Vehicle, charging system, and charging method for vehicle

Abstract

The invention provides a vehicle, a charging system, and a charging method of the vehicle. A vehicle is provided with: a battery pack that is charged with DC power from a charging device as charging power; a voltage sensor that detects a charging voltage of the charging power; a switching device configured so as to be able to switch charging modes for different charging voltages; and a vehicle controller that determines a charging mode. The vehicle controller acquires, from the voltage sensor, an insulation diagnosis voltage applied by the charging device, and determines a charging mode on the basis of the insulation diagnosis voltage.

Description

Technical Field

[0001] This disclosure relates to vehicles, charging systems, and methods for charging vehicles. Background Technology

[0002] Japanese Patent No. 7110159 discloses a power system installed in a vehicle. The power system includes a first battery, a second battery, and a switching unit. The switching unit can switch between a series circuit in which the first battery and the second battery are connected in series, and a parallel circuit in which the first battery and the second battery are connected in parallel.

[0003] In vehicles that can be externally charged by power supplied from a charging device located outside the vehicle, there are vehicles that can switch between charging methods with different charging voltages in order to shorten charging time. As an example, a vehicle is configured to switch between a high-voltage (e.g., 400V) charging method and an ultra-high-voltage (e.g., 800V) charging method.

[0004] For such vehicles, the inventors have discovered the following potential issues. Typically, during external charging, multiple messages are exchanged between the vehicle and the charging device before actual power supply / charging. These messages include a message sent from the charging device to the vehicle indicating the charging device's maximum output voltage. It is also considered that the vehicle receives this message from the charging device and determines the vehicle's charging method based on the charging device's maximum output voltage.

[0005] However, some charging devices exhibit the following behavior: if the vehicle changes its charging mode after sending the message, the normal communication sequence will be terminated, and power will not be supplied from the charging device to the vehicle. For more reliable external charging of the vehicle, it may sometimes be more prudent for the vehicle to autonomously determine its charging mode before receiving the message from the charging device that can be used to determine the charging mode. Summary of the Invention

[0006] This disclosure was made to solve the above-mentioned problems. One of the purposes of this disclosure is to enable the vehicle to determine its own charging method before receiving messages from the charging device that can be used to determine the charging method of the vehicle.

[0007] The vehicle involved in the first aspect of this disclosure is configured to be externally charged by direct current power supplied from a charging device via a charging cable.

[0008] The vehicle has the following features:

[0009] An energy storage device that uses DC power from a charging device as charging power to be charged;

[0010] A voltage sensor detects the charging voltage of the charging power.

[0011] The switching device is configured to switch between charging methods with different charging voltages; and

[0012] The control device determines the charging method.

[0013] The control device obtains the insulation diagnostic voltage applied by the charging device from the voltage sensor, and determines the charging mode based on the insulation diagnostic voltage.

[0014] The charging system according to the second aspect of this disclosure includes:

[0015] Charging device; and

[0016] The vehicle is configured to be externally charged by DC power supplied from a charging device via a charging cable.

[0017] The vehicle includes:

[0018] The energy storage device uses DC power from the charging device as the charging power for charging;

[0019] A voltage sensor detects the charging voltage of the charging power.

[0020] The switching device is configured to switch between charging methods with different charging voltages; and

[0021] The control device determines the charging method.

[0022] If the vehicle and the charging device are connected via a charging cable, the charging device performs an insulation check and then sends a message indicating the maximum output voltage of the charging device to the control device.

[0023] During the insulation diagnosis process, the control device obtains the insulation diagnosis voltage applied by the charging device from the voltage sensor and determines the charging method based on the insulation diagnosis voltage.

[0024] The third aspect of this disclosure relates to a vehicle charging method that uses direct current supplied from a charging device via a charging cable as the charging power to externally charge the vehicle.

[0025] The vehicle is configured to switch between different charging methods based on the charging voltage of the charging power.

[0026] The vehicle charging method includes the following steps:

[0027] If the vehicle and the charging device are connected via a charging cable, the charging device performs an insulation check.

[0028] During the insulation diagnostic procedure, the vehicle uses a voltage sensor to obtain the insulation diagnostic voltage applied by the charging device.

[0029] The vehicle determines the charging method based on the insulation diagnostic voltage; and

[0030] After determining the charging method, a message indicating the maximum output voltage of the charging device is sent from the charging device to the vehicle.

[0031] In the above structure and method, the vehicle (control device) obtains the insulation diagnostic voltage applied by the charging device from the voltage sensor, and determines the charging mode based on the insulation diagnostic voltage. Therefore, the vehicle can determine its own charging mode before receiving this message from the charging device.

[0032] The above and other objects, features, aspects and advantages of the invention will become clear from the following detailed description in relation to the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0033] Figure 1 This is a simplified diagram showing the overall structure of the charging system involved in this embodiment.

[0034] Figure 2 This is a circuit block diagram that details the structure of a charging system.

[0035] Figure 3 This is a circuit block diagram that details the structure of the switching device and the battery pack.

[0036] Figure 4 This diagram illustrates the control of a switching device used to achieve high-voltage operation.

[0037] Figure 5 This diagram illustrates the control of a switching device used to achieve ultra-high voltage mode.

[0038] Figure 6 This is a timing diagram representing an example of a communication sequence for external charging.

[0039] Figure 7 This is a flowchart illustrating an example of the processing sequence for determining the charging method in this embodiment.

