Electric vehicle

Abstract

The present invention achieves a balance between convenience and safety by allowing a high-voltage circuit including a drive system to be started when safety can be secured even when deterioration of insulation of the high-voltage circuit of an electric vehicle is detected. When insulation deterioration is detected and a high-voltage circuit (22) is being started, a lock mechanism is brought into a locked state. When a predetermined condition is satisfied after the high-voltage circuit (22) is stopped, it is determined whether or not unintended energization of a quick charging contactor (35) has occurred. When the determination indicates that the energization has occurred, the locked state is continued, and, when the determination indicates that the energization has not occurred, the locked state is released, and, when the determination indicates that the energization has occurred, starting of the high-voltage circuit (22) is permitted only during traveling, and, when the determination indicates that the energization has not occurred, starting of the high-voltage circuit (22) is permitted.

Description

Electric vehicle

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

[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 also allow external charging from an external power source. Since high voltages of 300 V or higher flow through the batteries of these electric vehicles and circuits charged from external power sources, 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, if the power to the drive system is uniformly cut off when the insulation performance of the high-voltage circuit decreases, the broken-down vehicle must be towed by a wrecker to move it to the responsible dealer. Especially when such a situation occurs when the vehicle is out, the driver and passengers will be unable to return home.

[0005] Accordingly, an object of the present invention is to balance convenience and safety by allowing the activation of a high-voltage circuit including a drive system when safety can be ensured even when it is detected that the insulation performance of the high-voltage circuit has decreased.

[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 for connecting a connector when supplying power from an external power source to the battery; 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 locking instruction unit that locks the locking mechanism when the decrease in insulation is detected by the insulation degradation detector and the high-voltage circuit is running; 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 switching unit that maintains the locked state when the main determination unit determines that power is supplied, and releases the locked state when the main determination unit determines 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 control unit may adopt a second solution further comprising: a pre-determination unit that determines whether or not the rapid charging contactor is unintentionally energized during the quasi-leakage current driving state from the time the lock instruction unit gives an instruction to enter the locked state until the high-voltage circuit is stopped; and a lock release unit that, if the pre-determination unit determines that energization is present, continues the locked state, and if the pre-determination unit determines that there is no energization, releases the locked state.

[0008] Furthermore, in the second solution, the present invention may employ a third solution in which the control unit further 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.

[0009] Furthermore, in a third solution, the present invention may employ a fourth solution, wherein the vehicle further has a receiving unit that receives a signal from the vehicle's key, and the condition for the control unit to execute the contactor operating unit is that the distance between the key and the receiving unit is greater than or equal to a predetermined distance.

[0010] Furthermore, in the second to fourth solutions of this invention, a fifth solution can be adopted, wherein the control unit further comprises a history unit that records when the pre-determination unit determines that power is supplied, and the predetermined condition is the condition in which the history unit has recorded when power is supplied and the vehicle is in a running state.

[0011] Furthermore, in the first to fifth solutions of this invention, a sixth solution may be adopted, wherein the vehicle has a notification unit that notifies the driver that the locked state continues when the main determination unit determines that power is supplied when the restart permission unit is executing.

[0012] Furthermore, in the first to sixth solutions of this invention, a seventh solution may be adopted, wherein the vehicle has a location information acquisition unit that acquires location information of the vehicle, the control unit further has a home location registration unit that registers the location of the home parking lot, and the restart permission unit prohibits the next activation of the high-voltage circuit if the determination of the main determination unit is that power is supplied and the location information obtained by the location information acquisition unit corresponds to the location of the home parking lot.

[0013] This invention enables the activation of the high-voltage circuit while ensuring safety. This is possible because, even if a decrease in the insulation of the high-voltage circuit or the battery is detected, the possibility of the driver touching the charging lid, as in driving, can be ignored, and it can be confirmed that the rapid charging contactor is not causing unintended energization. As a result, the high-voltage circuit can be activated without the driver suffering from electrical leakage. This allows the driver to activate the high-voltage circuit and drive the vehicle directly to the dealer, or to leave the vehicle at home and contact the dealer, thus avoiding being isolated with a vehicle that cannot be operated while out and about.

