Method for selecting charging mode, charging management device and computer program product

Abstract

The invention provides a method for selecting a charging mode for a vehicle, which comprises the following steps of: S1, before starting to charge a power battery of the vehicle by using charging equipment, receiving insulation inspection of the vehicle by the charging equipment; s2, in the insulation inspection process, the insulation inspection voltage applied by the charging equipment is detected; s3, comparing the detected insulation check voltage with a first voltage threshold value determined according to the maximum allowable charging voltage of the vehicle so as to select a charging mode between a parallel charging mode in which the plurality of battery modules of the power battery are connected in series with each other and a series charging mode in which the plurality of battery modules are connected in parallel with each other; and S4, selecting a parallel charging mode under the condition that the detected insulation check voltage is greater than the first voltage threshold value. The invention further provides a corresponding computer program product and a charging management device. Therefore, the vehicle can select the charging mode matched with the charging equipment, so that safe and efficient charging is realized.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular to a method for selecting a charging mode for a vehicle, a charging management device for a vehicle, and a computer program product. Background Art

[0002] With the popularity of electric vehicles, how to safely and efficiently charge the power batteries of electric vehicles has become a highly concerned issue.

[0003] At present, most vehicles can only adopt a single charging mode, which makes it impossible for the vehicle to adapt to the voltage output characteristics of different charging piles. When the output voltage of the charging pile does not match the requirements of the power battery, it is easy to cause low charging efficiency or battery overvoltage risk. For example, most charging piles provide a lower voltage value of 400V as the maximum charging pile voltage, and accordingly the vehicle is also set to be suitable for charging only at this lower voltage value. Although the use of a charging pile that can provide a maximum charging pile voltage (for example, 800V) can improve charging efficiency, vehicles with a single charging mode cannot be charged using such a charging pile.

[0004] While some existing technologies have proposed solutions that allow power batteries to switch between series and parallel charging modes, these solutions still have drawbacks. For example, it's difficult for vehicles to know the voltage output capacity of the charging station in advance, which can easily lead to charging failures. Alternatively, vehicles can only obtain the maximum charging station voltage information claimed by the charging station. This also makes charging failures prone to occur in practice. Furthermore, some solutions have deficiencies in the logic for selecting the charging mode, which can lead to charging failures or cause safety issues.

[0005] Therefore, the existing technology has some deficiencies in selecting the charging mode of the vehicle. Summary of the Invention

[0006] The purpose of the present application is to provide an improved method for selecting a charging mode for a vehicle and a corresponding charging management device and computer program product, so as to overcome at least one of the deficiencies of the prior art.

[0007] According to a first aspect of the present application, a method for selecting a charging mode for a vehicle is provided, the method comprising the following steps:

[0008] -S1, before starting to use the charging equipment to charge the vehicle's power battery, accept the insulation check of the vehicle by the charging equipment;

[0009] -S2, during the insulation check process, detects the insulation check voltage applied by the charging equipment;

[0010] - S3, comparing the detected insulation check voltage with a first voltage threshold determined according to a maximum allowable charging voltage of the vehicle to select a charging mode between a parallel charging mode and a series charging mode, wherein the plurality of battery modules of the power battery are connected in series with each other in the series charging mode and in parallel with each other in the parallel charging mode; and

[0011] - S4, when the detected insulation inspection voltage is greater than the first voltage threshold, selecting the parallel charging mode.

[0012] This allows the system to identify the output voltage level of the connected charging device and select the appropriate battery module connection method for charging, achieving safe and efficient charging. Based on the detected insulation check voltage, it can determine whether the output voltage level of the charging device supports series charging mode, allowing the system to selectively switch to series or parallel charging mode.

[0013] Generally, if the detected insulation inspection voltage is large (for example, greater than or equal to a certain voltage threshold), people will believe that the charging device has the ability to provide a higher output voltage, and will then select the series charging mode.

[0014] However, after analysis and research, the inventors propose that an insulation check voltage greater than the first voltage threshold likely indicates that the charging device lacks the ability to consistently and stably provide a high output voltage. This may be due to malfunctioning voltage regulation due to aging or a fault in the charging module. If the insulation check voltage is greater than the first voltage threshold, employing a parallel charging mode can improve the success rate of charging. This contributes to safe and efficient charging.

