inverse Clark transformation, and the control voltage values of each phase bridge arm are modulated with the bus voltage and the carrier to obtain the p_x phase bridge arm PWM differential mode duty cycles DD1_x, DD2_x,..., DDp_x.

[0125] DDp_x where p refers to the number of motor phases of each d-q coordinate system, x=1 refers to the first d-q coordinate system, x=2 refers to the second d-q coordinate system, for a six-phase motor, it can be controlled according to a d-q coordinate system, p=6, x=1. It can also be controlled according to two d-q coordinate systems, three phases each, where p=3 for each system. The A-phase differential mode duty ratio is DD1_1, the B-phase differential mode duty ratio is DD2_1, the C-phase differential mode duty ratio is DD3_1, the U-phase differential mode duty ratio is DD1_2, the V-phase differential mode duty ratio is DD2_2, and the W-phase differential mode duty ratio is DD3_2.

[0126] ②Battery charging and discharging function: DC boost charging / drop discharging

[0127] Charging and discharging instructions: whether direct charging or boost charging is determined according to the voltage level of the charging pile and the battery pack.

[0128] 1) Direct charging: when the voltage of the charging pile is higher than that of the power battery pack, direct charging is selected, i.e. attraction Figure 1 K1, K2, K3, K4 in the formula, the multi-phase bridge arm is not controlled.

[0129] 2) Battery boost charging function: the voltage of the charging pile at the DC charging and discharging port is lower than that of the power battery pack, boost charging is selected, i.e. attraction Figure 1 K1, K2, K3, K4 in the formula.

[0130] Single-voltage upper closed-loop control can also be used: in the voltage closed-loop link, the required charging port voltage instruction Un_x* is obtained by the instruction calculation module, the required voltage value Un_x* and the actual Un_x are obtained by sampling the voltage on the capacitor C2, and the current value closed-loop control obtains the required control voltage Un, i.e. the common mode voltage value, the common mode control voltage value of each phase bridge arm is equal to the control voltage Un, and the PWM common mode duty ratio Dp_x of each phase bridge arm in the xth d-q coordinate system is obtained by modulating the control voltage value of each phase bridge arm with the bus voltage and the carrier, and the required motor phase current value is obtained through the modulation of the bridge arm.

[0131] x refers to the xth number, x=1 refers to the first d-q coordinate system, and x=2 refers to the second d-q coordinate system.

[0132] For a three-phase motor, control is performed in a d-q coordinate system, p=3, and x=1.

[0133] For a six-phase motor, control can be performed in a d-q coordinate system, p=6, and x=1.

[0134] It can also be controlled according to two d-q coordinate systems, three phases each, where p=3 for each system.

[0135] Actual N1 line current is calculated by in1=-ia-ib-ic, and actual N2 line current is calculated by in2=-iu-iv-iw, for current monitoring protection.

[0136] For driving function and charging and discharging and self-heating function:

[0137] Take a three-phase motor as an example to explain the control process:

[0138] The control system receives the boost charging and discharging instruction, the battery self-heating current amplitude instruction, the self-heating current frequency instruction, and the self-heating battery equalization current instruction:

[0139] ③ Battery self-heating function: each set of d-q coordinate system obtains control target:

[0140] Given the self-heating current amplitude ipk_x, the current frequency f_x, and the self-heating battery active equalization current indc_x, the N_x line current in_x* = indc_x + ipk_x * sin(2pi * f_x * t) or in_x* = indc_x + ipk_x * cos(2pi * f_x * t) is obtained.

[0141] The required current value in_x* and the actual in_x current value (in_1=-ia-ib-ic, in_2=-iu-iv-iw) are controlled by PI or PR closed loop to obtain the required duty cycle Dn_x, and the upper bridge arm common mode duty cycle Dp_x=1-Dn_x.