[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 timing chart when determining the presence or absence of power and prohibiting the activation of the high-voltage circuit in an embodiment of the vehicle according to this invention Example timing chart when determining the presence or absence of power and not prohibiting the activation of the high-voltage circuit in an embodiment of the vehicle according to this invention Example flow diagram when insulation degradation is detected while driving Subflow in the pre-determination unit of Figure 6 Subflow in the main determination unit of Figure 6 Example flow diagram when insulation degradation is detected while other high-voltage circuits are activated

[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 charging port 21 which includes an inlet section for connecting the terminals of a connector 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 from an external source 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) capable of supplying power to an external source may also be used.

[0017] 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.

[0018] Vehicle 10 has a charging lid 24 that covers the charging port 21. While the charging lid 24 is covering the port, the operator cannot touch the charging port 21. If vehicle 10 has two charging ports 21, a fast charging port 21a and a normal charging port 21b, the charging lid 24 may cover each charging port 21a and 21b individually (fast charging lid 24a, normal charging lid 24b), or it may cover both ports together. If they are covered together, the fast charging port 21a and the normal charging port 21b are located 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 normal charging port 21b share some of their terminals include Combined Charging System (CCS) Type 1 and Type 2. One example of a specification where the fast charging port 21a and the standard charging port 21b share all of their terminals is NACS (North American Charging Standard). Figure 1 shows an example where each port is blocked individually, and the following explanation will also generally show the case where each port is blocked individually. Here, standard charging is the basic charging specification, and fast charging is a specification that charges at a higher voltage and faster than standard charging.

[0019] The vehicle 10 has a locking mechanism 25 to prevent the charging lid 24 from opening unintentionally. If there are multiple charging lids 24, the locking mechanism 25 may be provided for each charging lid 24. Figure 1 shows an embodiment in which a rapid charging locking mechanism 25a for locking the rapid charging lid 24a and a normal charging locking mechanism 25b for locking the normal charging lid 24b are provided.

[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 locking instruction unit that detects a decrease in the insulation performance of the high-voltage circuit 22 and, when the high-voltage circuit 22 is running, locks the locking mechanism 25 (rapid charging locking mechanism 25a and normal charging locking mechanism 25b). In other words, it closes the rapid charging lid 24a and the normal charging lid 24b, preventing the operator, passengers, or people in the vicinity from coming into contact with the rapid charging port 21a and the normal charging port 21b.

[0032] The control unit 11 has a start / stop unit that stops the high-voltage circuit 22 when it is determined to be necessary at the timing when the lock instruction unit is activated. When it is determined to be necessary, for example, when the vehicle has finished driving and can make contact with the rapid charging port 21a.

[0033] 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.

[0034] The control unit 11 has a lock release unit that maintains the locked state of the lock mechanism 25 if the pre-determination unit determines that power is supplied, and releases the locked state of the lock mechanism 25 if the pre-determination unit determines that power is not supplied. If the pre-determination unit determines that power is supplied, there is a risk that current may leak from the high-voltage circuit 22 if the vehicle body 10a and the charging port 21 (especially the rapid charging port 21a) are touched. Therefore, safety is ensured by maintaining the locked state of the lock mechanism 25 to prevent the driver or other persons from touching it. On the other hand, if the pre-determination unit determines that power is not supplied, it is determined that there is no risk of current leaking from the high-voltage circuit 22 even if touched, so there is no need to keep the lock mechanism 25 locked, and the lock state is released. After executing the pre-determination unit to determine whether or not unintended power is supplied, the main determination unit is executed if predetermined conditions are met. That is, even if the pre-determination unit determines that unintended power is supplied, the situation may improve afterward and unintended power supply may no longer occur. The main determination unit mainly makes a determination in such cases.

