Battery electric automobile

Abstract

The invention relates to a battery electric automobile. A battery electric vehicle is provided with a motor, a drive circuit for driving the motor, a power storage device for supplying power to the drive circuit via a power line, and a charging connector to which power is supplied from an external charging device. And an external charging unit that performs external charging for charging the power storage device by supplying power from the charging device to the power storage device via the charging connector and the power line, the battery electric vehicle includes an auxiliary device attached to a power line closer to a charging connector than a drive circuit, and a current sensor attached between the charging connector and the auxiliary device.

Description

Technical Field

[0001] This disclosure relates to a battery electric vehicle. Background Technology

[0002] As such a battery electric vehicle, the following battery electric vehicle is proposed. The battery electric vehicle includes a motor, a drive circuit (inverter) for driving the motor, an energy storage device (battery) that supplies power to the drive circuit via power lines, and a charging connector (input terminal). Power from an external charging device (external charger) is supplied to the charging connector. The battery electric vehicle performs external charging by supplying power from the charging device to the energy storage device via the charging connector and power lines to charge the energy storage device (see, for example, Japanese Patent Application Laid-Open No. 2024-67878). In this battery electric vehicle, when the actual electrical force supplied from the charging device to the energy storage device deviates from the electrical force requested from the energy storage device by the charging device, an anomaly is determined to have occurred at the charging device. Summary of the Invention

[0003] In the aforementioned battery-powered electric vehicles, when auxiliary equipment is present at the power line, most of this equipment lacks a current sensor, making it sometimes impossible to accurately detect the power consumption of the auxiliary equipment. In such cases, it may be difficult to properly determine malfunctions or incompatibilities with the charging equipment.

[0004] The main purpose of the battery electric vehicle disclosed herein is to more appropriately determine the abnormality of external charging equipment and the incompatibility with the charging equipment when it is not possible to detect the power consumption of auxiliary equipment with high precision.

[0005] To achieve the aforementioned main objectives, the battery electric vehicle disclosed herein adopts the following technical solution.

[0006] The battery electric vehicle disclosed herein includes a motor, a drive circuit that drives the motor, an energy storage device that supplies power to the drive circuit via a power line, and a charging connector that receives power from an external charging device. External charging is performed by supplying power from the charging device to the energy storage device via the charging connector and the power line to charge the energy storage device.

[0007] The battery electric vehicle includes:

[0008] Auxiliary equipment, installed on the side of the power line closer to the charging connector than the drive circuit; and

[0009] A current sensor is installed between the charging connector and the auxiliary device.

[0010] In the battery electric vehicle disclosed herein, there is an auxiliary device installed on the side of the power line closer to the charging connector than the drive circuit, and a current sensor installed between the charging connector and the auxiliary device. By utilizing the current detected by the current sensor, even when the power consumption of the auxiliary device cannot be detected with high precision, it is possible to more appropriately determine the malfunction of the external charging device or the mismatch with the charging device.

[0011] In such a battery electric vehicle disclosed herein, a determination device may also be included, which sends a current command to the charging device and determines, based on the current detected by the current sensor and the current command, whether the charging device is malfunctioning or incompatible with the charging device. This allows for a more appropriate determination of whether the charging device is malfunctioning or incompatible with the charging device.

[0012] Alternatively, the battery electric vehicle disclosed herein may also include a boost converter connected between the charging connector and the power line on the side of the auxiliary device closer to the charging connector, thereby boosting the power supplied to the charging connector and supplying it to the power line. In this way, with the boost converter, it is possible to more appropriately determine any malfunctions or incompatibility with the charging equipment. Attached Figure Description

[0013] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals show the same elements, and wherein:

[0014] Figure 1 This is a schematic structural diagram illustrating the structure of a battery electric vehicle according to an embodiment of the present disclosure.

[0015] Figure 2 This is a flowchart illustrating an example of a decision routine executed by the ECU. Detailed Implementation

[0016] Embodiments of this disclosure are described with reference to the accompanying drawings. Figure 1 This is a schematic structural diagram showing the structure of a battery electric vehicle according to an embodiment of the present disclosure. As shown, the battery electric vehicle 20 of the embodiment includes a driving motor 22, an inverter (drive circuit) 24, a battery (energy storage device) 30, and a system main relay SMR. The battery electric vehicle 20 includes a charging connector 34, a boost converter 40, a cut-off relay 50, a charging relay 51, auxiliary equipment 54, and an electronic control unit (control device, hereinafter referred to as "ECU") 60.