[0142] Dp_x here p refers to the number of motor phases of each d-q coordinate system, x refers to the xth number, x=1 refers to the first d-q coordinate system, and x=2 refers to the second d-q coordinate system.

[0143] For a three-phase motor, p=3, x=1. For a six-phase motor, it can be controlled according to one set of dq coordinate system, p=6, x=1. It can also be controlled according to two sets of dq coordinate system, each set of three phases, and the p of each set of system is 3.

[0144] ④ Torque control of driving function:

[0145] Each set of d-q coordinate system obtains the target torque of control, according to the target torque instruction, and the motor speed value, the battery bus voltage, the target id_x*, iq_x* that satisfies the torque instruction is found out through MTPA&MTPV curve, MTPA&MTPV curve can be calculated and bench calibrated in advance, generally, the target current instruction id_x*, iq_x* is obtained by voltage, torque, speed using the table lookup or linear fitting method, after the solving process, the target id_x*, iq_x* is obtained, the current vector on the dq axis is closed-loop controlled according to the vector control method of the motor.

[0146] The sampling p_x phase current values i1_x, i2_x,..., ip_x are converted to iα_x, iβ_x on the αβ coordinate system through Clark coordinate transformation, and the direct-axis current id_x and the quadrature-axis current iq_x are obtained through Park coordinate transformation, the difference between the current given target value id_x* and id_x is output after PID control Ud_x target value, the difference between the current given target value iq_x* and iq_x is output after PID control Uq_x target value. Ud_x, Uq_x is obtained through inverse Park transformation Uα_x, Uβ_x, Uα_x, Uβ_x is obtained through inverse Clark transformation U1_x, U2_x,..., Up_x, the control voltage value of each phase bridge arm is modulated with bus voltage and carrier to obtain the PWM differential mode duty ratio DD1_x, DD2_x,..., DDp_x in p_x phase.

[0147] DDp_x here p refers to the number of motor phases of each set of d-q coordinate system, x=1 refers to the first set of d-q coordinate system, and x=2 refers to the second set of d-q coordinate system.

[0148] For a three-phase motor, p=3, x=1. For a six-phase motor, it can be controlled according to one set of dq coordinate system, p=6, x=1. It can also be controlled according to two sets of dq coordinate system, each set of three phases, and the p of each set of system is 3.

[0149] Among them, the control instruction can include switch control instruction and bridge arm control instruction, the switch control instruction is used to control the charge and discharge on-off switch unit, the circulating current self-heating on-off switch unit and the self-heating on-off switch unit. Among them, the bridge arm control instruction can include the duty ratio of each phase bridge arm, whether it is circulating current self-heating, self-heating or boosting charging or step-down discharging, the corresponding function is realized through the control of common-mode voltage; the driving function is controlled through the differential-mode voltage of the bridge arm, the common-mode voltage and the differential-mode voltage are added to obtain the control voltage of each phase bridge arm, the duty ratio is output through the modulation of the bridge arm, each function is independently controlled, and the corresponding function is cooperatively controlled.

[0150] Clark transformation: stationary coordinate transformation, N-phase axis system is transformed to two-phase stationary coordinate system, generally does not contain zero-axis vector;

[0151] Extended Clark transformation: stationary coordinate transformation, N-phase axis system is transformed to two-phase stationary coordinate system, contains zero-axis vector;

[0152] PARK transformation: synchronous rotating coordinate transformation, two-phase stationary coordinate system is transformed to synchronous rotating coordinate system, generally does not contain zero-axis vector;

[0153] Extended PARK transformation: synchronous rotating coordinate transformation, two-phase stationary coordinate system is transformed to synchronous rotating coordinate system, contains zero-axis vector;

[0154] Inverse Clark transformation: inverse transformation of Clark transformation;

[0155] Inverse PARK transformation: inverse transformation of PARK transformation;

[0156] T e - motor shaft end output torque;

[0157] p- number of motor pole pairs;

[0158] (Or φf) represents the motor permanent magnet flux linkage;

[0159] L d represents the direct-axis inductance; L q represents the quadrature-axis inductance; i d represents the direct-axis current; i q represents the quadrature-axis current.