[0015] According to an exemplary embodiment of the present application, in step S3 , the detected insulation check voltage is additionally compared with a second voltage threshold value, which is determined according to a maximum allowable charging voltage of the vehicle.

[0016] The method further includes the following steps: - S5, if the detected insulation check voltage is not greater than a first voltage threshold and not less than a second voltage threshold, selecting a series charging mode; and - S6, if the detected insulation check voltage is less than the second voltage threshold, selecting a parallel charging mode. Thus, an appropriate charging mode can be selected based on the detected insulation check voltage.

[0017] According to an exemplary embodiment of the present application, the first voltage threshold is set as: U1 = Umax + ΔU, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter. The second voltage threshold can be set as: U2 = Umax - ΔU, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter. This helps to charge the power battery with higher charging efficiency.

[0018] According to an exemplary embodiment of the present application, the voltage parameter is set according to ambient temperature and / or ambient humidity.

[0019] The voltage parameter is optionally positively correlated with a deviation of the detected ambient temperature and / or ambient humidity from a reference temperature and / or reference humidity, respectively.

[0020] According to an exemplary embodiment of the present application, the first voltage threshold is set as: U1 = n * Umax, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and n is a voltage coefficient greater than 1. The second voltage threshold is set as: U2 = (2-n) * Umax, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and n is the voltage coefficient. This also helps to charge the power battery with higher charging efficiency.

[0021] According to an exemplary embodiment of the present application, the voltage coefficient is set according to ambient temperature and / or ambient humidity.

[0022] The voltage coefficient is optionally positively correlated with a deviation of the detected ambient temperature and / or ambient humidity from a reference temperature and / or reference humidity, respectively.

[0023] According to an exemplary embodiment of the present application, the method includes step S0 performed before step S1 , in which information including the maximum allowable charging voltage of the vehicle is sent to the charging device for the charging device to determine the insulation check voltage.

[0024] According to an exemplary embodiment of the present application, the method includes step S7 performed after step S4, S5 or S6. In step S7, charging mode information and a charging voltage requirement corresponding to the selected charging mode may be sent to the charging device according to the selected charging mode.

[0025] According to an exemplary embodiment of the present application, the method further includes step S8, wherein, during the charging process, the state parameters of the battery are periodically detected, and the state parameters include at least one of voltage, current, and temperature, so as to adjust the charging mode or interrupt charging when the detected state parameters exceed a preset safety range.

[0026] Optionally, if it is determined in step S3 that the insulation check voltage is greater than a first voltage threshold, then in step S8 the battery status parameters are periodically checked at a relatively high frequency. If it is determined in step S3 that the insulation check voltage is not greater than the first voltage threshold, then in step S8 the battery status parameters are periodically checked at a relatively low frequency. This is particularly helpful in improving the safety of the charging process.

[0027] According to a second aspect of the present application, a computer program product is provided, comprising computer program instructions, wherein when the computer program instructions are executed by one or more processors, the one or more processors are enabled to perform the method for selecting a charging mode according to the present application.

[0028] According to a third aspect of the present application, a charging management device for a vehicle is provided, wherein the charging management device includes a memory and a processor, the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the processor is capable of executing the method for selecting a charging mode according to the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0030] Figure 1 Schematically shows a flow chart of a method for selecting a charging mode for a vehicle according to an exemplary embodiment of the present application;

[0031] Figure 2 A vehicle is schematically shown that is charged using the method for selecting a charging mode;

[0032] Figure 3 A flowchart schematically illustrates a method for selecting a charging mode according to an exemplary embodiment of the present application; and

[0033] Figure 4 The data interaction process between the vehicle and the charging device is schematically shown.

