Charging control method of power battery of electric vehicle and electric vehicle

Abstract

The application provides a charging control method of a power battery of an electric vehicle and the electric vehicle. The charging control method comprises the following steps: determining a plug-in mode of the electric vehicle charging according to a charging connection signal and a first charging message; obtaining a second charging message of a charging pile and determining a charging mode according to the second charging message; determining a charging current according to the plug-in mode and the charging mode, and controlling the charging pile to charge the electric vehicle according to the charging current. Therefore, the application solves the technical problem that the conventional electric vehicle cannot simultaneously meet multiple charging currents, and provides the user with a more intelligent, safe and efficient charging experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a charging control method of a power battery of an electric vehicle and the electric vehicle. BACKGROUND

[0002] With the increasing number of electric vehicles, customers have higher and higher requirements for the use of electric vehicles, and longer endurance and faster charging speed have become the focus of attention. Especially for some large power demand models, such as heavy trucks, buses, engineering machinery vehicles, etc., on the basis of meeting the power demand, it is necessary to focus on improving the charging speed to reduce the charging time and improve the daily operating mileage.

[0003] At present, in order to improve the charging speed, many large power models are equipped with double charging ports, or large current charging is adopted. However, the existing charging strategy is usually to customize the charging current (such as large current) by the vehicle manufacturer, and only the customized charging current can be charged during charging, and multiple current charging modes cannot be compatible. SUMMARY

[0004] Therefore, the embodiments of the present application aim to provide a charging control method of a power battery of an electric vehicle and the electric vehicle to solve the problem that multiple charging currents cannot be compatible in the prior art.

[0005] In one aspect, the present application provides a charging control method of a power battery of an electric vehicle, which comprises:

[0006] determining a plug-in mode of the electric vehicle charging according to the charging connection signal and the first charging message;

[0007] obtaining a second charging message of a charging pile and determining a charging mode according to the second charging message;

[0008] determining a charging current according to the plug-in mode and the charging mode, and controlling the charging pile to charge the electric vehicle according to the charging current.

[0009] In one embodiment, the second charging message comprises a CRM message.

[0010] The step of determining the charging mode according to the second charging message comprises:

[0011] identifying message information of the CRM message, and judging whether the message information contains first preset information;

[0012] If the message information contains the first preset information, it is determined as a first current charging mode.

[0013] In one embodiment, the charging control method further comprises:

[0014] if the message information does not include the first preset information, determining whether the message information includes second preset information;

[0015] if the message information includes the second preset information, determining a second current charging mode;

[0016] if the message information does not include the second preset information, determining a third current charging mode.

[0017] In one embodiment, the step of identifying the message information of the CRM message comprises:

[0018] identifying field information of a preset field of the CRM message.

[0019] In one embodiment, the message information further includes a current number of plugged guns;

[0020] Before the step of determining a charging mode according to the second charging message, the charging control method further comprises:

[0021] determining whether the current number of plugged guns is consistent with a number of plugged guns detected by a BMS controller;

[0022] if the current number of plugged guns is consistent with the number of plugged guns detected by the BMS controller, performing the step of determining a charging mode according to the second charging message.

[0023] In one embodiment, the step of determining a charging current according to the plugged gun mode and the charging mode comprises:

[0024] determining an initial current of a charging gun according to the plugged gun mode;

[0025] determining a current offset during charging according to the charging mode;

[0026] determining the charging current according to the initial current, the current offset and a current resolution.

[0027] In one embodiment, the charging mode includes a group standard charging mode, a FAST charging mode and a national standard charging mode;

[0028] The step of determining a current offset during charging according to the charging mode further comprises:

[0029] if the charging mode is the group standard charging mode, determining the current offset as a first current offset;

[0030] if the charging mode is the FAST charging mode, determining the current offset as zero;

[0031] If the charging mode is the national standard charging mode, the current offset is determined as a second current offset.

[0032] In one embodiment, the charging control method further comprises:

[0033] determining whether the electric vehicle currently belongs to low-temperature charging;

[0034] If it belongs to low-temperature charging, determining a heating current according to the current charging parameter of the power battery of the electric vehicle;

[0035] The step of determining the charging current according to the plug-in mode and the charging mode further comprises:

[0036] determining the charging current according to the heating current, the plug-in mode and the charging mode.

