Electric automobile

Abstract

The present invention achieves a balance between convenience and safety, even when it is detected that the insulation of a high voltage circuit (22) of an electric vehicle (10) has decreased, by applying a predetermined condition and enabling limited charging when safety can be ensured. The presence or absence of an unintended energization of a quick charging contactor (31) is pre-determined, and the presence or absence of the unintended energization of the quick charging contactor (31) is principally determined after a high voltage circuit (22) is stopped. If the pre-determination indicates the presence of energization, a charging lid (24) that closes a charging port (21) used for quick charging is locked. If either the pre-determination or the principal determination indicates the presence of energization, the locking is continued. If both the pre-determination and the principal determination indicate the absence of energization, the locking is released.

Description

Electric vehicle

[0001] The present invention relates to control for ensuring safety against a decrease in insulation resistance in an electric vehicle.

[0002] Currently, electric vehicles that travel using a motor driven by electric power stored in a battery have become widespread. Among these, the use of electric vehicles whose batteries can be charged by an external power source has been expanding. Among such electric vehicles, there are also plug-in hybrid vehicles that allow the battery to be charged by a generator driven by an engine and can also be charged from an external power source. Since a high voltage of 300 V or more flows through the batteries of these electric vehicles and circuits for external charging from an external power source, there is a risk that a user may get an electric shock if insulation performance decreases and electric leakage occurs. For this reason, when it is detected that the insulation performance of a battery or a high-voltage circuit has decreased, the power of the drive system is cut off to ensure safety (for example, Patent Document 1).

[0003] Japanese Unexamined Patent Publication No. 2016-184995

[0004] However, when the insulation performance of a high-voltage circuit decreases, if the power of the drive system is uniformly cut off including cases where the battery is being charged, even charging becomes impossible, which may cause inconvenience to drivers and passengers.

[0005] Accordingly, an object of the present invention is to achieve a balance between convenience and safety by, even when it is detected that the insulation performance of a high-voltage circuit has decreased, imposing predetermined conditions when safety can be ensured, allowing limited charging to be performed.

[0006] This invention provides, as a first solution, a battery that supplies power to a drive motor that drives a vehicle; a high-voltage circuit that connects the drive motor and the battery; an insulation degradation detector that detects a decrease in insulation in the battery and the high-voltage circuit; a charging port having an inlet portion that connects to the terminals of a connector when power is supplied to the battery from an external power source; a charging lid that closes the charging port; a locking mechanism that locks the charging lid; a rapid charging contactor provided between the high-voltage circuit and the charging port; and a control unit that controls the restart of the high-voltage circuit by driver operation after detecting the decrease in insulation by the insulation degradation detector, wherein the control unit includes a pre-determination unit that determines whether or not the rapid charging contactor is unintentionally energized when the connector is connected, and a main determination unit that determines whether or not the rapid charging contactor is unintentionally energized when predetermined conditions are met after the high-voltage circuit has stopped. The above problem was solved by an electric vehicle having: a lock state continuation unit that locks the charging lid that covers the charging port used for the rapid charging after the connector is disconnected following the completion of the rapid charging when the pre-determination unit determines that power is supplied; a lock state switching unit that continues the locked state when at least one of the pre-determination unit and the main determination unit determines that power is supplied, and releases the locked state when both the pre-determination unit and the main determination unit determine that power is not supplied; and a restart permission unit that permits the activation of the high-voltage circuit to be limited to when the vehicle is in motion when the main determination unit determines that power is supplied, and permits the activation of the high-voltage circuit when the main determination unit determines that power is not supplied.

[0007] Furthermore, in the first solution of this invention, the vehicle has a connector lock mechanism that locks the connector to prevent it from coming loose under predetermined conditions, and the control unit has a connector lock maintenance unit that keeps the connector lock in place until the determination by the pre-determination unit is completed, while rapid charging using the rapid charging contactor which charges at a higher voltage than normal charging is continuing.

[0008] Furthermore, in the second solution, the present invention may employ a third solution, wherein the control unit has a connector locking unit that, if a decrease in insulation is detected by the insulation decrease detector after the rapid charging has finished but before the connector is disconnected, continues to lock the connector until the determination by the pre-determination unit is completed.

[0009] Furthermore, in the first to third solutions of this invention, the vehicle may have a charging port which includes a normal charging port for normal charging and a rapid charging port which is capable of charging at a higher voltage than normal charging, the rapid charging port and the normal charging port which share the charging lid, and the control unit which has a normal charging stop unit which stops the normal charging and terminates the high-voltage circuit when the insulation degradation detection unit detects an insulation degradation during normal charging and the pre-determination unit determines that power is being supplied.

[0010] Furthermore, in the fourth solution, the present invention may employ a fifth solution comprising: a contactor operating unit that repeatedly turns the rapid charging contactor on and off when the pre-determination unit determines that power is supplied; and a normal charging restart unit that, after operating the contactor operating unit, restarts the stopped normal charging when the main determination unit determines that power is not supplied.

[0011] Furthermore, in the first to fifth solutions of this invention, a sixth solution can be adopted in which the control unit restricts the execution of the pre-determination unit during normal charging.

[0012] Furthermore, in the sixth solution of this invention, if the control unit detects a decrease in insulation performance during normal charging, after the normal charging is completed, it can adopt a seventh solution, which involves turning off the main contactor responsible for turning the high-voltage circuit on and off, and then turning off the power to the vehicle.