[0035] 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.

[0036] 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.

[0037] 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, the rapid charging contactor 31 will no longer supply power unintentionally, and the risk of electric shock from contact with the charging port 21 (rapid charging port 21a, normal charging port 21b) is considered to be almost 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 efforts will be made to ensure safety by maintaining the locked state.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] To achieve this, it is preferable that the vehicle 10 has a location information acquisition unit 45 that acquires the location information of the vehicle 10 itself, and a home location registration unit that registers the location of the home parking lot. The location information acquisition unit 45 should be equipped with an antenna and processing software that supports satellite positioning systems such as GPS (Global Positioning System) and "Michibiki". With these location information acquisition units 45, the vehicle 10 can determine its own current location. On the other hand, as part of the functions of the control unit 11, the home location registration unit registers the location of the home parking lot in a format that can be compared with the current location from the location information acquisition unit 45 to a storage device equipped in the control unit 11 or an external storage device linked to it. For registration, it is convenient if the vehicle 10 has software that can register the location by visually viewing it on a map in conjunction with the car navigation system or the like equipped in the vehicle. Note that the home parking lot does not have to be the location of the house itself, but it is more preferable to register the location of a parking lot used at home, as the distance from the house to the parking lot may be considerable. It is convenient if the format for registering the home parking lot location allows for the registration of latitude and longitude values. If the location information of the vehicle 10 acquired by the location information acquisition unit 45 is compared with the location information of the home parking lot registered in the home location registration unit and the error is within a range of a few meters to several tens of meters, it can be determined that the location corresponds to the home parking lot. This is because some degree of error is unavoidable, such as when the home parking lot is located between buildings.

[0042] The pre-determination section determines whether unintended energization of the quick charging contactor 31 occurs in a pre-leakage traveling state from when the lock instruction section issues an instruction to enter a locked state until the start / stop section stops the high-voltage circuit 22. Here, the pre-leakage traveling state refers to a state where insulation performance has decreased and electric leakage may occur, regardless of whether electric leakage itself has occurred. It is preferable that the control unit 11, when the pre-determination section determines that energization is present, includes a history section for recording the fact of energization in an available storage device. Referencing data from the history section enables prompt processing in subsequent determinations.

[0043] The main determination section determines whether unintended energization of the quick charging contactor 31 occurs when a predetermined condition is satisfied after the high-voltage circuit 22 is stopped by the start / stop section. Here, the predetermined condition may be a condition that the history section has recorded a case where energization is present and the vehicle 10 has entered a traveling state. This is because, even after the pre-determination section determines that unintended energization is present, once the vehicle is in a traveling state, it is almost impossible to touch the charging port 21, so a state that is relatively safe against electric shock from contact can be ensured.

[0044] In the actual operation of the vehicle 10 according to the present invention, a timing chart showing an example of a procedure for determining whether unintended energization of the quick charging contactor 31 (31p, 31n) occurs after detecting a decrease in insulation performance of the high-voltage circuit 22 will be described with reference to FIGS. 4 and 5. The procedure described herein is applicable to both the pre-determination section and the main determination section. Both the embodiments shown in FIG. 4 and FIG. 5 are examples where a decrease in insulation performance is detected during traveling and the presence or absence of unintended energization is determined. FIG. 4 is an example where activation of the high-voltage circuit 22 is limited to during traveling when energization is present; however, in the example shown herein, since the determination is performed after traveling, the example is one where activation of the high-voltage circuit 22 is prohibited. On the other hand, FIG. 5 is an example where activation of the high-voltage circuit 22 is permitted.