[0017] Motor 22 is configured as a synchronous generator motor, having a rotor with embedded permanent magnets and a stator surrounded by three-phase coils. The rotor of motor 22 is connected to drive shaft 26, which is connected to drive wheels 28a and 28b via differential gear 27.

[0018] Inverter 24 is configured as a known inverter circuit with 6 transistors and 6 diodes, connected to motor 22 and to power line 32. Inverter 24 is controlled by ECU 60.

[0019] Battery 30, for example, has multiple lithium-ion secondary batteries or nickel-metal hydride secondary batteries connected to power line 32.

[0020] The system main relay SMR is installed on power line 32 and connects and disconnects the battery 30 from the inverter 24, auxiliary equipment 54, and the side of the disconnect relay 50 closer to the charging connector 34. The system main relay SMR is controlled by ECU 60.

[0021] The charging connector 34 is configured as a pile-side connector 92 that can be connected to the charging pile (charging device) 90. The charging connector 34 is connected to the charging cable 44. When the charging connector 34 is connected to the pile-side connector 92, power from the external power source 94 of the charging pile 90 can be supplied to the charging cable 44.

[0022] The boost converter 40 is connected between the charging cable 44 from the charging connector 34 and the power line 32, on the side of the auxiliary device 54 that is closer to the charging connector 34, thereby boosting the power supplied to the charging cable 44 and supplying it to the power line 32. The boost converter 40 is controlled by the ECU 60.

[0023] The disconnect relay 50 is installed on the power line 32, closer to the boost converter 40 than the auxiliary equipment 54, to connect and disconnect the boost converter 40 from the inverter 24, battery 30, and auxiliary equipment 54. A discharge resistor Rd is installed on the power line 32, closer to the boost converter 40 than the disconnect relay 50. The disconnect relay 50 is controlled by the ECU 60.

[0024] The charging relay 51 is installed on the charging cable 44 and is used to connect and disconnect the charging connector 34 from the boost converter 40. The charging relay 51 is controlled by the ECU 60.

[0025] Auxiliary equipment 54 is connected to power line 32, such as an air conditioning system or other electrical equipment that operates in conjunction with the power consumption of power line 32. Auxiliary equipment 54 is controlled by ECU 60.

[0026] The ECU 60 is equipped with a microcomputer, including a CPU. Signals from various sensors are input to the ECU 60 via input ports. For example, the voltage V1 from the voltage sensor 44V, which detects the voltage on the side of the charging cable 44 closer to the boost converter 40 than the charging relay 51, can be listed as an input signal to the ECU 60. The charging current Ic from the current sensor 44i, mounted on the side of the charging cable 44 closer to the boost converter 40 than the charging relay 51 (located between the charging connector 34 and the auxiliary device 54), can detect the current supplied to the charging cable 44. For example, the voltage V2 from the voltage sensor 46V, which detects the voltage on the side of the power line 32 closer to the boost converter 40 than the disconnect relay 50, can be listed as an input signal to the ECU 60. Other input signals to the ECU 60 include connection signals from the connection detection sensor that detects the connection between the charging connector 34 and the terminal connector 92, and start signals from the start switch 62. The ECU 60 outputs various control signals via its output port to the inverter 24, including control signals for multiple switching elements and drive signals for the system main relay SMR. It also outputs control signals to the boost converter 40, drive signals to the cut-off relay 50, drive signals to the charging relay 51, and control signals to the auxiliary equipment 54. If the charging connector 34 is connected to the charging pile side connector 92, the ECU 60 can connect the signal lines of the charging pile 90's charging pile side connector 92 to the signal lines of the charging connector 34, enabling various signal exchanges with the charging pile 90.

[0027] In the battery electric vehicle 20 configured in this way, if the user turns on the start switch 62, the ECU 60 turns on the system main relay SMR and prepares it (system on). Subsequently, if the start switch 62 is turned off, the system main relay SMR is turned off and the preparation is canceled (system off).

