Electric vehicle charging control method

Abstract

The invention discloses an electric vehicle charging control method, an electric vehicle is provided with four charging interfaces, a first charging interface and a second charging interface share a first communication link to interact with a charging pile, and a third charging interface and a fourth charging interface share a second communication link to interact with the charging pile. When the battery management system detects that the charging gun is inserted into the charging interface, the battery management system executes the following steps: when detecting that the charging gun is inserted into one charging interface, entering a single-pile single-gun charging mode for charging; when it is detected that charging guns are inserted into the two charging interfaces, a single-pile double-gun charging mode or a double-pile double-gun charging mode is entered for charging based on communication link attributes of the two charging interfaces; and when it is detected that the charging guns are inserted into the more than two charging interfaces, a double-pile multi-gun charging mode is entered for charging. The number of the charging guns and the number of the charging piles can be automatically recognized in the whole charging process, corresponding charging modes are matched, and single-pile single-gun charging, single-pile double-gun charging, double-pile double-gun charging and double-pile multi-gun charging are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging control, and in particular to an electric vehicle charging control method. Background Art

[0002] As electric vehicles become more and more popular, consumers have higher and higher requirements for the use of electric vehicles. Longer battery life and faster charging speed have become the goals of electric vehicles. Especially for some models with large power requirements, such as large buses and heavy trucks, in addition to meeting power requirements, it is more necessary to focus on improving charging speed to reduce charging time. In order to increase charging speed, many large-power models are equipped with dual or even quad charging ports to support multiple guns charging at the same time.

[0003] Multi-gun charging can be single-pile dual-gun charging, dual-pile dual-gun charging, or dual-pile four-gun charging. Single-pile dual-gun charging is simpler for the battery management system. It only needs one communication interaction with the charging pile. The battery management system sends the charging demand current to the charging pile, and the charging pile is responsible for controlling the output current distribution of the two guns. Dual-pile dual-gun or dual-pile four-gun charging is more complicated. The battery management system needs to communicate with the two charging piles separately and determine the demand current for each charging pile based on the output capacity of the charging piles. At the same time, it is also necessary to process the status feedback of the charging piles separately so that the two charging paths do not affect each other. Therefore, dual-pile multi-gun charging has higher technical requirements for the battery management system.

[0004] Most of the existing dual-gun charging strategies only support single-pile dual-gun charging. The technical solutions that can support dual-pile dual-gun charging are relatively limited. They require the addition of additional communication protocols or the need to bind multiple charging piles in advance. They are not very universal and their application scenarios are limited.

[0005] In the charging control method, device, system, charging equipment and battery management system disclosed in CN114851892A, when the battery management system and the charging equipment detect that the number of valid plug guns is more than two, they need to send two messages (the first message CFC and the second message BFC) that are re-agreed outside the national standard charging protocol "GB / T27930" respectively, redefine the current offset and other information, and start dual-gun fast charging after the two are successfully matched. This technology can only be applied to single-pile dual-gun charging, and requires both the battery management system and the charging pile to add additional agreed communication protocols, which is not universal.

[0006] CN111645553A discloses a charging control method for dual-charger parallel charging of electric vehicles. The invention supports dual-charger charging between different charging piles, but the premise is that the charging station needs to bind the charging piles in the area together to form a local parallel charging network; and a parallel charging switch is required at the battery end. The user needs to turn on the parallel charging switch first to support parallel charging of charging piles in the network. For both vehicles and charging piles, additional conditions need to be added to realize dual-charger charging of different charging piles, which is not universal.

[0007] In the vehicle charging control method, system and vehicle disclosed in CN118386929A, single-gun or dual-gun charging mode is selected by identifying the charging pile information of two guns, and four-gun charging is not supported. The charging efficiency is not high for large vehicles such as heavy trucks, and in the dual-pile charging mode, if one charging pile fails, the other charging pile will also be affected. There is no intelligent judgment of the actual situation to adjust the charging strategy in real time. Summary of the invention

[0008] The purpose of the present invention is to solve the problem that the multi-gun charging technology of electric vehicle batteries has poor versatility and is unable to automatically switch the charging mode after automatically identifying the number of guns and the number of charging piles, and to provide a charging control method and system that can be simultaneously applicable to single-pile double-guns, double-pile double-guns, and double-pile four-guns. The communication status of the charging gun and the charging pile can be monitored in real time during the entire charging process, the charging mode can be identified, and automatic switching of multiple charging modes such as single-pile single-gun, single-pile double-gun, double-pile double-gun, and double-pile multiple-gun can be realized.