[0045] In the case of Figure 4, first, with the high-voltage circuit 22 turned on while driving (S01), the control unit 11 detects a decrease in insulation performance using the battery management sensor 38 (S02). Upon detecting the decrease in insulation performance, the lock instruction unit is activated and the start / stop unit is executed to stop the high-voltage circuit 22 (S03). Next, the pre-determination unit is executed to determine whether or not there is unintended energization of the rapid charging contactor 31 (S04). Specifically, first the P-side rapid charging contactor 31p is turned on (S05), and then the N-side rapid charging contactor 31n is turned on (S06). Note that the order of S05 and S06 may be reversed. Here, as an example, we show a case where unintended energization occurs on the rapid charging contactor 31p side. When the rapid charging contactor 31n is turned on in S06, a voltage is applied. As a result, the determination result for unintended energization of the rapid charging contactor 31 is energized, and this fact is registered in the history unit (S07). In this state, the activation of the high-voltage circuit 22 is prohibited.

[0046] In the case of Figure 5, the procedure up to S04 is the same as in the case of Figure 4. As a result of the determination by the pre-determination unit, no voltage was detected in either the rapid charging contactor 31p or 31n (S05, S06). Consequently, the determination result for unintended energization of the rapid charging contactor 31 is "no energization," and the activation of the high-voltage circuit 22 is not prohibited (S08).

[0047] Next, the procedure for actually operating the vehicle 10 according to this invention will be explained with reference to the flowchart from Figure 6. First, the driver operates the vehicle 10 to the READY state (S101). This turns on the main contactor 35 and activates the high-voltage circuit 22. Here, READY means that the high-voltage circuit 22 is activated and the drive motor 16 is drivable. Even if the high-voltage circuit 22 is activated, if the drive motor 16 is not drivable, it is not READY. The vehicle is driven in the READY state (S102), and if no decrease in the insulation performance of the high-voltage circuit 22 is detected during driving (S103 → No), the driving is completed successfully and the main contactor turns OFF (S104). In this case, there are no particular restrictions on activating the high-voltage circuit 22 again.

[0048] On the other hand, when a decrease in insulation performance of the high-voltage circuit 22 is detected during traveling (S103→Yes), the control unit 11 executes a lock instruction unit that locks the charging lid 24 (S111). Subsequently, the control unit 11 performs pre-diagnosis by the pre-determination unit (S112).

[0049] FIG. 7 shows a flow of pre-diagnosis performed by this pre-determination unit. It is determined whether or not the rapid charging contactor 31 is conducting electricity unintentionally (S121). As a result, if it is determined that there is no unintended energization at the rapid charging port 21a (no energization) (S122→No), the rapid charging lock mechanism 25a, which is the lock mechanism 25 for the rapid charging lid 24a, is released (S123). This is because safety is ensured even if contact is made in this state. If no other problem occurs in this state, the traveling is ended by the driver's operation, READY is turned off, and the main contactor 35 is turned off (S124). In this case, the traveling itself ends along with the execution of the pre-determination unit, and no particular restriction is imposed on the next activation of the high-voltage circuit 22. It is assumed that in the example shown here, as shown in FIG. 1, the rapid charging port 21a and the normal charging port 21b are provided separately. That is, the charging lid 24 also includes a separate rapid charging lid 24a and a separate normal charging lid 24b, and the lock mechanisms 25 that lock each of them are also separate for the rapid charging lock mechanism 25a and the normal charging lock mechanism 25b.

[0050] On the other hand, if it is determined that there is unintended power supplied to the rapid charging port 21a (power supplied) (S122 → Yes), the main contactor 35 is turned off when the driver finishes driving (S126). In other words, the startup of the high-voltage circuit 22 is temporarily terminated. At this stage, both the rapid charging lock mechanism 25a and the normal charging lock mechanism 25b are kept in a lid-locked state to prohibit both rapid charging using the rapid charging port 21a and normal charging using the normal charging port 21b (S127). However, high-voltage connections other than normal and rapid charging may be permitted if they can be turned on and off separately internally. This is because, with both charging ports 21 locked, safety against electric shock is ensured for the time being, 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 (S128).