[0040] Figure 8 This is a conceptual diagram used to illustrate the insulation diagnosis in this embodiment.

[0041] Figure 9 This is a diagram used to illustrate the method for setting the maximum permissible voltage in the comparative example.

[0042] Figure 10 This is a diagram used to illustrate the method for setting the maximum permissible voltage in this variation. Detailed Implementation

[0043] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, identical or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0044] [Implementation Method]

[0045] <Overall Structure of the Charging System>

[0046] Figure 1 This is a simplified diagram showing the overall structure of the charging system according to this embodiment. The charging system 100 includes a vehicle 1, a charging device 2, and a charging cable 3. Figure 1 The image shows a vehicle 1 and a charging device 2 connected via a vehicle plug 31 and a vehicle socket 11, with the charging device 2 externally charging the vehicle 1.

[0047] Vehicle 1 is, for example, a battery electric vehicle (BEV). However, vehicle 1 can be any vehicle that can be externally charged, such as a plug-in hybrid electric vehicle (PHEV).

[0048] Charging device 2 is, for example, a DC (Direct Current) charging device that supplies direct current power. Charging device 2 can also be a fast charging device 2B installed at a public charging station (also called a charging station) (see reference). Figure 4 It can also be a super-fast charging device 2A (see reference). Figure 5 ).

[0049] Figure 2 This is a circuit block diagram illustrating an example of the structure of the charging system 100. The charging device 2 converts the supplied power (AC power) from the system power supply 900 (typically a commercial power supply) into charging power (DC power) for the vehicle 1, and supplies this DC power to the vehicle 1. The charging device 2 includes a contactor K0, a power conversion device 21, a current sensor 22, a fuse F, a discharge circuit 23, an insulation monitoring device (IMD) 24, an electromagnetic contactor circuit 25, a voltage sensor 26, an auxiliary power supply 27, an electromagnetic contactor circuit 28, a resistor R1, and a charging device controller 29.

[0050] Contactor K0 is electrically connected between system power supply 900 and power conversion device 21. Contactor K0 switches the supply and disconnection of AC power from system power supply 900 according to the control of charging device controller 29.

[0051] The power conversion device 21 converts the AC power from the system power supply 900 into DC power for charging the battery pack 15 (described later) mounted on the vehicle 1. The power conversion device 21 includes, for example, an AC / DC converter 211, a transformer 212, a DC / DC converter 213, and a diode 214. The power conversion device 21 outputs DC power to power supply lines DC+ and DC-.

[0052] A current sensor 22 is electrically connected, for example, to the power supply line DC+. The current sensor 22 detects the current flowing through the power supply line DC+ and outputs the detection result to the charging device controller 29. A fuse F is electrically connected, for example, to the power supply line DC+. A discharge circuit 23 is electrically connected between the power supply lines DC+ and DC-. The discharge circuit 23 discharges a capacitor (not shown) located on the output side of the power conversion device 21.

[0053] Insulation monitoring device 24 is electrically connected between power supply line DC+ and power supply line DC-. Insulation monitoring device 24 performs insulation diagnosis on charging device 2. More specifically, insulation monitoring device 24 applies an insulation diagnosis voltage Vdiag (described in detail below) between power supply line DC+ and power supply line DC-, and measures the insulation resistance under this condition.

[0054] The electromagnetic contactor circuit 25 includes a contactor K1 connected to the power supply line DC+ and a contactor K2 connected to the power supply line DC-. The electromagnetic contactor circuit 25 switches the supply and disconnection of DC power from the power conversion device 21 according to the control of the charging device controller 29.

[0055] Voltage sensor 26 is electrically connected between power supply line DC+ and power supply line DC-. Voltage sensor 26 detects the voltage between power supply line DC+ and power supply line DC- and outputs the detection result to charging device controller 29.

[0056] The auxiliary power supply 27 supplies a low voltage, which is used to enable communication between the charging device controller 29 and the vehicle controller 16 (described later) of the vehicle 1, to the vehicle controller 16 via wires A+ and A-.

[0057] The electromagnetic contactor circuit 28 includes a contactor K3 connected to wire A+ and a contactor K4 connected to wire A-. The electromagnetic contactor circuit 28 switches the supply and disconnection of a low voltage from the auxiliary power supply 27 according to control by the charging device controller 29.

[0058] Resistor R1 is connected between circuit CC1 from charging device controller 29 and pull-up voltage U1.

[0059] The charging device controller 29 includes a processor, a memory, and input / output interfaces (none of which are shown). The processor controls the power supply operation from the charging device 2 to the vehicle 1 based on the current detected by the current sensor 22, the voltage detected by the voltage sensor 26, communication with the vehicle 1, and the mapping and programs stored in the memory.

[0060] Vehicle connector 31 includes resistors R2 and R3 and switch S. Resistor R2 and switch S are connected in series between circuit CC1 and ground GND. Resistor R3 is connected between circuit CC2 from vehicle controller 16 and ground GND.

[0061] Vehicle 1 includes a vehicle socket 11, an electromagnetic contactor circuit 12, a voltage sensor 13, a switching device 14, a battery pack 15, a resistor R5, and a vehicle controller 16.

[0062] The vehicle socket 11 is configured to allow the vehicle plug 31, which is mechanically connected to the charging cable 3, to be inserted. The vehicle socket 11 includes a resistor R4. The resistor R4 is connected between the circuit CC1 and the ground wire GND.

