vehicle

Abstract

This invention relates to a vehicle. A vehicle (1) configured to receive power from an external power source to charge an onboard battery (100), the vehicle comprising: an input port (220); a voltage sensor (230) for detecting an input voltage, the input voltage being a voltage input from the power source to the input port (220); and a control device configured to perform a detection process while connected to the input port (220). The detection process includes: a first process, in which charging is temporarily stopped if the difference between the input voltage before charging begins and the input voltage after charging begins is greater than or equal to a threshold; and a second process, in which charging is stopped if the difference between the input voltage at the time of the temporary stop in the first process and the input voltage after charging resumes is greater than or equal to the threshold.

Description

Technical Field

[0001] This disclosure relates to a vehicle configured to charge its onboard battery using power supplied from a power source outside the vehicle. Background Technology

[0002] Japanese Patent No. 5660203 discloses a vehicle configured to perform AC (Alternating Current) charging of an onboard battery using AC power supplied from an external AC power source via a charging cable. The vehicle includes a charging circuit that converts the AC power supplied from the AC power source into DC power for charging the battery. Furthermore, if the vehicle experiences a decrease in the input voltage from the AC power source to the charging circuit exceeding a threshold value for a predetermined period of time, an impedance abnormality in the charging path from the AC power source to the vehicle is detected. Summary of the Invention

[0003] Here, in addition to impedance abnormalities in the charging path, the main reasons for the decrease in input voltage of the charging circuit (charger) can also be listed as the decrease in the voltage of the power supplied from the AC power source (hereinafter also referred to as "system voltage"). In the method disclosed in Japanese Patent No. 5660203 based on the amount of decrease in input voltage input to the charger, it may not be able to properly distinguish between impedance abnormalities in the charging path and the decrease in system voltage.

[0004] This disclosure solves the above-mentioned problems and can properly detect impedance anomalies in the charging path.

[0005] (1) The vehicle of the first technical solution of this disclosure is a vehicle configured to receive power supplied via a charging cable from a power source outside the vehicle to charge an on-board battery. The vehicle includes: an interface configured to connect to a connector provided on the charging cable; a voltage sensor for detecting an input voltage, the input voltage being the voltage input from the power source to the interface; and a control device configured to perform a detection process when the connector is connected to the interface. The detection process includes: a first process, in which charging is temporarily stopped when the difference between the input voltage before charging begins (i.e., a first voltage) and the input voltage after charging begins (i.e., a second voltage) is greater than or equal to a threshold; and a second process, in which charging is stopped when the difference between the input voltage when charging is temporarily stopped in the first process (i.e., a third voltage) and the input voltage after charging resumes (i.e., a fourth voltage) is greater than or equal to a threshold.

[0006] According to the above structure, firstly, the first process is executed. If the difference between the first voltage and the second voltage is above a threshold, charging is temporarily stopped. If charging is temporarily stopped in the first process, then the second process is executed. If the difference between the third voltage and the fourth voltage is above a threshold, charging is stopped. If the system voltage decreases after the first voltage is obtained, and the difference between the first voltage and the second voltage is above a threshold in the first process due to the decrease in system voltage, it is assumed that the difference between the third voltage and the fourth voltage is less than the threshold in the second process. On the other hand, if the difference between the first voltage and the second voltage becomes above a threshold in the first process due to an impedance anomaly in the charging path from the power supply to the interface, it is assumed that the difference between the third voltage and the fourth voltage becomes above a threshold in the second process. Instead of judging the impedance anomaly in the charging path from the power supply to the interface solely through the first process, the second process is further executed to compare the difference between the third voltage and the fourth voltage with the threshold difference when charging is temporarily stopped through the first process. This allows for an appropriate distinction between impedance anomalies in the charging path and a decrease in system voltage. Therefore, it is possible to properly detect impedance anomalies in the charging path.

[0007] (2) In the vehicle of the above technical solution, in the first process, when the difference between the first voltage and the second voltage is above a threshold, the control device temporarily detects an impedance abnormality in the charging path from the power source to the interface, and in the second process, when the difference between the third voltage and the fourth voltage is above a threshold, the control device determines that the charging path impedance is abnormal.

[0008] According to the above structure, in the first process, if the difference between the first voltage and the second voltage is above a threshold, the control device temporarily detects an impedance abnormality in the charging path from the power supply to the interface and temporarily stops charging. At this point, it is not possible to properly distinguish between the impedance abnormality of the charging path and the drop in system voltage. Therefore, the control device further performs a second process to compare the third voltage and the fourth voltage, and if the difference between the third voltage and the fourth voltage is above a threshold, it determines that the impedance abnormality of the charging path is abnormal and stops charging. In this way, the impedance abnormality of the charging path can be detected appropriately.

[0009] (3) In the vehicle of the above technical solution, it is also possible that in the second process, when the difference between the third voltage and the fourth voltage is less than the threshold, the control device continues charging.

[0010] If the difference between the third and fourth voltages in the second process is less than a threshold, it is assumed that if the difference between the first and second voltages in the first process exceeds the threshold, it is due to a decrease in the system voltage. Therefore, charging continues as long as the impedance of this charging path is not abnormal. This prevents charging from stopping at a point where it should not have stopped.

[0011] (4) In the vehicle of the above technical solution, the voltage sensor can also detect the third voltage and the fourth voltage multiple times, and in the second process, if the difference between the third voltage and the fourth voltage is above the threshold multiple times, the control device can determine that the charging path impedance is abnormal.

[0012] Based on the above structure, by comparing the difference between the third and fourth voltages with a threshold multiple times in the second process, it is possible to suppress the generation of misjudgments caused by noise, etc.

[0013] (5) In the vehicle of the above technical solution, in the first process, the control device acquires the second voltage within a predetermined time period starting from the acquisition of the first voltage, and in the second process, the control device acquires the fourth voltage within a predetermined time period starting from the acquisition of the third voltage.

[0014] According to the above structure, by acquiring the second voltage within a predetermined time period starting from acquiring the first voltage, fluctuations in the system voltage from acquiring the first voltage until acquiring the second voltage can be suppressed. Therefore, the occurrence of temporary detection of impedance anomalies in the charging path can be suppressed. Thus, the charging time required to the extent that temporary stops accompanying temporary detection of charging can be omitted can be shortened. Furthermore, by acquiring the fourth voltage within a predetermined time period starting from acquiring the third voltage, fluctuations in the system voltage from acquiring the third voltage until acquiring the fourth voltage can be suppressed. Therefore, false detection of impedance anomalies in the charging path can be suppressed.

[0015] (6) In the vehicle of the above technical solution, the control device may also set a threshold based on the rated current of the charging cable.

[0016] The voltage drop from the input voltage before charging begins to the input voltage after charging begins is proportional to the magnitude of the charging current. Therefore, by setting a threshold based on the rated current of the charging cable, it is possible to properly determine the difference between the first and second voltages, as well as the difference between the third and fourth voltages.

[0017] (7) In the vehicle described above, the vehicle may also be equipped with a current sensor that detects the current from the power input to the interface, i.e., the input current. The control device sets a threshold based on the input current.

[0018] By setting thresholds based on the actual input current (i.e., charging current), it is possible to properly determine the difference between the first and second voltages, as well as the difference between the third and fourth voltages.

