CN114750628A

CN114750628A - Vehicle charging and discharging method, battery management system and charging and discharging system

Info

Publication number: CN114750628A
Application number: CN202210397747.XA
Authority: CN
Inventors: 郭昌伦; 潘志强
Original assignee: Lantu Automobile Technology Co Ltd
Current assignee: Lantu Automobile Technology Co Ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2022-07-15

Abstract

The invention provides a vehicle charging and discharging method, a battery management system and a charging and discharging system, wherein the method comprises the following steps: when the fact that the vehicle is inserted into the charging gun is detected, charging information interaction is conducted between the vehicle and the direct current charging pile, and if the fact that charging preparation conditions are met is determined, the vehicle enters a charging state; receiving a discharging request sent by an on-board charger, and executing a charging and discharging power balance strategy according to the discharging request, wherein the charging and discharging power balance strategy is used for avoiding charging interruption and discharging interruption; therefore, the vehicle can discharge the external load while charging, and execute a charge-discharge power balance strategy to avoid discharge interruption and charge interruption; the discharging efficiency is improved, and the use experience of the user on the discharging function is further improved.

Description

Vehicle charging and discharging method, battery management system and charging and discharging system

Technical Field

The application relates to the technical field of new energy automobiles, in particular to a vehicle charging and discharging method, a battery management system and a charging and discharging system.

Background

At present, new energy vehicles all have a charging function, and part of new energy vehicles have an external discharging function, but at present, the external discharging by using vehicles is a common function, and for example, in a long-distance journey, vehicle-mounted electric appliances need to be powered, such as an electric cooker and a vehicle-mounted refrigerator.

However, when the new energy automobile discharges to the outside, the charging and the discharging to the high-power load cannot be simultaneously realized at present. Therefore, when the electric quantity of the vehicle is insufficient to charge in the charging station, the power supply to the external load cannot be carried out at the moment, and the use of the external load is directly influenced; for example, when the electric cooker is used for cooking in the car, the electric cooker cannot continue to cook at this time.

It can be seen that the new energy automobile can not discharge when charging, can seriously influence the efficiency of discharging, influences the use experience of user to the function of discharging.

Disclosure of Invention

Aiming at the problems in the prior art, the embodiment of the invention provides a vehicle charging and discharging method, a battery management system and a charging and discharging system, so as to solve or partially solve the technical problem that when a new energy automobile cannot be charged and simultaneously discharges an external load, the discharging efficiency is influenced, and further the use experience of a user on a discharging function is influenced.

The invention provides a vehicle charging and discharging method, which is applied to a battery management system and comprises the following steps:

when the fact that a vehicle is inserted into a charging gun is detected, charging information interaction is carried out between the vehicle and a direct current charging pile, and if the fact that charging preparation conditions are met is determined, a charging state is entered;

receiving a discharging request sent by a vehicle-mounted charger, and executing a charging and discharging power balance strategy according to the discharging request; the charge-discharge power balance strategy is used for avoiding charge interruption and discharge interruption.

In the foregoing solution, the executing the charge-discharge power balancing policy according to the discharge request includes:

acquiring a current State Of Charge (SOC) value;

and if the difference value between the charging cut-off SOC value of the vehicle and the current SOC value is larger than or equal to a preset threshold value, controlling the charging current to reach the maximum value.

In the foregoing solution, if it is determined that the difference between the cut-off SOC value of the vehicle and the current SOC value is smaller than the preset threshold, the method further includes:

acquiring the power and the value of the whole vehicle load power of the vehicle and the external discharge power of a vehicle-mounted charger;

and controlling the charging power to be consistent with the power sum value.

In the foregoing solution, after the controlling the charging power is consistent with the power sum, the method further includes:

acquiring the current SOC value of the vehicle in a preset acquisition period;

and controlling the difference value between the charging cut-off SOC value and the current SOC value to be smaller than or equal to the preset threshold value.