[0034] Reference Signs List

[0035] 1 vehicle

[0036] 11 Power Battery

[0037] 111 First battery module

[0038] 112 Second battery module

[0039] 113 Switching Circuit

[0040] 12 Charging port

[0041] 13. Charging management device

[0042] 131 Memory

[0043] 132 processors

[0044] 14 Voltage detection circuit

[0045] 15 Temperature sensor

[0046] 16 Humidity Sensor

[0047] 2 Charging equipment

[0048] 21 Charging gun DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by this application more clearly understood, this application will be further described in detail below with reference to the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit the scope of protection of this application.

[0050] Figure 1 A flowchart of a method for selecting a charging mode for a vehicle 1 according to an exemplary embodiment of the present application is schematically shown. Figure 2 A vehicle 1 is schematically shown being charged using the method for selecting a charging mode.

[0051] The vehicle 1 includes a power battery 11, which can provide driving force for driving the vehicle 1. The power battery 11 is particularly a lithium-ion battery, such as a ternary lithium-ion battery. In other embodiments, the power battery 11 may also include other types of batteries.

[0052] The power battery 11 includes multiple battery modules, for example, a first battery module 111 and a second battery module 112. The power battery 11 also includes a switching circuit 113 for switching the circuit connections between the multiple battery modules. The switching circuit 113 can connect the first battery module 111 and the second battery module 112 in parallel or in series, as needed.

[0053] The vehicle 1 may also include a charging port 12 for connecting to a charging device 2. The charging device 2 may be, for example, a DC charging station equipped with a charging gun 21. By plugging the charging gun 21 into the charging port 12, a charging connection may be established between the charging device 2 and the power battery 11 of the vehicle 1.

[0054] Vehicle 1 may also include a charging management device 13 and a voltage detection circuit 14. Voltage detection circuit 14 may, for example, include a voltage divider circuit and an analog-to-digital converter connected to charging port 12. Charging management device 13 may execute the method for selecting a charging mode according to an exemplary embodiment of the present application. This method for selecting a charging mode may be executed after charging gun 21 is connected to charging port 12 and before charging device 2 charges power battery 11.

[0055] like Figure 1 As shown, the method for selecting a charging mode may include at least steps S1, S2, S3 and S4.

[0056] In step S1, before charging the power battery 11 of the vehicle 1 begins using the charging device 2, the vehicle 1 undergoes an insulation check by the charging device 2. This insulation check is performed at an insulation check voltage U_ISO. Typically, the insulation check voltage U_ISO is set to the smaller of the maximum allowable charging voltage Umax of the vehicle 1 and the maximum output voltage U_C of the charging device 2, i.e., U_ISO = min(Umax, U_C).

[0057] In step S2, during the insulation check process, the insulation check voltage applied by the charging device 2 is detected. The insulation check voltage can be detected by the voltage detection circuit 14. The voltage detection circuit 14 can determine the insulation check voltage by detecting the voltage between the positive and negative terminals of the charging interface 12.

[0058] In step S3, the detected insulation check voltage is compared with a first voltage threshold U1, which is determined based on the maximum allowable charging voltage of vehicle 1, for both parallel charging mode and series charging mode. The multiple battery modules of power battery 11 are connected in series in series charging mode and in parallel in parallel charging mode. First voltage threshold U1 is specifically set to be greater than or equal to the maximum allowable charging voltage of vehicle 1. If the detected insulation check voltage is greater than first voltage threshold U1, step S4 is executed.

[0059] In step S4, when the detected insulation check voltage is greater than the first voltage threshold, the parallel charging mode is selected. Accordingly, when the charging device 2 charges the power battery 11, the multiple battery modules of the power battery 11 are connected in parallel.

[0060] This allows the appropriate battery module connection method to be selected for charging based on the output voltage level of the connected charger 2, achieving safe and efficient charging. The detected insulation test voltage can be used to determine whether the charger 2's output voltage level supports series charging mode, allowing the system to selectively switch between series and parallel charging modes.

[0061] Generally, if the detected insulation inspection voltage is relatively large (for example, greater than or equal to a certain voltage threshold), people will believe that the charging device 2 has the ability to provide a relatively high output voltage, and will then select the series charging mode.