[0063] The electromagnetic contactor circuit 12 includes a contactor K5 connected to the power supply line DC+ and a contactor K6 connected to the power supply line DC-. The electromagnetic contactor circuit 12 switches the reception and disconnection of charging power supplied via the vehicle socket 11 according to control by the vehicle controller 16.

[0064] Voltage sensor 13 is electrically connected between power supply line DC+ and power supply line DC-. Voltage sensor 13 detects the charging voltage between power supply line DC+ and power supply line DC-, and outputs the detection result to vehicle controller 16. Voltage sensor 13 is equivalent to the "voltage sensor" involved in this disclosure.

[0065] The switching device 14 is electrically connected between the electromagnetic contactor circuit 12 and the battery pack 15. The switching device 14 is configured to switch between charging methods with different charging voltages. Regarding the structure of the switching device 14, refer to... Figures 3-5 Please provide an explanation.

[0066] The battery pack 15 is electrically connected to the switching device 14. The battery pack 15 is a battery assembly containing multiple battery modules. Each battery module contains multiple individual cells. Each individual cell is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. Each individual cell can also be a solid-state battery. For the structure of the battery pack 15, refer to... Figure 3 The following explanation is provided. The battery pack 15 is equivalent to the "energy storage device" involved in this disclosure. The "energy storage device" may also be a capacitor such as a double-layer capacitor.

[0067] Resistor R5 is connected between circuit CC2 and pull-up voltage U2.

[0068] The vehicle controller 16 is an on-board ECU (Electronic Control Unit), comprising a processor 161, a memory 162, and input / output interfaces (not shown). The processor 161 includes processing circuitry such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). The memory 162 includes volatile storage devices such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory), and non-volatile storage devices such as HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory. The memory 162 stores system programs, including the OS (Operating System), and programs used to control the charging operations of the vehicle 1. The processor 161 executes and performs various processes by reading the system programs and expanding them in the memory 162. The vehicle controller 16 is equivalent to the "control device" disclosed herein.

[0069] In addition, Figure 1 In this specification, only one processor is shown, but vehicle 1 may also contain multiple processors. In this specification, "processor" is not limited to a processor in the narrow sense that executes processing in a stored-program manner, but can include hard-wired circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field-Programmable Gate Arrays). Therefore, the term "processor" can also be understood as a circuitry or processing circuitry that predefines processing through computer-readable code and / or hard-wired circuitry.

[0070] <Switching charging methods>

[0071] Figure 3This is a circuit block diagram illustrating, for example, the structure of the switching device 14 and the battery pack 15. The switching device 14 includes, for example, five contactors 41-45 and two current sensors 46 and 47. The battery pack 15 includes, for example, two battery modules 51 and 52. Battery modules 51 and 52 are modules with the same voltage level (typically modules containing the same number of single cells of the same type). The fully charged voltage of each battery module 51 and 52 is, for example, 400V.

[0072] Contactor 41 is electrically connected between vehicle socket 11 and node N1 in the DC+ power supply line. Contactor 42 is electrically connected between vehicle socket 11 and node N2 in the DC- power supply line. Contactor 43 is electrically connected between node N1 and the positive terminal of battery module 52. Contactor 44 is electrically connected between node N2 and the negative terminal of battery module 51. Contactor 45 is electrically connected between the negative terminal of battery module 51 and the positive terminal of battery module 52. Each contactor 41-45 is closed (connected) / opened (disconnected) according to the control of the vehicle controller 16.

[0073] Current sensor 46 is electrically connected between node N1 and the positive terminal of battery module 51. Current sensor 47 is electrically connected between node N2 and the negative terminal of battery module 52.

[0074] The switching device 14 and the battery pack 15 are configured to switch between high-voltage and ultra-high-voltage modes. The charging voltage of the ultra-high-voltage mode is higher than that of the high-voltage mode.

[0075] Figure 4 This diagram illustrates the control of the switching device 14 used to achieve high-voltage charging. When the fast charging device 2B is connected to the vehicle plug 31, the vehicle controller 16 closes contactors 41-44 and opens contactor 45. This connects battery module 51 and battery module 52 in parallel. Thus, the battery pack 15 is configured for charging in high-voltage mode.

[0076] Figure 5 This diagram illustrates the control of the switching device 14 used to achieve ultra-high voltage charging. When the ultra-fast charging device 2A is connected to the vehicle plug 31, the vehicle controller 16 closes contactors 41, 42, and 45, and opens contactors 43 and 44. This connects battery modules 51 and 52 in series. Thus, the battery pack 15 is configured for charging in ultra-high voltage mode.

[0077] The ultra-high voltage method is equivalent to the "first method" disclosed herein. The high voltage method is equivalent to the "second method" disclosed herein. Here, for ease of understanding, the charging voltage of the "first method" is twice that of the "second method," and correspondingly, an example of switching the connection between battery module 51 and battery module 52 between series connection and parallel connection will be described. However, the charging voltage of the "first method" and the charging voltage of the "second method" are not limited to this. For example, when there are more battery modules (more than three), the connection relationship between the battery modules will be switched in a more complex way to accommodate the voltage relationship (voltage difference or voltage ratio) between the "first method" and the "second method."

[0078] <Communication sequence>

[0079] Figure 6 This is a timing diagram illustrating an example of a communication sequence during external charging. In the diagram, the processes executed by charging device 2 (charging device controller 29) are shown on the left, and the processes executed by vehicle 1 (vehicle controller 16) are shown on the right. This communication sequence begins with vehicle 1 and charging device 2 mechanically connected via charging cable 3, and a low voltage is supplied to enable communication between vehicle 1 and charging device 2. Each process (denoted by P) is categorized as a handshake phase, configuration phase, charging phase, or termination phase.