[0013] This invention ensures safety while charging and provides convenience for drivers and passengers by maintaining a locked state after disconnecting the connector or preventing the connector itself from disconnecting at the necessary time, even when a decrease in the insulation performance of the high-voltage circuit or the battery is detected.

[0014] Functional block diagram of the first embodiment of the vehicle according to this invention Functional block diagram of the second embodiment of the vehicle according to this invention Conceptual diagram of the electric shock situation to be prevented by the vehicle according to this invention Example of a timing chart when insulation degradation is detected during normal charging in an embodiment of the vehicle according to this invention, the presence or absence of current is determined, and the activation of the high-voltage circuit is prohibited Example of a timing chart when insulation degradation is not detected during normal charging in an embodiment of the vehicle according to this invention, the presence or absence of current is determined, and the activation of the high-voltage circuit is not prohibited Example of a timing chart when insulation degradation is detected during rapid charging in an embodiment of the vehicle according to this invention, the presence or absence of current is determined, and the activation of the high-voltage circuit is prohibited Example of a timing chart when insulation degradation is not detected during rapid charging in an embodiment of the vehicle according to this invention, the presence or absence of current is determined, and the activation of the high-voltage circuit is not prohibited Example of a flow when insulation degradation is detected during normal charging Subflow in immediate response of Figure 8 Subflow in the main determination unit of Figure 8 Example of a flow when insulation degradation is detected during rapid charging Subflow in the pre-determination unit of Figure 11 Another flow when insulation degradation is detected during rapid charging Subflow in the pre-determination unit of Figure 13

[0015] The embodiments of this invention will now be described. This invention is a vehicle 10, which is an electric vehicle. A functional block diagram of this embodiment is shown in Figure 1. The vehicle 10 has a drive motor 16 for driving the vehicle and a battery 17 that supplies power to the drive motor 16. The battery 17 is a high-voltage battery, mainly of about 300 to 400V, and is provided separately from the 12V system battery that supplies power to accessories. At present, lithium-ion batteries are often used, but the type of battery is not particularly limited as long as it can output a similar high voltage.

[0016] Vehicle 10 has a high-voltage circuit 22 that connects the drive motor 16 and the battery 17 when READY. Since this high-voltage circuit 22 and the battery 17 have a high voltage exceeding 300V, sufficient insulation is required for the circuit. For this reason, vehicle 10 is equipped with an insulation degradation detector 23 that detects when the insulation of the battery 17 or the high-voltage circuit 22 deteriorates.

[0017] The vehicle 10 has a charging port 21 that includes an inlet section for connecting connector terminals when supplying power from an external power source to the battery 17. Here, as an example, a plug-in hybrid vehicle (PHEV) having an engine 13 and a generator 18 and capable of external charging is described, but an electric vehicle without an engine 13 and a generator 18 may also be used. Although not specifically shown, a plug-in hybrid vehicle (PHEV) equipped with an external power supply capable of supplying power to an external source may also be used. In Figure 1, the vehicle 10 is described as having two charging ports 21: a fast charging port 21a and a normal charging port 21b. Here, normal charging is the basic charging specification, and fast charging is a specification that charges at a higher voltage and faster than normal charging. The fast charging port 21a and the normal charging port 21b are provided adjacent to each other, or some or all of their terminals are shared and they are adjacent or integrated. Examples of specifications in which the fast charging port 21a and the standard charging port 21b share some of their terminals include Combined Charging System (CCS) Type 1 and Type 2. Examples of specifications in which the fast charging port 21a and the standard charging port 21b share all of their terminals include NACS (North American Charging Standard).

[0018] Vehicle 10 has a charging lid 24 that covers the charging port 21. While the charging lid 24 is covering it, the operator cannot touch the charging port 21. The charging lid 24 covers both charging ports 21a and 21b together.

[0019] The vehicle 10 has a locking mechanism 25 to prevent the charging lid 24 from opening unintentionally. The vehicle 10 also has a connector locking mechanism 26 that locks the terminals of the connector inserted into the inlet portion of the charging port 21 to prevent them from coming loose under predetermined conditions.

[0020] The high-voltage circuit 22 is provided with a main contactor 35 (35p, 35n) for switching the high-voltage current entering and leaving the battery 17 on and off. In this specification, p is the positive terminal side and n is the negative terminal side (mainly 0V). When the main contactor 35 is turned off by instruction from the control unit 11, power from the battery 17 will not reach the area to the right of the main contactor 35, and charging of the battery 17 will also stop.

[0021] The high-voltage circuit 22 is provided with rapid charging contactors 31 (31p, 31n) that switch on and off the wiring connected to the positive and negative terminals of the rapid charging port 21a, respectively. When the rapid charging contactors 31 are turned off by an instruction from the control unit 11, power is no longer supplied to the rapid charging port 21a.

[0022] The vehicle 10 has a high-voltage sensor 37 that can check whether or not there is power flowing between the rapid charging contactor 31 and the rapid charging port 21a. Voltage information is transmitted from the high-voltage sensor 37 to the control unit 11, which can check whether or not there is power flowing to the rapid charging port 21a.

[0023] The control unit 11 may be configured as part of the ECU (Electronic Control Unit) responsible for controlling the vehicle 10 itself, or it may be configured as hardware attached separately from the ECU. When the control unit 11 is configured as part of the ECU, it is easy to combine with the hardware used for normal driving and easy to implement.