In the foregoing solution, after executing the charge-discharge power balancing policy according to the discharge request, the method further includes:

and if a discharging stopping instruction sent by the vehicle-mounted charger is received, giving up executing the charging and discharging balance strategy, and entering a pure charging state.

In a second aspect of the present invention, there is provided a battery management system comprising:

the detection unit is used for performing charging information interaction with the direct current charging pile when the vehicle is detected to be inserted into the charging gun, and entering a charging state if the charging preparation condition is met;

the execution unit is used for receiving a discharging request sent by the vehicle-mounted charger and executing a charging and discharging power balance strategy according to the discharging request; the charge-discharge power balance strategy is used for avoiding charge interruption and discharge interruption.

In the foregoing solution, the execution unit is specifically configured to:

acquiring a current state of charge (SOC);

In the foregoing solution, the execution unit is specifically configured to:

and controlling the charging power to be consistent with the power sum value.

In the above solution, the system further includes: a control unit for:

acquiring the current SOC value of the vehicle in a preset acquisition period;

In a third aspect of the present invention, there is provided a vehicle charging and discharging system, the system comprising:

the battery management system is used for performing charging information interaction with the direct current charging pile when a vehicle is detected to be inserted into the charging gun, and entering a charging state if the charging preparation condition is met;

the vehicle-mounted charger is used for sending a discharging request to the battery management system, and starting a discharging function when the discharging request is confirmed;

the battery management system is further configured to: receiving a discharging request sent by the vehicle-mounted charger, and executing a charging and discharging power balance strategy according to the discharging request; the charge-discharge power balance strategy is used for avoiding charge interruption and discharge interruption.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings.

In the drawings:

FIG. 1 is a schematic diagram of a vehicle charging and discharging system provided by an embodiment of the invention;

FIG. 2 is a schematic flow chart illustrating a vehicle charging and discharging method according to an embodiment of the invention;

fig. 3 is a schematic structural diagram of a vehicle charging and discharging device according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

In order to better understand the technical solution of the present application, the following vehicle charging and discharging system is introduced, as shown in fig. 1, the charging and discharging system includes: a Battery Management System (BMS), and an On-Board Charger (OBC).

The battery management system BMS is used for carrying out charging information interaction with the direct current charging pile when the vehicle is detected to be inserted into the charging gun, and entering a charging state if the charging preparation condition is met;

the vehicle-mounted charger OBC is used for sending a discharging request to the battery management system BMS and starting a discharging function when the discharging request is confirmed;

the battery management system BMS is further configured to: receiving a discharging request sent by an OBC (on-board battery charger), and executing a charging and discharging power balance strategy according to the discharging request; the charge-discharge power balance strategy is used for avoiding charge interruption and discharge interruption.

The vehicle of the present embodiment generally includes a dc charging interface 11 and an ac charging interface 12, and when discharging an external load while charging, the vehicle can be charged by the dc charging interface 11 and discharged by the ac charging interface 12.

When the vehicle needs to be discharged to an external load while charging, a user can insert a charging gun of the direct current charging pile 13 into the vehicle direct current charging interface 11, one end of the discharging gun 14 is connected with the alternating current charging interface 12, and the other end of the discharging gun 14 is connected with the external load 15 to supply power to the external load. For example, the external load 15 may include: electric rice cooker, water boiling kettle, external sound box, vehicle-mounted refrigerator, etc.

Specifically, a plurality of interfaces for connecting with a vehicle are arranged in a gun head of a charging gun of the direct current charging pile. Such as a stub charging interface, a stub grounding interface (PE interface), a stub charging connection confirmation interface (CC interface), a stub control confirmation interface (CP interface), and the like. And the vehicle end also has corresponding interfaces, such as a vehicle end charging interface, a vehicle end PE interface, a vehicle end CC interface, a vehicle end CP interface, and the like.

Likewise, a plurality of interfaces for connection to a vehicle are provided in the head of the discharge gun. Such as a discharge interface, a ground interface, a discharge connection confirmation interface, a control confirmation interface, and the like.