[0009] A charging control method for an electric vehicle, wherein the electric vehicle has four charging interfaces, wherein charging interface 1 and charging interface 2 share a first communication link to interact with a charging pile, and charging interface 3 and charging interface 4 share a second communication link to interact with the charging pile. When a battery management system detects that a charging gun is inserted into the charging interface, the following steps are performed:

[0010] When a charging port is detected to be plugged into a charging gun, the single-pile single-gun charging mode is entered for charging;

[0011] When it is detected that two charging ports are plugged into charging guns, the single-pile dual-gun charging mode or dual-pile dual-gun charging mode is entered for charging based on the communication link properties of the two charging ports;

[0012] When it is detected that more than two charging ports are plugged into charging guns, the dual-pile multi-gun charging mode is entered for charging.

[0013] Wherein, when it is detected that two charging ports are plugged into charging guns, charging is performed in a single-pile dual-gun charging mode or a dual-pile dual-gun mode based on the communication link properties of the two charging ports, including:

[0014] Determine whether the two charging interfaces inserted into the charging gun are the same communication link. If so, enter the single-pile dual-gun charging mode for charging; otherwise, enter the dual-pile dual-gun mode for charging.

[0015] Among them, when entering the single-pile single-gun charging mode / single-pile dual-gun charging mode for charging, the requested current of the charging pile is set according to the preset single-pile charging current matching method. When the charging end conditions are met, the requested current to the charging pile is reduced to 0, and charging is exited.

[0016] Wherein, the preset single pile charging current matching method includes:

[0017] When it is detected that the maximum output current I1 of the charging pile is ≥ the battery system demand current I, the requested current to the charging pile is set to I, otherwise the requested current to the charging pile is set to I1.

[0018] Among them, after entering the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, the battery management system identifies the maximum output current of charging pile one that is connected to the communication first, and the maximum output current of charging pile two that is connected to the communication later, and then compares the maximum output current of the two charging piles with the required current of the battery system, and distributes the current according to the preset dual-pile charging current distribution method.

[0019] The dual-pile charging current allocation method determines the requested current setting size of the charging pile according to the comparison result of the battery system demand current I with the maximum output current I1 of the charging pile 1 and the maximum output current I2 of the charging pile 2, including:

[0020] If I1≥0.5*I and I2≥0.5*I, the requested current to both charging piles is set to 0.5*I;

[0021] If I1<0.5*I and I2<0.5*I, the requested current to charging pile 1 is set to I1, and the requested current to charging pile 2 is set to I2;

[0022] If I1<I2, the requested current to charging pile 1 is set to I1; if I2≥I-I1, the requested current to charging pile 2 is set to I-I1, otherwise the requested current to charging pile 2 is set to I2;

[0023] If I2<I1, the requested current to charging pile 2 is set to I2; if I1≥I-I2, the requested current to charging pile 1 is set to I-I2, otherwise the requested current to charging pile 1 is set to I1.

[0024] Among them, during the charging process of the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, the battery management system monitors the charging status of the two charging circuits of the two charging piles in real time. When the charging end conditions are met, the requested current to the two charging piles is reduced to 0 and charging is stopped.

[0025] Among them, during the charging process of the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, if the charging circuit of charging pile one stops charging, the requested current to charging pile one is reduced to 0. If the charging circuit of charging pile two stops charging within the preset time, the requested current to charging pile two is reduced to 0, and charging is exited. Otherwise, current adjustment is requested according to the single-pile charging current matching method.

[0026] The reasons for stopping charging include stopping charging due to a charging pile failure, stopping charging due to manual control, or actively stopping charging due to the battery management system detecting a battery system failure in the charging circuit.

[0027] Among them, after entering the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, if the battery management system does not detect the other charging pile when completing the parameter configuration with the charging pile that was plugged in first, and cannot perform parameter configuration with the other charging pile, the request current setting is made to the charging pile that was plugged in first according to the single-pile charging current matching method.