[0160] SVPWM: space vector pulse width modulation algorithm. θ is the angle between the rotor direct axis of the vehicle power motor and the A-phase winding of the vehicle power motor. U d and u q are the voltages in the d-q axis coordinate system of the stator, respectively. I d and i q are the currents in the d-q axis coordinate system of the stator, respectively. L d and L q are the winding inductances in the d-q axis coordinate system, respectively. R s is the resistance of the stator winding, the phase resistance; R sn is the resistance of the N line to the phase line. ω e is the electrical angular velocity, P n is the number of motor pole pairs, ω e = P n ω m ;

[0161] φf is the permanent magnet flux linkage.

[0162] In another exemplary embodiment, a vehicle is also provided, comprising the battery charging system provided by the embodiments of the present disclosure.

[0163] The preferred embodiments of the present disclosure are described in detail above with reference to the drawings, but the present disclosure is not limited to the specific details in the above-described embodiments. Various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0164] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the present disclosure.

[0165] In addition, any combination of various different embodiments of the present disclosure can also be made, as long as it does not deviate from the idea of the present disclosure, and it should also be considered as disclosed in the present disclosure.

Claims

1. A battery control system, characterized by, The system comprises: a charge-discharge port (1); a power battery pack; a multiphase bridge arm (4), a first bus end of the multiphase bridge arm (4) is connected with a positive electrode of the power battery pack, and a second bus end of the multiphase bridge arm (4) is respectively connected with a negative electrode of the power battery pack and a negative electrode of the charge-discharge port (1); a multiphase motor (5), the multiphase motor (5) comprises a winding, the winding comprises a plurality of sets of windings, a first end of the multiphase motor (5) is connected with the multiphase bridge arm (4), and a second end of the multiphase motor (5) is connected with a positive electrode of the charge-discharge port (1); the power battery pack, the multiphase bridge arm (4) and the multiphase motor (5) can form a circulating self-heating loop; the charge-discharge port (1), the power battery pack, the multiphase bridge arm (4) and the multiphase motor (5) can form a boost charging loop; a controller configured to, in a case that a battery temperature is less than a preset temperature, control a mode of a circulating self-heating function of taking power from the charge-discharge port by a control instruction, and in a case that the battery temperature is greater than the preset temperature, control the circulating self-heating function and a charge-discharge function by the control instruction. The control instruction comprises a bridge arm control instruction for controlling the multiphase bridge arm (4), the bridge arm control instruction can comprise a duty cycle of each phase bridge arm, the circulating self-heating, the boost charging or the step-down discharging function is realized by control of a common-mode voltage of the bridge arm, the driving function is realized by control of a differential-mode voltage of the bridge arm, the common-mode voltage and the differential-mode voltage are added to obtain a control voltage of each phase bridge arm, and then the duty cycle of each phase bridge arm is obtained.

2. The battery control system according to claim 1, wherein the multiphase motor (5) comprises a plurality of pole pairs, each pole pair comprises three coil branches, first ends of the three coil branches of the same phase of the plurality of pole pairs are connected in common and connected with a midpoint of a corresponding bridge arm in the multiphase bridge arm (4), second ends of the three coil branches of each pole pair are connected in common to form a neutral point, the neutral points of the plurality of pole pairs are connected in common and an N line is led out, and the N line is connected to the positive electrode of the charge-discharge port (1).

3. The battery control system of claim 2, wherein, The system further comprises: a charging on-off switch unit configured to make the boost charging loop conductive or disconnected; a circulating self-heating on-off switch unit configured to make the circulating self-heating loop conductive or disconnected.