[0019] (8) In the vehicle of the above technical solution, the control device may compare the rated current of the charging cable with a predetermined threshold current, and if the rated current is above the predetermined threshold current, the detection process is not performed.

[0020] (9) The second technical solution of this disclosure pertains to a vehicle configured to receive power supplied via a charging cable from an external power source to charge an onboard battery. The vehicle includes: an access port configured to connect to a connector provided on the charging cable; a voltage sensor for detecting an input voltage, the input voltage being the voltage input from the power source to the access port; and a control device configured to perform a detection process when the connector is connected to the access port. The detection process includes: a first process in which charging is temporarily stopped if the change in input voltage per unit time is greater than or equal to a threshold; and a second process in which charging is stopped if, after charging has been temporarily stopped in the first process and then resumes, the change in input voltage per unit time is greater than or equal to the threshold.

[0021] From a long-term perspective, the system voltage will gradually change. Therefore, for example, due to system voltage fluctuations, the input voltage after charging begins may drop significantly from the input voltage before charging started. If this is temporarily detected as an impedance anomaly in the charging path, charging will be temporarily stopped. According to the above structure, charging is temporarily stopped when the change in input voltage per unit time exceeds a threshold, and then stopped again when the change in input voltage per unit time exceeds the threshold after charging resumes. By using the change in input voltage per unit time, even if the system voltage changes gradually, its effects can be eliminated. Therefore, it is possible to suppress the temporary detection of impedance anomalies in the charging path due to system voltage fluctuations.

[0022] According to this disclosure, impedance anomalies in the charging path can be properly detected. Attached Figure Description

[0023] 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 denote the same elements, and wherein:

[0024] Figure 1 This is an overall structural diagram of the vehicle according to the implementation method.

[0025] Figure 2 This is a diagram showing an example of the structure of a circuit related to AC charging.

[0026] Figure 3 It is a diagram showing the correspondence between the states of switches SW1 and SW2, the potential of the pilot signal CPLT, and the state of the CCID relay.

[0027] Figure 4 This is a timing diagram (1) used to illustrate the detection process.

[0028] Figure 5This is a timing diagram used to illustrate the detection process (part 2).

[0029] Figure 6 It is a flowchart representing the steps of the detection and processing performed by the ECU.

[0030] Figure 7 This is a flowchart illustrating the detection and processing steps of Modified Example 1.

[0031] Figure 8 This is a flowchart illustrating the detection and processing steps of variation example 4.

[0032] Figure 9 This is a diagram used to illustrate the detection process of variation example 5.

[0033] Figure 10 This is a flowchart showing the steps of the detection process performed in Variation 5. Detailed Implementation

[0034] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same or equivalent parts in the drawings are labeled with the same reference numerals, and their descriptions will not be repeated.

[0035] <Overall Structure>

[0036] Figure 1 This is an overall structural diagram of vehicle 1 according to this embodiment. Vehicle 1 is configured to perform AC charging by using AC power supplied from an external charging device 500 to charge the battery 100 mounted on vehicle 1.

[0037] The charging device 500 of this embodiment is installed in a home or similar location. The charging device 500 includes an AC power supply 510 and a socket 520. The socket 520 is, for example, a typical household AC socket.

[0038] During AC charging, the charging device 500 and the vehicle 1 are connected via a charging cable 400. The charging cable 400 includes an AC power line 440, a charging connector 410 at one end of the AC power line 440, a plug 420 at the other end of the AC power line 440, and a charging circuit interrupter (hereinafter also referred to as "CCID"). The charging connector 410 is configured to connect to the inlet 220 of the vehicle 1. The plug 420 is configured to connect to the socket 520 of the charging device 500. The CCID 430 is a circuit used to switch the supply and disconnection of power from the charging device 500 to the vehicle 1.

[0039] Vehicle 1 is an electric vehicle that uses electricity stored in battery 100 to drive a driving motor (not shown). It should be noted that vehicle 1 can be any vehicle configured to be externally charged, capable of charging the on-board battery 100 using electricity supplied from an external charging device, such as a fuel cell vehicle or a plug-in hybrid electric vehicle.

[0040] Vehicle 1 includes a battery 100, a charger 200, a charging cover 210, an inlet 220, a voltage sensor 230, a current sensor 240, an ECU (Electronic Control Unit) 300, and a notification device 600.

[0041] Battery 100 is installed in vehicle 1 as a drive power source (i.e., a power source). Battery 100 is configured to include multiple batteries stacked together. The battery is, for example, a nickel-metal hydride battery, a lithium-ion battery, or a secondary battery. Furthermore, the battery can be either a battery with a liquid electrolyte between the positive and negative electrodes, or a battery with a solid electrolyte (all-solid-state battery). It should be noted that battery 100 can be any rechargeable DC power source, and can also use a large-capacity capacitor.

[0042] ECU300 includes CPU (Central Processing Unit) 310 (see reference). Figure 2 The system includes a memory (not shown) and an input / output buffer (not shown) to receive signals from sensors, output control signals to various devices, and control each device. It should be noted that this control is not limited to software-based processing; it can also be implemented using dedicated hardware (electronic circuitry).

[0043] The input port 220 is configured as a charging connector 410 capable of connecting the charging cable 400. The input port 220 is normally covered by a charging cover 210. When the charging cover 210 is open, the user can connect the charging connector 410 to the input port 220. During AC charging, the charging connector 410 is connected to the input port 220.

[0044] A locking device 250 is provided near the access port 220. The locking device 250 is configured to switch between a locked state and an unlocked state. In the locked state, plugging and unplugging the charging connector 410 (charging cable 400) connected to the access port 220 from the access port 220 is restricted. In the unlocked state, plugging and unplugging the charging connector 410 connected to the access port 220 from the access port 220 is allowed.

[0045] The charger 200 is electrically connected between the battery 100 and the input port 220. The charger 200 includes, for example, an AC / DC converter, a DC / AC converter, and an insulation transformer. The charger 200 converts the power received from the charging device 500 via the input port 220 into power for charging the battery 100 and supplies this power to the battery 100. The charger 200 is controlled by the ECU 300.

[0046] Voltage sensor 230 detects the voltage (input voltage) VIN between the power lines CPL and CNL that electrically connect the input port 220 and the charger 200, and outputs a signal indicating its detection result to ECU 300. Voltage sensor 230 can also be located inside the charger 200, for example.

[0047] The current sensor 240 detects the current (charging current) IIN flowing in the power lines CPL and CNL, and outputs a signal indicating its detection result to the ECU 300. The current sensor 240 can also be installed in the charger 200, for example.

[0048] The notification device 600 is configured to include at least one of a display device, a lighting device, and a sound output device. The notification device 600, according to instructions from the ECU 300, causes the display device to display information, or the lighting device to light up, or the sound output device to output sound (e.g., read aloud information).

[0049] Figure 2 This is a diagram illustrating a circuit structure example related to AC charging. Figure 2 In the middle, the charging connector 410 of the charging cable 400 is connected to the inlet 220.

[0050] The ECU 300 of vehicle 1 receives a connection signal PISW, the potential of which changes according to the connection status between the input port 220 and the charging connector 410. The ECU 300 determines whether the charging connector 410 is connected to the input port 220 based on the potential of the connection signal PISW.