[0037] In one embodiment, the step of determining the plug-in mode of the electric vehicle charging according to the charging connection signal and the first charging message comprises:

[0038] identifying the charging connection signal;

[0039] If only one charging connection signal is obtained within a preset time, it is determined that the plug-in mode is single-pile single-gun charging;

[0040] If two charging connection signals are obtained simultaneously or sequentially within the preset time, it is determined that the plug-in mode is double-gun charging;

[0041] identifying the number of the first charging messages;

[0042] If the first charging message is one set, it is determined that the plug-in mode is single-pile double-gun charging;

[0043] If the first charging message is two sets, it is determined whether the two sets of first charging messages are transmitted by two CAN communication branches;

[0044] If the two sets of first charging messages are transmitted by two CAN communication branches, the plug-in mode is determined to be different-pile double-gun double-CAN charging;

[0045] If the two sets of first charging messages are transmitted by one CAN communication branch, the plug-in mode is determined to be different-pile double-gun single-CAN charging.

[0046] In another aspect, the application provides an electric vehicle, which applies the charging control method described above.

[0047] Advantages

[0048] The embodiment of the application is devoted to providing a charging control method of a power battery of an electric vehicle and the electric vehicle. The charging control method comprises the following steps: firstly, determining a plug-in mode of the electric vehicle charging according to a charging connection signal and a first charging message; further, acquiring a second charging message of a charging pile and determining a charging mode according to the second charging message; finally, determining a charging current according to the plug-in mode and the charging mode, and controlling the charging pile to charge the electric vehicle according to the charging current. Therefore, the combination mode of the plug-in mode and the charging mode is identified, and the charging current parameter can be matched and dynamically adjusted. That is, the optimal charging current value can be calculated according to the detected plug-in mode (such as single gun, double gun, etc.) and charging demand (such as fast charging mode, standard charging mode, etc.). The electric vehicle can adapt to various charging scenes, and the demand for high-power fast charging or low-power safe charging can be met. Compared with the single fixed charging current scheme in the prior art, the compatibility of the electric vehicle is significantly improved, the technical problem that the traditional electric vehicle cannot meet multiple charging currents at the same time is solved, and a more intelligent, safe and efficient charging experience is provided for the user. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a charging scene schematic diagram of an electric vehicle provided by the embodiment of the application.

[0050] Figure 2 is a flowchart of a charging control method of a power battery of an electric vehicle provided by the embodiment of the application.

[0051] Figure 3 is a flowchart of a specific embodiment of step S2 shown in Figure 2

[0052] Figure 4 is a flowchart of a specific embodiment of step S3 shown in Figure 2

[0053] Figure 5 is a flowchart of another charging control method of a power battery of an electric vehicle provided by the embodiment of the application.

[0054] Figure 6 is a principle schematic diagram of a charging control method of a power battery of an electric vehicle provided by the embodiment of the application.

[0055] Figure 7 is a flowchart of a specific embodiment of step S1 shown in Figure 2 DETAILED DESCRIPTION

[0056] ​​​With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0057] The prior art electric vehicle charges according to a single fixed charging current set in advance when charging, and cannot be compatible with charging of multiple charging currents, thereby limiting the use demand of the electric vehicle.

[0058] To solve the above technical problems, the present application provides a charging control method for a power battery of an electric vehicle and an electric vehicle. Specifically, the charging control method comprises: determining a plug-in gun mode of the electric vehicle charging according to a charging connection signal and a first charging message; obtaining a second charging message of a charging pile and determining a charging mode according to the second charging message; determining a charging current according to the plug-in gun mode and the charging mode, and controlling the charging pile to charge the electric vehicle according to the charging current. Therefore, the present application can match and dynamically adjust the charging current parameter by identifying the combination mode of the plug-in gun mode and the charging mode. That is, the optimal charging current value can be calculated according to the detected plug-in gun mode (such as single gun, double gun, etc.) and charging demand (such as fast charging mode, standard charging mode, etc.). The electric vehicle can adapt to various charging scenarios, and both high-power fast charging and low-power safe charging demand can be met. Compared with the single fixed charging current scheme in the prior art, the present application significantly improves the compatibility of the electric vehicle, solves the technical problem that the traditional electric vehicle cannot simultaneously meet multiple charging currents, and provides a more intelligent, safe and efficient charging experience for users.