[0028] If, during a parking period while in a state of "cancellation preparation," a connection detection sensor (not shown) installed on charging connector 34 detects a connection between charging connector 34 and pile-side connector 92, ECU 60 outputs a current command I* to charging pile 90. ECU 60 activates the system main relay SMR, disconnect relay 50, and charging relay 51, outputting the current command I* to charging pile 90. The current command I* is obtained by dividing the smaller of a predetermined base value Ib for charging battery 30 and the input limit Win of battery 30 by the inter-terminal voltage of battery 30. The input limit Win is the maximum allowable input power to battery 30, determined based on the battery 30's state of charge (SOC) and temperature. The SOC is the ratio of the charged capacity to the total capacity of battery 30. Upon receiving the current command I*, charging pile 90 supplies DC power from external power source 94 via pile-side connector 92 and charging connector 34 to charging cable 44. ECU60 controls booster 40 to make the voltage V2 of power line 32 higher than the inter-terminal voltage of battery 30, so as to perform external charging of battery 30 by using DC power from external power source 94 from charging pile 90.

[0029] Next, the operation of the battery electric vehicle 20 configured in this embodiment will be explained. In particular, the operation when the charging pile 90 is found to be abnormal or incompatible with the charging pile 90 (the charging pile 90 does not meet the standards of the battery electric vehicle 20) will be explained. Figure 2 This is a flowchart illustrating an example of a decision routine executed by ECU60. This routine is repeatedly executed at predetermined intervals tref1 (e.g., every few milliseconds) during external charging.

[0030] If this routine is executed, the CPU of ECU60 inputs the current command I* and the charging current Ic detected by the current sensor 44i (S100). Next, the CPU of ECU60 determines whether the absolute value of the difference between the current command I* and the charging current Ic (=|I*-Ic|) is greater than a predetermined difference dI (S110). The predetermined difference dI is a threshold used to determine whether the current command I* and the charging current Ic are the same; for example, it is set to a value of 0 or a value slightly larger than 0. It is generally believed that when an abnormality occurs at the charging station 90, the current command I* and the charging current Ic deviate. Furthermore, it is generally believed that when the charging station 90 does not meet the standards of the battery electric vehicle 20 and is incompatible with the battery electric vehicle 20, the current command I* and the charging current Ic deviate. Therefore, S110 is a process for determining whether an abnormality has occurred at the charging station 90. Additionally, S110 is a process for determining whether the charging station 90 does not meet the standards of the battery electric vehicle 20 and is incompatible with the battery electric vehicle 20. The charging current Ic includes the current (power) consumed by the auxiliary device 54, therefore, S110 is a highly accurate determination. When the absolute value of the difference between the current command I* and the charging current Ic is less than or equal to a predetermined difference dI, the CPU of ECU60 determines that the charging pile 90 is normal and that the standard of the charging pile 90 conforms to the standard of the battery electric vehicle 20. Then, the CPU of ECU60 terminates this routine.

[0031] When the absolute value of the difference between the current command I* and the charging current Ic is greater than a predetermined difference dI in S110, the CPU of ECU60 makes a further judgment. That is, the CPU of ECU60 determines that there is a possibility that an abnormality has occurred at the charging pile 90, or that the charging pile 90 does not meet the standards of the battery electric vehicle 20 and is not compatible with the battery electric vehicle 20. Next, the CPU of ECU60 determines whether the duration tc is longer than a predetermined time tref2 (S120). The duration tc is the duration for which the absolute value of the difference between the current command I* and the charging current Ic is greater than the predetermined difference dI. Due to detection errors of the current sensor 44i, the absolute value of the difference between the current command I* and the charging current Ic may sometimes become the same after temporarily becoming greater than the predetermined difference dI. The predetermined time tref2 is a threshold used to determine whether the absolute value of the difference between the current command I* and the charging current Ic is temporarily greater than the predetermined difference dI, and is, for example, set to be longer than the predetermined time tref1. That is, S120 is the process of determining whether an abnormality has occurred at the charging station 90 or whether the charging station 90 and the battery electric vehicle 20 are mismatched. When the duration tc is less than or equal to the predetermined time tref2, the CPU of ECU60 determines that there is a possibility that an abnormality has occurred at the charging station 90 or that the charging station 90 and the battery electric vehicle 20 are mismatched, but cannot determine it. Then, the CPU of ECU60 ends this routine. In addition, when the absolute value of the difference between the current command I* and the charging current Ic becomes less than or equal to the predetermined difference dI, the CPU of ECU60 resets the duration tc to the value 0.