[0051] Additionally, when the charging cable 400 is connected to the charging device 500 and the input port 220, the ECU 300 receives the pilot signal CPLT from the CCID 430 of the charging cable 400 via signal line L1. The pilot signal CPLT is used to notify the ECU 300 of the rated current of the charging cable 400 from the CPLT control circuit 470. Furthermore, the pilot signal CPLT is used by the ECU 300 operating potential of the vehicle 1 as a signal for remotely operating the CCID relay 450 from the ECU 300.

[0052] The CCID 430 within the charging cable 400 includes a CCID relay 450, a CCID controller 460, a CPLT control circuit 470, an electromagnetic coil 471, a leakage current detector 480, a voltage sensor 481, and a current sensor 482.

[0053] CCID relay 450 is located in the power supply path to vehicle 1 and is controlled by CPLT control circuit 470. When CCID relay 450 is in the open state, the power supply path is cut off, and power cannot be supplied to vehicle 1 from charging device 500. When CCID relay 450 is in the closed state, power can be supplied to vehicle 1 from charging device 500 via charging cable 400.

[0054] The CCID control unit 460 includes a CPU, memory, input / output ports, etc. (not shown), performs input / output of signals from various sensors and the CPLT control circuit 470, and controls the operation of the CPLT control circuit 470.

[0055] The CPLT control circuit 470 outputs a pilot signal CPLT to the ECU 300 via the charging connector 410 and the input port 220. The pilot signal CPLT, derived from the operating potential of the ECU 300 of vehicle 1, serves as a signal for remotely operating the CCID relay 450 from the ECU 300. The CPLT control circuit 470 controls the CCID relay 450 based on the potential of the pilot signal CPLT. Additionally, the pilot signal CPLT also serves as a signal from the CPLT control circuit 470 to the ECU 300 to notify it of the rated current of the charging cable 400.

[0056] Specifically, the CPLT control circuit 470 includes an oscillation device 472, a resistor R20, and a voltage sensor 473.

[0057] When the potential of the pilot signal CPLT detected by the voltage sensor 473 is a predetermined potential V1 (e.g., 12V), the oscillation device 472 outputs a non-oscillating pilot signal CPLT. When the potential of the pilot signal CPLT drops to a potential V2 (e.g., 9V) that is lower than the predetermined potential V1, the CCID control unit 460 controls the output of a pilot signal CPLT that oscillates at a predetermined frequency (e.g., 1kHz) and duty cycle.

[0058] The duty cycle of the pilot signal CPLT is set according to the rated current of the charging cable 400. The ECU 300 of vehicle 1 can detect the rated current of the charging cable 400 based on the duty cycle of the pilot signal CPLT received from the CPLT control circuit 470 via signal line L1.

[0059] When the potential of the pilot signal CPLT drops to V3 (e.g., 6V), which is lower than V2, the CPLT control circuit 470 supplies current to the electromagnetic coil 471. When current is supplied from the CPLT control circuit 470 to the electromagnetic coil 471, the electromagnetic coil 471 generates an electromagnetic force, and the CCID relay 450 closes. As a result, the supply voltage (the voltage from the charging device 500) is applied to the inlet 220 of the vehicle 1 via the charging cable 400.

[0060] A leakage current detector 480 is located inside the CCID 430, midway along the AC power line 440 of the charging cable 400, to detect any leakage current. Specifically, the leakage current detector 480 detects the balance of currents flowing in opposite directions in the power line pairs constituting the AC power line 440. When this balance is disrupted, leakage current is detected. When leakage current is detected by the leakage current detector 480, power supply to the electromagnetic coil 471 is stopped, and the CCID relay 450 is deactivated.

[0061] When the plug 420 of the charging cable 400 is inserted into the socket 520, the voltage sensor 481 detects the power voltage transmitted from the charging device 500 and notifies the CCID control unit 460 of its detected value. Additionally, the current sensor 482 detects the charging current flowing through the AC power line 440 and notifies the CCID control unit 460 of its detected value.

[0062] Resistors R6 and R7 and switch SW20 are provided in the charging connector 410. Resistors R6, R7 and switch SW20, together with power node 350 of ECU 300 in vehicle 1 and pull-up resistor R10 and resistor R5 in interface 220, constitute a circuit for detecting the connection status of charging connector 410 and interface 220.

[0063] Resistors R6 and R7 are connected in series between ground wire L2 and signal line L3. Switch SW20 is connected in parallel with resistor R7. Switch SW20 is, for example, a limit switch; when charging connector 410 is connected to input port 220, the contacts of switch SW20 close. Additionally, switch SW20 is linked to a button (not shown) located on charging connector 410. When charging connector 410 is removed from input port 220, the button is operated by the user. When the button is not pressed, switch SW20 is in the closed state; when the button is pressed, switch SW20 is in the open state.

[0064] According to the circuit structure described above, when the charging connector 410 is not connected to the input port 220, a signal PISW, which is a potential Vx determined by the voltage of the power supply node 350, the pull-up resistor R10, and the resistor R5, is generated on the connection signal line L3.

[0065] When the charging connector 410 is connected to the input port 220 (button not operated), a connection signal PISW is generated on the connection signal line L3, having a potential Vy determined by the voltage of the power supply node 350, the pull-up resistor R10, and resistors R5 and R6. When the button is operated while the charging connector 410 is inserted into the input port 220, a connection signal PISW is generated on the connection signal line L3, having a potential Vz determined by the voltage of the power supply node 350, the pull-up resistor R10, and resistors R5 to R7. Therefore, the ECU 300 can detect the connection status between the charging connector 410 and the input port 220 by detecting the potential of the connection signal PISW.

[0066] It should be noted that the value of resistor R6 can also be selected based on the rated current of charging cable 400. In this case, the ECU 300 of vehicle 1 can detect the rated current of charging cable 400 based on the potential of connection signal PISW when charging connector 410 is connected to input port 220 (button not operated).

[0067] In vehicle 1, in addition to the power node 350 and pull-up resistor R10 mentioned above, ECU 300 also includes CPU 310, resistor circuit 320 and input buffers 330 and 340.

[0068] Resistor circuit 320 is used to operate the potential of the pilot signal CPLT, which is communicated via signal line L1. Resistor circuit 320 includes pull-down resistors R1 and R2 and switches SW1 and SW2. Pull-down resistor R1 and switch SW1 are connected in series between signal line L1, through which the pilot signal CPLT is communicated, and vehicle ground 360. Pull-down resistor R2 and switch SW2 are also connected in series between signal line L1 and vehicle ground 360. Furthermore, switches SW1 and SW2 are controlled to be in an on (connected) state or a non-conducting (disconnected) state according to control signals S1 and S2 from CPU 310, respectively.

[0069] Input buffer 330 is a circuit used to draw the pilot signal CPLT from signal line L1 into CPU 310. Input buffer 340 is a circuit used to draw the connection signal PISW from connection signal line L3 into CPU 310.

[0070] CPU 310 receives the pilot signal CPLT from input buffer 330. Additionally, CPU 310 receives the connection signal PISW from input buffer 340. CPU 310 detects the potential of the connection signal PISW and, based on the potential of the connection signal PISW, detects the connection status between input port 220 and charging connector 410. Furthermore, CPU 310 detects the rated current of charging cable 400 by detecting the oscillation state and duty cycle of the pilot signal CPLT.