[0051] 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 away from the vehicle 10, that is, that the driver or passengers are away from the vehicle 10 (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 / off cycle 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 processing of the pre-determination unit ends (S134).

[0052] 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).

[0053] Figure 8 shows the flow of the main diagnosis performed by this main determination unit. Similar to the pre-determination unit in Figure 7, it determines whether or not the rapid charging contactor 31 is experiencing 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), similar to S123 onwards in Figure 7. If no other problems arise, the driver can end the ride, 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 power flow to the rapid charging port 21a (power flow present) (S152 → Yes), the main determination unit terminates and the process returns to the original flow (S153).

[0054] The process returns to the flow shown in Figure 6 (S153). In this case, since there is a possibility of electric shock if contact is made, 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.

[0055] On the other hand, in the flow shown in Figure 6, 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 S111 continues, it is possible to start the high-voltage circuit 22 while ensuring safety. Once the vehicle 10 starts moving (S162), contact with the charging lid 24 becomes almost impossible, so the main determination unit is executed at this time (S163). The flow in the main determination unit is similar to the flow shown in Figure 8. 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, once the driving is finished and the driver turns off READY and the main contactor 35 is turned off (S166), the high-voltage circuit 22 is disabled when the next vehicle 10 is started (S159).

[0056] 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.

[0057] 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.

[0058] Furthermore, Figure 9 shows the flow when insulation degradation is detected while the high-voltage circuit 22 is activated, other than during driving or charging. The basic flow is the same as in Figure 6, and the processes with the same step number S are the same as in Figure 6. The main contactor 35 is turned on for some process (S101a), and the high-voltage circuit 22 remains activated (S102a). The processes from S103 onwards can be the same as the flow in Figure 6.

[0059] 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 24a Fast Charging Lid 24b Standard Charging Lid 25 Locking Mechanism 25a Fast Charging Locking Mechanism 25b Standard Charging 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 for connecting a connector when supplying power from an external power source to the battery; 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 locking instruction unit that locks the locking mechanism when the decrease in insulation is detected by the insulation degradation detector and the high-voltage circuit is running; 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 switching unit that maintains the locked state when the main determination unit determines that power is supplied, and releases the locked state when the main determination unit determines 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 running 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.

2. The electric vehicle according to claim 1, wherein the control unit further comprises: a pre-determination unit that determines whether or not the rapid charging contactor is unintentionally energized during a quasi-leakage current driving state from the time the lock instruction unit gives an instruction to enter the locked state until the high-voltage circuit is stopped; and a lock release unit that, if the pre-determination unit determines that energization is present, continues the locked state, and if the pre-determination unit determines that there is no energization, releases the locked state.

3. The electric vehicle according to claim 2, wherein the control unit further 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.

4. The electric vehicle according to claim 3, wherein the vehicle further has a receiving unit that receives a signal from the vehicle's key, and the condition for the control unit to execute the contactor operating unit is that the distance between the key and the receiving unit is greater than or equal to a predetermined distance.

5. The electric vehicle according to any one of claims 2 to 4, wherein the control unit further comprises a history unit that records when the pre-determination unit determines that power is supplied, and the predetermined condition is the condition in which the history unit has recorded when power is supplied and the vehicle is in a running state.

6. The electric vehicle according to any one of claims 1 to 5, wherein, when the restart permission unit is executed, the vehicle has a notification unit that notifies the driver that the locked state continues if the main determination unit determines that power is supplied.

7. The electric vehicle according to any one of claims 1 to 6, wherein the vehicle has a location information acquisition unit that acquires location information of the vehicle, the control unit further has a home location registration unit that registers the location of the home parking lot, and the restart permission unit prohibits the next startup of the high-voltage circuit if the determination of the main determination unit is that power is supplied and the location information acquired by the location information acquisition unit corresponds to the location of the home parking lot.

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