[0024] Regardless of its configuration, the control unit 11 includes an arithmetic unit, a temporary memory used for calculations, and a non-temporary computer-readable storage medium for storing programs and data. The control unit 11 also has an interface for exchanging data and signals with each component of the vehicle 10. In Figure 1, the thick lines represent the high-voltage lines constituting the high-voltage circuit 22; other lines can be ordinary copper wires or CAN wires.

[0025] The vehicle 10 may have an onboard charger 33 (OBC 33) which, as part of the control unit 11 or in cooperation with the control unit 11, turns the rapid charging contactors 31n and 31p on and off, detects whether or not charging is being done from the normal charging port 21b and whether or not to cut off the charge, determines whether or not insulation has deteriorated and determines whether or not unintended current has been supplied. Figure 1 shows a configuration in which the OBC 33 cooperates with the control unit 11 based on its instructions, but as shown in Figure 2, the OBC 33 may also operate as a control unit 11a in cooperation with the ECU 12 and the BMS 38, etc., which will be described later.

[0026] The vehicle 10 may have a battery management sensor 38 (BMS 38) that controls information related to the battery 17, either as part of the control unit 11 or in cooperation with the control unit 11. Figure 1 shows a configuration in which the BMS 38 collects information and transmits it to the control unit 11, but as shown in Figure 2, the BMS 38 may also operate as a control unit 11a in cooperation with the ECU 12 and OBC 33, etc.

[0027] In addition, the high-voltage circuit 22 may include other devices such as the MCU 39, which is responsible for controlling devices other than the control unit 11.

[0028] Figure 3 shows a conceptual diagram of the situation that the vehicle 10 according to this invention aims to prevent. The inside of the high-voltage circuit 22 is omitted. Assuming the battery 17 is 400V, the vehicle body 10a is grounded and at 0V, while the other terminal of the rapid charging port 21a is at 400V. Even if a person touches the vehicle body 10a and the 400V terminal of the rapid charging port 21a at the same time, normally the vehicle body 10a is insulated from the high-voltage circuit 22, and if the switches of the rapid charging contactors 31n and 31p are off, no electricity will flow and it will be safe. However, if the insulation resistance of a part of the high-voltage circuit 22 decreases ("Case 1" in Figure 3), it becomes possible for leakage current to occur through to the vehicle body 10a. Furthermore, if either the rapid charging contactor 31p or 31n is submerged in water or partially welded, it becomes possible for unintended current to flow ("Case 2" in Figure 3). Here, unintended energization refers to a situation where, despite the contactor being controlled to be off and therefore not energized according to the specifications, energization occurs. This can occur due to low resistance caused by welding, or due to slightly higher resistance caused by water penetration. Other cases where energization occurs contrary to the control are also collectively referred to as unintended energization. When Case 1 and Case 2 overlap, even though the rapid charging contactor 31 is off, there is a risk of electric shock if the vehicle body 10a and the 400V terminal of the rapid charging port 21a are touched simultaneously. Conventionally, safety was ensured by turning off the main contactor 35 and not allowing the high-voltage circuit 22 to start when Case 1 was detected. In the vehicle 10 according to the present invention, the main contactor 35 is turned on and the high-voltage circuit 22 is allowed to start in limited situations where safety can be confirmed.

[0029] The behavior of the vehicle 10 according to the present invention will now be described. First, the control unit 11 has an insulation degradation detection unit that detects a decrease in insulation in the high-voltage circuit 22 using an insulation degradation detector 23. At this stage, even if a leakage current has not actually occurred, it is desirable that the system can detect an insulation degradation when it is confirmed that a state in which a leakage current may occur has been established.

[0030] Furthermore, the control unit 11 has a high-voltage circuit detection unit that detects whether or not the high-voltage circuit 22 is running. Basically, if the main contactor 35 is ON, a high voltage is applied to the high-voltage circuit 22, and it can be determined that it is running.

[0031] The control unit 11 has a start / stop unit that stops the high-voltage circuit 22 when it is determined to be necessary. When it is determined to be necessary, for example, when normal charging or rapid charging is completed and the connector is locked to the inlet, or when the connector is subsequently removed from the inlet and the charging port is blocked by the charging lid 24.

[0032] The control unit 11 has a pre-determination unit and a main determination unit that determine whether or not the rapid charging contactor 31 is unintentionally energized. The pre-determination unit and the main determination unit determine the same object, but the conditions under which they operate are different. Unintentional energization of the rapid charging contactor 31 becomes a problem when the insulation performance of the high-voltage circuit 22 deteriorates. Therefore, when executing the pre-determination unit and the main determination unit, it is advisable to detect the deterioration of insulation performance using the insulation performance deterioration detection unit beforehand or in parallel.

[0033] The control unit 11 has a contactor operating unit that repeatedly turns the rapid charging contactor 31 on and off when the pre-determination unit determines that power is supplied. That is, the control unit 11 instructs the rapid charging contactor 31 to operate the physical switch part of the rapid charging contactor 31. This is because if the reason for power supply is a situation that can be resolved by applying an impact, such as a film of water forming on the surface due to flooding, then physically moving the rapid charging contactor 31 can apply an impact and resolve the power supply situation. The number of on / off cycles and intervals may be set appropriately according to the specifications of the rapid charging contactor 31. Note that it is not necessary to operate both rapid charging contactors 31p and 31n; if it is possible to determine which side is powered, it is sufficient to turn either the powered rapid charging contactor 31p or 31n on or off.