[0071] Furthermore, when the charging connector 410 is connected to the access port 220, the CPU 310 controls the switches SW1 and SW2 in the resistor circuit 320 to operate the potential of the pilot signal CPLT, thereby requesting and stopping power supply to the charging device 500. Specifically, the CPU 310 remotely operates the CCID relay 450 within the charging cable 400 by operating the potential of the pilot signal CPLT.

[0072] When the contacts of the CCID relay 450 within the charging cable 400 are closed via remote operation of the CPU 310, AC power from the charging device 500 is supplied to the charger 200, completing the preparation for AC charging. The CPU 310 controls the charger 200 to convert the AC power from the charging device 500 into DC power capable of charging the battery 100 and outputs it to the battery 100. This performs AC charging of the battery 100.

[0073] Figure 3 This is a diagram showing the correspondence between the states of switches SW1 and SW2, the potential of the pilot signal CPLT, and the state of the CCID relay 450. Figure 3 The horizontal axis represents time, and the vertical axis represents the potential of the pilot signal CPLT, the state of switches SW1 and SW2, and the state of CCID relay 450.

[0074] Before time t1, the charging cable 400 is not connected to either the vehicle 1 or the charging device 500. In this state, all switches SW1, SW2 and CCID relay 450 are open, and the pilot signal CPLT is at a potential of 0V.

[0075] At time t1, when the plug 420 of the charging cable 400 is connected to the socket 520 of the charging device 500, the CPLT control circuit 470 receives power from the charging device 500 and generates a pilot signal CPLT. It should be noted that at this time t1, the charging connector 410 of the charging cable 400 is not connected to the input port 220. Furthermore, the potential of the pilot signal CPLT is V1 (e.g., 12V), and the pilot signal CPLT is in a non-oscillating state.

[0076] At time t2, when the charging connector 410 is connected to the input port 220, the potential of the connection signal PISW input to the CPU 310 changes. Based on this change in the potential of the connection signal PISW, the CPU 310 turns on the switch SW2. As a result, the potential of the pilot signal CPLT is reduced to V2 (e.g., 9V) through the pull-down resistor R2.

[0077] When the CCID controller 460 detects that the potential of the pilot signal CPLT has dropped to V2, at time t3, the CCID controller 460 outputs an oscillation command to the oscillation device 472 to cause the pilot signal CPLT to oscillate.

[0078] When the CPU310 detects the oscillation of the pilot signal CPLT, the CPU310 detects the rated current of the charging cable 400 by the duty cycle of the pilot signal CPLT.

[0079] At time t4, if the CPU 310 detects a charging start operation, it will also turn on switch SW1 in addition to switch SW2. As a result, the potential of the pilot signal CPLT is further reduced to V3 (e.g., 6V) through the pull-down resistor R1. The charging start operation can be, for example, pressing the charging start button (not shown) displayed on the HMI device (not shown) of vehicle 1, or pressing the charging start button (not shown) provided on the charging device 500.

[0080] At time t5, if the potential of the pilot signal CPLT drops to V3, the contacts of the CCID relay 450 are closed via the CPLT control circuit 470. Thus, power from the charging device 500 is transferred to the vehicle 1 via the charging cable 400. Subsequently, in the vehicle 1, the charger 200 is controlled by the CPU 310 (see reference). Figure 1 This initiates AC charging of battery 100.

[0081] <Detection and Processing>

[0082] Here, during AC charging, if the charger 200 is activated when there are insufficient connections or near-disconnections in the charging path (from the AC power supply 510 to the input port 220), a voltage drop will occur due to the increased impedance at these locations. Furthermore, if an extension cable is used between the socket 520 of the charging device 500 and the plug 420 of the charging cable 400, the impedance of the charging path also increases, resulting in a voltage drop. When the voltage drop becomes significant, for example, if the input voltage VIN falls below the lower operating limit of the charger 200, the charger 200 will stop. Therefore, it is desirable to properly detect any abnormalities in the impedance of the charging path.

[0083] On the other hand, there is also a situation where the system voltage (the voltage of AC power supply 510) drops. For example, even if the detection value of voltage sensor 230 is obtained to monitor the input voltage VIN of charger 200, it is impossible to properly determine whether the drop in input voltage VIN is caused by an abnormal impedance of the charging path or by a drop in system voltage.

[0084] Therefore, in this embodiment, the ECU 300 of vehicle 1 separately detects impedance abnormalities and system voltage drops in the charging path by performing detection processing, and appropriately detects impedance abnormalities in the charging path. The detection processing includes a first process for temporarily detecting impedance abnormalities in the charging path and a second process for determining impedance abnormalities in the charging path.

[0085] Specifically, firstly, ECU 300 performs the first process with charging connector 410 connected to input port 220. In the first process, ECU 300 compares the input voltage VIN0 before AC charging starts with the input voltage VIN1 after AC charging starts. If the difference Δ1 between the two is above the threshold Vth, ECU 300 temporarily detects an impedance abnormality in the charging path and controls charger 200 to temporarily stop AC charging.

[0086] When ECU300 temporarily detects an impedance abnormality in the charging path during the first process (i.e., when AC charging is temporarily stopped), it proceeds with the second process after the first process.

[0087] In the second process, the ECU 300 acquires the input voltage VIN2, indicating that AC charging has been temporarily stopped, and controls the charger 200 to restart AC charging. The ECU 300 acquires the input voltage VIN3 after AC charging has restarted. The ECU 300 compares the input voltage VIN2 and the input voltage VIN3, and determines whether the difference Δ2 between them is greater than or equal to the threshold Vth. If the difference Δ2 is greater than or equal to the threshold Vth, the ECU 300 determines that there is an impedance abnormality in the charging path (determining an impedance abnormality in the charging path). On the other hand, if the difference Δ2 is less than the threshold Vth, the ECU 300 determines that the difference Δ1 being greater than or equal to the threshold Vth in the first process was caused by a decrease in the system voltage (the voltage of the AC power supply 510). By performing the detection process described above, an impedance abnormality in the charging path can be appropriately determined. It should be noted that the input voltages VIN0, VIN1, VIN2, and VIN3 in this embodiment correspond to the first voltage, second voltage, third voltage, and fourth voltage of this disclosure, respectively.

[0088] The following examples illustrate the detection process in further detail. Figure 4 and Figure 5 This is a timing diagram used to illustrate the detection process. Figure 4 and Figure 5 The table above shows, from top to bottom, the time variations of the system voltage, the input voltage of the charger 200, and the charging current. Figure 4 In this context, we assume a constant system voltage and a high (abnormal) impedance (system impedance) in the charging path. Figure 5 In this case, we assume a situation where the system voltage fluctuates and the impedance of the charging path (system impedance) is low (normal).

[0089] First, refer to Figure 4 This section explains the situation where the system voltage is constant but the impedance of the charging path is abnormal.

[0090] At time t10, the charging connector 410 connects to the input port 220, initiating the charging operation. Consequently, the input voltage VIN from the charging device 500 is applied to the input port 220 (charger 200). When the ECU 300 detects that the charging connector 410 is connected to the input port 220, it begins detection processing and executes the first process.

[0091] At time t11, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN0 input to charger 200 before AC charging begins.

[0092] At time t12, ECU300 controls charger 200 to start AC charging. With the start of AC charging, charging current flows from charging device 500 to vehicle 1 via charging cable 400, and the input voltage VIN of charger 200 decreases.