[0028] The present invention can automatically identify the number of charging guns and charging piles during the entire charging process, match the corresponding charging mode, and realize charging of single pile with single gun, single pile with two guns, two piles with two guns, and two piles with multiple guns, thereby maximizing the charging speed, reducing the charging time, having good compatibility, and being easy to operate.

[0029] The present invention can automatically identify the number of charging guns and charging piles during the entire charging process, match the corresponding charging mode, and can communicate with two charging piles at the same time. It can adjust the requested current in real time according to the required current and the charging pile capacity, and can support fast charging with two charging piles through four charging guns at the same time, thereby maximizing the charging speed and reducing the charging time.

[0030] The present invention can realize dual-pile dual-gun fast charging and improve the charging speed of the power battery. The charging method is compatible with all DC charging piles that meet national standards on the market without the need to add additional auxiliary devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall flow of the electric vehicle charging control method according to an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of a charging system for an electric vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Figure 1The electric vehicle charging control flow chart provided by the embodiment of the present invention, the electric vehicle charging control method specifically includes:

[0035] Among them, the electric vehicle has four charging interfaces, wherein charging interface 1 and charging interface 2 share a communication link to interact with the charging pile, and charging interface 3 and charging interface 4 share a communication link to interact with the charging pile; Figure 2 As shown, the charging system of the electric vehicle of the present application includes four charging ports, namely, 1# gun charging port, 2# gun charging port, 3# gun charging port, and 4# gun charging port. Each charging port is connected to the positive and negative poles of the battery pack through a wiring harness; 1# gun charging port and 2# gun charging port are connected to the battery management system through charging CAN 1, and 3# gun charging port and 4# gun charging port are connected to the battery management system through charging CAN 2.

[0036] The battery management system of the electric vehicle detects the plug-in signals of the four charging interfaces, and controls different charging modes according to the detected plug-in signals, including the following steps:

[0037] If there is only one gun plug signal, that is, only one charging port has a charging gun inserted, the charging port serial number is identified and the corresponding charging CAN (CAN bus connecting the battery management system BMS and the charging device) is selected to communicate with the charging pile to enter the single-gun charging mode.

[0038] When it is detected that there are two charging ports with charging guns inserted, the battery management system first determines whether they are from two ports of the same communication chain or from two ports of two-way communication by identifying the connected charging port numbers. If they are from two ports of the same channel and the charging circuit has not been started for charging, it will automatically enter the single-pile dual-gun charging mode; if the circuit has been started for charging, it will keep charging the circuit with a single gun; if the two charging ports are from two-way communication, it will automatically enter the dual-pile dual-gun charging mode and detect the message signals of the two charging CANs respectively.

[0039] When it is detected that the number of charging guns connected at the same time is greater than two, the battery management system automatically enters the dual-pile multi-gun charging mode, while separately determining the number of charging guns connected to each charging circuit and detecting the two charging CAN signals.

[0040] In one embodiment, after entering the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, the charging pile that first enters the communication interaction is charging circuit one, and the battery management system identifies the maximum output current of the charging pile in the maximum output capacity message of the charger of charging circuit one. The charging pile that enters the communication interaction later is charging circuit two, and the battery management system identifies the maximum output current of the charging pile in the maximum output capacity message of the charger of charging circuit two. The output capabilities of the two charging piles and the required current of the battery system are comprehensively compared, and the current is distributed according to the dual-pile charging current distribution rule.

[0041] Among them, if the battery management system still does not detect the message interaction with the later charging pile when completing the parameter configuration with the charging pile inserted first, it will be processed according to the single-pile charging process and obtain the requested current for the charging pile according to the single-pile charging current matching rule.

[0042] In an embodiment of the present invention, in a single pile charging mode, a current requested from a communicating charging pile is calculated according to a preset single pile charging current matching method. The single pile charging current matching method includes:

[0043] Assume that the battery system demand current of the electric vehicle is I, and the maximum output current capacity of the charging pile is I1. If I1≥I, the requested current to the charging pile is set to I, otherwise the requested current to the charging pile is set to I1.

[0044] For example, in single-pile charging mode, the battery system requires a current of 250A, and the maximum output current capacity of the charging pile is 400A, then the current requested from the charging pile is set to 250A.