[0062] However, after analysis and research, the inventors proposed that an insulation check voltage greater than the first voltage threshold value may very likely mean that the charging device 2 does not have the ability to continuously and stably provide a high output voltage. An insulation check voltage greater than the first voltage threshold value may be caused by the aging or failure of the charging module of the charging device 2, which causes the voltage regulation function to fail. For example, aging and failure of the filter capacitor may cause the charging device 2 to be unable to output voltage stably. Alternatively, the looseness or saturation of the magnetic core of the inductor element may cause excessive output ripple, making the output voltage unstable. When the detected insulation check voltage is greater than the first voltage threshold value, the use of a parallel charging mode can improve the success rate of charging.

[0063] In contrast, the series charging mode requires a higher charging voltage. If the series charging mode is adopted in this case, it will be difficult for the charging device 2 to stably provide the required output voltage during the charging process, which is likely to cause charging failure.

[0064] It is particularly advantageous that the output voltage level of the charging device 2 can be identified during the insulation check, so that the charging mode can be selected at an earlier point in time.

[0065] In step S3, the detected insulation check voltage may be additionally compared with a second voltage threshold. Like the first voltage threshold, the second voltage threshold is determined based on the maximum permissible charging voltage of vehicle 1. If the detected insulation check voltage is not greater than the first voltage threshold and not less than the second voltage threshold, step S5 is executed. If the detected insulation check voltage is less than the second voltage threshold, step S6 is executed.

[0066] In step S5 , when the detected insulation inspection voltage is not greater than the first voltage threshold and not less than the second voltage threshold, the series charging mode is selected.

[0067] In step S6 , when the detected insulation inspection voltage is less than the second voltage threshold, the parallel charging mode is selected.

[0068] The appropriate charging mode can be selected based on the detected insulation test voltage. If the output voltage of charger 2 is high, vehicle 1 can choose series charging mode, improving charging efficiency. If the output voltage of charger 2 is low, vehicle 1 can choose parallel charging mode, improving charging success rate. This output voltage level is obtained through actual measurement on the vehicle side.

[0069] In one example, the first voltage threshold and the second voltage threshold may be set equal to a maximum allowable charging voltage.

[0070] In a preferred embodiment, the first voltage threshold can be set as: U1 = Umax + ΔU, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter. The second voltage threshold can be set as: U2 = Umax - ΔU, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter. This helps to charge the power battery 11 with higher charging efficiency.

[0071] ΔU can be preset. As an example, ΔU can be set to 20V.

[0072] According to an exemplary embodiment of the present application, the voltage parameter ΔU may be set according to ambient temperature and / or ambient humidity.

[0073] For example, vehicle 1's temperature sensor 15 can detect the ambient temperature of the vehicle's current environment. If the detected ambient temperature deviates significantly from the reference temperature, ΔU can be set to a larger value. The detection results of voltage detection circuit 14 may be affected by the ambient temperature, potentially leading to an erroneous judgment of the output voltage level of charging device 2. Therefore, when the ambient temperature is high or low, ΔU can be increased accordingly. For example, at an ambient temperature of 25°C, ΔU can be set to 20V; at an ambient temperature of -10°C, ΔU can be set to 30V.

[0074] Similarly, the ambient humidity of the environment in which the vehicle 1 is currently located may be detected by the humidity sensor 16 of the vehicle 1. If the detected ambient humidity deviates from the reference humidity by a large humidity difference, ΔU may be set to a larger value.

[0075] In a preferred embodiment, the first voltage threshold can be set as: U1 = n*Umax, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and n is the voltage coefficient. The second voltage threshold can be set as: U2 = (2-n)*Umax, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and n is a voltage coefficient greater than 1. This also helps to charge the power battery 11 with higher charging efficiency.

[0076] n can be preset. As an example, n can be set to 1.02.

[0077] According to an exemplary embodiment of the present application, the voltage coefficient n can be set according to the ambient temperature and / or ambient humidity. The voltage parameter can optionally be positively correlated with the deviation of the detected ambient temperature and / or ambient humidity from a reference temperature and / or reference humidity.