[0080] exist Figure 6 The following examples illustrate a specific charging standard (specifically GB / T 18487.1). For details regarding each message, see, for example, GB / T 27930. However, those skilled in the art will be able to apply the following descriptions by analogy to various charging standards.

[0081] Reference Figure 2 and Figure 6 If the vehicle plug 31 of the charging cable 3 is connected to the vehicle socket 11 and the switch S is turned on, the voltage of circuit CC1 in the charging device 2 becomes a pull-up voltage U1 (e.g., 4V) (P1), and the voltage of circuit CC2 in the vehicle 1 becomes a pull-up voltage U2 (e.g., 6V) (P2). If the charging device controller 29 detects that the voltage of circuit CC1 has become a pull-up voltage U1, it locks the electronic lock (not shown) located at the connection between the vehicle plug 31 and the vehicle socket 11 (P3). Next, the charging device controller 29 closes the contactors K3 and K4 of the electromagnetic contactor circuit 28 (P4).

[0082] <Handshake Phase>

[0083] During the handshake phase, a communication link is established between vehicle 1 (vehicle controller 16) and charging device 2 (charging device controller 29). Specifically, charging device controller 29 sends a CHM message to vehicle controller 16 (P5) to confirm the handshake between vehicle 1 and charging device 2.

[0084] If the voltage of circuit CC2 in vehicle 1 becomes pull-up voltage U2 and a message CHM is received from charging device controller 29, then vehicle controller 16 sends a message BHM to charging device controller 29 (P6) to confirm the handshake. Message BHM may also include the maximum permissible voltage Vmax, described later.

[0085] If message BHM is received from vehicle controller 16, charging device controller 29 performs insulation diagnosis of charging device 2 using insulation monitoring device 24 (P7). If the insulation condition of charging device 2 is normal, charging device controller 29 engages discharge circuit 23 to discharge the voltage accumulated in power conversion device 21 accompanying the insulation diagnosis (P8).

[0086] If the discharge by the discharge circuit 23 ends, the charging device controller 29 sends the message CRM to the vehicle controller 16 (P9). The message CRM is an identification message sent from the charging device controller 29 to the vehicle controller 16 to confirm that the communication link between the charging device 2 and the vehicle 1 is correct. is a specified parameter contained in the message CRM, indicating that the charging device controller 29 has not yet recognized the vehicle 1.

[0087] If the message CRM is received from the charging device controller 29, the vehicle controller 16 sends the message BRM to the charging device controller 29 (P10). The message BRM contains identification information of the vehicle 1. The message BRM may contain information such as the version number of the communication protocol installed in the vehicle 1, the type of battery pack 15, its rated capacity, and its rated voltage.

[0088] If the BRM message is received from the vehicle controller 16, the charging device controller 29 sends the CRM message � to the vehicle controller 16 (P11). � is a parameter contained in the CRM message, indicating that the charging device controller 29 can recognize the vehicle 1. Thus, the handshake between the vehicle 1 and the charging device 2 ends, and the process enters the configuration phase.

[0089] Configuration Phase

[0090] During the configuration phase, the charging conditions are determined, and the completion of charging preparation is confirmed. Specifically, if the message CRM� is received from the charging device controller 29, the vehicle controller 16 sends the message BCP to the charging device controller 29 (P12). The message BCP is a message related to the charging parameters (charging conditions) of the battery pack 15. The message BCP may contain information such as the maximum allowable total charging voltage, the maximum allowable charging current, the fully charged capacity (nominal total energy), the maximum allowable temperature, the current SOC (State of Charge), and the current total voltage of the battery pack 15.

[0091] Hereinafter, the maximum permissible total charging voltage will be referred to as "maximum permissible voltage Vmax". The maximum permissible voltage Vmax refers to the voltage at which the battery pack 15 is fully charged when the charging mode is switched by the switching device 13 to the highest charging voltage mode (ultra-high voltage mode in this example). In short, it is the highest voltage that the battery pack 15 can withstand. The maximum permissible voltage Vmax is a fixed value predetermined based on the specifications of the battery pack 15 (the fully charged voltage of each individual cell, the number of individual cells connected in series, etc.).

[0092] If message BCP is received from vehicle controller 16, charging device controller 29 sends message CTS to vehicle controller 16 (P13). Message CTS is timing information for synchronization between vehicle 1 and charging device 2. Furthermore, charging device controller 29 sends message CML to vehicle controller 16 (P14). Message CML contains information related to the maximum output capability of charging device 2. Message CML includes, for example, information such as the maximum output voltage, minimum output voltage, maximum output current, and minimum output current of charging device 2.

[0093] If the CML message is received from the charging device controller 29, the vehicle controller 16 sends the BRO message to the charging device controller 29 (P15). The BRO message indicates whether the charging preparation in the vehicle 1 is complete. is a specified parameter contained in the BRO message, indicating that the charging preparation in the vehicle 1 is not yet complete.

[0094] If the vehicle controller 16 sends the message BRO to the charging device controller 29, it closes contactors K5 and K6 of the electromagnetic contactor circuit 12 (P16). Furthermore, the vehicle controller 16 uses an insulation monitoring device installed in the vehicle 1 (in... Figure 2(P17) The insulation diagnosis of vehicle 1 is performed. If the insulation of vehicle 1 is normal, vehicle controller 16 sends message BRO � to charging device controller 29 (P18). � is the parameter of message BRO, indicating that charging preparation in vehicle 1 is complete.