[0034] However, it is preferable to set conditions for operating the contactor activation unit. Turning the contactor on and off often produces a distinct operating sound or switching sound. For this reason, it is desirable to limit the activation of the contactor activation unit to when a person has left the vehicle 10, so as not to startle the driver or passengers. For this purpose, it is preferable for the vehicle 10 to have a receiving unit 41 that receives a signal from the vehicle 10's key 42. Here, the signal may be a generally standardized radio signal. The key 42 is, in principle, held by the driver, and it is assumed that the driver or passenger has left the vehicle 10 when they have moved to a distance where the receiving unit 41 can no longer receive a signal from the key 42. For this reason, the conditions for activating the contactor activation unit can be set to when the distance between the key 42 and the receiving unit 41 is greater than a predetermined distance, or when the receiving unit 41 can no longer receive a signal from the key 42. Other conditions may also be used as conditions for activating the contactor activation unit, as long as they do not startle the driver or others.

[0035] The control unit 11 has a lock state continuation unit that, if a decrease in insulation is detected during rapid charging and the pre-determination unit determines that power is being supplied, locks the charging lid 24 that closes the charging port 21 (rapid charging port 21a) used for rapid charging after the connector has been disconnected following the completion of rapid charging. After the terminals of the connector are disconnected from the inlet, there is a possibility of electric shock if the exposed inlet is touched, but by locking the charging lid 24, safety can be ensured thereafter.

[0036] The control unit 11 has a lock state switching unit that maintains the locked state if the main determination unit determines that power is supplied, and releases the locked state if the main determination unit determines that power is not supplied. Even if the pre-determination unit determines that power is supplied, if the main determination unit subsequently determines that power is not supplied due to a change in circumstances, it is considered that the rapid charging contactor 31 will no longer cause unintended power supply, and the risk of current leakage from the high-voltage circuit 22 even when contacting the charging port 21 (rapid charging port 21a, normal charging port 21b) is virtually eliminated. In that case, it is judged that no problem will occur even if the lock state of the lock mechanism 25 (rapid charging lock mechanism 25a, normal charging lock mechanism 25b) is released. On the other hand, if the pre-determination unit determines that power is supplied, and the main determination unit subsequently determines that power is supplied, there is a risk of current leakage from the high-voltage circuit 22, so the locked state will be maintained to ensure safety.

[0037] The control unit 11 has a restart permission unit that, if the main determination unit determines that power is supplied, permits the activation of the high-voltage circuit 22, but only during driving, and permits the activation of the high-voltage circuit 22, if the main determination unit determines that power is not supplied. Here, whether or not to permit means that when the driver starts the vehicle 10 and tries to drive it, the high-voltage circuit 22 is not activated in response to the driver's operation, but is controlled to be prohibited in predetermined cases. Also, permitting the activation of the high-voltage circuit when power is not supplied means that it is permitted without being limited to driving. That is, when power is supplied, there is a risk of current leakage from the high-voltage circuit 22 if the vehicle body 10a comes into contact with the rapid charging port 21a, so the activation of the high-voltage circuit 22 is permitted only during driving, where the possibility of contact can be almost ignored. On the other hand, when power is not supplied, since the condition has improved after the pre-determination unit determined that power is supplied, it is assumed that there is no longer a risk of current leakage from the high-voltage circuit 22 not only during driving but also when stopped or parked, and the activation of the high-voltage circuit 22 is permitted.

[0038] The control unit 11 has a connector lock maintenance unit that keeps the connector lock mechanism 26 locked while rapid charging using the rapid charging contactor, which charges at a higher voltage than normal charging, is continuing until the determination by the pre-determination unit is completed. Even if unintended current flows through the rapid charging contactor 31, as long as the connector is not detached by the connector lock mechanism 26, it will not be able to contact the inlet portion even if charging is in progress and the high-voltage circuit 22 is activated, thus ensuring safety.

[0039] Furthermore, the control unit 11 has a left-on connector locking unit that, if the insulation degradation detector detects a decrease in insulation after the rapid charging has finished but before the connector is removed, continues to lock the connector locking mechanism 26 until the determination by the pre-determination unit is completed. For example, when normal charging is performed in a charging space provided in the parking lot of a commercial facility, the connector may remain inserted into the inlet for some time even after normal charging is complete. In such cases, safety is not particularly compromised as long as the connector does not come out.

[0040] The control unit 11 has a normal charging stop unit that stops normal charging and terminates the high-voltage circuit 22 if the insulation degradation detector 23 detects an insulation degradation during normal charging and the pre-determination unit determines that power is being supplied. As a result, even if there is a possibility of current leakage from the high-voltage circuit 22, the circuit connecting the normal charging port 21b to the main contactor 35 is closed, thus ensuring safety.

[0041] The control unit 11 has a normal charging restart unit that, when it detects a decrease in insulation during normal charging, and the pre-determination unit determines that power is being supplied, and the contactor operating unit is activated, then the main determination unit determines that power is not being supplied, it restarts the normal charging that had been stopped. Restarting here means continuing the charging that was partially done. In cases where charging is based on charging capacity or charging time, it restarts from the state just before it stopped, rather than starting from the beginning.