[0093] At time t13, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN1 input to charger 200 after AC charging begins.

[0094] At time t14, ECU300 calculates the difference Δ1 between input voltage VIN0 and input voltage VIN1, and compares Δ1 with a threshold Vth. The threshold Vth is pre-prepared based on the rated current of the charging cable 400, for example, by pre-storing it in a memory (not shown) of ECU300. The larger the charging current, the greater the voltage drop during AC charging; therefore, the larger the rated current, the larger the threshold Vth is set. Alternatively, a mapping representing the relationship between the threshold Vth and the rated current can be prepared. ECU300 sets the threshold Vth by comparing the rated current with the mapping. Here, due to an impedance anomaly in the charging path, the difference Δ1 becomes a value larger than the threshold Vth. When ECU300 determines that the difference Δ1 is above the threshold Vth, it temporarily detects the impedance anomaly in the charging path and controls the charger 200 to temporarily stop AC charging. As a result, the charging current stops flowing, and the input voltage VIN of the charger 200 rises.

[0095] When an impedance abnormality in the charging path is temporarily detected in the first process, the ECU300 continues the first process and begins the second process.

[0096] At time t15, when AC charging is temporarily stopped, ECU300 obtains a detection value from voltage sensor 230 and stores the detection value as the input voltage VIN2 input to charger 200 when AC charging is temporarily stopped.

[0097] At time t16, ECU300 controls charger 200 again to restart AC charging. As a result, charging current flows again, and the input voltage VIN of charger 200 decreases.

[0098] At time t17, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN3 after AC charging resumes.

[0099] At time t18, ECU300 calculates the difference Δ2 between input voltage VIN2 and input voltage VIN3, and compares Δ2 with the threshold Vth. Here, due to an impedance anomaly in the charging path, Δ2, similar to the difference Δ1 mentioned above, is also a value larger than the threshold Vth. When ECU300 determines that Δ2 is above the threshold Vth, it identifies an impedance anomaly in the charging path and controls charger 200 to stop AC charging. As a result, the charging current stops flowing, and the input voltage VIN of charger 200 rises. Thereafter, ECU300 resumes the state of stopped AC charging.

[0100] ECU 300 can also cause notification device 600 to notify of an impedance abnormality in the charging path, for example. Notification device 600, according to instructions from ECU 300, may display an impedance abnormality in the charging path or emit a sound indicating an impedance abnormality in the charging path.

[0101] Next, refer to Figure 5 This section explains the situation where the impedance of the charging path is normal, but the system voltage fluctuates.

[0102] At time t20, the charging connector 410 connects to the input port 220, initiating the charging operation. Consequently, the input voltage VIN from the charging device 500 is applied to the input port 220 (charger 200). Upon detecting that the charging connector 410 is connected to the input port 220, the ECU 300 begins detection processing and executes the first process.

[0103] At time t21, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN0 input to charger 200 before AC charging begins.

[0104] At time t22, ECU300 controls charger 200 to begin AC charging. With the start of AC charging, charging current flows from charging device 500 to vehicle 1 via charging cable 400, and the input voltage VIN of charger 200 decreases. Since the impedance of the charging path is normal, the decrease in input voltage VIN at this time is greater than... Figure 4 The decrease in input voltage VIN at time t12 is small.

[0105] At time t23, assume the system voltage, i.e., the voltage of AC power supply 510, decreases. As the system voltage decreases, the input voltage VIN of charger 200 also decreases.

[0106] At time t24, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN1 input to charger 200 after AC charging begins.

[0107] At time t25, ECU300 calculates the difference Δ1 between the input voltage VIN0 and the input voltage VIN1, and compares Δ1 with the threshold Vth. Here, since the system voltage decreases after acquiring the input voltage VIN0, the difference Δ1 becomes a value larger than the threshold Vth. When ECU300 determines that the difference Δ1 is above the threshold Vth, it temporarily detects an impedance abnormality in the charging path and controls charger 200 to temporarily stop AC charging. As a result, the charging current stops flowing, and the input voltage VIN of charger 200 rises. Since the impedance of the charging path is normal, the increase in input voltage VIN here is less than... Figure 4 The rise in input voltage VIN at time t14 is small.

[0108] When an impedance abnormality in the charging path is temporarily detected in the first process, the ECU300 continues the first process and begins the second process.

[0109] At time t26, when AC charging is temporarily stopped, ECU300 obtains a detection value from voltage sensor 230 and stores the detection value as the input voltage VIN2 input to charger 200 when AC charging is temporarily stopped.

[0110] At time t27, ECU300 controls charger 200 again to restart AC charging. As a result, charging current flows again, and the input voltage VIN of charger 200 decreases.

[0111] At time t28, ECU300 obtains the detection value from voltage sensor 230 and stores the detection value as the input voltage VIN3 after AC charging resumes.

[0112] At time t29, ECU300 calculates the difference Δ2 between input voltage VIN2 and input voltage VIN3, and compares Δ2 with the threshold Vth. Here, since the impedance of the charging path is normal, the difference Δ2 is smaller than the threshold Vth. When ECU300 determines that the difference Δ2 is less than the threshold Vth, it determines that the difference Δ1 being above the threshold Vth in the first process was caused by a decrease in the system voltage (the voltage of AC power supply 510), and confirms that the impedance of the charging path is normal. In this case, ECU300 then continues AC charging.

[0113] As described above, by performing the detection process of this embodiment, impedance abnormalities in the charging path and system voltage drops can be detected separately, and impedance abnormalities in the charging path can be detected appropriately.

[0114] <Flowchart>

[0115] Figure 6 This is a flowchart illustrating the steps of the detection process performed by ECU 300. It begins when charging connector 410 is connected to input port 220. Figure 6 The processing in the flowchart. For Figure 6 And as will be discussed later Figure 7 , Figure 8 , Figure 10 The process flow (hereinafter referred to as "S") is described in terms of how each step is implemented by the software processing of the ECU300, but some or all of them can also be implemented by hardware (circuit) made in the ECU300.

[0116] In S1, ECU300 determines whether a charging start operation has been performed. If ECU300 determines that a charging start operation has not been performed (NO in S1), it waits for a charging start operation to be performed. If ECU300 determines that a charging start operation has been performed (YES in S1), it proceeds to S3.

[0117] In S3, ECU300 acquires the detection value of voltage sensor 230 as the input voltage VIN0 of charger 200 before AC charging begins.

[0118] In S5, ECU300 sets the threshold Vth by comparing the rated current of the charging cable 400, which is detected based on the duty cycle of the pilot signal CPLT, with the above mapping.

[0119] In the S7, ECU300 controls charger 200 to start AC charging.

[0120] In S9, ECU300 acquires the detection value of voltage sensor 230 as the input voltage VIN1 of charger 200 after AC charging starts.

[0121] In S11, ECU300 determines whether the difference Δ1 between the input voltage VIN0 and the input voltage VIN1 is greater than or equal to the threshold Vth. If ECU300 determines that the difference Δ1 is less than the threshold Vth (NO in S11), it proceeds to S13. If ECU300 determines that the difference Δ1 is greater than or equal to the threshold Vth (YES in S11), it proceeds to S15.

[0122] In S13, since the relationship between input voltage VIN0 and input voltage VIN1 is normal, ECU300 directly continues to perform AC charging.