[0095] If the message BRO � is received from the vehicle controller 16, the charging device controller 29 closes contactors K1 and K2 of the electromagnetic contactor circuit 25 (P19). Furthermore, the charging device controller 29 sends the message CRO � to the vehicle controller 16 (P20). The message CRO indicates whether charging preparation in the charging device 2 is complete. � contains the specified parameters in the message CRO, indicating that charging preparation in the charging device 2 is complete. Thus, the process of supplying power from the charging device 2 and charging the vehicle 1 can be transferred to the charging phase.

[0096] ≪Charging Stage≫

[0097] During the charging phase, in the charging device 2, the power conversion device 21 is driven to supply power to the vehicle 1, charging the battery pack 15 in the vehicle 1. Specifically, the vehicle controller 16 sends a message BCS and a message BCL to the charging device controller 29 (P21, P22). The message BCS includes, for example, information related to the charging voltage, charging current, and SOC of the battery pack 15, as well as an estimated value of the remaining charging time. The message BCL includes, for example, information related to the requested voltage and current from the vehicle 1 to the charging device 2, and the charging mode (constant voltage charging mode or constant current charging mode).

[0098] The charging device controller 29 regulates the charging current by appropriately controlling the power conversion device 21 (P23). Additionally, the charging device controller 29 sends a message CCS to the vehicle controller 16 (S24). The message CCS is a message used to notify that charging has started (continued), and may contain information related to the output voltage and output current of the charging device 2.

[0099] During the charging of battery pack 15, vehicle controller 16 sends messages BSM, BMV, BML, and BSP to charging device controller 29 (P25~P28). Message BSM indicates the State of Charge (SOC) of battery pack 15. Message BMV indicates the voltage of battery pack 15. Message BMT indicates the temperature of battery pack 15. Message BSP is a preparatory message used to notify the charging device controller 29 of the status of battery pack 15.

[0100] Then, the charging device controller 29 determines whether the condition for stopping power supply is met. If the condition is met, it stops power supply from the charging device 2 to the vehicle 1 (P29). On the other hand, the vehicle controller 16 determines whether the condition for stopping charging is met. If the condition is met, it stops charging the vehicle 1 (P30). At this time, the vehicle controller 16 sends a message BST indicating that charging of the vehicle 1 has been stopped to the charging device controller 29 (P31). The message BST may contain information related to the reason why charging of the vehicle 1 has been stopped. Additionally, the charging device controller 29 sends a message CST indicating that power supply from the charging device 2 has been stopped to the vehicle controller 16. The message CST may contain information related to the reason why power supply from the charging device 2 has been stopped.

[0101] Subsequently, the charging device controller 29 disconnects contactors K1 and K2 of the electromagnetic contactor circuit 25 (P32). The vehicle controller 16 disconnects contactors K5 and K6 of the electromagnetic contactor circuit 12 (P33). Furthermore, the charging device controller 29 engages the discharge circuit 23, discharging the voltage accumulated in the power conversion device 21 (P34). Thus, the charging phase ends, and the process enters the final stage.

[0102] End Phase

[0103] During the final stage, statistical data related to the current charging process is exchanged between vehicle 1 and charging device 2. Specifically, vehicle controller 16 sends a BSD message representing the statistical data of vehicle 1 during the current charging process to charging device controller 29 (P35). On the other hand, charging device controller 29 sends a CSD message representing the statistical data of charging device 2 during the current charging process to vehicle controller 16 (P36).

[0104] Next, the charging device controller 29 disconnects contactors K3 and K4 of the electromagnetic contactor circuit 28 (P37). Finally, the charging device controller 29 releases the electronic lock at the connection between the vehicle plug 31 and the vehicle socket 11 (P38). Thus, the external charging specified in the communication protocol is completed.

[0105] <Maximum output capacity of the charging device>

[0106] exist Figure 6In the illustrated communication protocol, the maximum output capacity (specifically, the maximum output voltage) of the charging device 2 is sent from the charging device 2 to the vehicle 1 via the configuration phase message CML (see P14). It is also considered that the vehicle 1 determines its charging method based on the maximum output voltage of the charging device 2. However, it is sometimes more appropriate for the vehicle 1 to determine the charging method before receiving the CML message from the charging device 2. This is because if the vehicle 1 changes its charging method after the charging device 2 has sent the CML message, it is possible that abnormal actions performed by the vehicle 1 could cause… Figure 6 The communication sequence shown ends without power supply from charging device 2 to vehicle 1.

[0107] Therefore, in this embodiment, the vehicle controller 16 utilizes the opportunity of the insulation diagnostic (refer to P7) performed by the charging device controller 29 during the handshake phase prior to the configuration phase to determine the charging mode of the vehicle 1. This suppresses the possibility of the charging mode of the vehicle 1 being changed after the charging device 2 sends the CML message to the vehicle 1. Therefore, even if the charging device 2 is a device that does not correspond to a change in the charging mode after the CML message is sent, external charging of the vehicle 1 can still be performed more reliably.