[0042] Furthermore, when the restart permission unit is executed, if the main determination unit determines that power is supplied, it is desirable that the driver be able to confirm that the locked state continues. This is to ensure safety and to allow the driver to recognize that the charging port 21 cannot be used because it is locked. For this reason, it is preferable that the vehicle 10 has a notification unit 43 that notifies the driver that the locked state continues in this case. Specifically, the notification unit 43 can be easily confirmed if it is provided on the dashboard in front of the driver, alongside other instruments and meters, as an LED icon display or a screen display using an LCD or organic EL.

[0043] However, if the restart permission unit only permits the activation of the high-voltage circuit 22 when the vehicle is in motion and prohibits its activation at other times, the driver and passengers may be unable to return home if the high-voltage circuit 22 is prohibited from activating when they are away from home, such as on a trip, business trip, or shopping trip. Therefore, it is preferable to limit the condition for prohibiting the activation of the high-voltage circuit 22 to when the vehicle 10 is in the home parking lot. If the driver is at home, they will not be stranded away from home, and they can easily contact their dealer to have the broken-down vehicle 10 picked up.

[0044] As a mechanism for this purpose, it is preferable that the vehicle 10 includes a position information acquisition unit 45 that acquires position information of the vehicle 10 itself, and a home position registration unit that registers the position of a home parking lot. The position information acquisition unit 45 is preferably provided with an antenna compatible with satellite positioning systems such as GPS (Global Positioning System) and Michibiki, and corresponding processing software. By means of these position information acquisition units 45, the vehicle 10 can recognize the current position of the vehicle 10 itself. On the other hand, as a part of the functions of the control unit 11, the home position registration unit registers the position of the home parking lot in a format that can be compared with the current position from the position information acquisition unit 45 in a storage device included in the control unit 11 or an external storage device linked thereto. For registration, it is easy to use if software that enables visual recognition and registration of a position on a map in conjunction with a car navigation system or the like provided in the vehicle 10 is provided. It should be noted that the home parking lot does not need to be the position of the home itself, and it is more preferable to register the position of the parking lot used at home. This is because there are cases where the parking lot is located away from the home. As for the format for registration as the position of the home parking lot, it is easy to use if latitude and longitude values can be registered. If the error between the position information of the vehicle 10 acquired by the position information acquisition unit 45 and the position information of the home parking lot registered in the home position registration unit is within a range of about several meters to several tens of meters, it may be determined that the vehicle is located at the position of the home parking lot. This is because a certain degree of error is unavoidable, such as when the home parking lot is located between buildings.

[0045] Said pre-determination unit determines whether there is unintended energization of the quick charging contactor 31 when said connector is in a connected state to said charging port. It is preferable that when the pre-determination unit determines that energization is present, the control unit 11 includes a history unit that records the fact of the energization in an available storage device. In subsequent determinations, prompt processing can be performed by referring to the data in said history unit.

[0046] The main determination unit determines whether or not the rapid charging contactor 31 is unintentionally energized, after the high-voltage circuit 22 has been stopped by the start / stop unit and predetermined conditions have been met. The predetermined conditions can be that the history unit has recorded the case where energization was present, and a predetermined amount of time has elapsed since the high-voltage circuit 22 stopped and the lid lock mechanism 25 entered the locked state. This is because, after the pre-determination unit has determined that unintentional energization was present, there is a possibility that the water ingress state may be resolved by evaporation after a long period of time has passed, and this unit confirms that it has been resolved. Alternatively, the condition can be that the contactor operation unit has been executed.

[0047] In actually operating the vehicle 10 according to this invention, a timing chart showing an example of the procedure for detecting a decrease in the insulation performance of the high-voltage circuit 22 during normal charging and determining whether or not unintended current has been supplied to the rapid charging contactor 31 (31p, 31n) will be used will be explained with reference to Figures 4 and 5. The procedure described here can be applied to both the pre-determination unit and the main determination unit. Both embodiments in Figures 4 and 5 are examples in which a decrease in insulation performance is detected during normal charging and whether or not unintended current has been supplied is determined. Figure 4 is an example in which the activation of the next high-voltage circuit 22 is restricted when current is supplied, while Figure 5 is an example in which the activation of the next high-voltage circuit 22 is permitted.

[0048] In the case of FIG. 4, first, in a state where the high-voltage circuit 22 is turned on during normal charging (S01), the control unit 11 detects a decrease in insulation via the battery management sensor 38 (S02). Subsequently, the pre-determination unit that determines whether there is unintended energization of the quick charging contactor 31 is executed (S03). Specifically, first, the P-side quick charging contactor 31p is turned on (S04), and then the N-side quick charging contactor 31n is turned on (S05). Note that the order of S04 and S05 may be reversed. Here, as an example, a case where unintended energization occurs on the quick charging contactor 31p side is illustrated. When turning on the quick charging contactor 31n in S05, voltage is applied. As a result, the determination result for unintended energization of the quick charging contactor 31 is that energization is present, and that effect is registered in the history unit (S06). In this state, the next activation of the high-voltage circuit 22 is prohibited. However, at this stage, the high-voltage circuit 22 after normal charging is still in an activated state, so the high-voltage circuit 22 is temporarily stopped (S07). Accordingly, activation of the high-voltage circuit is prohibited thereafter.

