CN117284141B

CN117284141B - Vehicle battery charge and discharge control method, device and circuit

Info

Publication number: CN117284141B
Application number: CN202311576913.3A
Authority: CN
Inventors: 张�雄; 喻皓; 张光臻; 赵小坤; 夏铸亮
Original assignee: GAC Aion New Energy Automobile Co Ltd
Current assignee: GAC Aion New Energy Automobile Co Ltd
Priority date: 2023-11-24
Filing date: 2023-11-24
Publication date: 2024-03-26
Anticipated expiration: 2043-11-24
Also published as: CN117284141A

Abstract

The invention relates to the technical field of vehicles. The invention discloses a vehicle battery charge and discharge control method, device and circuit. The vehicle battery charge-discharge control method includes: identifying the voltage of a charging pile electrically connected with a vehicle charging and discharging interface, detecting the battery voltage of a vehicle power battery, wherein the vehicle charging and discharging interface is electrically connected with the vehicle power battery through a vehicle charging and discharging circuit, and the vehicle charging and discharging circuit comprises a voltage transformation circuit based on a motor system and a direct-connection charging circuit; when the voltage of the battery is greater than or equal to the voltage of the charging pile, the charging pile is controlled to charge the vehicle power battery through the voltage transformation circuit; when the voltage of the battery is smaller than that of the charging pile, the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit. Based on the comparison of the battery voltage and the charging pile voltage, different circuits are selected to charge the battery, so that the battery charging system can comprehensively adapt to different charging pile voltages, increase the charging scene and meet the charging requirements of users.

Description

Vehicle battery charge and discharge control method, device and circuit

Technical Field

The invention relates to the technical field of vehicles, in particular to a vehicle battery charge and discharge control method, a vehicle battery charge and discharge control device, electronic equipment, a storage medium, a vehicle and a vehicle battery charge and discharge circuit.

Background

In order to improve the endurance mileage of the electric automobile and the charging rate requirement of the electric automobile. Batteries of electric vehicles move toward high electric power, high voltage, and high energy density. Improving the charging rate and shortening the charging time is beneficial to improving the use experience of customers. However, when the voltage of the battery is higher than the voltage of the charging pile, the battery cannot be charged, so that when the electric vehicle using the high-voltage battery uses the low-voltage charging pile, a set of boosting system is needed to boost the voltage of the charging pile to the voltage of the battery.

However, the battery voltage is not fixed, the voltage of different charging piles can be different, a boosting system is directly added in the vehicle, and the charging cannot be performed when the battery voltage is lower than the charging column voltage.

Disclosure of Invention

Accordingly, it is necessary to provide a vehicle battery charge/discharge control method, a vehicle battery charge/discharge control device, an electronic device, a storage medium, a vehicle, and a vehicle battery charge/discharge circuit, which solve the problem that the conventional technology cannot accommodate different voltages of a battery and a charge pile.

The invention provides a vehicle battery charge and discharge control method, which comprises the following steps:

the method comprises the steps of identifying the voltage of a charging pile electrically connected with a vehicle charging and discharging interface, detecting the voltage of a battery of a vehicle power battery, wherein the vehicle charging and discharging interface is electrically connected with the vehicle power battery through a vehicle charging and discharging circuit, the vehicle charging and discharging circuit comprises a voltage transformation circuit based on a motor system and a direct-connection charging circuit, the vehicle charging and discharging interface is connected with the vehicle power battery through the voltage transformation circuit and the direct-connection charging circuit which are connected in parallel, the voltage transformation circuit comprises a first inductor, a second inductor, a third inductor, a first motor control loop, a second motor control loop and a third motor control loop of the motor system, a first end of the first inductor is electrically connected with the vehicle power battery through the first motor control loop, a first end of the second inductor is electrically connected with the vehicle power battery through the third motor control loop, and a second end of the first inductor, a second end of the second inductor and a second end of the third inductor are electrically connected with the first end of the vehicle charging and discharging interface;

When the battery voltage is greater than or equal to the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the voltage transformation circuit; and when the battery voltage is smaller than the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

Further, the vehicle charging and discharging circuit further comprises an input capacitor connected with the voltage transformation circuit in an on-off mode;

the control of the charging pile to charge the vehicle power battery through the voltage transformation circuit comprises the following steps:

carrying out charging parameter configuration;

the input capacitor is controlled to be electrically connected with the transformation circuit, and the vehicle charging and discharging interface is controlled to be disconnected with the transformation circuit so as to precharge the input capacitor;

after the input capacitor is precharged, the vehicle charging and discharging interface is controlled to be electrically connected with the voltage transformation circuit, and the motor system is controlled to enter a boosting and charging mode;

and sending a charging start request to the charging pile.

Still further, the vehicle charging and discharging circuit further includes an output capacitor electrically connected to the vehicle power battery, and the control unit is configured to control the charging pile to charge the vehicle power battery via the voltage transformation circuit, and further includes:

After the charging is completed, the input capacitor is electrically connected with the voltage transformation circuit, and meanwhile, the electric connection between the vehicle charging and discharging interface and the voltage transformation circuit is disconnected, and the input capacitor is discharged;

after a first preset time, discharging the output capacitor;

and after a second preset time, disconnecting the input capacitor from the voltage transformation circuit.

Still further, the vehicle charging and discharging circuit further comprises a first switch, a second switch and a third switch, the vehicle charging and discharging interface is connected with the first end of the first inductor through the second switch and the first switch, one end of the input capacitor is connected with the first end of the first inductor through the first switch, the other end of the input capacitor is grounded, the direct-connection charging circuit comprises the third switch, one end of the third switch is electrically connected with the vehicle charging and discharging interface, and the other end of the third switch is electrically connected with the vehicle power battery;

the control of the vehicle charge-discharge interface is electrically connected with the voltage transformation circuit, and the control of the motor system to enter a boost charging mode comprises the following steps:

controlling the first switch to be closed, controlling the second switch to be closed, and opening the third switch;

And controlling the first motor control loop to be disconnected, and controlling the second motor control loop and the third motor control loop to enter a boost charging mode.