[0108] <Processing Flow>

[0109] Figure 7 This is a flowchart illustrating an example of the processing sequence for determining the charging method in this embodiment. The processing shown in the flowchart is executed when predefined conditions are met (e.g., when it is detected that vehicle 1 and charging device 2 are connected via charging cable 3). In the figure, the processing performed by charging device 2 (charging device controller 29) is shown on the left, and the processing performed by vehicle 1 (vehicle controller 16) is shown on the right. Typically, each step is implemented by software processing, but it can also be implemented by hardware processing. Hereinafter, the steps will be abbreviated as S.

[0110] Reference Figure 2 and Figure 7 In S11, during the handshake phase, vehicle 1 sends a pre-defined maximum permissible voltage Vmax to charging device 2. As mentioned above, the maximum permissible voltage Vmax is the highest voltage that battery pack 15 can withstand. Figures 3-5 In the example, battery module 51 and battery module 52 are connected in series, and the voltage of both battery modules 51 and 52 when fully charged is specified as the maximum allowable voltage Vmax. With each battery module 51 and 52 having a fully charged voltage of 400V, the maximum allowable voltage Vmax is approximately 800V. Figure 6 In the previously described communication sequence, vehicle 1 may also include the maximum permissible voltage Vmax in the BHM message used for confirming the handshake (see reference). Figure 6(P6). This message is equivalent to the "maximum permissible voltage message" as covered in this disclosure.

[0111] In S21 to S24, the charging device 2 uses the insulation monitoring device 24 to perform insulation diagnosis of the charging device 2 (see reference). Figure 6 (P7). In insulation diagnosis, the charging device 2 sets the insulation diagnosis voltage Vdiag based on the maximum permissible voltage Vmax received from the vehicle 1.

[0112] Figure 8 This is a conceptual diagram used to illustrate the insulation diagnosis in this embodiment. (Refer to...) Figure 7 and Figure 8 When charging device 2 is an ultra-fast charging device 2A, the rated voltage (maximum voltage that charging device 2 can supply) Vrated of charging device 2 is higher than that when charging device 2 is a fast charging device 2B. For vehicle 1, during the insulation diagnosis phase of charging device 2, the rated voltage of charging device 2 is unknown, while for charging device 2 itself, the rated voltage Vrated is known.

[0113] In S21, if the charging device 2 receives the maximum permissible voltage Vmax from the vehicle 1 in S11, it compares the maximum permissible voltage Vmax with the rated voltage Vrated and determines which voltage is lower (S21). This is to set the insulation diagnostic voltage Vdiag to the lower of the rated voltage Vrated and the maximum permissible voltage Vmax.

[0114] Specifically, when the charging device 2 is an ultra-fast charging device 2A, the maximum permissible voltage Vmax is lower than the rated voltage Vrated (Vmax < Vrated in S21). Therefore, the charging device 2 sets the insulation diagnostic voltage Vdiag to the maximum permissible voltage Vmax (S22). Conversely, when the charging device 2 is a fast charging device 2B, the rated voltage Vrated is below the maximum permissible voltage Vmax (Vrated ≤ Vmax in S21). Therefore, the charging device 2 sets the insulation diagnostic voltage Vdiag to the rated voltage Vrated (S23).

[0115] In S24, the charging device 2 applies the insulation diagnostic voltage Vdiag set in S22 or S23 between the power supply line DC+ and the power supply line DC-. Then, the charging device 2 measures the insulation resistance between the power supply line DC+ and the power supply line DC- when the insulation diagnostic voltage Vdiag is applied.

[0116] During the insulation diagnostic process performed by the charging device 2, in S12, the vehicle 1 obtains the insulation diagnostic voltage Vdiag applied by the charging device 2 from the voltage sensor 13. Then, the vehicle 1 compares the insulation diagnostic voltage Vdiag with a pre-defined reference voltage Vref to determine which voltage is higher (S13). The reference voltage Vref is a positive fixed voltage other than 0V. The reference voltage Vref is defined to be higher than the allowable voltage when the battery pack 15 (at least one of the parallel-connected battery modules 51, 52) is fully charged in the high-voltage mode, and lower than the allowable voltage (i.e., the maximum allowable voltage Vmax) when the battery pack 15 (the series-connected battery modules 51, 52) is fully charged in the ultra-high-voltage mode.

[0117] If the insulation diagnostic voltage Vdiag is higher than the reference voltage Vref (Vdiag > Vref in S13), it can be presumed that the charging device 2 is likely to be an ultra-fast charging device 2A. Therefore, vehicle 1 will determine the charging method of vehicle 1 as ultra-high voltage mode (refer to...). Figure 5 (S14). On the other hand, if the insulation diagnostic voltage Vdiag is below the reference voltage Vref (Vdiag≤Vref in S13), it is highly likely that the charging device 2 is a fast charging device 2B, therefore the vehicle 1 will determine the charging method of the vehicle 1 as the high voltage method (refer to...). Figure 4 (S15).

[0118] Although not shown, vehicle 1 can also control the switching device 14 to conform to the determined charging method (see reference). Figure 4 and Figure 5 However, the timing of controlling the switching device 14 is not limited to this. The switching device 14 may be controlled at an appropriate time after the processing of S14 or S15 and before the start of the charging phase of S17, which will be described later.

[0119] In S16, vehicle 1 will send the charging signal to charging device 2 using the charging method determined in S14 or S15. Figure 6 In the previously described communication protocol, vehicle 1 can also include its charging method in the BRM message containing vehicle 1's identification information (see [reference]). Figure 6 (P10). Alternatively, vehicle 1 may also include the charging method of vehicle 1 in the BCP message used to notify charging device 2 of the charging parameters of battery pack 15 (see P10). Figure 6 (See page 12). These messages are equivalent to the "charging method messages" covered in this disclosure.