[0049] In the case of FIG. 5, the process up to S03 is the same as that in the case of FIG. 4. As a result of the determination by the pre-determination unit, application of voltage was not detected in both the quick charging contactors 31p and 31n (S04, S05). Then, the determination result for unintended energization of the quick charging contactor 31 is that no energization is present, and the next activation of the high-voltage circuit 22 is not prohibited (S08).

[0050] Further, FIGS. 6 and 7 show timing charts illustrating an example of a procedure for determining whether there is unintended energization of the quick charging contactors 31 (31p, 31n) after detecting a decrease in insulation of the high-voltage circuit 22 during quick charging instead of normal charging. FIG. 6 illustrates a case where the determination of unintended energization in the quick charging contactor is that energization is present, and activation of the next high-voltage circuit 22 is not permitted. FIG. 7 illustrates a case where the determination is that no energization is present, and activation of the next high-voltage circuit 22 is permitted. Unlike the examples of FIGS. 4 and 5, during quick charging, the P side and N side of the quick charging contactor are turned on.

[0051] Next, the procedure for actually charging and operating the vehicle 10 according to this invention will be explained with reference to the flowchart from Figure 8. First, the driver connects the connector of the normal charging gun to the inlet portion of the normal charging port 21b in order to perform normal charging on the battery 17 of the vehicle 10 (S101). This turns on the main contactor 35 and activates the high-voltage circuit 22 (S102). If no decrease in the insulation performance of the high-voltage circuit 22 is detected during normal charging (S103 → No), the normal charging is successfully completed and the main contactor turns off (S104). In this case, there are no particular restrictions on activating the high-voltage circuit 22 next.

[0052] On the other hand, if a decrease in the insulation performance of the high-voltage circuit 22 is detected during normal charging (S103 → Yes), the control unit 11 temporarily terminates (stops) normal charging and turns off the main contactor 35 (S111). Accordingly, the driver removes the normal charging gun from the inlet. Subsequently, when the driver closes the charging lid 24, the control unit 11 executes a lock instruction to lock the charging lid 24 (S112). The control unit 11 then executes the contactor operation unit to resolve the issue at this stage (S113).

[0053] Figure 9 shows the flow of immediate response by this contactor operating unit. At this initial stage, since the charging lid 24 is locked, both the rapid charging port 21a and the normal charging port 21b are closed, and both normal and rapid charging are prohibited (S121). In this state, the vehicle 10 itself remains running (S122). This is because subsequent processing requires the vehicle to be running.

[0054] In that state, the receiving unit 41 continues to check whether the key is beyond a predetermined distance by checking whether it can receive a signal from the key 42 (S131). If it is confirmed that the key 42 is beyond the vehicle 10, that is, that the driver and passengers are beyond the vehicle 10 after charging has been set (S131 → Yes), the control unit 11 operates the contactor operating unit which repeatedly turns the rapid charging contactor 31 on and off (S132). If the unintended current flow is caused by a film formed by water ingress, the unit attempts to eliminate the unintended current flow by repelling the water with vibration. After repeating the on and off cycles a predetermined number of times, the vehicle 10 is turned off (S133), and the processing of the pre-determination unit ends (S134). If it is not confirmed that the key 42 is beyond a predetermined distance from the vehicle 10 (S131 → No), the rapid charging contactor 31 is not turned on or off, and the vehicle 10 is turned off as is (S133), and the immediate response process ends (S134).

[0055] Subsequently, the system determines whether the vehicle 10 has been left unattended for a long period of time until the driver requests that the vehicle be started (S141 → No → S142). If the vehicle has been left unattended for a long period of time, it is possible that any unintended energization of the rapid charging contactor 31 due to water ingress may have been resolved by evaporation. If the vehicle 10 has been left unattended for a long period of time (S142 → Yes) and there is no immediate request to start the vehicle (S143 → No), the control unit 11 automatically turns on the main contactor 35 (S144) and starts the high-voltage circuit 22 (S145). Then, the main determination unit is executed (S146).

[0056] Figure 10 shows the flow of this diagnosis by the main determination unit. It determines whether or not the rapid charging contactor 31 is causing unintended energization (S151). If it is determined that there is no unintended energization at the rapid charging port 21a (no energization) (S152 → No), the rapid charging lock mechanism 25a, which is the lock mechanism 25 of the rapid charging lid 24a, is released (S123). If no other problems arise, READY is turned off and the main contactor 35 is turned off (S124). In this case, the power to the vehicle 10 may be turned off at the same time as the execution of the main determination unit. This is because the control unit 11 was performing the determination process spontaneously while there was no driver or the vehicle was not moving. On the other hand, if it is determined that there is unintended energization at the rapid charging port 21a (enough energization) (S152 → Yes), the main determination unit is terminated at the same time as the determination and the flow returns to the original state (S153).

[0057] The process returns to the flow shown in Figure 8 (S153). In this case, since contact could cause current to leak from the high-voltage circuit 22, the locking mechanism 25 (rapid charging lock mechanism 25a) of the charging lid 24 (rapid charging lid 24a) remains locked (S155). In this case, after turning off the main contactor 35 (S156), regardless of the driver's operation requesting the vehicle to start, the high-voltage circuit 22 is disabled when the next vehicle 10 is started (S159). This is to ensure continued safety.