Further, the method further comprises the following steps:

responding to a discharging request, and carrying out charging handshake with an external vehicle through the vehicle charging and discharging interface;

the input capacitor is controlled to be electrically connected with the voltage transformation circuit, the vehicle charging and discharging interface is controlled to be electrically connected with the voltage transformation circuit, and the motor system is controlled to enter a boosting charging mode;

controlling the motor system to enter a step-down discharging mode;

and controlling the voltage-reducing discharge of the motor system to enter a constant voltage output state or a constant current output state according to the external charging requirement.

The invention provides a vehicle battery charge and discharge control device, comprising:

the vehicle charging and discharging circuit comprises a voltage transformation circuit based on a motor system and a direct-connection charging circuit, the vehicle charging and discharging interface is connected with the vehicle power battery through the voltage transformation circuit and the direct-connection charging circuit which are connected in parallel, the voltage transformation circuit comprises a first inductor, a second inductor, a third inductor, a first motor control loop, a second motor control loop and a third motor control loop of the motor system, a first end of the first inductor is electrically connected with the vehicle power battery through the first motor control loop, a first end of the second inductor is electrically connected with the vehicle power battery through the second motor control loop, a first end of the third inductor is electrically connected with the vehicle power battery through the third motor control loop, a second end of the first inductor, a second end of the second inductor and a third end of the third inductor are electrically connected with the vehicle power battery, and the first end of the third inductor is electrically connected with the vehicle power battery;

The control module is used for controlling the charging pile to charge the vehicle power battery through the voltage transformation circuit when the battery voltage is greater than or equal to the charging pile voltage; and when the battery voltage is smaller than the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

The present invention provides an electronic device including:

at least one processor; the method comprises the steps of,

a memory communicatively coupled to at least one of the processors; wherein,

the memory stores instructions executable by at least one of the processors to enable the at least one processor to perform a vehicle battery charge and discharge control method as previously described.

The present invention provides a storage medium storing computer instructions that, when executed by a computer, are operable to perform all the steps of a vehicle battery charge-discharge control method as described above.

The invention provides a vehicle, comprising the vehicle battery charge-discharge control device or the electronic equipment.

The invention provides a vehicle battery charging and discharging circuit, comprising: the direct-connected charging circuit comprises a voltage transformation circuit, a direct-connected charging circuit, an input capacitor and an output capacitor;

The transformation circuit comprises a first inductor, a second inductor, a third inductor, a first motor control loop, a second motor control loop and a third motor control loop of the motor system, wherein the first end of the first inductor is electrically connected with a vehicle power battery through the first motor control loop, the first end of the second inductor is electrically connected with the vehicle power battery through the second motor control loop, the first end of the third inductor is electrically connected with the vehicle power battery through the third motor control loop, the second end of the first inductor, the second end of the second inductor and the second end of the third inductor are electrically connected, the vehicle charge-discharge interface is electrically connected with the first end of the first inductor through a second switch, the first switch is electrically connected with the first end of the first inductor, one end of the input capacitor is electrically connected with the first end of the first inductor, the other end of the output capacitor is electrically connected with the vehicle power battery, the other end of the output capacitor is electrically connected with the ground, and the direct-connection charging circuit comprises a third switch, and the third switch is electrically connected with the vehicle charge-discharge interface.

The invention identifies the voltage of a charging pile electrically connected with a vehicle charging and discharging interface, detects the battery voltage of a vehicle power battery, and controls the charging pile to charge the vehicle power battery through a voltage transformation circuit when the battery voltage is greater than or equal to the charging pile voltage; or when the voltage of the battery is smaller than the voltage of the charging pile, the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit. Based on the comparison of the battery voltage and the charging pile voltage, different circuits are selected to charge the battery, so that the battery charging system can comprehensively adapt to different charging pile voltages, increase the charging scene and meet the charging requirements of users. Meanwhile, according to the vehicle battery charging and discharging circuit, the single-phase outgoing line of the motor system is used for reducing motor torque fluctuation when the voltage transformation circuit works.

Drawings

FIG. 1 is a flowchart illustrating a method for controlling charge and discharge of a vehicle battery according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for controlling charge and discharge of a vehicle battery according to another embodiment of the present invention;

FIG. 3 is a schematic circuit diagram of a vehicle battery charging and discharging circuit according to an embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 5 is a schematic circuit diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 6 is a schematic charging diagram of a vehicle battery charging and discharging circuit according to an embodiment of the invention;

FIG. 7 is a schematic discharging diagram of a vehicle battery charging and discharging circuit according to an embodiment of the invention;

FIG. 8 is a schematic charging diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 9 is a schematic charging diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 10 is a schematic discharging diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 11 is a schematic discharging diagram of a vehicle battery charging and discharging circuit according to another embodiment of the present invention;

FIG. 12 is a flowchart of the boost charging operation according to the preferred embodiment of the present invention;

FIG. 13 is a flowchart of the operation of discharging the boosted charge voltage according to the preferred embodiment of the present invention;

FIG. 14 is a schematic diagram of a software state jump control of the motor controller;

FIG. 15 is a schematic diagram of a vehicle battery charge/discharge control device according to an embodiment of the present invention;

fig. 16 is a schematic diagram of a hardware structure of an electronic device according to the present invention.

Description of the marking

1-a voltage transformation circuit; 11-a first inductance; 12-a second inductance; 13-a third inductance; 14-a first motor control loop; 141-a first field effect transistor; 142-a second field effect transistor; 15-a second motor control loop; 151-a third field effect transistor; 152-fourth field effect transistor; 16-a third motor control loop; 161-fifth field effect transistor; 162-sixth field effect transistor; 2-a direct-connection charging circuit; 3-vehicle charge-discharge interface; 4-a vehicle power battery; 5-input capacitance; 6-output capacitance; 71-a first switch; 72-a second switch; 73-a third switch; 8-a controller; a 9-filter; 10-charging piles; 100-an external vehicle; 110-BMS;120-VCU;130-MCU.