[0059] Please refer to Figure 1 , Figure 1 is a charging scenario schematic diagram of an electric vehicle provided by the embodiments of the present application. As shown in Figure 1 , when charging, the electric vehicle can insert different charging guns according to different scenarios. According to the plug-in gun mode with the charging pile, it can be divided into single-pile single-gun charging, single-pile double-gun charging and different-pile double-gun charging, etc. The main difference between the three plug-in gun modes is the number of charging piles, the number of charging guns and the power distribution relationship between them. Specifically, single-pile single-gun charging refers to that one charging gun on one charging pile is electrically connected with the electric vehicle to charge the electric vehicle, and the current output by the charging pile is transmitted only through the charging gun. Single-pile double-gun charging refers to that two charging guns on one charging pile are electrically connected with the electric vehicle to charge the electric vehicle, and the current output by the charging pile is evenly distributed to the two charging guns for transmission. Different-pile double-gun charging refers to that two charging guns on two charging piles are electrically connected with the electric vehicle to charge the electric vehicle, and the two charging piles are independently charged, and the current output by each charging pile is transmitted by the charging gun thereof.

[0060] Please refer to Figure 2 , Figure 2 is a flowchart of a charging control method of a power battery of an electric vehicle provided by an embodiment of the present application. As shown in Figure 2 , the charging control method comprises:

[0061] Step S1: determining a plug-in mode of charging of the electric vehicle according to a charging connection signal and a first charging message.

[0062] Step S2: acquiring a second charging message of a charging pile and determining a charging mode according to the second charging message.

[0063] Step S3: determining a charging current according to the plug-in mode and the charging mode and controlling the charging pile to charge the electric vehicle according to the charging current.

[0064] As introduced in Figure 1 , the electric vehicle can plug in different charging guns according to different scenarios when charging. For example, if the electric vehicle is configured with one charging port, only one charging gun can be plugged in, if the electric vehicle is configured with two charging ports, one charging gun or two charging guns can be plugged in according to needs, further, in the scenario of plugging in two charging guns, it can be further distinguished whether the two charging guns are plugged in the same charging pile or different charging piles. That is to say, in step S1, the plug-in mode of charging of the electric vehicle can be determined according to the number and mode (the case of the charging pile to which the charging gun belongs) of the charging gun plugged in by the electric vehicle, and the number and mode of the charging gun can be identified through the charging connection signal and the first charging message. As described above, different plug-in modes will result in different currents transmitted by the charging gun. Therefore, by determining the plug-in mode currently adopted in the initial stage of the charging process through step S1, different currents on the charging gun can be determined according to different plug-in modes.

[0065] In step S2, the second charging message data information transmitted by the charging pile is collected and acquired in real time, and the message contains important data such as the current working state and operating parameters of the charging pile. By analyzing the second charging message, the specific charging mode type currently adopted in the charging process can be determined, such as the group standard charging mode, the FAST charging mode and the national standard charging mode, and the required current is different for each charging mode.

[0066] After the plug-in mode and the charging mode which have an impact on the charging current are determined in steps S1 and S2 respectively, the charging current can be determined according to the plug-in mode and the charging mode through step S3, so that the electric vehicle can be charged according to the determined charging current.

[0067] Therefore, the embodiment of the application can calculate the optimal charging current value according to the detected gun insertion mode (such as single gun, double gun, etc.) and charging demand (such as fast charging mode, standard charging mode, etc.), so that the electric vehicle can adapt to various charging scenes, and both high-power fast charging and low-power safe charging demand can be met. Compared with the single fixed charging current scheme in the prior art, the application significantly improves the compatibility of the electric vehicle and solves the technical problem that the traditional electric vehicle cannot meet multiple charging currents at the same time, thereby providing the user with a more intelligent, safe and efficient charging experience.