The connection of the vehicle end charging interface and the connection of the pile end charging interface are correspondingly arranged, and the vehicle end charging interface and the pile end charging interface are matched together to realize a charging function. The connection of the vehicle-end charging interface and the connection of the pile-end charging interface are both realized in a control guide circuit, the control guide circuit is a circuit specified in the national standard, and the control guide circuit is a communication circuit for charging between the direct-current charging pile and the vehicle. The control guide circuit comprises a pile end detection point 1 and a vehicle end detection point 2, when a user inserts a charging gun of the direct current charging pile 13 into the direct current charging interface 11, the direct current charging pile 13 and a BMS (battery management system) of a vehicle can detect the gun inserting action of the user, and at the moment. And when the direct current charging pile 13 detects that the voltage at the detection point 1 jumps to 4v, the charging gun is successfully connected. Similarly, when the vehicle end detects that the voltage at the detection point 2 jumps to 6v, the charging gun is successfully connected.

After the gun insertion is completed, the direct current charging pile 13 and the vehicle end start to send identification messages to each other, and necessary parameter information of the battery and the charger is determined. Then entering a stage of mutual configuration of the vehicle end and the pile end, the OBC sends a maximum output capacity message of a charger to the BMS, and the BMS judges whether charging can be carried out according to the maximum output capacity of the OBC; if the charging voltage is enough, the vehicle end controls the charging circuit to be conducted, and the vehicle enters a charging preparation state.

The above-mentioned preparation condition of charging all satisfies the back, gets into the state of charge, and the car end can be according to the BMS demand to filling electric pile 13 and sending the message that sets up the battery charging demand, and the pile end can be according to needs such as voltage, the electric current that this message parameter real-time adjustment charges in order to guarantee that charging process normally goes on, and the two can continuously send each other real-time state of charge information mutual monitoring state simultaneously.

In the charging process, if the external load needs to be discharged, a user can insert one end of the discharging gun 14 into the alternating current charging interface 12 of the vehicle, and the other end of the discharging gun 14 is connected with the external load 15, and at the moment, if the OBC detects that the resistance value of the corresponding detection point jumps to the resistance value corresponding to the success of the discharging gun 14, the OBC sends a discharging request to the BMS.

After receiving the discharging request, the BMS sends discharging confirmation information to the OBC, and the discharging request executes a charging and discharging power balance strategy; the charge-discharge power balancing strategy is used to avoid charge interruption and discharge interruption.

And after receiving the discharge confirmation information, the OBC starts the discharge function and discharges to an external load. And reporting the external discharge power to the BMS in real time in the discharge process.

The specific implementation of the BMS executing the charging and discharging power balancing policy will be described in the following embodiments of the battery management system, and thus will not be described herein again.

Based on the same inventive concept, the present embodiment further provides a vehicle discharging method, which is applied in a battery management system BMS, as shown in fig. 2, the method includes the following steps:

and S210, when the vehicle is detected to be inserted into the charging gun, performing charging information interaction with the direct current charging pile, and entering a charging state if the charging preparation condition is met.

As described above, when the external load needs to be discharged while the vehicle is being charged, the user may insert the charging gun of the dc charging pile into the dc charging interface of the vehicle. A plurality of interfaces used for being connected with a vehicle are arranged in a gun head of a charging gun of the direct current charging pile. Such as a stub charging interface, a stub grounding interface (PE interface), a stub charging connection confirmation interface (CC interface), a stub control confirmation interface (CP interface), and the like. And the vehicle end also has corresponding interfaces, such as a vehicle end charging interface, a vehicle end PE interface, a vehicle end CC interface, a vehicle end CP interface, and the like.