Detailed Description

Specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Wherein like parts are designated by like reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings, and the words "inner" and "outer" refer to directions toward or away from, respectively, the geometric center of a particular component.

Fig. 1 is a flowchart of a method for controlling charge and discharge of a vehicle battery according to an embodiment of the present invention, including:

step S101, identifying the voltage of a charging pile electrically connected with a vehicle charging and discharging interface, and detecting the battery voltage of a vehicle power battery, wherein the vehicle charging and discharging interface is electrically connected with the vehicle power battery 4 through a vehicle charging and discharging circuit, the vehicle charging and discharging circuit comprises a voltage transformation circuit based on a motor system and a direct-connection charging circuit, the vehicle charging and discharging interface is connected with the vehicle power battery on-off through the voltage transformation circuit and the direct-connection charging circuit which are connected in parallel, the voltage transformation circuit comprises a first inductor, a second inductor, a third inductor, a first motor control loop, a second motor control loop and a third motor control loop of the motor system, a first end of the first inductor is electrically connected with the vehicle power battery through the first motor control loop, a first end of the second inductor is electrically connected with the vehicle power battery through the third motor control loop, a second end of the first inductor and a second end of the second inductor are electrically connected with the first end of the third inductor, and the first end of the third inductor is electrically connected with the vehicle charging and discharging interface;

Step S102, when the battery voltage is greater than or equal to the voltage of the charging pile, controlling the charging pile to charge the vehicle power battery through the voltage transformation circuit; and when the battery voltage is smaller than the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

In particular, the present invention may be applied to electronic devices having processing capabilities, such as a battery management system (Battery Management System, BMS), a vehicle controller (Vehicle Control Unit, VCU), a motor controller (Moter Controller Unit, MCU), and the like.

And in the charging mode, charging the electricity of the charging pile into the whole vehicle battery. Because of the different voltage levels of the charging piles on the market. When the voltage of the electric automobile battery is higher than the voltage of the charging pile, the charging function cannot be realized. Therefore, in order to be compatible with different charging piles, the electric automobile is integrated with a boosting charger based on a motor system, and the charging pile with low voltage can be pumped to the battery voltage through the boosting charger, so that the electric automobile can be charged. Meanwhile, the voltage of the charging pile is higher than the voltage of the electric automobile, and in this case, the electric automobile can be directly charged with the electricity of the charging pile by a circuit switching method without charging by a pumping charger.

Specifically, step S101 is first performed to identify the charging stake voltage of the charging stake electrically connected with the vehicle charging and discharging interface electrically connected with the vehicle power battery 4 through the vehicle charging and discharging circuit, and detect the battery voltage of the vehicle power battery.

Fig. 3 shows a vehicle battery charging and discharging circuit according to an embodiment of the invention, including: the direct-connection charging circuit comprises a transformation circuit 1, a direct-connection charging circuit 2, an input capacitor 5 and an output capacitor 6;

the voltage transformation circuit 1 comprises a first inductor 11, a second inductor 12, a third inductor 13, a first motor control loop 14, a second motor control loop 15 and a third motor control loop 16 of a motor system, wherein a first end of the first inductor 11 is electrically connected with the vehicle power battery 4 through the first motor control loop 14, a first end of the second inductor 12 is electrically connected with the vehicle power battery 4 through the second motor control loop 15, a first end of the third inductor 13 is electrically connected with the vehicle power battery 4 through the third motor control loop 16, a second end of the first inductor 11, a second end of the second inductor 12 and a second end of the third inductor 13 are electrically connected, the vehicle charge-discharge interface 3 is electrically connected with the first end of the first inductor 11 through a second switch 72, a first switch 71, one end of the input capacitor 5 is electrically connected with the first end of the first inductor 11 through the first switch 71, the other end of the input capacitor is grounded, one end of the output capacitor 6 is electrically connected with the vehicle power battery 4 through the third switch 73, the other end of the input capacitor is electrically connected with the vehicle power battery 4 through the second switch 73, and the other end of the input capacitor 3 is electrically connected with the vehicle power battery 3 through the third switch 73.

The first inductor 11, the second inductor 12 and the third inductor 13 are inductance groups of a vehicle motor system, namely motor windings. The first motor control loop 14, the second motor control loop 15 and the third motor control loop 16 are motor control loops of a motor system. The first motor control loop 14 includes a first fet 141 and a second fet 142 connected in parallel, the second motor control loop 15 includes a third fet 151 and a fourth fet 152 connected in parallel, and the third motor control loop 16 includes a fifth fet 161 and a sixth fet 162 connected in parallel.

Preferably, the vehicle battery charge-discharge circuit further includes a controller 8 and a filter 9.

Wherein, the controller 8 detects the voltage V at two ends of the input capacitor 5 through a sampling circuit _in As the voltage of the charging pile, the voltage V across the output capacitor 6 is detected _dc As battery voltage. At the same time, the controller 8 can also detect the three-phase current I passing through the first inductor 11, the second inductor 12 and the third inductor 13 _uvw 。

The filter 9 is preferably an electromagnetic compatibility (Electro Magnetic Compatibility, EMC) filter. The filter 9 is disposed between the second ends of the first inductor 11, the second inductor 12, and the third inductor 13 and the vehicle charge-discharge interface 3 for filtering.

Comparing the battery voltage with the voltage of the charging pile, and executing step S102, wherein when the battery voltage is greater than or equal to the voltage of the charging pile, the charging pile is controlled to charge the vehicle power battery through the voltage transformation circuit; and when the battery voltage is smaller than the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

Specifically, the circuits shown in fig. 3 and 6 include a direct fast charge mode and a boost fast charge mode:

boost fast charge mode: when the battery voltage is greater than or equal to the charging pile voltage, the first switch 71 and the second switch 72 are closed, and the third switch 73 is opened, so that the charging pile is controlled to charge the vehicle power battery through the voltage transformation circuit.

Direct fast charge mode: when the battery voltage is smaller than the charging pile voltage, the first switch 71 and the second switch 72 are opened, and the third switch 73 is closed, so that the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit.