[0068] Optionally, the second charging message can include a CRM (Charge Realize Message) message. The message information of the CRM message includes a frame header, a command byte, a status code, a voltage / current parameter, a timestamp and a checksum field, and needs to meet the data structure required by the protocol. Among them, the frame header is used to identify the beginning of a complete message, the command byte indicates the current operation type, such as a start request, the status code reflects the current device running status, the dynamic parameter such as the output voltage and the current value, and the checksum field guarantees the data integrity. Generally, if it is detected that the electric vehicle and the charging pile complete the gun insertion, the charging pile generates a CRM message containing a "connection success" status code and a power parameter. Since the charging current of different charging modes is different, that is, the power is different, the power parameter can represent the charging mode. Therefore, the foregoing step S2 can specifically determine the charging mode by identifying the message information of the CRM message. Please refer to Figure 3 , Figure 3 is a flowchart of a specific embodiment of the foregoing step S2. As shown in Figure 3 , the foregoing step S2 specifically includes the following steps:

[0069] Step S21: Identify the message information of the CRM message, and determine whether the message information contains the first preset information.

[0070] Step S22: If the message information includes the first preset information, it is determined as the first current charging mode.

[0071] Step S23: If the message information does not include the first preset information, it is determined whether the message information includes the second preset information.

[0072] Step S24: If the message information includes the second preset information, it is determined as the second current charging mode.

[0073] Step S25: If the message information does not contain the second preset information, it is determined as the third current charging mode.

[0074] The first preset information corresponds to the first current charging mode, and thus when it is judged in step S22 that the message information of the CRM message includes the first preset information, it is determined that the charging mode is the first current charging mode.

[0075] Similarly, the second preset information corresponds to the second current charging mode, and thus when it is judged that the message information of the CRM message does not include the first preset information, it is further judged whether the message information includes the second preset information, and when it is judged in step S24 that the message information of the CRM message includes the second preset information, it is determined that the charging mode is the second current charging mode.

[0076] If the message information of the CRM message does not include the first preset information and the second preset information, it is determined in step S25 that the charging mode is the third current charging mode.

[0077] It can be understood that the third current charging mode can be regarded as a default charging mode, which does not need special message information, i.e., it is firstly judged from the CRM message whether special message information (the first preset information or the second preset information) is included, if yes, it is determined that the charging mode is corresponding, otherwise, it is determined that the charging mode is the default charging mode.

[0078] The embodiment determines the required charging mode by pre-configuring a specific CMR (charging mode request) message data structure and automatically carrying a charging mode identification mark (the first preset information or the second preset information) in the communication interaction process. The mode recognition is performed by using the message field in the existing communication protocol, which not only avoids the process of sending an independent control instruction, but also accurately determines the charging mode. The embedded design reduces the communication bandwidth occupation and realizes the optimization effect of "information multiplexing and intelligent recognition".

[0079] Optionally, in the step of identifying the message information of the CMR message in step S21, the field information of a preset field of the CRM message can be identified. The CRM message includes a plurality of positions, each of which is provided to set a type of field information, and thus the embodiment specifically identifies whether the field information of a preset position of the CRM message includes the first preset information or the second preset information. That is, the preset position in the CRM message can be detected to judge whether the field information of the position includes the first preset information or the second preset information. The specific type of the current charging mode can be quickly and accurately identified, which provides reliable data support for subsequent charging management and control.

[0080] Optionally, the charging mode can include three different charging standards, namely, a group standard charging mode, a FAST charging mode and a national standard charging mode. The group standard charging mode refers to a charging standard formulated by an industry group or an enterprise alliance, which has high flexibility and adaptability. The FAST charging mode is a fast charging technology, which can supplement a large amount of power to the device in a short time. The national standard charging mode is a charging specification formulated in accordance with the national standard, which has mandatory and universal characteristics. The three charging modes have different characteristics and can meet the charging needs in different scenarios, providing users with diversified charging options.

[0081] In summary, by identifying the message information of the CRM message, the corresponding charging mode can be determined. The scheme for determining the charging mode through the message information of the CMR message will be described in detail below.

[0082] If the CRM message is received in the handshake stage, it is identified that special message information is added in byte1-byte4 of the CRM message, and it is judged whether it corresponds to the hexadecimal information of **** character. If the special message information is received, the BRM (Batter Realize Message, vehicle and BMS identity recognition information) message replies **** character in byte12-byte15 to respond, and it is determined as the FAST large current charging mode.