[0120] In S25, the charging device 2 sends its maximum output voltage to the vehicle 1. Figure 6In the communication sequence described herein, the maximum output voltage is sent as part of a message CML that includes information related to the maximum output capability of the charging device 2 (see P14).

[0121] In addition, it is also implemented in Figure 6 The handshake phase and other processes in the configuration phase are described in detail. Regarding these processes, in Figure 6 The details have already been explained in detail, so to avoid further complexity, they will not be repeated here.

[0122] Then, vehicle 1 and charging device 2 perform the various processes of the charging phase (S17, S26). Finally, vehicle 1 and charging device 2 perform the various processes of the ending phase (S18, S27).

[0123] As described above, in this embodiment, before receiving the message CML indicating the maximum output voltage of the charging device 2 from the charging device controller 29, the vehicle controller 16 takes advantage of the insulation diagnostic opportunity of the charging device 2 to obtain the insulation diagnostic voltage Vdiag of the charging device 2 using the voltage sensor 13. Then, the vehicle controller 16 compares the insulation diagnostic voltage Vdiag with a pre-defined reference voltage Vref. If the insulation diagnostic voltage Vdiag is higher than the reference voltage Vref, it can be inferred that the rated voltage Vrated of the charging device 2 is higher than the maximum permissible voltage Vmax (it is an ultra-high voltage). Conversely, if the insulation diagnostic voltage Vdiag is lower than the reference voltage Vref, it can be inferred that the rated voltage Vrated of the charging device 2 is lower than the maximum permissible voltage Vmax (it is a high voltage). Since the rated voltage Vrated and the maximum output voltage are strongly correlated, if the rated voltage Vrated is an ultra-high voltage, the maximum output voltage is also an ultra-high voltage, and if the rated voltage Vrated is a high voltage, the maximum output voltage is also a high voltage. Therefore, even if the maximum output voltage of the charging device 2 is not obtained, the vehicle controller 16 can still determine the charging mode of the vehicle 1 based on the rated voltage Vrated of the charging device 2. Thus, according to this embodiment, the charging mode of the vehicle 1 can be determined before the maximum output voltage of the charging device 2 is sent from the charging device 2 to the vehicle 1.

[0124] [Variation Example]

[0125] exist Figure 7 The text describes the transmission of a message indicating the maximum permissible voltage Vmax of vehicle 1 from vehicle controller 16 to charging device controller 29. In this modified example, the accuracy of determining the charging method of vehicle 1 is improved based on the method for setting the maximum permissible voltage Vmax. For ease of understanding, a comparative example is initially used in the explanation.

[0126] <Setting the maximum allowable voltage>

[0127] Figure 9 This diagram illustrates the method for setting the maximum permissible voltage Vmax in the comparative example. As described above, when the maximum permissible voltage Vmax is lower than the rated voltage Vrated of the charging device 2 (in the case of an ultra-fast charging device), the insulation diagnostic voltage Vdiag may be affected by the output error of the charging device 2 when it is set to the maximum permissible voltage Vmax. Furthermore, the voltage sensor 13 that detects the insulation diagnostic voltage Vdiag may also be affected by detection errors. Therefore, the insulation diagnostic voltage Vdiag when the maximum permissible voltage Vmax is lower than the rated voltage Vrated may have an error range ER1, indicated by the diagonal line in the diagram. This error range ER1 can also be referred to as the error range of the permissible voltage in ultra-fast charging (first method).

[0128] On the other hand, when the rated voltage Vrated is lower than the maximum permissible voltage Vmax (in the case of a fast charging device), the insulation diagnostic voltage Vdiag is set to the rated voltage Vrated. At this time, the insulation diagnostic voltage Vdiag may also be affected by the output error of the charging device 2 and the detection error of the voltage sensor 13. Therefore, the insulation diagnostic voltage Vdiag when the rated voltage Vrated is lower than the maximum permissible voltage Vmax may also have an error range ER2, indicated by a slash. This error range ER2 can also be referred to as the error range of the permissible voltage in fast charging (method 2).

[0129] If we assume that the voltage difference between the maximum allowable voltage Vmax and the rated voltage Vrated of the fast charging device is relatively small, then a portion of the error range ER1 and a portion of the error range ER2 may overlap. When the reference voltage Vref is set within this overlapping portion, in... Figure 7 In the processing of S13, the vehicle controller 16 may incorrectly determine the relationship between the insulation diagnostic voltage Vdiag and the reference voltage Vref. In this case, the vehicle controller 16 may be unable to correctly determine the charging method for the vehicle 1.

[0130] Figure 10This diagram illustrates the method for setting the maximum permissible voltage in this modified example. In this embodiment, the vehicle controller 16 raises the maximum permissible voltage to a level higher than Vmax in the comparative example by a predetermined voltage Vα. In other words, the vehicle controller 16 sets the maximum permissible voltage Vmax' in this modified example as Vmax' = Vmax + Vα (Vα > 0). Vα is a value defined to ensure that the error ranges ER1 and ER2 do not overlap completely, taking into account the output error of the charging device 2 and the detection error of the voltage sensor 13. In other words, the maximum permissible voltage Vmax is defined as the lower limit voltage of the error range ER1 of the maximum permissible voltage being higher than the upper limit voltage of the error range ER2 of the rated voltage Vrated of the fast charging device. As a result, since the reference voltage Vref is no longer included in both the error ranges ER1 and ER2, the vehicle controller 16 can correctly determine the relationship between the insulation diagnostic voltage Vdiag and the reference voltage Vref. Therefore, the accuracy of determining the charging mode of the vehicle 1 by the vehicle controller 16 can be improved.