Preferably, the first switch 71, the second switch 72 are boost relays, and the third switch 73 is a dc fast charging relay.

The direction of current flow is from the charging stake to the vehicle power cell as shown in fig. 6.

Compared with a three-phase outgoing line charging and discharging circuit, the vehicle battery charging and discharging circuit has the advantages that the inductance is larger through the single-phase outgoing line of the motor system, so that the motor torque fluctuation can be reduced when the voltage transformation circuit works.

In some embodiments, the method of the present invention may also be applied to a vehicle battery charge-discharge circuit with three-phase outgoing lines as shown in fig. 4 and 5.

Fig. 4 shows a charge and discharge circuit of a vehicle battery according to another embodiment of the present invention, including: the direct-connection charging circuit comprises a transformation circuit 1, a direct-connection charging circuit 2, an input capacitor 5 and an output capacitor 6;

the voltage transformation circuit 1 comprises a first inductor 11, a second inductor 12, a third inductor 13, a first motor control loop 14, a second motor control loop 15 and a third motor control loop 16 of a motor system, wherein a first end of the first inductor 11 is electrically connected with the vehicle power battery 4 through the first motor control loop 14, a first end of the second inductor 12 is electrically connected with the vehicle power battery 4 through the second motor control loop 15, a first end of the third inductor 13 is electrically connected with the vehicle power battery 4 through the third motor control loop 16, a second end of the first inductor 11, a second end of the second inductor 12 and a second end of the third inductor 13 are electrically connected, the vehicle charge-discharge interface 3 is electrically connected with the second end of the first inductor 11 through a second switch 72, a first switch 71, one end of the input capacitor 5 is electrically connected with the second end of the first inductor 11 through the first switch 71, the other end of the input capacitor 6 is grounded, one end of the output capacitor 6 is electrically connected with the vehicle power battery 4 through the third switch 73, the other end of the input capacitor 5 is electrically connected with the vehicle power battery 3 through the third switch 73, and the other end of the input capacitor 3 is electrically connected with the vehicle power battery 3 through the third switch 73.

The first inductor 11, the second inductor 12, and the third inductor 13 are inductance groups of the vehicle motor system. The first motor control loop 14, the second motor control loop 15 and the third motor control loop 16 are motor control loops of a motor system. The first motor control loop 14 includes a first fet 141 and a second fet 142 connected in parallel, the second motor control loop 15 includes a third fet 151 and a fourth fet 152 connected in parallel, and the third motor control loop 16 includes a fifth fet 161 and a sixth fet 162 connected in parallel.

Preferably, the vehicle battery charging and discharging circuit further comprises a controller 8 and a filter 9, the filter 9 preferably being an electromagnetic compatibility (Electro Magnetic Compatibility, EMC) filter.

The circuits shown in fig. 4 and 8 include a direct fast charge mode and a boost fast charge mode:

boost fast charge mode: when the battery voltage is greater than or equal to the voltage of the charging pile, the first switch 71 and the second switch 72 are closed, the third switch 73 is opened, the whole vehicle and the charging pile are subjected to charging handshake signal interaction, and the motor system is enabled to enter a boosting charging mode, so that the charging pile is controlled to charge the vehicle power battery through the voltage transformation circuit.

Direct fast charge mode: when the battery voltage is smaller than the charging pile voltage, the first switch 71 and the second switch 72 are opened, the third switch 73 is closed, and the whole vehicle and the charging pile are subjected to charging handshake signal interaction to realize charging, so that the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit.

The direction of current flow is from the charging stake to the vehicle power cell as shown in fig. 8.

Fig. 5 shows a vehicle battery charging and discharging circuit according to still another embodiment of the present invention, including: the direct-connection charging circuit comprises a transformation circuit 1, a direct-connection charging circuit 2, an input capacitor 5 and an output capacitor 6;

the voltage transformation circuit 1 comprises a first inductor 11, a second inductor 12, a third inductor 13, a first motor control loop 14, a second motor control loop 15 and a third motor control loop 16 of a motor system, wherein a first end of the first inductor 11 is electrically connected with a vehicle power battery 4 through the first motor control loop 14, a first end of the second inductor 12 is electrically connected with the vehicle power battery 4 through the second motor control loop 15, a first end of the third inductor 13 is electrically connected with the vehicle power battery 4 through the third motor control loop 16, a second end of the first inductor 11, a second end of the second inductor 12 and a second end of the third inductor 13 are electrically connected, a vehicle charge-discharge interface 3 is electrically connected with a second end of the first inductor 11 through a first switch 71, meanwhile, one end of the input capacitor 5 is electrically connected with a second end of the first inductor 11 through the first switch 71, another end of the input capacitor 6 is electrically connected with the vehicle power battery 3 through the first switch 71, another end of the input capacitor is electrically connected with the vehicle power battery 3 through the second switch 73, and the other end of the input capacitor is electrically connected with the vehicle power battery 3 through the other end of the input capacitor is electrically connected with the vehicle power battery 73.

The circuit shown in fig. 5 and 9 includes a direct fast charge mode and a boost fast charge mode:

Direct fast charge mode: when the battery voltage is smaller than the charging pile voltage, the second switch 72 is opened, the first switch 71 and the third switch 73 are closed, and the whole vehicle and the charging pile are subjected to charging handshake signal interaction to realize charging, so that the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit.

The direction of current flow is to charge the pile to the vehicle power battery as shown in fig. 9.

The invention identifies the voltage of a charging pile electrically connected with a vehicle charging and discharging interface, detects the battery voltage of a vehicle power battery, and controls the charging pile to charge the vehicle power battery through a voltage transformation circuit when the battery voltage is greater than or equal to the charging pile voltage; or when the voltage of the battery is smaller than the voltage of the charging pile, the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit. Based on the comparison of the battery voltage and the charging pile voltage, different circuits are selected to charge the battery, so that the battery charging system can comprehensively adapt to different charging pile voltages, increase the charging scene and meet the charging requirements of users.