[0083] If the CRM message is received in the handshake stage, it is identified that special C message information is added in byte1-byte4 of the CRM message. If the special C message information is received, the BRM message responds in byte12-byte15, and the charging pile receives the CRM message AA after sending, the handshake is successful, and it is determined as the group standard large current charging mode.

[0084] If the CRM message is received in the handshake stage, no special message information is detected in byte1-byte4 of the CRM message, and it is determined as the standard national standard charging mode.

[0085] Further, the message information further includes the current number of inserted guns. When it is identified that the CRM message includes special message information (such as the first preset information or the second preset information), it can be further judged whether the current number of inserted guns of the message information is consistent with the number of inserted guns detected by the BMS (‌Battery Management System‌, battery management system) controller. If the current number of inserted guns is consistent with the number of inserted guns detected by the BMS controller, the corresponding charging mode is determined according to the second charging message, otherwise, an error is prompted.

[0086] Specifically, after determining the plug-in mode of the electric vehicle charging, the BMS controller saves the number of plugs corresponding to the plug-in mode, receives the CMR message of the charging pile, analyzes the message information of the CMR message, obtains the current number of plugs transmitted by the charging pile, and if the numbers are the same, it indicates that the current plug-in mode recognition is correct and has not been operated (such as unplugging or plugging), and the charging mode is determined according to the message information of the CMR message. Otherwise, an error is prompted, and relevant personnel are reminded to check and confirm.

[0087] When it is detected that the message information of the CRM message includes specific information (first preset information or second preset information), the message information is further identified. Specifically, the current plug number data recorded in the message information of the CRM message is compared with the actual plug number monitored by the BMS controller to ensure that the two data are completely consistent. It can effectively avoid various error situations caused by human error or system misjudgment during charging. For example, the current charging mode may be incorrectly identified (such as incorrectly identifying fast charging as slow charging), or the plug state may be incorrectly judged (such as incorrectly judging single-gun charging as double-gun charging), which may further cause the system to read incorrect charging current values that do not match the actual values, ultimately affecting the safety and reliability of the entire charging process.

[0088] After determining the plug-in mode and the charging mode, the charging current is further determined. Please refer to Figure 4 , Figure 4 is a flowchart of an embodiment of step S3 in the preceding step S3: determining the charging current scheme according to the plug-in mode and the charging mode, as shown in Figure 4 , the preceding step S3 includes the following steps:

[0089] Step S31: determining the initial current of the charging gun according to the plug-in mode.

[0090] Step S32: determining the current offset during charging according to the charging mode.

[0091] Step S33: determining the charging current according to the initial current, the current offset, and the current resolution.

[0092] As described in the preceding, different plug-in modes require different charging currents to be transmitted by the charging gun. For example, if the battery pack requires a charging current of 100A, the initial current required to be transmitted by the charging gun is 100A if it is single-pile single-gun charging, and the initial current required to be transmitted by each charging gun is 50A if it is double-gun charging. Therefore, step S31 determines the initial current of the charging gun according to the plug-in mode, so that the initial current meets the transmission requirements of the current plug-in mode.

[0093] Similarly, different charging modes have different current offset amounts of charging piles. Specifically, if the charging mode is the group standard charging mode, the current offset amount is determined as the first current offset; if the charging mode is the FAST charging mode, the current offset amount is determined as zero; and if the charging mode is the national standard charging mode, the current offset amount is determined as the second current offset. Therefore, in step S32, the current offset amount during charging is determined according to the charging mode, so that the current offset amount meets the characteristics of the current charging mode.

[0094] In step S33, the charging current is determined according to the initial current, the current offset amount, and the current resolution. Not only the dynamic influence of the initial current and the current offset amount on the charging current is considered, but also the parameter of the current resolution is concerned. The current resolution, as an index to measure the identification ability of the electric vehicle to the slight current change, its precision determines the precision and stability of the charging process. In practical application, the high-precision current resolution can effectively improve the perception ability of the electric vehicle to the state of the power battery, thereby ensuring that the charging process is safe and efficient.