[0123] In step S15, due to the abnormal relationship between input voltage VIN0 and input voltage VIN1, ECU300 temporarily detects an impedance abnormality in the charging path. At this time, ECU300 controls charger 200 to temporarily stop AC charging.

[0124] In S17, ECU300 acquires the detection value of voltage sensor 230 as the input voltage VIN2 of charger 200 when AC charging is temporarily stopped.

[0125] In S19, ECU300 controls charger 200 to restart the temporarily stopped AC charging.

[0126] In S21, ECU300 acquires the detection value of voltage sensor 230 as the input voltage VIN3 of charger 200 after AC charging restarts.

[0127] In S23, ECU300 determines whether the difference Δ2 between input voltage VIN2 and input voltage VIN3 is greater than or equal to the threshold Vth. If ECU300 determines that the difference Δ2 is less than the threshold Vth (NO in S23), it proceeds to S13. If ECU300 determines that the difference Δ2 is greater than or equal to the threshold Vth (YES in S23), it proceeds to S25.

[0128] In step S25, due to the abnormal relationship between input voltages VIN2 and VIN3, ECU300 determines that the charging path impedance is abnormal. At this time, ECU300 controls charger 200 to stop AC charging.

[0129] In S27, ECU300 controls notification device 600 to notify the user of vehicle 1 that AC charging has stopped due to abnormal impedance of the charging path.

[0130] As described above, the ECU 300 of the vehicle 1 in this embodiment performs a detection process when AC charging begins, detecting impedance abnormalities in the charging path separately from system voltage drops. The ECU 300 performs a first process with the charging connector 410 connected to the input port 220, comparing the input voltage VIN0 before AC charging begins with the input voltage VIN1 after AC charging begins. If the difference Δ1 between the two is greater than or equal to a threshold Vth, the ECU 300 temporarily detects an impedance abnormality in the charging path and controls the charger 200 to temporarily stop AC charging. When the ECU 300 temporarily detects an impedance abnormality in the charging path during the first process, it then performs a second process, comparing the input voltage VIN2 when AC charging is temporarily stopped with the input voltage VIN3 after AC charging resumes, and determining whether the difference Δ2 between the two is greater than or equal to the threshold Vth. If the difference Δ2 is greater than or equal to the threshold Vth, the ECU 300 determines that an impedance abnormality in the charging path has occurred. On the other hand, if the difference Δ2 is less than the threshold Vth, the ECU 300 determines that a system voltage drop has occurred. The system temporarily detects impedance anomalies in the charging path. Based on the input voltage VIN2 during the temporary halt of AC charging and the input voltage VIN3 after AC charging resumes, it detects the impedance anomalies in the charging path, thus appropriately distinguishing between impedance anomalies in the charging path and a drop in system voltage. Therefore, it can accurately detect impedance anomalies in the charging path.

[0131] [Variation Example 1]

[0132] In the implementation, the following example is described: After a temporary impedance anomaly in the charging path is detected, the impedance anomaly in the charging path is determined by a single comparison between the difference Δ2 between the input voltage VIN2 when AC charging is temporarily stopped and the input voltage VIN3 after AC charging resumes, and a threshold Vth. In Variation 1, an example of determining the impedance anomaly in the charging path based on multiple comparisons between the difference Δ2 and the threshold Vth is described.

[0133] Figure 7 This is a flowchart illustrating the detection processing steps of Modified Example 1. Similar to the embodiment, when the charging connector 410 is connected to the input port 220, the process begins from the ECU 300. Figure 7 The processing in the flowchart. It should be noted that, Figure 7 The flowchart is relative to Figure 6 The flowchart has been updated with additional processing steps S30 and S32. Regarding... Figure 7 The flowchart, excluding S30 and S32, includes the following processes: Figure 6 The flowcharts are the same, so the same step numbers are used, and the descriptions are not repeated.

[0134] In the detection processing of Variation Example 1, a variable n is used to represent the number of times the difference Δ2 is above the threshold Vth in the comparison between the difference Δ2 and the threshold Vth. n is a natural number. Figure 7 At the beginning of the flowchart, the value 1 is entered for variable n.

[0135] In S23, when ECU300 determines that the difference Δ2 is above the threshold Vth (YES in S23), it causes the processing to proceed to S30.

[0136] In S30, ECU300 determines whether variable n is a predetermined value M. The predetermined value M is a natural number greater than 2, and it determines the number of times the difference Δ2 is greater than or equal to the threshold Vth in the comparison between the difference Δ2 and the threshold Vth. The predetermined value M can be appropriately set. If variable n is not the predetermined value M, i.e., variable n is smaller than the predetermined value M (NO in S30), ECU300 proceeds to S32. On the other hand, if variable n is the predetermined value M (YES in S30), ECU300 proceeds to S25.

[0137] In S32, ECU300 increments the variable n by 1 and returns the processing to S15. Thus, the processing after S15 is repeated, i.e., the difference Δ2 is repeatedly compared with the threshold Vth.

[0138] Then, when variable n reaches a predetermined value M, ECU300 initiates process S25 to determine an impedance anomaly in the charging path. In other words, ECU300 determines an impedance anomaly in the charging path if the differential Δ2 exceeds the threshold Vth for M consecutive times.

[0139] For example, noise or other factors may cause the differential Δ2 to be calculated as a large value. In Modification 1, by determining the impedance anomaly of the charging path when the differential Δ2 is above the threshold Vth for M consecutive times, the detection accuracy of the impedance anomaly of the charging path can be improved.

[0140] [Variation Example 2]

[0141] In the first process, the input voltage VIN1 can also be acquired within a predetermined time period, from the acquisition of input voltage VIN0 to the acquisition of input voltage VIN1. For example, if the time from acquiring input voltage VIN0 to acquiring input voltage VIN1 becomes longer, the possibility of system voltage fluctuations during this period increases. When the system voltage fluctuates during the period from acquiring input voltage VIN0 to acquiring input voltage VIN1, even if the impedance of the charging path is normal, an impedance anomaly of the charging path may be temporarily detected by the first process. When an impedance anomaly of the charging path is temporarily detected, AC charging is temporarily stopped, thus increasing the time required for AC charging.

[0142] By setting the time from acquiring the input voltage VIN0 to acquiring the input voltage VIN1 within a predetermined time period, the differential Δ1 can be acquired during a period of stable system voltage. This suppresses the occurrence of temporary detection of charging path impedance anomalies due to system voltage fluctuations. Therefore, the temporary halt to AC charging accompanying temporary detection can be omitted, and the time required for AC charging can be shortened accordingly.

[0143] Similarly, in the second process, the input voltage VIN3 can also be acquired by making the time from acquiring the input voltage VIN2 to becoming the input voltage VIN3 a predetermined time period. By setting the time from acquiring the input voltage VIN2 to becoming the input voltage VIN3 to a predetermined time period, the differential Δ2 can be acquired during a period when the system voltage is stable. Therefore, it is possible to suppress the situation where the differential Δ2 is judged to be above the threshold Vth due to system voltage fluctuations.

[0144] It should be noted that Modification 2 can also be combined with Modification 1.

[0145] [Variation Example 3]

[0146] In this embodiment, an example is described where the charging device 500 is installed at home or elsewhere, and the user of vehicle 1 connects the plug 420 of the charging cable 400 to a typical household socket 520 for AC charging. The charging device for AC charging may also be, for example, a public charging station (not shown).