4. The battery control system of claim 3, wherein, The system further comprises: a controller connected with the multiphase bridge arm (4), the charging on-off switch unit and the circulating self-heating on-off switch unit respectively; the controller is configured to control the multiphase bridge arm (4), the charging on-off switch unit and the circulating self-heating on-off switch unit, so that at least one of the functions of the charge-discharge function, the circulating self-heating function and the driving function is realized.

5. The battery control system of claim 4, wherein, The controller is configured to: when in the first state, control the multiphase bridge arm (4), the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the power battery pack outputs the electric energy to the multiphase motor (5) to make the multiphase motor (5) generate heat to heat the power battery pack, and the charging and discharging port (1) inputs the electric energy to the power battery pack through the winding and the multiphase bridge arm (4) to boost charge the power battery pack.

6. The battery control system of claim 4, wherein, The controller is configured to: when in the second state, control the multiphase bridge arm (4), the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the power battery pack outputs the electric energy to the multiphase motor (5) to make the multiphase motor (5) generate heat to heat the power battery pack, and the power battery pack outputs the electric energy to the charging and discharging port (1) through the multiphase bridge arm (4) and the winding to supply power to the load.

7. The battery control system of claim 4, wherein, The controller is configured to: when in the third state, control the multiphase bridge arm (4) and the circulating current self-heating on-off switch unit, so that the power battery pack outputs the electric energy to the multiphase motor (5) to make the multiphase motor (5) generate heat to heat the power battery pack, and the power battery pack outputs the electric energy to the multiphase motor (5) to drive the vehicle.

8. The battery control system of claim 4, wherein, The controller is configured to: when in the fourth state, control the multiphase bridge arm (4) and the charging on-off switch unit, so that the power battery pack outputs the electric energy to the charging and discharging port (1) through the multiphase bridge arm (4) and the winding to supply power to the load, and the power battery pack outputs the electric energy to the multiphase motor (5) to drive the vehicle.

9. The battery control system of claim 4, wherein, The controller is configured to: when in the fifth state, control the multiphase bridge arm (4) and the charging on-off switch unit, so that the charging and discharging port (1) inputs the electric energy to the power battery pack through the winding and the multiphase bridge arm (4) to charge the power battery pack, and the charging and discharging port (1) inputs the electric energy to the multiphase motor (5) to drive the vehicle.

10. The battery control system of claim 4, wherein, The controller is configured to: when in the sixth state, control the multiphase bridge arm (4), the circulating current self-heating on-off switch unit and the charging on-off switch unit, so that the power battery pack outputs the electric energy to the multiphase motor (5) to make the multiphase motor (5) generate heat to heat the power battery pack, and the charging and discharging port (1) inputs the electric energy to the power battery pack to boost charge the power battery pack, and the power battery pack outputs the electric current or the charging and discharging port (1) inputs the electric current to the multiphase motor (5) to drive the vehicle.

11. The battery control system of claim 4, wherein, The controller is configured to control the multi-phase bridge arm (4) and the charging and discharging switch unit when in the seventh state, so that the power energy input by the charging and discharging port (1) is input to the multi-phase motor (5) to make the multi-phase motor (5) generate heat to heat the power battery pack.

12. The battery control system of claim 4, wherein, The power battery pack comprises a first battery group (2) and a second battery group (3) connected in series, and the N lines are further connected between the first battery group (2) and the second battery group (3); The power battery pack, the multi-phase bridge arm (4) and the multi-phase motor (5) can further constitute a self-heating loop; The system further comprises a self-heating on-off switch unit configured to make the self-heating loop conductive or disconnected; The controller is connected with the self-heating on-off switch unit, and the controller is configured to control the multi-phase bridge arm (4) and the self-heating on-off switch unit in the eighth state, so that the first battery group (2) and the second battery group (3) are alternately charged and discharged to heat the power battery pack, or / and the power energy output by the power battery pack is output to the multi-phase motor (5) to drive the vehicle.

13. A vehicle characterized by comprising: The battery control system according to any one of claims 1-12.

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