The connection of the vehicle end charging interface and the connection of the pile end charging interface are correspondingly arranged, and the vehicle end charging interface and the pile end charging interface are matched together to realize a charging function. The connection of the vehicle-end charging interface and the connection of the pile-end charging interface are both realized in a control guide circuit, and the control guide circuit is a circuit specified in the national standard, in particular to a communication circuit for charging between a direct-current charging pile and a vehicle. The control guide circuit comprises a pile end detection point 1 and a vehicle end detection point 2, when a user inserts a charging gun of the direct current charging pile into a direct current charging interface, the direct current charging pile and a BMS (battery management system) of a vehicle can detect the gun inserting action of the user, and when the direct current charging pile 13 detects that the voltage jump of the detection point 1 is 4v, the charging gun is confirmed to be successfully connected. Similarly, when the vehicle end detects that the voltage at the detection point 2 jumps to 6v, the charging gun is successfully connected.

The above-mentioned preparation condition of charging all satisfies the back, gets into the state of charge, and the car end can be according to the BMS demand to filling electric pile transmission and setting up the message of battery charging demand, and the stake end can be according to the needs such as voltage, the electric current that this message parameter real-time adjustment charges in order to guarantee that charging process normally goes on, and the two can continuously send real-time state of charge information each other with mutual monitored control state simultaneously.

S211, receiving a discharging request sent by a vehicle-mounted charger, and executing a charging and discharging power balance strategy according to the discharging request; the charge and discharge power balancing strategy is used for avoiding charge interruption and discharge interruption.

In this embodiment, one end of the discharging gun is connected to the ac charging interface 12, and the other end of the discharging gun 14 is connected to the external load to supply power to the external load. For example, the external load may include: electric rice cooker, water boiling kettle, external sound box, vehicle-mounted refrigerator, etc.

In the charging process, if the external load needs to be discharged, a user can insert one end of the discharging gun into an alternating current charging interface of the vehicle, the other end of the discharging gun is connected with the external load, and at the moment, if the OBC detects that the resistance value of the corresponding detection point jumps to the resistance value corresponding to the successful connection of the discharging gun, the OBC sends a discharging request to the BMS.

In one embodiment, executing a charge-discharge power balancing strategy according to a discharge request includes:

acquiring a current state of charge (SOC) value;

and if the difference value between the charging cut-off SOC value of the vehicle and the current SOC value is larger than or equal to the preset threshold value, controlling the charging current to reach the maximum value. The preset threshold value may be determined based on the actual condition of the vehicle, for example, 2-3%, which is not limited herein.

In one embodiment, if it is determined that the difference between the cut-off-charge SOC value and the current SOC value of the vehicle is less than the preset threshold, the method further includes:

acquiring the power and the value of the load power of the whole vehicle and the external discharge power of a vehicle-mounted charger;

the charging power is controlled to be consistent with the power sum value. For example, the charging power and the power sum are controlled to be equal to avoid stopping charging after the charging is carried out to the charging cut-off SOC.

It should be noted that, in the charging and discharging processes, after controlling the charging power to be consistent with the power sum value in order to avoid the interruption of charging and the interruption of discharging, the method further includes:

acquiring the current SOC value of the vehicle in a preset acquisition period;

and controlling the difference value between the charging cut-off SOC value and the current SOC value to be smaller than or equal to a preset threshold value.

That is, it is assumed that when the threshold value is 3%, it is necessary to control the difference between the charge cut-off SOC value and the current SOC value to be less than or equal to 3%.

Further, in the charging process, if the external load does not need to be powered, the user can pull out the discharging gun, the OBC detects a discharging stopping instruction at the moment, a discharging stopping message is sent to the BMS, and when the BMS receives the discharging stopping instruction message, the charging and discharging power balancing strategy is not executed any more, and the vehicle enters a pure charging state.

And when the vehicle or the charging pile receives a charging stopping instruction sent by the user, finishing charging.

Therefore, the vehicle can discharge the external load while charging, and execute a charge-discharge power balance strategy to avoid discharge interruption and charge interruption; the discharging efficiency is improved, and the use experience of the user on the discharging function is further improved. In addition, the power can be supplied to the external load under the state that the electric quantity of the new energy automobile is not consumed, the endurance mileage of the new energy automobile is guaranteed, and the situation that a user feels anxious about electric quantity consumption is avoided.