[0045] Among them, in the single-pile charging mode, if another charging pile signal is detected and the CAN communication message is received, the dual-pile charging mode is entered. If the charging end condition is met during charging, the charging request current drops to 0 and the charging is exited.

[0046] In an embodiment of the present invention, in a dual-pile charging mode, the requested power is calculated according to a dual-pile charging current allocation method. Assuming that the battery system demand current is I, the maximum output current of the charging pile 1 is I1, and the maximum output current of the charging pile 2 is I2, the current request method includes:

[0047] If I1≥0.5*I and I2≥0.5*I, the requested current of both charging piles is set to 0.5*I;

[0048] If I1<0.5*I and I2<0.5*I, the requested current of charging pile 1 is set to I1, and the requested current of charging pile 2 is set to I2;

[0049] If I1<I2, the requested current of charging pile 1 is set to I1; if I2≥I-I1, the requested current of charging pile 2 is set to I-I1, otherwise the requested current of charging pile 2 is set to I2;

[0050] If I2<I1, the requested current of charging pile 2 is set to I2; if I1≥I-I2, the requested current of charging pile 1 is set to I-I2, otherwise the requested current of charging pile 1 is set to I1.

[0051] The current request method for the above dual-pile charging is described in four cases below:

[0052] Case 1: The output capacities of both charging piles are greater than half of the required current. For example, the battery demand current is 400A, the maximum output current capacity of charging pile 1 is 300A, and the maximum output capacity of charging pile 2 is 400A. Then the requested currents to charging pile 1 and charging pile 2 are both set to 200A.

[0053] Case 2: The output capacities of both charging piles are less than half of the required current. For example, the battery demand current is 400A, the maximum output current capacity of charging pile one is 150A, and the maximum output capacity of charging pile two is 180A. Then the requested current to charging pile one is set to 150A, and the requested current to charging pile two is set to 180A.

[0054] Case 3: The maximum output current capacity of charging pile one is smaller than half of the demand current, and the maximum output current capacity of charging pile two is larger than half of the demand current. For example, the battery demand current is 350A, the maximum output current capacity of charging pile one is 150A, and the maximum output current capacity of charging pile two is 300A. Then the requested current to charging pile one is set to 150A, and the requested current to charging pile two is set to 200A.

[0055] Case 4: The maximum output current capacity of charging pile 2 is smaller than half of the demand current, and the maximum output current capacity of charging pile 1 is larger than half of the demand current. For example, the battery demand current is 400A, the maximum output current capacity of charging pile 1 is 250A, and the maximum output capacity of charging pile 2 is 100A. Then the requested current to charging pile 1 is set to 250A, and the requested current to charging pile 2 is set to 100A.

[0056] In dual-pile charging mode, when it is detected that the communication of one of the charging piles has stopped or the charging gun is unplugged, the charging request current of that charging pile will be immediately reduced to 0. At the same time, if the other charging pile also stops charging within the preset time, the charging request current of the other charging pile will also be reduced to 0, and charging will be exited.

[0057] If the other charging pile does not stop charging within the preset time, the charging mode is switched to single-pile charging mode, and the requested current is recalculated according to the single-pile charging current matching rule.

[0058] Exemplarily, the preset time can be 1 minute. In the dual-pile charging mode, the battery system requires a current of 300A, the maximum output current capacity of charging pile one is 250A, and the maximum output current capacity of charging pile two is 250A. The battery management system requests a current of 150A from both charging pile one and charging pile two. If the output of charging pile one is manually stopped, the battery management system requests the current of charging pile one to be reduced to 0. If the output of charging pile two does not stop within 1 minute, the battery management system requests the current of charging pile two to be increased to 250A.

[0059] Similarly, if the charging end conditions are met during the charging process, it may be because the battery management system detects a battery system failure in the charging circuit, or it may be manually selected to stop. The battery management system will reduce the charging request current of both circuits to 0 and exit charging.