[0095] Optionally, the above introduces that when determining the charging current, the influence of the initial current, the current offset amount, and the current resolution on the charging current is comprehensively considered. In the actual charging process, the influence of temperature on the charging current is also important. When the ambient temperature or the temperature of the power battery changes, the charging current will produce obvious fluctuations. This is because the temperature change will directly affect the chemical reaction rate inside the power battery and the conductivity of the electrolyte, thereby changing the charging characteristics of the power battery. Especially under extreme temperature conditions, too high or too low temperature can cause the charging efficiency to decrease significantly, and even can cause irreversible damage to the service life of the power battery. Therefore, the temperature factor is further considered, and corresponding temperature compensation measures are taken to ensure the safety and efficiency of the charging process. For details, please refer to Figure 5 , Figure 5 is another flowchart of a charging control method of a power battery of an electric vehicle provided by an embodiment of the present application. As shown in Figure 5 , the control method further includes the following steps:

[0096] Step S51: determining the plug-in mode of the electric vehicle charging according to the charging connection signal and the first charging packet.

[0097] Step S52: obtaining the second charging packet of the charging pile, and determining the charging mode according to the second charging packet.

[0098] Step S53: judging whether the electric vehicle currently belongs to low-temperature charging.

[0099] Step S54: if it does not belong to low-temperature charging, determining the charging current according to the plug-in mode and the charging mode.

[0100] Step S55: If it belongs to low-temperature charging, determine the heating current according to the current charging parameters of the power battery of the electric vehicle.

[0101] Step S55: Determine the charging current according to the heating current, the plug-in mode and the charging mode.

[0102] The technical solutions of steps S51, S52 and S54 are respectively the corresponding technical solutions in steps S1, S2 and S3 as previously described, and will not be repeated here.

[0103] In view of the influence of temperature on charging of the electric vehicle, in the process of determining the charging current, the embodiment further judges whether the electric vehicle currently belongs to low-temperature charging through step S53. Specifically, the temperature parameters such as the ambient temperature and the battery pack temperature of the electric vehicle can be collected, and it is further judged whether the temperature parameters are less than the preset temperature threshold. If yes, it is judged that it belongs to low-temperature charging.

[0104] After it is judged that the electric vehicle belongs to low-temperature charging, the heating current can be further determined according to the current charging parameters of the power battery of the electric vehicle. Specifically, the heating current can be determined according to the charge parameters such as the power of the power battery and the chemical material of the battery cell. Finally, the charging current is determined by comprehensively considering the heating current, the plug-in mode and the charging mode.

[0105] Therefore, in the charging process of the electric vehicle, the determination of the charging current of the embodiment comprehensively considers multiple key factors, mainly including three parameters of temperature, connection mode of the charging gun and selected charging mode. Specifically, the temperature directly affects the charging efficiency and safety performance of the power battery, so it is necessary to dynamically adjust the charging current according to the real-time monitored temperature data; the plug-in mode relates to the number and connection mode of the charging gun, and the current transmitted by the charging gun is different in different plug-in modes; and the selection of the charging mode, such as fast charging and slow charging, directly determines the size and change curve of the charging current. Systematic analysis and evaluation of these factors can determine the charging current value most suitable for the current charging demand.

[0106] For the convenience of understanding, the determination process of the charging current will be introduced by example in the following. Please refer to Figure 6 , and the determination process of the charging current is as follows:

[0107] First, it is determined whether it belongs to low-temperature charging according to the ambient temperature of the electric vehicle. If it does not belong to low-temperature charging, only the current required by the power battery is determined according to the charging parameters of the power battery, which is the required current. If it belongs to low-temperature charging, the heating current needs to be provided, and the heating current plus the current required by the power battery determined according to the charging parameters of the power battery is the required current.

[0108] Further identify whether the plug-in mode is single-gun charging or double-gun charging. If it is single-gun charging, the demand current is the initial current. If it is double-gun charging, the demand current is divided by 2 to obtain the initial current transmitted by each charging gun.

[0109] Further identify the charging mode, and each charging mode corresponds to a current offset. Specifically, if the charging mode is the national standard charging mode and the current offset is -2000A, the initial current is reduced by the current offset -2000A, and then divided by the current resolution (for example, 0.1) to obtain the charging current. The charging current is output to the charging pile and transmitted through the current bus during charging.

[0110] If the charging mode is the FAST charging mode, there is no current offset, and the initial current is directly divided by the current resolution (for example, 0.1) to obtain the charging current. The charging current is output to the charging pile.