[0032] If, in S120, it is determined that the duration tc is longer than the predetermined time tref2, an abnormality has occurred at the charging station 90 or the charging station 90 is not compatible with the battery electric vehicle 20 (mismatch) (S130). Then, this routine ends. In this way, the charging current Ic detected by the current sensor 44i is used to determine whether an abnormality has occurred at the charging station 90 or whether the charging station 90 is mismatched with the battery electric vehicle 20. In this way, when it is not possible to detect the power consumption of the auxiliary device 54 with high precision, it is possible to more appropriately determine the abnormality of the charging station 90 and the mismatch with the battery electric vehicle 20.

[0033] The battery electric vehicle 20 of this embodiment, as described above, includes an auxiliary device 54 installed on the power line 32 on the side closer to the charging connector 34 than the inverter 24, and a current sensor 44i installed between the charging connector 34 and the auxiliary device 54. Therefore, when it is impossible to detect the power consumption of the auxiliary device 54 with high precision, it is possible to more appropriately determine any abnormalities in the external charging station 90 or any incompatibility with the charging station 90.

[0034] Furthermore, a current command I* is sent to the charging station 90, and an abnormality or mismatch with the charging station 90 is determined based on the charging current Ic detected by the current sensor 44i and the current command I*. This allows for a more appropriate determination of whether an abnormality or mismatch with the charging station 90 is present.

[0035] Furthermore, a booster 40 is provided, which is connected between the charging cable 44 from the charging connector 34 and the power line 32, on the side of the auxiliary device 54 closer to the charging connector 34, to boost the power supplied to the charging cable 44 and supply it to the power line 32. Therefore, with the booster 40 provided, it is possible to more appropriately determine any malfunctions or incompatibility with the charging station 90.

[0036] In the above embodiment, a booster 40 is provided between the charging cable 44 from the charging connector 34 and the power line 32 on the side of the auxiliary device 54 that is closer to the charging connector 34, but the booster 40 may not be provided.

[0037] In the above embodiments, the operation of applying this disclosure to a battery electric vehicle 20 capable of external charging has been described. However, this disclosure can also be applied to a hybrid electric vehicle capable of external charging and powered by a motor and an engine.

[0038] This section explains the correspondence between the main elements of the implementation method and the main elements of the invention described in the section on technical solutions for solving the problem. In the implementation method, motor 22 is an example of a "motor," and inverter 24 is an example of a "drive circuit." Battery 30 is an example of an "energy storage device," and charging connector 34 is an example of a "charging connector." Auxiliary device 54 is an example of an "auxiliary device," and current sensor 44i is an example of a "current sensor."

[0039] Furthermore, regarding the correspondence between the main elements of the implementation method and the main elements of the invention described in the Summary of the Invention section, the implementation method is used to specifically illustrate an example of a way of carrying out the invention described in the Summary of the Invention section. Therefore, the above correspondence is not limited to the elements of the invention described in the Summary of the Invention section. That is, the interpretation of the invention described in the Summary of the Invention section should be based on the description in that section, and the implementation method is merely a specific example of the invention described in the Summary of the Invention section.

[0040] The above describes the methods for implementing this disclosure using embodiments, but this disclosure is not limited to such embodiments in any way, and can of course be implemented in various ways without departing from the spirit of this disclosure.

[0041] This disclosure can be applied to industries such as the manufacturing of battery electric vehicles.

Claims

1. A battery-powered electric vehicle, The device includes a motor, a drive circuit that drives the motor, an energy storage device that supplies power to the drive circuit via a power line, and a charging connector that receives power from an external charging device. It performs external charging by supplying power from the charging device to the energy storage device via the charging connector and the power line to charge the energy storage device. in, The battery-powered electric vehicle has the following features: Auxiliary equipment, installed on the side of the power line closer to the charging connector than the drive circuit; and A current sensor is installed between the charging connector and the auxiliary device.

2. The battery electric vehicle according to claim 1, wherein, The battery electric vehicle includes a determination device that sends a current command to the charging device and determines whether the charging device is abnormal or incompatible with the charging device based on the current detected by the current sensor and the current command.

3. The battery electric vehicle according to claim 1 or 2, wherein, The battery electric vehicle includes a booster connected between the charging connector and the power line on the side of the auxiliary device closer to the charging connector, thereby boosting the power supplied to the charging connector and supplying it to the power line.

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