[0060] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0061] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that all changes falling within the meaning and range of equivalent elements of the claims are included in the present invention.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An electric vehicle charging control method, characterized in that: The electric vehicle has four charging interfaces, wherein charging interface 1 and charging interface 2 share a first communication link to interact with the charging pile, and charging interface 3 and charging interface 4 share a second communication link to interact with the charging pile. When the battery management system detects that a charging gun is inserted into the charging interface, the following steps are performed: When a charging port is detected to be plugged into a charging gun, the single-pile single-gun charging mode is entered for charging; When it is detected that two charging ports are plugged into charging guns, the single-pile dual-gun charging mode or dual-pile dual-gun charging mode is entered for charging based on the communication link properties of the two charging ports; When it is detected that more than two charging ports are plugged into charging guns, the dual-pile multi-gun charging mode is entered for charging.

2. The electric vehicle charging control method according to claim 1, characterized in that: When it is detected that two charging ports are plugged into charging guns, charging is performed in a single-pile dual-gun charging mode or a dual-pile dual-gun mode based on the communication link properties of the two charging ports, including: Determine whether the two charging interfaces inserted into the charging gun are the same communication link. If so, enter the single-pile dual-gun charging mode for charging; otherwise, enter the dual-pile dual-gun mode for charging.

3. The electric vehicle charging control method according to claim 1, characterized in that: When entering the single-pile single-gun charging mode / single-pile dual-gun charging mode for charging, the requested current of the charging pile is set according to the preset single-pile charging current matching method. When the charging end conditions are met, the requested current to the charging pile is reduced to 0, and charging is exited.

4. The electric vehicle charging control method according to claim 3, characterized in that: The preset single pile charging current matching method includes: When it is detected that the maximum output current I1 of the charging pile is ≥ the battery system demand current I, the requested current to the charging pile is set to I, otherwise the requested current to the charging pile is set to I1.

5. The electric vehicle charging control method according to claim 1, characterized in that: After entering the dual-pile dual-gun charging mode or dual-pile multi-gun charging mode, the battery management system identifies the maximum output current of charging pile one that is connected to communication first, and the maximum output current of charging pile two that is connected to communication later, and then compares the maximum output current of the two charging piles with the required current of the battery system, and distributes the current according to the preset dual-pile charging current distribution method.

6. The electric vehicle charging control method according to claim 5, characterized in that: The dual-pile charging current distribution method determines the requested current setting size of the charging pile according to the comparison result of the battery system demand current I with the maximum output current I1 of the charging pile 1 and the maximum output current I2 of the charging pile 2, including: If I1≥0.5*I and I2≥0.5*I, the requested current to both charging piles is set to 0.5*I; If I1<0.5*I and I2<0.5*I, the requested current to charging pile 1 is set to I1, and the requested current to charging pile 2 is set to I2; If I1<I2, the requested current to charging pile 1 is set to I1; if I2≥I-I1, the requested current to charging pile 2 is set to I-I1, otherwise the requested current to charging pile 2 is set to I2; If I2<I1, the requested current to charging pile 2 is set to I2; if I1≥I-I2, the requested current to charging pile 1 is set to I-I2, otherwise the requested current to charging pile 1 is set to I1.

7. The electric vehicle charging control method according to claim 1, characterized in that: During the charging process in the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, the battery management system monitors the charging status of the two charging circuits of the two charging piles in real time. When the charging end conditions are met, the requested current to the two charging piles is reduced to 0 and charging is stopped.

8. The electric vehicle charging control method according to claim 1, characterized in that: During the charging process of the dual-pile dual-gun charging mode or the dual-pile multi-gun charging mode, if the charging circuit of charging pile one stops charging, the requested current to charging pile one drops to 0. If the charging circuit of charging pile two stops charging within the preset time, the requested current to charging pile two drops to 0 and charging is exited. Otherwise, current adjustment is requested according to the single-pile charging current matching method.

9. The electric vehicle charging control method according to claim 8, characterized in that: The reasons for stopping charging include stopping charging due to a charging pile failure, stopping charging due to manual control, or actively stopping charging due to the battery management system detecting a battery system failure in the charging circuit.

10. The electric vehicle charging control method according to claim 1, characterized in that: After entering the dual-pile dual-gun charging mode or dual-pile multi-gun charging mode, if the battery management system does not detect the other charging pile when completing parameter configuration with the charging pile that was plugged in first, and cannot perform parameter configuration with the other charging pile, the requested current setting is made to the charging pile that was plugged in first according to the single-pile charging current matching method.

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