[0111] If the charging mode is the national standard charging mode and the current offset is -400A, the initial current is reduced by the current offset -400A, and then divided by the current resolution (for example, 0.1) to obtain the charging current. The charging current is output to the charging pile.

[0112] Please refer to Figure 7 , Figure 7 is a flowchart of an embodiment of the preceding step S1. As shown in Figure 7 , the preceding step S1: determining the plug-in mode of the electric vehicle charging according to the charging connection signal and the first charging message, specifically includes the following steps:

[0113] Step S11: identify the charging connection signal. The charging connection signal can be a CC2 signal.

[0114] Step S12: if only one charging connection signal is obtained within a preset time, it is determined that the plug-in mode is single-pile single-gun charging.

[0115] Step S13: if two charging connection signals are obtained simultaneously or sequentially within a preset time, it is determined that the plug-in mode is double-gun charging.

[0116] Step S14: identify the number of first charging messages.

[0117] Step S15: if the first charging message is one set, it is determined that the plug-in mode is single-pile double-gun charging.

[0118] Step S16: if the first charging message is two sets, it is determined whether the two sets of first charging messages are transmitted by two CAN communication branches.

[0119] Step S17: if transmitted by two CAN communication branches, the plug-in mode is determined to be different-pile double-gun double-CAN charging.

[0120] Step S18: If transmitted by one CAN communication branch, the gun insertion mode is determined as the different-pole double-gun one-way charging.

[0121] One of the solutions of step S12 and step S13 is to determine whether it is single-gun charging or double-gun charging by identifying the charging connection signal obtained within the preset time. It is considered that when double-gun charging is performed, the way of inserting the charging gun can include two kinds. The first kind is to insert the charging gun at the same time. The second kind is to insert one charging gun first, start the corresponding charging process, and then insert the other charging gun and start the corresponding charging process. If it is the second insertion way of the gun, two-way charging connection signals will be obtained within the preset time. If only the charging connection signal at one time point is judged, the second double-gun insertion way will be ignored, thereby causing the wrong judgment of the gun insertion mode.

[0122] When it is determined to be double-gun charging, the number of first charging messages is further identified by step S14 to determine whether it is single-pole double-gun or different-pole double-gun. Specifically, if there is only one set of first charging messages, it is determined to be single-pole double-gun charging, because single-pole double-gun charging can be realized by one charging gun (defined as the main gun) and the charging pole for CAN communication interaction, i.e. the transmission of the first charging message. Therefore, in the case of identifying two-way charging connection signals and only one set of first charging messages, it is determined to be single-pole double-gun charging.

[0123] If the number of first charging messages is two sets, it is determined to be different-pole double-gun charging, and each charging pole respectively communicates with the BMS for CAN communication interaction, i.e. respectively transmits the first charging message. It is worth noting that the hardware structure of the BMS controller of the electric vehicle can have different CAN communication branches, i.e. the BMS controller can be provided with one CAN communication branch to transmit messages with the charging pole, or two CAN communication branches to transmit messages with the charging pole. Therefore, after identifying that there are two sets of first charging messages, it is further determined whether the two sets of first charging messages are transmitted by two-way CAN communication branches. If they are transmitted by two-way CAN communication branches, the gun insertion mode is determined to be different-pole double-gun two-way CAN charging. If they are transmitted by one-way CAN communication branch, the gun insertion mode is determined to be different-pole double-gun one-way CAN charging. Since the same ID of the first charging message cannot be transmitted by the same CAN communication branch, based on this, the number of CAN communication branches can be determined by the ID of the first charging message, i.e. when the same ID of the first charging message is respectively received, it is determined that two CAN communication branches respectively transmit the first charging message, i.e. the gun insertion mode is determined to be different-pole double-gun two-way CAN charging. Conversely, if two sets of first charging messages with different IDs are received by one CAN communication branch, it is determined that one CAN communication branch respectively transmits two sets of first charging messages with different IDs, i.e. the gun insertion mode is determined to be different-pole double-gun one-way CAN charging.

[0124] The application also provides an electric vehicle, which can perform the charging control method described in the foregoing embodiments.