Fig. 2 is a flowchart of a method for controlling charge and discharge of a vehicle battery according to another embodiment of the present invention, including:

step S201, the voltage of a charging pile electrically connected with a vehicle charging and discharging interface is identified, and the battery voltage of a vehicle power battery is detected, the vehicle charging and discharging interface is electrically connected with the vehicle power battery through a vehicle charging and discharging circuit, the vehicle charging and discharging circuit comprises a voltage transformation circuit based on a motor system, a direct connection charging circuit, an input capacitor electrically connected with the voltage transformation circuit in an on-off manner, and an output capacitor electrically connected with the vehicle power battery, the vehicle charging and discharging interface is electrically connected with the vehicle power battery through the voltage transformation circuit and the direct connection charging circuit which are connected in parallel, the voltage transformation circuit comprises a first inductor, a second inductor, a third inductor, a first motor control loop and a third motor control loop of the motor system, a first end of the first inductor is electrically connected with the vehicle power battery through the first motor control loop, a first end of the second inductor is electrically connected with the vehicle power battery through the second motor control loop, a first end of the third inductor is electrically connected with the vehicle power battery through the third motor control loop, a second end of the first inductor is electrically connected with the first end of the vehicle power battery through the direct connection charging and discharging switch, and the first end of the first inductor is electrically connected with the vehicle power battery through the first end of the first inductor, and the second end of the first inductor is electrically connected with the vehicle power battery through the first end of the first switch, and the second end of the first inductor is electrically connected with the vehicle power battery through the first end of the first switch;

Step S202, when the battery voltage is greater than or equal to the charging pile voltage, charging parameter configuration is carried out;

step S203, controlling the input capacitor to be electrically connected with the voltage transformation circuit, and controlling the vehicle charge-discharge interface to be disconnected with the voltage transformation circuit, so as to precharge the input capacitor;

step S204, after the input capacitor is precharged, the vehicle charge-discharge interface is controlled to be electrically connected with the voltage transformation circuit, and the motor system is controlled to enter a boost charging mode;

in one embodiment, the controlling the vehicle charge-discharge interface to be electrically connected with the voltage transformation circuit controls the motor system to enter a boost charging mode includes:

Step S205, sending a charging start request to a charging pile;

step S206, after the charging is completed, the input capacitor is electrically connected with the voltage transformation circuit, and meanwhile, the electric connection between the vehicle charge-discharge interface and the voltage transformation circuit is disconnected, and the input capacitor is discharged;

Step S207, after a first preset time, discharging the output capacitor;

step S208, after a second preset time, the input capacitor is disconnected from the voltage transformation circuit.

And step S209, when the battery voltage is smaller than the voltage of the charging pile, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

Specifically, step S201 is performed to identify the charging pile voltage of the charging pile electrically connected to the vehicle charging/discharging interface. Then, when the battery voltage is greater than or equal to the charging pile voltage, steps S202 to S208 are performed, and when the battery voltage is less than the charging pile voltage, step S209 is performed.

Specifically, the boost charging mode is initiated by the BMS, the VCU controls the whole vehicle energy management, the MCU realizes the boost of the voltage of the charging pile to charge the power battery, in the process, the BMS performs current and voltage control with the direct current charging pile according to the whole vehicle demand current and voltage sent by the VCU, and the MCU controls the direct current charging port side voltage and the power battery side current according to the request charging current and voltage sent by the VCU. Wherein the MCU is preferably the controller 8 of the vehicle charge-discharge circuit.

Wherein, the BMS executes step S201 to identify the voltage of the charging pile, detect the voltage of the battery, confirm whether to enter boost charging, and if so, the BMS executes step S202 to perform charging parameter configuration. The charging parameter configuration adopts the existing charging parameter configuration mode.

Then, step S203 is executed, the BMS sends a boost charging request to the VCU, and after receiving the boost charging request, the BMS controls the input capacitor to be electrically connected with the voltage transformation circuit, controls the vehicle charge-discharge interface to be disconnected with the voltage transformation circuit, and controls the voltage transformation circuit 1 to precharge the input capacitor by the MCU.

Specifically, for the circuits of fig. 3, 4, and 5, i.e., the first switch 71 is closed so that the input capacitor 5 is connected to the vehicle transforming circuit 1, while the second switch 72 is opened, the transforming circuit 1 is kept disconnected from the vehicle charging and discharging interface 3, and the input capacitor 5 is precharged by the vehicle power battery 4 by controlling the transforming circuit 1. The duty ratios of the first motor control loop 14, the second motor control loop 15 and the third motor control loop 16 can be controlled by the MCU in an existing step-down control manner, so that the first motor control loop 14, the second motor control loop 15 and the third motor control loop 16, the first inductor 11, the second inductor 12 and the third inductor 13 form a step-down loop, and precharge of the input capacitor 5 is achieved.

After the input capacitor is precharged, for example, after a preset time passes, or the input capacitor voltage reaches a preset precharge threshold, step S204 is performed, where the BMS sends a precharge completion request to the VCU, the VCU requests the MCU to enter a boost charging mode, the MCU controls the motor system to enter the boost charging mode, and the BMS controls the vehicle charge/discharge interface 3 to be electrically connected with the transformer circuit 1. The voltage detection of the input capacitor CAN be detected by an independent ECU of a voltage detection circuit and sent to the BMS through a controller area network (Controller Area Network, CAN) bus.

Specifically, for the circuit shown in fig. 3, the vehicle charging and discharging interface is controlled to be electrically connected with the voltage transformation circuit, and the motor system is controlled to enter a boost charging mode, which specifically includes:

The first switch 71 is controlled to be closed, the second switch 72 is controlled to be closed, and the third switch 73 is controlled to be opened, so that the vehicle charge-discharge interface 3, the voltage transformation circuit 1 and the vehicle power battery 4 are electrically connected. Meanwhile, the MCU controls the first motor control loop 14 to be disconnected, and controls the duty ratio of the second motor control loop 15 and the third motor control loop 16, so that the second motor control loop 15 and the third motor control loop 16 form a boost loop, and enter a boost charging mode, so that after the current passes through the first inductor 11, the current passes through the second inductor 12 and the third inductor 13, and then enters the second motor control loop 15 and the third motor control loop 16 respectively. More specifically, the first fet 141 and the second fet 142 are kept inactive, and the boosting is completed by controlling the duty ratios of the third fet 151, the fourth fet 152, the fifth fet 161, and the sixth fet 162.