[0058] On the other hand, in the flow shown in Figure 8, regardless of whether the vehicle has been left idle for a long time (S142), if the vehicle is started by the driver, the main contactor 35 is turned on (S161). However, since the locked state of the charging lid 24 from S112 continues, it is possible to start the high-voltage circuit 22 while ensuring safety. If the vehicle 10 starts moving (S162), contact with the charging lid 24 becomes almost impossible, so the main determination unit is executed at this timing (S163). The flow in the main determination unit is similar to the flow shown in Figure 10. Even after the main determination unit has finished its diagnosis, unintended energization to the rapid charging port 21a continues, so the locked state of the charging lid 24 continues (S165). After that, when the vehicle has finished moving and the driver has turned off READY and the main contactor 35 has turned off (S166), the high-voltage circuit 22 is prohibited from starting when the vehicle 10 is started again (S159).

[0059] In either flow, even if the driver operates the system to turn on READY when starting the next vehicle 10, the activation of the high-voltage circuit 22 is prohibited (S159). However, at this stage, the drive motor 16 is still in a drivable state. At this point, the control unit 11 acquires location information from the location information acquisition unit 45 and determines whether or not it corresponds to the location of the home parking lot registered in the home location registration unit. If it does not correspond to the location of the home parking lot, the driver has not yet returned home, so the drive motor 16 is allowed to operate and the vehicle is left drivable. On the other hand, if it does correspond to the location of the home parking lot, the driver has already returned home and is in a state where they can contact their assigned dealer, so the drive motor 16 is also turned off.

[0060] Exceptions may be made to these location-based actions. For example, if the acquired location is clearly farther from the home parking lot than the driving range expected from the remaining SOC of the battery 17, and the vehicle 10 does not have an engine 13, charging is not possible, making it impossible to return home. In this case, the drive motor 16 is stopped even while the vehicle is out, and a request for assistance that can reach that distant location is made through the assigned dealer. On the other hand, if the vehicle has arrived directly at a repair shop where the assigned dealer is located, rather than the home parking lot, repairs can be made there, and the drive motor 16 does not need to be started. In this case, an instruction is sent to the control unit 11 via the user interface, and driving may be prohibited as an exception.

[0061] Furthermore, the flow when a decrease in the insulation performance of the high-voltage circuit is detected between the start and end of rapid charging will be explained with reference to Figure 11. The process corresponding to each step number is basically the same as in Figure 8. The difference from the flow in Figure 8 is that in S101a the rapid charging gun is connected, in S102a rapid charging is performed, and in S104a rapid charging is terminated because no decrease in insulation performance was detected. On the other hand, the process when a decrease in insulation performance is detected is significantly different. The control unit 11 operates the connector lock maintenance unit to lock the connector lock mechanism 26 so that the rapid charging gun cannot be removed (S115a). Then, the pre-determination unit performs a pre-diagnosis.

[0062] Figure 12 shows the flow of the pre-diagnosis performed by this pre-determination unit. It determines whether or not the rapid charging contactor 31 is causing unintended energization (S171). If it is determined that there is no unintended energization at the rapid charging port 21a (no energization) (S172 → No), the rapid charging lock mechanism 25a, which is the lock mechanism 25 of the rapid charging lid 24a, is released (S173). This is because safety is ensured even if contact occurs in this state. If no other problems arise, the driver's operation ends the ride, READY is turned off, and the main contactor 35 is turned off (S174). In this case, the ride itself ends at the same time as the execution of the pre-determination unit, and there are no particular restrictions on starting the next high-voltage circuit 22. In this example, as shown in Figure 1, the rapid charging port 21a and the normal charging port 21b are provided adjacent to each other and can be covered together by a single charging lid 24 and locked together by the lock mechanism 25.

[0063] On the other hand, if it is determined that there is unintended power flowing to the rapid charging port 21a (power flowing) (S172 → Yes), rapid charging is terminated and the main contactor 35 is turned off (S175). In other words, the activation of the high-voltage circuit 22 is temporarily terminated. The driver who has finished rapid charging disconnects the connector of the rapid charging gun from the inlet. At this stage, if the driver also closes the charging lid 24, the control unit 11 locks the lock mechanism 25 (S176). This disables both normal charging and rapid charging (S177). However, high-voltage connections other than normal charging and rapid charging may be permitted if they can be turned on and off separately internally. This is because if both charging ports 21 are locked, safety against the risk of current leakage from the high-voltage circuit 22 is ensured, and it is unlikely that any particular problems will occur even if several other accessories are activated. The vehicle 10 is kept running in this state, and parts other than those related to charging are made operational (S178).

[0064] In this state, the control unit 11 checks whether the key is beyond a predetermined distance by checking whether the receiving unit 41 can receive a signal from the key 42 (S181). If it is beyond that distance, the control unit 11 attempts to resolve the unintended energization by operating the contactor operating unit. Subsequent steps S181 to S184 are the same as S131 to S134 above.

[0065] Furthermore, an alternative flow in the event of a decrease in the insulation performance of the high-voltage circuit during rapid charging will be explained with reference to Figure 13. The corresponding processes for each step are basically the same as in Figures 8 and 11. There are differences in the following points. When rapid charging is completed, the main contactor 35 is turned off (S191). At this time, it is checked whether the rapid charging gun remains connected to the inlet (S192). If the rapid charging gun has been unplugged by the driver shortly after the rapid charging is completed (S192 → No), the charging lid 24 is locked to prohibit both normal charging and rapid charging (S193). Then, the control unit 11 activates the contactor operating unit to attempt to resolve the unintended energization of the rapid charging contactor 31 (S194). After that, it waits for the driver's operation (S141).