Based on the same inventive concept, the present embodiment further provides a battery management system, as shown in fig. 3, the battery management system includes:

the detection unit 31 is used for performing charging information interaction with the direct current charging pile when the vehicle is detected to be inserted into the charging gun, and entering a charging state if the charging preparation condition is met;

the execution unit 32 is configured to receive a discharge request sent by the vehicle-mounted charger, and execute a charge-discharge power balance strategy according to the discharge request; the charge-discharge power balance strategy is used for avoiding charge interruption and discharge interruption.

In one embodiment, the execution unit 32 is specifically configured to:

acquiring a current state of charge (SOC) value;

The execution unit 32 is specifically configured to:

and controlling the charging power to be consistent with the power sum value.

With continued reference to fig. 3, the system further comprises: a control unit 33 for:

acquiring the current SOC value of the vehicle in a preset acquisition period;

Since the device described in the embodiment of the present invention is a device used for implementing the vehicle charging and discharging method in the embodiment of the present invention, based on the method described in the embodiment of the present invention, a person skilled in the art can understand the specific structure and the deformation of the device, and thus the detailed description is omitted here. All devices used in the method of the embodiment of the present invention belong to the protection scope of the present invention.

The vehicle charging and discharging method, the battery management system and the charging and discharging system provided by the embodiment of the invention have the beneficial effects that at least:

the invention provides a vehicle charging and discharging method, a battery management system and a charging and discharging system, wherein the method comprises the following steps: when the fact that the vehicle is inserted into the charging gun is detected, charging information interaction is conducted between the vehicle and the direct current charging pile, and if the fact that charging preparation conditions are met is determined, the vehicle enters a charging state; receiving a discharging request sent by an on-board charger, and executing a charging and discharging power balance strategy according to the discharging request, wherein the charging and discharging power balance strategy is used for avoiding charging interruption and discharging interruption; therefore, the vehicle can discharge the external load while charging, and execute a charge-discharge power balance strategy to avoid discharge interruption and charge interruption; the discharging efficiency is improved, and the use experience of a user on the discharging function is further improved.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims

1. A vehicle charging and discharging method is applied to a battery management system, and comprises the following steps:

when the fact that the vehicle is inserted into the charging gun is detected, charging information interaction is conducted between the vehicle and the direct current charging pile, and if the fact that charging preparation conditions are met is determined, the vehicle enters a charging state;

2. The method of claim 1, wherein the performing a charge-discharge power balancing strategy according to the discharge request comprises:

acquiring a current state of charge (SOC) value;

3. The method of claim 2, wherein if it is determined that the difference between the cut-off-charge SOC-value of the vehicle and the current SOC-value is less than a preset threshold, the method further comprises:

and controlling the charging power to be consistent with the power sum value.

4. The method of claim 3, wherein after the controlling the charging power is consistent with the power sum, the method further comprises:

acquiring the current SOC value of the vehicle in a preset acquisition period;

5. The method of claim 1, wherein after performing a charge-discharge power balancing strategy according to the discharge request, the method further comprises:

6. A battery management system, characterized in that the battery management system comprises:

7. The battery management system of claim 6, wherein the execution unit is specifically configured to:

acquiring a current state of charge (SOC);

8. The battery management system of claim 7, wherein the execution unit is specifically configured to:

and controlling the charging power to be consistent with the power sum value.

9. The battery management system of claim 7, wherein the system further comprises: a control unit for:

acquiring the current SOC value of the vehicle in a preset acquisition period;

10. A vehicle charging and discharging system characterized in that the system comprises:

the battery management system is used for performing charging information interaction with the direct current charging pile when the vehicle is detected to be inserted into the charging gun, and entering a charging state if the charging preparation condition is met;