[0131] Let's take a specific example. Assume the rated voltage Vrated of the fast charging device is 400V (lower limit voltage of error range ER2 = 300V and upper limit voltage = 500V), and the rated voltage Vrated of the ultra-fast charging device is 800V (lower limit voltage of error range ER1 = 700V and upper limit voltage = 900V). In this case, the maximum permissible voltage Vmax is specified in the range of 500V to 700V, preferably, for example, in the range of 610V to 650V. The reference voltage Vref can be set to 600V.

[0132] Furthermore, in the above-described embodiments and variations, the charging method was described as either one of two methods (ultra-high voltage method and high voltage method). However, for example, it is also possible that there are three charging methods (three charging devices 2), and the vehicle 1 corresponds to these three charging methods. In this case, by setting two reference voltages, one of the three charging methods can be selected. Thus, according to this embodiment, even when the vehicle 1 corresponds to N (N is any natural number of 3 or more) methods, the appropriate charging method for the charging device 2 can be determined by setting (N-1) reference voltages.

[0133] Embodiments of the present invention have been described, but the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is shown by the technical solutions and is intended to include all modifications within the meaning and scope of equivalent technical solutions.

Claims

1. A vehicle configured to be externally charged via DC power supplied from a charging device through a charging cable, wherein, The vehicle has the following features: The energy storage device is charged using the DC power from the charging device as the charging power. A voltage sensor is used to detect the charging voltage of the charging power. The switching device is configured to switch between charging methods with different charging voltages; as well as The control device determines the charging method. The control device obtains the insulation diagnostic voltage applied by the charging device from the voltage sensor, and determines the charging mode based on the insulation diagnostic voltage.

2. The vehicle according to claim 1, wherein, The control device sends a maximum permissible voltage message, representing the maximum permissible voltage of the vehicle, to the charging device. The maximum allowable voltage refers to the voltage at which the charging mode is switched to the highest charging voltage mode by the switching device and the energy storage device is fully charged.

3. The vehicle according to claim 2, wherein, The control device sends a charging mode message, indicating the charging mode determined based on the insulation diagnostic voltage, to the charging device.

4. The vehicle according to claim 3, wherein, The vehicle complies with the charging standard GB / T18487. The maximum permissible voltage message is message BHM. The charging method message is either message BRM or message BCP.

5. The vehicle according to any one of claims 2 to 4, wherein, The charging method includes a first method and a second method in which the charging voltage is lower than that of the first method. When the insulation diagnostic voltage is higher than the predetermined reference voltage, the control device determines the charging mode as the first mode. on the other hand, When the insulation diagnostic voltage is lower than the reference voltage, the control device determines the charging method to be the second method.

6. The vehicle according to claim 5, wherein, The reference voltage is a fixed voltage that is lower than the maximum permissible voltage.

7. The vehicle according to claim 6, wherein, The lower limit of the error range of the maximum permissible voltage is specified to be higher than the upper limit of the error range of the permissible voltage in the second method. The reference voltage is specified between the lower limit voltage and the upper limit voltage.

8. A charging system, wherein, have: Charging device; and The vehicle is configured to be externally charged via DC power supplied from the charging device through a charging cable. The vehicle includes: The energy storage device is charged using the DC power from the charging device as the charging power. A voltage sensor is used to detect the charging voltage of the charging power. The switching device is configured to switch between charging methods with different charging voltages; as well as The control device determines the charging method. If the vehicle and the charging device are connected via the charging cable, the charging device performs an insulation check, and after performing the insulation check, sends a first message indicating the maximum output voltage of the charging device to the control device. During the insulation diagnosis process, the control device obtains the insulation diagnosis voltage applied by the charging device from the voltage sensor, and determines the charging method based on the insulation diagnosis voltage.

9. The charging system according to claim 8, wherein, Before performing the insulation diagnostic via the charging device, the control device sends a second message indicating the maximum permissible voltage of the vehicle to the charging device. The maximum allowable voltage refers to the voltage at which the charging mode is switched to the highest charging voltage mode by the switching device, and the energy storage device is fully charged. The charging device applies the insulation diagnostic voltage using the lower of the maximum permissible voltage and the rated voltage of the charging device.

10. The charging system according to claim 9, wherein, Before receiving the first message, the control device sends a third message to the charging device, indicating the charging method determined based on the insulation diagnostic voltage.

11. The charging system according to claim 10, wherein, The vehicle and the charging device comply with the charging standard GB / T18487. The first message is message CML. The second message is message BHM. The third message is either message BRM or message BCP.

12. A method for charging a vehicle, wherein direct current supplied from a charging device via a charging cable is used as charging power to externally charge the vehicle, wherein, The vehicle is configured to switch between different charging methods based on the charging voltage of the charging power. The vehicle charging method includes the following steps: If the vehicle and the charging device are connected via the charging cable, the charging device performs an insulation test. In the insulation diagnostic step, the vehicle uses a voltage sensor to obtain the insulation diagnostic voltage applied by the charging device; The vehicle determines the charging method based on the insulation diagnostic voltage; as well as After determining the charging method, a message indicating the maximum output voltage of the charging device is sent from the charging device to the vehicle.

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