[0078] As described above, the charging management device 13 of the vehicle 1 can be configured to execute the method for selecting a charging mode according to an exemplary embodiment of the present application. It should be understood that the features and advantages described herein for the method for selecting a charging mode are also applicable to the charging management device 13, and vice versa.

[0079] The charging management device 13 may be implemented as, for example, a control unit dedicated to controlling the charging operation of the power battery 11 .

[0080] The charge management device 13 can, in particular, be part of a battery management system of the vehicle 1 .

[0081] like Figure 2 As shown, the charging management device 13 may include a memory 131 and a processor 132 , wherein the memory 131 stores computer program instructions. When the computer program instructions are executed by the processor 132 , the processor 132 can, for example, execute a method for selecting a charging mode for the vehicle 1 .

[0082] The computer program product may be stored in a computer-readable storage medium. The computer-readable storage medium may include, for example, a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory card, a plug-in hard disk, a smart memory card, a secure digital card, a flash memory card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. The processor 132 may be a central processing unit, or may be another general-purpose processor, a digital signal processor, an application-specific integrated circuit, an off-the-shelf programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or the like.

[0083] Figure 3 Schematically shows a flow chart of a method for selecting a charging mode according to an exemplary embodiment of the present application. Figure 1 Similar to the embodiment shown, the method includes steps S1, S2, S3, S4, S5 and S6, which will not be described in detail here.

[0084] like Figure 3 As shown, the method may further include step S0 performed before step S1. In step S0, information including the maximum allowable charging voltage of the vehicle 1 is sent to the charging device 2, so that the charging device 2 can determine the insulation check voltage.

[0085] After receiving the information including the maximum allowable charging voltage of the vehicle 1, the charging device 2 may set the insulation check voltage U_ISO to the smaller value of the maximum allowable charging voltage Umax and the maximum output voltage U_C of the charging device 2. The charging device 2 may then perform an insulation check at the insulation check voltage.

[0086] The charging management device 13 may select a charging mode according to the detected insulation test voltage.

[0087] The method may further include step S7 performed after step S4, S5 or S6. In step S7, according to the selected charging mode, the charging mode information and the charging voltage requirement corresponding to the selected charging mode are sent to the charging device 2.

[0088] Optionally, the method further includes step S8. In step S8, during the charging process, a battery status parameter is periodically detected, wherein the status parameter includes at least one of voltage, current, and temperature, so as to adjust the charging mode or interrupt charging when the detected status parameter exceeds a preset safety range.

[0089] According to an exemplary embodiment of the present application, if it is determined in step S3 that the insulation check voltage is greater than the first voltage threshold, then in step S8, the battery status parameters are periodically checked at a relatively high frequency. If it is determined in step S3 that the insulation check voltage is not greater than the first voltage threshold, then in step S8, the battery status parameters are periodically checked at a relatively low frequency. This helps improve the safety of the charging process.

[0090] Figure 4 The data interaction process between the vehicle 1 and the charging device 2 is schematically shown.

[0091] After the charging gun 21 of the charging device 2 is plugged into the charging port 12 of the vehicle 1, a handshake operation is performed between the charging device 2 and the vehicle 1. Only after the handshake is successful can the charging device 2 be used to charge the power battery 11 of the vehicle 1.

[0092] First, after the charging gun 21 is plugged into the charging interface 12, the charging device 2 may send a charging device handshake message CHM to the vehicle 1. The vehicle 1 (specifically, the battery management system BMS of the vehicle 1) may receive the charging device handshake message CHM.

[0093] In response to the charging device handshake message CHM, the vehicle 1 may send a battery management system handshake message BHM to the charging device 2. The battery management system handshake message BHM may include information indicating the maximum allowable charging voltage Umax of the vehicle 1. The maximum allowable charging voltage is, for example, 800V.