The embodiment realizes boost charging control of the single-phase outgoing circuit.

In some embodiments, for the circuits of fig. 4 and 5, the first switch 71 and the second switch 72 are kept closed, and the input capacitor is electrically connected to the boost charging circuit, and the vehicle charge-discharge interface, the boost charging circuit, and the vehicle power battery are electrically connected.

In some embodiments, for the circuits of fig. 4, 5, the MCU controlling the motor system to enter boost charging mode includes: the MCU adopts the existing boost control mode to control the duty ratios of the first motor control loop 14, the second motor control loop 15 and the third motor control loop 16, so that the first motor control loop 14, the second motor control loop 15 and the third motor control loop 16, the first inductor 11, the second inductor 12 and the third inductor 13 form a boost loop.

Then, the BMS performs step S205 of transmitting a handshake signal to the charging post, issuing a start charging request, and starting charging.

After the charging is completed, execution of step S206 is performed, and the input capacitor is discharged by disconnecting the electrical connection between the vehicle charging and discharging interface and the transformer circuit while maintaining the electrical connection between the input capacitor and the transformer circuit.

Specifically, for the circuits of fig. 3, 4 and 5, the first switch 71 is kept closed, so that the input capacitor can be kept electrically connected with the voltage transformation circuit, meanwhile, the second switch 72 and the third switch 73 are opened, so that the electric connection between the vehicle charging and discharging interface and the voltage transformation circuit is disconnected, and meanwhile, the MCU controls the motor system to keep the boost charging mode, so that the input capacitor 5 is discharged.

After a first preset time, for example 1 second, step S207 is performed to control the bleed-off output capacitor 6. Specifically, three-phase current through the motor is output, thereby discharging the output capacitor 6 through the motor windings.

After a second preset time, for example, after 2 seconds passes, step S208 is performed to disconnect the input capacitor from the voltage transformation circuit. For the circuits of fig. 3, 4 and 5, the first switch 71 is turned off, and the input capacitor can be electrically disconnected from the transformer circuit.

As shown in fig. 12, which is a flowchart illustrating the boost charging operation of the preferred embodiment of the present invention, including the BMS 110, the VCU 120, and the MCU 130, the MCU may preferably be the controller 8 of the vehicle charging and discharging circuit, the method includes:

step S1201, in the parameter matching stage, the voltage range of the charging pile is identified, whether to enter boost charging is confirmed, if yes, step S1202 is executed, otherwise, the direct-connection charging circuit is directly closed for charging;

step S1202, parameter configuration is successful, and a boost charging request is sent to the VCU;

step S1203, the VCU requests high voltage on the BMS, the BMS opens the second switch 72 and the third switch 73, closes the first switch 71, and the vuc requests the MCU to enter boost charging precharge;

Step S1204, the MCU is controlled according to the target value sent by the VCU, and sends a state jump signal to the VCU;

step S1205, the BMS confirms that the input capacitance 5 reaches (within + -15V of the target value), and sends a precharge completion request;

step S1206, the VCU requests the MCU to enter a boost charging mode;

step S1207, the MCU jumps to a boost charging mode;

step S1208, the VCU requests the BMS to enter a boost charging mode;

in step S1209, the BMS closes the second switch 72, and sends brd=0 xaa.

As shown in fig. 13, which is a flowchart illustrating the operation of discharging the boosted charge voltage according to the preferred embodiment of the present invention, including the BMS 110, the VCU 120, and the MCU 130, which may preferably be the controller 8 of the vehicle charge-discharge circuit, the method includes:

step S1301, when the power-down condition is met, the VCU limits the load of the whole vehicle and stops working;

step S1302, VCU keeps requesting BMS to power down, opens the relay, and keeps closing the first switch 71 when the BMS boost charging process jumps to power down, and opens other switches;

step S1303, after the VCU confirms that the BMS breaks the main loop, requesting the MCU to start discharging the input capacitor 5, and requesting the output capacitor 6 to discharge after 1 second, wherein the MCU discharges the input capacitor 5;

in step S1304, the BMS turns off the first switch 71 after receiving power down (off) for 2 seconds.

Fig. 14 is a schematic diagram of software state jump control of the motor controller. The states of the MCU include:

a boost capacitor precharge (CapPrecharge) state in which the MCU controls the motor system to precharge the input capacitor;

a boost charge (boost charge) state in which the MCU controls the motor system to perform boost charge;

a boost capacitance bleed (CapDischarge) state in which the input capacitance is bled off;

and a buck output (buck discharge) state, in which the MCU controls the motor system to perform buck discharge.

According to the embodiment, based on comparison of the battery voltage and the charging pile voltage, different circuits are selected to charge the battery, so that different charging pile voltages can be comprehensively adapted, a charging scene is increased, and the charging requirement of a user is met. Meanwhile, the input capacitor is pre-charged before charging, and is balanced with the voltage of the charging pile, so that larger impact current is avoided. Before power-down, the input capacitor and the output capacitor are sequentially discharged, so that the safety problem caused by human body contact due to voltage is prevented. According to the vehicle battery charge and discharge control method, the electric vehicle with the high-voltage battery can be compatible with the charge piles with different voltage levels, and the problem of charge compatibility caused by insufficient voltage is avoided.