[0147] The charging station is equipped with a charging cable, which the user of vehicle 1 cannot disconnect from the charging station. The user of vehicle 1 connects the charging connector located at the front end of the charging cable to the inlet 220 for AC charging.

[0148] In the case of a charging device 500 used in a typical household, there is a high risk of increased impedance in the charging path, such as poor connection between the socket 520 and the plug 420, or the use of an extension cable between the socket 520 and the plug 420. On the other hand, in a charging station, where wiring is installed by the operator, the risk of increased impedance in the charging path is low. Therefore, in Modification 3, the ECU 300 of vehicle 1 performs detection processing when AC charging is performed using the charging device 500, but does not perform detection processing when AC charging is performed using a charging station.

[0149] Whether the AC charging performed uses the AC charging equipment 500 or the AC charging station can be determined, for example, based on the rated current of the charging cable. Typically, the rated current of the charging cable 400 of the charging equipment 500 is less than the rated current of the charging cable of the charging station. A threshold current Ith is predetermined, and by comparing the rated current of the charging cable with the threshold current Ith, it can be determined whether AC charging is using the charging equipment 500 or the charging station. The threshold current Ith can be pre-stored in the memory of the ECU 300.

[0150] The ECU300 detects the rated current of the charging cable based on the duty cycle of the pilot signal CPLT or the potential of the connection signal PISW. The ECU300 compares the rated current with a threshold current Ith. If the rated current is less than the threshold current Ith, the ECU300 determines that AC charging using the charging device 500 is being performed and executes the detection process. If the rated current is greater than or equal to the threshold current Ith, the ECU300 determines that AC charging using a charging station is being performed and does not execute the detection process. Therefore, detection processing can be performed only when required. This eliminates unnecessary processing and saves computational resources.

[0151] It should be noted that Modification 3 can also be combined with Modifications 1 and 2.

[0152] [Variation Example 4]

[0153] In this embodiment, the threshold Vth is set based on the rated current of the charging cable 400. In Variation 4, an example of setting the threshold Vth based on the charging current will be described.

[0154] Figure 8 This is a flowchart illustrating the detection processing steps of Modified Example 4. Similar to the embodiment, when the charging connector 410 is connected to the input port 220, the process begins from the ECU 300. Figure 8 The processing of the flowchart. It should be noted that, Figure 8 The flowchart is relative to Figure 6 The flowchart is as follows: Process S5 is deleted; process S9 is changed to process S40; process S21 is changed to process S44; and processes S42 and S46 are added. Regarding... Figure 8 Other processing of the flowchart, due to... Figure 6 The flowcharts are the same, so the same step numbers are used, and the descriptions are not repeated.

[0155] In S7, when ECU300 controls charger 200 to start AC charging, it causes processing to enter S40.

[0156] In S40, ECU300 acquires the detection value from voltage sensor 230 as the input voltage VIN1 of charger 200 after AC charging begins. Additionally, ECU300 acquires the detection value from current sensor 240 as the charging current.

[0157] In S42, ECU300 reads the mapping between the determined threshold Vth1 and the charging current from the memory, and uses the charging current obtained in S40 as the independent variable to set the threshold Vth1. It should be noted that the mapping used in S42 can be, for example, the mapping described in the embodiment.

[0158] In S11, ECU300 determines whether the difference Δ1 between the input voltage VIN0 and the input voltage VIN1 is greater than or equal to the threshold Vth1. If ECU300 determines that the difference Δ1 is less than the threshold Vth1 (NO in S11), it proceeds to S13. If ECU300 determines that the difference Δ1 is greater than or equal to the threshold Vth1 (YES in S11), it proceeds to S15.

[0159] In S19, when the ECU300 controls the charger 200 to restart the temporarily stopped AC charging, the process enters S44.

[0160] In step S44, the ECU 300 acquires the detection value from the voltage sensor 230 as the input voltage VIN3 of the charger 200 after AC charging resumes. Additionally, the ECU 300 acquires the detection value from the current sensor 240 as the charging current.

[0161] In S46, ECU300 reads the mapping between the determined threshold Vth2 and the charging current from the memory, and sets the threshold Vth2 using the charging current obtained in S44 as the independent variable. It should be noted that the mapping used in S46 can be, for example, the mapping described in the implementation embodiment.

[0162] In S23, ECU300 determines whether the difference Δ2 between input voltage VIN2 and input voltage VIN3 is greater than or equal to the threshold Vth2. If ECU300 determines that the difference Δ2 is less than the threshold Vth2 (NO in S23), it proceeds to S13. If ECU300 determines that the difference Δ2 is greater than or equal to the threshold Vth2 (YES in S23), it proceeds to S25.

[0163] The voltage drop caused by the impedance of the charging path is proportional to the charging current. Therefore, with a large charging current, even if the impedance of the charging path is normal, the voltage drop will be greater. If the same threshold Vth is used, it may be impossible to properly detect impedance anomalies in the charging path when the charging current is small, and impedance anomalies in the charging path when the charging current is large. As described above, by setting thresholds Vth1 and Vth2 according to the charging current, impedance anomalies in the charging path can be properly detected regardless of the magnitude of the charging current.

[0164] It should be noted that a threshold impedance can also be used instead of the threshold Vth. In this case, the ECU300 calculates the impedance by dividing the differential Δ1 by the charging current obtained in S40. Then, the calculated impedance is compared with the threshold impedance, and if the calculated impedance is above the threshold impedance, an impedance anomaly in the charging path is temporarily detected.

[0165] Then, ECU300 divides the differential Δ2 by the charging current obtained in S44 to calculate the impedance. The calculated impedance is then compared to a threshold impedance; if the calculated impedance is above the threshold impedance, an impedance anomaly in the charging path is identified.

[0166] It should be noted that Modification 4 can also be combined with Modifications 1 to 3.

[0167] [Variation Example 5]

[0168] From a long-term perspective, the system voltage can change slowly. Therefore, in Variation 5, an example is given of using the differential value of the input voltage input to charger 200 to detect impedance anomalies in the charging path.

[0169] Figure 9 This is a diagram used to illustrate the detection process in variation example 5. Figure 9 The table shows, from top to bottom, the time variations of the system voltage, the input voltage VIN of the charger 200, the charging current, and the differential value (hereinafter also referred to as "differential value") of the input voltage of the charger 200.

[0170] At time t30, the charging connector 410 connects to the input port 220, initiating the charging operation. Consequently, the input voltage VIN from the charging device 500 is applied to the input port 220 (charger 200). Upon detecting that the charging connector 410 is connected to the input port 220, the ECU 300 begins detection processing and executes the first process.

[0171] At time t31, ECU 300 controls charger 200 to begin AC charging. Upon initiation of AC charging, charging current flows from charging device 500 to vehicle 1 via charging cable 400, and the input voltage VIN of charger 200 decreases. During AC charging, ECU 300 acquires detection values ​​from voltage sensor 230 at predetermined intervals and calculates a differential value. ECU 300 then compares the differential value with a threshold value Vdth. The threshold value Vdth is predetermined based on statistics of past system voltage fluctuations and is stored in ECU 300's memory. If the differential value exceeds the threshold value Vdth, ECU 300 temporarily detects an impedance anomaly in the charging path.