[0094] After the charging device 2 receives the battery management system handshake message BHM, it can initiate an insulation check to detect the insulation performance of the charging circuit, battery system, and related components, preventing safety accidents such as electric leakage, short circuit, and even electric shock caused by insulation failure. The charging device 2 can set the insulation check voltage U_ISO as the smaller value between the maximum allowable charging voltage Umax of the vehicle 1 and the maximum output voltage U_C of the charging device 2, that is, U_ISO = min(Umax, U_C). If U_C ≥ Umax, then U_ISO = Umax; if U_C < Umax, then U_ISO = U_C. Here, taking U_C ≥ Umax as an example, correspondingly U_ISO = Umax = 800V. This means that the insulation check voltage U_ISO is theoretically set to 800V. The charging device 2 performs an insulation check on the vehicle 1 with the set insulation check voltage U_ISO.

[0095] During the insulation check, the voltage detection circuit 14 of the vehicle 1 can detect the insulation check voltage actually applied by the charging device 2. The charging management device 13 can select an appropriate charging mode by comparing the detected insulation check voltage with the first voltage threshold, especially by comparing it with the first voltage threshold and the second voltage threshold. The first voltage threshold and the second voltage threshold are set to Umax + 20V and Umax - 20V respectively, for example.

[0096] According to the selected charging mode, the corresponding charging voltage requirement can be determined. The charging voltage requirement can be sent to the charging device 2 in the subsequent battery charging parameter message BCP.

[0097] As described above, the insulation check voltage U_ISO is theoretically set to 800V, however, the actually detected insulation check voltage may deviate from this set value.

[0098] The following table exemplarily lists different comparison results between the detected insulation check voltage and the first voltage threshold and the second voltage threshold.

[0099] Detected insulation check voltage Charging mode BCP_1 BCP_2 U_ISO>U1 Parallel charging mode Umax Pd U_ISO∈[U2,U1] Series charging mode Umax Sd U_ISO<U2 Parallel charging mode Umax Pd

[0100] In this example, the first voltage threshold U1 is set to Umax + 20V; U2 is set to Umax - 20V.

[0101] Take Umax = 800V and U_C > Umax as an example. In this case, the insulation check voltage U_ISO is theoretically set to 800V. If the insulation check voltage U_ISO detected by the voltage detection circuit 14 of the vehicle 1 is equal to 800V or the deviation from 800V is within 20V (i.e., U_ISO ∈ [U2, U1]), then the series charging mode can be selected, see the second row in the table above. Correspondingly, the charging voltage requirement corresponding to the selected charging mode is the series charging voltage Sd.

[0102] In practice, although the insulation check voltage U_ISO is theoretically set to 800V, the insulation check voltage U_ISO detected by the voltage detection circuit 14 of the vehicle 1 may be less than 800V, especially less than 800V with a difference of more than 20V (i.e., U_ISO < U2). This means that the charging device 2 actually cannot provide an output voltage that meets the requirements of the series charging mode. Based on this comparison result, the parallel charging mode can be selected, see the third row in the table above. Correspondingly, the charging voltage requirement corresponding to the selected charging mode is the parallel charging voltage Pd. The parallel charging voltage Pd can be significantly less than the series charging voltage Sd. Even if the maximum output voltage of the charging device 2 is relatively small, it can still charge the power battery 11 of the vehicle 1.

[0103] In addition, although the insulation check voltage U_ISO is theoretically set to 800V, the insulation check voltage U_ISO detected by the voltage detection circuit 14 of the vehicle 1 may be greater than 800V, especially greater than 800V with a difference of more than 20V (i.e., U_ISO > U1). In this case, it can be predicted that the charging device 2 is very likely unable to provide a stable and reliable output voltage that meets the requirements of the series charging mode. Therefore, the parallel charging mode can be selected, see the first row in the table above. Correspondingly, the charging voltage requirement corresponding to the selected charging mode is the parallel charging voltage Pd. On the contrary, if the series charging mode is selected in this case, then during the subsequent charging process, the charging device 2 is likely unable to continuously and stably provide the required output voltage, resulting in a charging failure.

[0104] In addition, if Umax = 800V and the rated maximum output voltage of the charging device 2 is only 400V (i.e., U_C = 400V < Umax), then the insulation check voltage U_ISO can be theoretically set to 400V. The insulation check voltage U_ISO detected by the voltage detection circuit 14 of the vehicle 1 will be significantly less than the second voltage threshold U2 = 800V - 20V, then the parallel charging mode can be selected, see the third row in the table above. Correspondingly, the charging voltage requirement corresponding to the selected charging mode is the parallel charging voltage Pd.