[0125] To sum up, the application first determines the plug-in mode of the electric vehicle according to the charging connection signal and the first charging message; further acquires the second charging message of the charging pile and determines the charging mode according to the second charging message; finally, determines the charging current according to the plug-in mode and the charging mode, and controls the charging pile to charge the electric vehicle according to the charging current. Therefore, the application can match and dynamically adjust the charging current parameters by identifying the combination of the plug-in mode and the charging mode. That is, the optimal charging current value can be calculated according to the detected plug-in mode (such as single gun, double gun, etc.) and charging demand (such as fast charging mode, standard charging mode, etc.). The electric vehicle can adapt to various charging scenarios, and both high-power fast charging and low-power safe charging requirements can be met. Compared with the single fixed charging current scheme in the prior art, the application significantly improves the compatibility of the electric vehicle and solves the technical problem that the traditional electric vehicle cannot meet multiple charging currents at the same time, thereby providing users with a more intelligent, safe and efficient charging experience.

[0126] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A method of charge control of a power battery of an electric vehicle, characterized by, The charging control method comprises: determining a plug-in mode of the electric vehicle charging according to a charging connection signal and a first charging message; obtaining a second charging message of a charging pile, and determining a charging mode according to the second charging message; determining a charging current according to the plug-in mode and the charging mode, and controlling the charging pile to charge the electric vehicle according to the charging current; wherein the second charging message comprises a CRM message; the step of determining the charging mode according to the second charging message comprises: identifying message information of the CRM message, and judging whether the message information contains first preset information; if the message information contains the first preset information, determining a first current charging mode; if the message information does not contain the first preset information, judging whether the message information contains second preset information; if the message information contains the second preset information, determining a second current charging mode; if the message information does not contain the second preset information, determining a third current charging mode; the step of determining the charging current according to the plug-in mode and the charging mode comprises: determining an initial current of a charging gun according to the plug-in mode; determining a current offset during charging according to the charging mode; determining the charging current according to the initial current, the current offset and a current resolution; wherein the charging mode comprises a group standard charging mode, a FAST charging mode and a national standard charging mode; the step of determining the current offset during charging according to the charging mode further comprises: if the charging mode is the group standard charging mode, determining that the current offset is a first current offset; if the charging mode is the FAST charging mode, determining that the current offset is zero; if the charging mode is the national standard charging mode, determining that the current offset is a second current offset.

2. The charge control method according to claim 1, characterized by, the step of identifying the message information of the CRM message comprises: identifying field information of a preset field of the CRM message.

3. The charge control method according to claim 1 or 2, characterized by, the message information further comprises a current number of plug-ins; before the step of determining the charging mode according to the second charging message, the charging control method further comprises: judging whether the current number of plug-ins is consistent with a number of plug-ins detected by a BMS controller; if the current number of plug-ins is consistent with the number of plug-ins detected by the BMS controller, performing the step of determining the charging mode according to the second charging message.

4. The charge control method according to claim 1, characterized by, the charging control method further comprises: judging whether the electric vehicle currently belongs to low-temperature charging; if it belongs to low-temperature charging, determining a heating current according to a current charging parameter of a power battery of the electric vehicle; the step of determining the charging current according to the plug-in mode and the charging mode further comprises: determining the charging current according to the heating current, the plug-in mode and the charging mode.

5. The charge control method according to claim 1, characterized by, the step of determining the plug-in mode of the electric vehicle charging according to the charging connection signal and the first charging message comprises: identifying the charging connection signal; if only one charging connection signal is obtained within a preset time, determining that the plug-in mode is single-pile single-gun charging; If two charging connection signals are acquired simultaneously or sequentially within the preset time, it is determined that the gun insertion mode is double-gun charging. The number of the first charging messages is identified. If the first charging message is one set, it is determined that the gun insertion mode is single-pole double-gun charging. If the first charging message is two sets, it is determined whether the two sets of first charging messages are transmitted by two CAN communication branches. If the two sets of first charging messages are transmitted by two CAN communication branches, the gun insertion mode is determined to be different-pole double-gun double-CAN charging. If the two sets of first charging messages are transmitted by one CAN communication branch, the gun insertion mode is determined to be different-pole double-gun single-CAN charging.

6. An electric vehicle, characterized by The electric vehicle is applied to the charging control method according to any one of claims 1-5.

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