In one embodiment, the method further comprises:

controlling the motor system to enter a step-down discharging mode;

The present embodiment is a discharge mode. In the discharging mode, the electric automobile with more electric quantity can carry out emergency quick charging on the automobile with less electric quantity. The high-power electric vehicle needs to have a step-down discharging function, and as shown in the electrical principles of fig. 7, 10 and 11, the high voltage of the battery is output in a step-down manner through the voltage transformation circuit 1. When charging, as shown in fig. 6, 8 and 9, current flows from the vehicle charge-discharge interface 3 to the vehicle power battery 4, so the voltage transformation circuit 1 plays a role of boost charging as a boost charging circuit. When discharging, as shown in fig. 7, 10 and 11, current flows from the vehicle power battery 4 to the vehicle charge-discharge interface 3, and therefore, the voltage transformation circuit 1 at this time plays a role of step-down discharge as a step-down discharge circuit. The voltage transformation circuit 1 may be set to a constant voltage output or a constant current output mode (a control mode of an analog charging pile).

In addition, in order to realize the V2V charging function of the whole vehicle, besides the motor system, other auxiliary devices are needed to realize the voltage reduction output function.

1) A double-end quick charging line is needed and used for connecting the quick charging ports of two electric automobiles;

2) The quick charge signal pin of the charging port of the high-power vehicle needs to have a quick charge output function of the analog charging pile for carrying out quick charge handshake interaction with other vehicles.

Description of discharge modes:

for the circuits shown in fig. 3 and 7, when the step-down discharge is performed, the first switch 71 and the second switch 72 are closed, the third switch 73 is opened, the whole vehicle and the external vehicle 100 charge and handshake, and then the motor system is enabled to enter the step-down discharge mode. That is, the first fet 141 and the second fet 142 are kept inactive, and the voltage is reduced by controlling the duty ratios of the third fet 151, the fourth fet 152, the fifth fet 161, and the sixth fet 162 to form a voltage reducing circuit. Meanwhile, according to the external charging requirement, the step-down discharging of the motor system is controlled to enter a constant voltage output or constant current output state.

For the circuits shown in fig. 4 and 8, when the step-down discharge is performed, the first switch 71 and the second switch 72 are closed, the third switch 73 is opened, the whole vehicle and the external vehicle 100 charge and handshake, and then the motor system is enabled to enter the step-down discharge mode. Meanwhile, according to the external charging requirement, the step-down discharging of the motor system is controlled to enter a constant voltage output or constant current output state.

For the circuits shown in fig. 5 and 9, when the step-down discharge is performed, the first switch 71 and the second switch 72 are closed, the third switch 73 is opened, the whole vehicle and the external vehicle 100 charge and handshake, and then the motor system is enabled to enter the step-down discharge mode. Meanwhile, according to the external charging requirement, the step-down discharging of the motor system is controlled to enter a constant voltage output or constant current output state.

The work flow of the buck discharge is basically the same as that of the boost charge, and specifically includes:

the input capacitor 5 is controlled to be electrically connected with the transformation circuit 1, and the vehicle charging and discharging interface 3 is controlled to be disconnected with the transformation circuit 1 so as to precharge the input capacitor;

after the input capacitor is precharged, the vehicle charging and discharging interface 3 is controlled to be electrically connected with the voltage transformation circuit 1, and the motor system is controlled to enter a step-down discharging mode;

The embodiment provides a discharging mode, and realizes that an electric automobile with more electric quantity carries out emergency fast charging and supplementing for a vehicle with less electric quantity. According to the embodiment, the electric vehicle can be used as a temporary charging pile to charge other electric vehicles in an emergency.

Based on the same inventive concept, fig. 15 is a schematic diagram of a vehicle battery charge and discharge control device according to an embodiment of the present invention, including:

the identification module 1501 is configured to identify a charging pile voltage of a charging pile electrically connected to a vehicle charging and discharging interface, and detect a battery voltage of a vehicle power battery, where the vehicle charging and discharging interface is electrically connected to the vehicle power battery through a vehicle charging and discharging circuit, the vehicle charging and discharging circuit includes a voltage transformation circuit based on a motor system and a direct charging circuit, the vehicle charging and discharging interface is connected to the vehicle power battery through the voltage transformation circuit and the direct charging circuit that are connected in parallel, the voltage transformation circuit includes a first inductor, a second inductor, a third inductor, a first motor control loop, a second motor control loop, and a third motor control loop of the motor system, a first end of the first inductor is electrically connected to the vehicle power battery through the first motor control loop, a first end of the second inductor is electrically connected to the vehicle power battery through the third motor control loop, a second end of the first inductor, a second end of the second inductor, and a third end of the second inductor are electrically connected to the vehicle charging and discharging interface;

A control module 1502, configured to control the charging pile to charge the vehicle power battery through the voltage transformation circuit when the battery voltage is greater than or equal to the charging pile voltage; and when the battery voltage is smaller than the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the direct-connection charging circuit.

In one embodiment, the vehicle charging and discharging circuit further comprises an input capacitor connected with the voltage transformation circuit in an on-off mode;

Carrying out charging parameter configuration;

and sending a charging start request to the charging pile.

In one embodiment, the vehicle charging and discharging circuit further includes an output capacitor electrically connected to the vehicle power battery, and the control unit further includes:

after a first preset time, discharging the output capacitor;

In one embodiment, the vehicle charging and discharging circuit further comprises a first switch, a second switch and a third switch, the vehicle charging and discharging interface is connected with the first end of the first inductor in an on-off manner through the second switch and the first switch, one end of the input capacitor is connected with the first end of the first inductor in an on-off manner through the first switch, the other end of the input capacitor is grounded, the direct-connection charging circuit comprises the third switch, one end of the third switch is electrically connected with the vehicle charging and discharging interface, and the other end of the third switch is electrically connected with the vehicle power battery;

In one embodiment, the device further comprises a discharge module for:

controlling the motor system to enter a step-down discharging mode;

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

Fig. 16 is a schematic diagram of a hardware structure of an electronic device according to the present invention, including:

at least one processor 1601; the method comprises the steps of,

a memory 1602 communicatively coupled to at least one of the processors 1601; wherein,

the memory 1602 stores instructions executable by at least one of the processors to enable the at least one processor to perform a vehicle battery charge and discharge control method as previously described.

One processor 1601 is shown in fig. 16 as an example.

The electronic device may further include: an input device 1603 and a display device 1604.