[0105] As can be seen from the table above, series charging mode is selected only when the insulation check voltage U_ISO is within the range [U2, U1]. As mentioned above, setting the voltage parameter ΔU or voltage coefficient n to an appropriate value helps ensure that vehicle 1 selects series charging mode when charging device 2 has a high output voltage level, thereby improving charging efficiency.

[0106] After selecting the charging mode, the charging management device 13 may generate a connection instruction for controlling the switching circuit 113. The switching circuit 113 may connect the first battery module 111 and the second battery module 112 of the power battery 11 in parallel or in series according to the connection instruction.

[0107] After the charging device 2 confirms that the insulation resistance is normal through insulation inspection, it can send a charging device identification message CRM to the vehicle 1. For example, the charging device 2 can send a charging device identification message CRM 0X00, which includes basic information of the charging device 2, such as the charging device number, the charging device location, etc. After receiving the charging device identification message CRM 0X00, the vehicle 1 can send a battery management system identification message BRM to the charging device 2. The battery management system identification message BRM may include the unique identification code, voltage platform, battery capacity, hardware production information, and software development information of the power battery 11. The charging device 2 identifies the information in the battery management system identification message BRM. If the identification is successful, it sends a charging device identification message CRM 0XAA to the vehicle 1. This means that the power battery 11 and the charging device 2 have successfully shaken hands.

[0108] Then, the configuration phase can be entered. Vehicle 1 can send a charging parameter message BCP for the power battery 11 to the charging device 2. The charging parameter message BCP for the power battery 11 may include information such as the maximum allowable charging voltage and the charging voltage requirement. Vehicle 1 must send the charging parameter message BCP for the power battery 11 within a maximum of 5 seconds after receiving the charging device identification message CRM. Prior to this, the charging management device 13 can select a suitable charging mode and determine the charging voltage requirement based on the detected insulation check voltage. It can be seen that according to the embodiment of the present application, the selection of the charging mode can be completed at an earlier time.

[0109] After receiving the power battery charging parameter message (BCP), charging device 2 can send a charging device maximum output capability message (CML) to vehicle 1. This CML message may include information such as charging device 2's maximum output voltage. After charging device 2 and vehicle 1's battery management system confirm that the parameters contained in the message are correct, vehicle 1 can send a battery management system charging readiness message (BRO 0X00) to charging device 2. The relay switch on the power battery side closes, connecting the charging circuit on the power battery side. After confirming that the relay switch on the power battery side is closed, vehicle 1 can send a battery management system charging readiness message (BRO 0XAA) to charging device 2. After receiving the battery management system charging readiness message (BRO 0XAA), charging device 2 sends a charging device 2 output readiness message (CRO 0X00) to the battery management system and controls the relay switch on the charging device side to close. After confirming that the relay switch on the charging device side is closed, charging device 2 sends a charging device output readiness message (CRO 0XAA) to the battery management system. The configuration phase ends, and the charging circuit between the charging device 2 and the power battery 11 is connected.

[0110] Finally, the charging phase can begin. Charging device 2 can deliver electrical energy to vehicle 1 based on the charging voltage requirements corresponding to the selected charging mode. After receiving CRO 0XAA, vehicle 1 can send a battery charging requirement message (BCL) to charging device 2. This BCL message can contain battery charging requirement information. Vehicle 1 can also send a battery charging status message (BCS) to charging device 2. This BCS message can contain the battery's real-time charging status (voltage, current, SOC, etc.). This information can be collected by sensors in the battery management system.

[0111] When describing exemplary embodiments herein, the method and / or process may be presented as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific sequence of steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art can readily appreciate that these sequences can vary and still remain within the spirit and scope of the embodiments of the present application.

[0112] Although specific embodiments of the present application are described in detail herein, they are provided for illustrative purposes only and should not be considered to limit the scope of the present application. Various replacements, changes, and modifications may be conceived without departing from the spirit and scope of the present application.