[0172] exist Figure 9 In the example shown, at time t32, the system voltage begins to decrease slowly. The system voltage decreases slowly over a long period of time.

[0173] For example, in a structure that temporarily detects impedance anomalies in the charging path based on variations in the input voltage VIN, for instance, at time t32, if the voltage drop relative to the input voltage VIN exceeds a threshold Vth before AC charging begins (during the period from time t30 to time t31), an impedance anomaly in the charging path is temporarily detected. Thus, even though the impedance of the charging path is normal, AC charging will temporarily stop. Therefore, by using a differential value, it is possible to suppress the temporary detection of impedance anomalies in the charging path when the impedance of the charging path is normal.

[0174] Figure 10 This is a flowchart illustrating the steps of the detection process performed in Modified Example 5. Similar to the embodiment, when the charging connector 410 is connected to the input port 220, the process begins from the ECU 300. Figure 10 The processing in the flowchart.

[0175] In S50, ECU300 determines whether a charging start operation has been performed. If ECU300 determines that a charging start operation has not been performed (NO in S50), it waits for a charging start operation to be performed. If ECU300 determines that a charging start operation has been performed (YES in S50), it proceeds to S52.

[0176] In S52, ECU300 reads the memory threshold Vdth from the unillustrated memory.

[0177] In S54, ECU300 controls charger 200 to start AC charging.

[0178] In S56, ECU300 acquires the detection value from voltage sensor 230 as the input voltage VIN. It should be noted that after the start of this flowchart, during the initial execution of S56, the process is executed twice at a predetermined periodic interval.

[0179] In S58, ECU300 calculates the differential value based on the previously acquired input voltage VIN and the input voltage VIN acquired in S56. It should be noted that after the start of this flowchart, during the initial execution of S56, ECU300 calculates the differential value based on the two input voltages VIN acquired in S56.

[0180] In S60, ECU300 determines whether the differential value is above the threshold Vdth. If ECU300 determines that the differential value is less than the threshold Vdth (NO in S60), it causes the process to proceed to S62. If ECU300 determines that the differential value is above the threshold Vdth (YES in S60), it causes the process to proceed to S64.

[0181] In S62, since the differential value is normal, ECU300 continues to perform AC charging directly.

[0182] In S64, because the derivative value is an abnormal value, ECU300 temporarily detects an impedance abnormality in the charging path. At this time, ECU300 controls charger 200 to temporarily stop AC charging.

[0183] In S66, ECU300 controls charger 200 to restart the temporarily stopped AC charging.

[0184] In S68, ECU300 acquires the detection value of voltage sensor 230 twice at predetermined periodic intervals as input voltage VIN.

[0185] In S70, ECU300 calculates the differential value based on the input voltage VIN obtained in S68.

[0186] In S72, ECU300 determines whether the differential value is above the threshold Vdth. If ECU300 determines that the differential value is less than the threshold Vdth (NO in S72), it causes the process to proceed to S62. If ECU300 determines that the differential value is above the threshold Vdth (YES in S72), it causes the process to proceed to S74.

[0187] In S74, due to the abnormal derivative value, ECU300 determines that the charging path impedance is abnormal. At this time, ECU300 controls charger 200 to stop AC charging.

[0188] In S76, ECU300 controls notification device 600 to notify the user of vehicle 1 that AC charging has stopped due to abnormal impedance of the charging path.

[0189] As mentioned above, when the system voltage changes slowly over a long period of time, by using the differential value, it is possible to suppress the situation where the impedance of the charging path is temporarily detected as abnormal when the impedance of the charging path is normal.

[0190] The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of this disclosure is defined not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A vehicle configured to receive power supplied via a charging cable from an external power source to charge an onboard battery, characterized in that, The vehicles include: The input port is configured to connect to a connector provided on the charging cable; A voltage sensor detects an input voltage, which is the voltage input from the power source to the interface; and The control device is configured to perform detection processing when the connector is connected to the interface. The detection process includes: The first process involves temporarily stopping charging if the difference between the input voltage before charging begins (i.e., the first voltage) and the input voltage after charging begins (i.e., the second voltage) is greater than or equal to a threshold value; and In the second process, charging is stopped if the difference between the input voltage (third voltage) when charging was temporarily stopped in the first process and the input voltage (fourth voltage) after charging resumes is greater than or equal to the threshold value. When the difference between the third voltage and the fourth voltage is greater than or equal to the threshold, it is determined that the charging path impedance is abnormal. When the difference between the third voltage and the fourth voltage is less than the threshold, it is determined that the difference between the first voltage and the second voltage exceeding the threshold is due to a decrease in system voltage. The threshold is prepared in advance based on the rated current of the charging cable. A mapping representing the relationship between the threshold and the rated current is prepared in advance, and the threshold is set by comparing the rated current with the mapping.

2. The vehicle according to claim 1, characterized in that, In the first process, if the difference between the first voltage and the second voltage is greater than or equal to the threshold, the control device temporarily detects an impedance anomaly in the charging path from the power source to the interface. In the second process, if the difference between the third voltage and the fourth voltage is above the threshold, the control device determines that the charging path has an impedance anomaly.

3. The vehicle according to claim 2, characterized in that, In the second process, if the difference between the third voltage and the fourth voltage is less than the threshold, the control device allows charging to continue.

4. The vehicle according to claim 2 or 3, characterized in that, The voltage sensor repeatedly detects the third voltage and the fourth voltage, and In the second process, if the difference between the third voltage and the fourth voltage is above the threshold multiple times consecutively, the control device determines that the charging path has an impedance anomaly.

5. The vehicle according to any one of claims 1 to 3, characterized in that, In the first process, the control device acquires the second voltage within a predetermined time period from the acquisition of the first voltage. In the second process, the control device acquires the fourth voltage within the predetermined time period starting from the acquisition of the third voltage.

6. The vehicle according to any one of claims 1 to 3, characterized in that, Also includes: A current sensor that detects the current from the power input to the interface, i.e., the input current. The control device sets the threshold based on the input current.

7. The vehicle according to any one of claims 1 to 3, characterized in that, The control device compares the rated current of the charging cable with a predetermined threshold current. If the rated current is above the predetermined threshold current, the detection process is not performed.

8. A vehicle configured to receive power supplied via a charging cable from an external power source to charge an onboard battery, characterized in that, The vehicles include: The input port is configured to connect to a connector provided on the charging cable; A voltage sensor detects an input voltage, which is the voltage input from the power source to the interface; and The control device is configured to perform detection processing when the connector is connected to the interface. The detection process includes: The first process involves temporarily stopping charging when the change in the input voltage per unit time exceeds a threshold value; and The second process involves stopping charging if, after charging has been temporarily stopped in the first process and then resumes, the change in the input voltage per unit time exceeds the threshold value. If, after charging is temporarily stopped in the first process and then resumes, the change in the input voltage per unit time exceeds the threshold, it is determined that there is an impedance abnormality in the charging path. If, after charging is temporarily stopped in the first process and then resumes, the change in input voltage per unit time is less than the threshold, it is determined that the change in input voltage per unit time exceeding the threshold in the first process is due to a decrease in system voltage. The threshold is prepared in advance based on the rated current of the charging cable. A mapping representing the relationship between the threshold and the rated current is prepared in advance, and the threshold is set by comparing the rated current with the mapping.

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