The processor 1601, memory 1602, input device 1603, and display device 1604 may be connected by a bus or other means, which is illustrated as a bus connection.

The memory 1602 is a non-volatile computer readable storage medium, and may be used to store non-volatile software programs, non-volatile computer executable programs, and modules, such as program instructions/modules corresponding to the vehicle battery charge/discharge control method in the embodiments of the present application, for example, the method flows shown in fig. 1 and 2. The processor 1601 executes various functional applications and data processing by executing nonvolatile software programs, instructions, and modules stored in the memory 1602, that is, implements the vehicle battery charge-discharge control method in the above-described embodiment.

Memory 1602 may include a storage program area that may store an operating system, at least one application program required for functionality, and a storage data area; the storage data area may store data created according to the use of the vehicle battery charge-discharge control method, and the like. In addition, memory 1602 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 1602 may optionally include memory located remotely from the processor 1601, which may be connected by a network to a device performing the vehicle battery charge and discharge control method. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 1603 may receive input user clicks and generate signal inputs related to user settings and function controls of the vehicle battery charge-discharge control method. The display 1604 may include a display device such as a display screen.

The vehicle battery charge-discharge control method in any of the method embodiments described above is performed when executed by the one or more processors 1601, while the one or more modules are stored in the memory 1602.

An embodiment of the present invention provides a storage medium storing computer instructions that, when executed by a computer, perform all the steps of a vehicle battery charge-discharge control method as described above.

An embodiment of the present invention provides a vehicle including the vehicle battery charge-discharge control device as described above, or the electronic apparatus as described above. It will be appreciated that the vehicle may also include: a processor, a memory and a computer program. Wherein the computer program is stored in the memory and configured to be executed by the processor to implement the vehicle battery charge and discharge control method provided by the embodiments of the present disclosure. The portions of the processor and the memory that are described in the embodiment shown in fig. 16 are not described herein.

The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A vehicle battery charge-discharge control method, characterized by comprising:

When the battery voltage is greater than or equal to the charging pile voltage, controlling the charging pile to charge the vehicle power battery through the voltage transformation circuit; when the battery voltage is smaller than the charging pile voltage, the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit;

the vehicle charging and discharging circuit further comprises an input capacitor connected with the voltage transformation circuit in an on-off mode;

carrying out charging parameter configuration;

after the input capacitor is precharged, the first motor control loop is controlled to be disconnected, the duty ratio of the second motor control loop and the third motor control loop is controlled, so that the second motor control loop and the third motor control loop form a boost loop, and a boost charging mode is entered;

and sending a charging start request to the charging pile.

2. The vehicle battery charge-discharge control method according to claim 1, wherein the vehicle charge-discharge circuit further includes an output capacitor electrically connected to the vehicle power battery, the control of the charging stake to charge the vehicle power battery via the voltage transformation circuit further includes:

after a first preset time, discharging the output capacitor;

3. The vehicle battery charge-discharge control method according to claim 1, wherein the vehicle charge-discharge circuit further comprises a first switch, a second switch and a third switch, the vehicle charge-discharge interface is connected with a first end of the first inductor in an on-off manner through the second switch and the first switch, one end of the input capacitor is connected with a first end of the first inductor in an on-off manner through the first switch, the other end of the input capacitor is grounded, the direct-connection charging circuit comprises the third switch, one end of the third switch is electrically connected with the vehicle charge-discharge interface, and the other end of the third switch is electrically connected with the vehicle power battery;

4. The vehicle battery charge-discharge control method according to claim 1, characterized by further comprising:

controlling the motor system to enter a step-down discharging mode;

5. A vehicle battery charge-discharge control device, characterized by comprising:

The control module is used for controlling the charging pile to charge the vehicle power battery through the voltage transformation circuit when the battery voltage is greater than or equal to the charging pile voltage; when the battery voltage is smaller than the charging pile voltage, the charging pile is controlled to charge the vehicle power battery through the direct-connection charging circuit;

carrying out charging parameter configuration;

and sending a charging start request to the charging pile.

6. An electronic device, comprising:

At least one processor; the method comprises the steps of,

a memory communicatively coupled to at least one of the processors; wherein,

the memory stores instructions executable by at least one of the processors to enable the at least one of the processors to perform the vehicle battery charge-discharge control method according to any one of claims 1 to 4.

7. A storage medium storing computer instructions which, when executed by a computer, are adapted to carry out all the steps of the vehicle battery charge-discharge control method according to any one of claims 1 to 4.

8. A vehicle comprising the vehicle battery charge-discharge control device according to claim 5, or the electronic apparatus according to claim 6.

9. A vehicle battery charge-discharge circuit, comprising: the direct-connected charging circuit comprises a transformation circuit (1), a direct-connected charging circuit (2), an input capacitor (5) and an output capacitor (6);

the voltage transformation circuit (1) comprises a first inductor (11), a second inductor (12), a third inductor (13), a first motor control loop (14), a second motor control loop (15) and a third motor control loop (16) of a motor system, wherein the first end of the first inductor (11) is electrically connected with a vehicle power battery (4) through the first motor control loop (14), the first end of the second inductor (12) is electrically connected with the vehicle power battery (4) through the second motor control loop (15), the first end of the third inductor (13) is electrically connected with the vehicle power battery (4) through the third motor control loop (16), the second end of the first inductor (11), the second end of the second inductor (12) and the second end of the third inductor (13) are electrically connected, the vehicle charge-discharge interface (3) is electrically connected with the first end of the first inductor (11) through a second switch (72) and a first switch (71), the first end of the first inductor (12) is electrically connected with the vehicle power battery (4) through the third motor control loop (16), the first end of the first inductor (3) is electrically connected with the other end of the vehicle power battery (4) through the first switch (73), one end of the third switch (73) is electrically connected with the vehicle charging and discharging interface (3), the other end of the third switch is electrically connected with the vehicle power battery (4), and the vehicle charging and discharging interface (3) is not connected with the first end of the second inductor (12) and the first end of the third inductor (13).