[0066] On the other hand, if the rapid charging gun remains connected to the inlet (S192 → Yes), a diagnosis is performed by the pre-determination unit. The flow of this pre-diagnosis by the pre-determination unit is shown in Figure 14. The basic flow is the same as in Figure 12. However, in this flow, the main contactor is turned off in S191, so S196 is added to turn on the main contactor. This is because the high-voltage circuit 22 needs to be activated for the preliminary determination.

[0067] Further embodiments will be described. In an embodiment where a decrease in insulation is detected during normal charging, the control unit 11 may be restricted from executing the pre-determination unit. For example, in the case of Figure 8, the pre-determination unit is not performed, and only the immediate response is performed. During normal charging, this can be done without activating most of the high-voltage circuit 22, including the rapid charging contactor 31. For the control unit 11 to execute the pre-determination unit, the main contactor 35 must be turned on and the high-voltage circuit 22 must be fully activated, but with only the immediate response, this can be avoided, and the processing can be done by simply energizing a part of it, thus greatly reducing the load and effort on the device. Furthermore, there is a possibility that the situation can be resolved by the contactor activation unit alone, such as the immediate response. In this case, after normal charging is completed, the power to the vehicle 10 is turned off after confirming that the main contactor 35 has been turned off.

[0068] 10 Vehicle 10a Body 11, 11a Control Unit 12 ECU 13 Engine 16 Drive Motor 17 Battery 18 Generator 21 Charging Port 21a Fast Charging Port 21b Standard Charging Port 22 High Voltage Circuit 23 Insulation Degradation Detector 24 Charging Lid 25 Locking Mechanism 31, 31p, 31n Fast Charging Contactor 33 Onboard Charger 35, 35p, 35n Main Contactor 37 High Voltage Sensor 38 Battery Management Sensor 39 MCU 41 Receiving Unit 42 Key 43 Notification Unit 45 Location Information Acquisition Unit

Claims

1. A battery that supplies power to a drive motor that drives a vehicle; a high-voltage circuit that connects the drive motor and the battery; an insulation degradation detector that detects a decrease in insulation in the battery and the high-voltage circuit; a charging port having an inlet portion that connects to the terminals of a connector when power is supplied to the battery from an external power source; a charging lid that closes the charging port; a locking mechanism that locks the charging lid; a rapid charging contactor provided between the high-voltage circuit and the charging port; and a control unit that controls the restart of the high-voltage circuit by the driver's operation after detecting the decrease in insulation by the insulation degradation detector, wherein the control unit includes a pre-determination unit that determines whether or not the rapid charging contactor is unintentionally energized when the connector is connected; and a main determination unit that determines whether or not the rapid charging contactor is unintentionally energized when predetermined conditions are met after the high-voltage circuit has stopped. An electric vehicle having: a lock state continuation unit that, when the pre-determination unit determines that power is supplied, locks the charging lid that covers the charging port used for the rapid charging after the connector has been disconnected following the completion of the rapid charging; a lock state switching unit that continues the locked state when at least one of the pre-determination unit and the main determination unit determines that power is supplied, and releases the locked state when both the pre-determination unit and the main determination unit determine that power is not supplied; and a restart permission unit that, when the main determination unit determines that power is supplied, permits the activation of the high-voltage circuit to be limited to when the vehicle is in motion, and permits the activation of the high-voltage circuit when the main determination unit determines that power is not supplied.

2. The electric vehicle according to claim 1, wherein the vehicle has a connector lock mechanism that locks the connector to prevent it from coming loose under predetermined conditions, and the control unit has a connector lock maintenance unit that keeps the connector lock in place until the determination by the pre-determination unit is completed, while rapid charging using the rapid charging contactor which charges at a higher voltage than normal charging is continuing.

3. The electric vehicle according to claim 2, wherein the control unit has a connector locking unit that, if a decrease in insulation is detected by the insulation decrease detector after the rapid charging has finished but before the connector is disconnected, continues to lock the connector until the determination by the pre-determination unit is completed.

4. The electric vehicle according to any one of claims 1 to 3, wherein the vehicle has a charging port, which includes a normal charging port for normal charging and a rapid charging port capable of charging at a higher voltage than normal charging, the rapid charging port and the normal charging port share the charging lid, and the control unit has a normal charging stop unit that stops normal charging and terminates the high-voltage circuit when a decrease in insulation is detected by the insulation decrease detection unit during normal charging and the pre-determination unit determines that power is supplied.

5. The electric vehicle according to claim 4, wherein the control unit comprises a contactor operating unit that repeatedly turns the rapid charging contactor on and off when the pre-determination unit determines that power is supplied, and a normal charging restart unit that, after operating the contactor operating unit, restarts the stopped normal charging when the main determination unit determines that power is not supplied.

6. The electric vehicle according to any one of claims 1 to 5, wherein the control unit restricts the execution of the pre-determination unit during normal charging.

7. The electric vehicle according to claim 6, wherein the control unit detects a decrease in insulation performance during normal charging, and after the normal charging is completed, turns off the main contactor responsible for turning the high-voltage circuit on and off, and then turns off the power to the vehicle.

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