Claims

1. A method for selecting a charging mode for a vehicle, the method comprising the following steps: - S1, before starting to charge the power battery (11) of the vehicle (1) using the charging device (2), accepting the insulation check of the vehicle (1) by the charging device (2); - S2, during the insulation check process, detecting the insulation check voltage applied by the charging device (2); as well as - S3, comparing the detected insulation inspection voltage with a first voltage threshold value determined according to a maximum allowable charging voltage of the vehicle (1) to select a charging mode between a parallel charging mode and a series charging mode, wherein the plurality of battery modules of the power battery (11) are connected in series with each other in the series charging mode and in parallel with each other in the parallel charging mode; as well as - S4, when the detected insulation inspection voltage is greater than the first voltage threshold, selecting the parallel charging mode.

2. The method for selecting a charging mode according to claim 1, wherein: In step S3, the detected insulation check voltage is additionally compared with a second voltage threshold value, which is determined according to the maximum permissible charging voltage of the vehicle (1); The method further comprises the steps of: -S5, when the detected insulation check voltage is not greater than the first voltage threshold and not less than the second voltage threshold, selecting the series charging mode; as well as - S6, when the detected insulation inspection voltage is less than the second voltage threshold, selecting the parallel charging mode.

3. The method for selecting a charging mode according to claim 2, wherein: The first voltage threshold is set as: U1 = Umax + ΔU, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter; The second voltage threshold is set as: U2 = Umax - ΔU, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and ΔU is a voltage parameter.

4. The method for selecting a charging mode according to claim 3, wherein: The voltage parameter is set as a function of the ambient temperature and / or ambient humidity, wherein the voltage parameter is optionally positively correlated with a deviation of the detected ambient temperature and / or ambient humidity from a reference temperature and / or reference humidity, respectively.

5. The method for selecting a charging mode according to claim 2, wherein: The first voltage threshold is set as: U1 = n*Umax, where U1 represents the first voltage threshold, Umax represents the maximum allowable charging voltage, and n is a voltage coefficient greater than 1; The second voltage threshold is set as: U2 = (2-n) * Umax, where U2 represents the second voltage threshold, Umax represents the maximum allowable charging voltage, and n is the voltage coefficient.

6. The method for selecting a charging mode according to claim 5, wherein: The voltage coefficient is set as a function of the ambient temperature and / or ambient humidity, wherein the voltage coefficient is optionally positively correlated with a deviation of the detected ambient temperature and / or ambient humidity from a reference temperature and / or reference humidity, respectively.

7. The method for selecting a charging mode according to any one of claims 2 to 6, wherein: The method comprises a step S0 performed before step S1, in which information containing the maximum permissible charging voltage of the vehicle (1) is sent to the charging device (2) for the charging device (2) to determine the insulation check voltage; and / or The method comprises a step S7 performed after step S4, S5 or S6, in which, according to the selected charging mode, charging mode information and a charging voltage requirement corresponding to the selected charging mode are sent to the charging device (2).

8. The method for selecting a charging mode according to any one of claims 1 to 7, wherein: The method further includes step S8, wherein during the charging process, a state parameter of the battery is periodically detected, wherein the state parameter includes at least one of voltage, current, and temperature, so as to adjust the charging mode or interrupt charging when the detected state parameter exceeds a preset safety range. Among them, optionally, if it is identified in step S3 that the detected insulation check voltage is greater than the first voltage threshold, then in step S8, the battery status parameters are periodically detected at a relatively high frequency; if it is identified in step S3 that the detected insulation check voltage is not greater than the first voltage threshold, then in step S8, the battery status parameters are periodically detected at a relatively low frequency.

9. A computer program product comprising computer program instructions, wherein: The computer program instructions, when executed by one or more processors (132), enable the one or more processors (132) to perform the method of selecting a charging mode according to any one of claims 1-8.

10. A charging management device for a vehicle, wherein: The charging management device (13) comprises a memory (131) and a processor (132), wherein the memory (131) stores computer program instructions, and when the computer program instructions are executed by the processor (132), the processor (132) is capable of executing the method for selecting a charging mode according to any one of claims 1 to 8.

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