Contact failure determination device for vehicle

Abstract

Provided is a contactor failure determination device for a vehicle that can properly determine a failure of a contactor provided in the vehicle. A detection device that can detect an increase or decrease in a voltage of a second circuit including an external charging device is provided, and when a vehicle start request is issued, a first control that closes one external charging contactor is implemented, a second control that closes a pre-charge contactor is implemented after implementation of the first control, and a third control that closes a main contactor that is not parallel to the pre-charge contactor is implemented after implementation of the second control, and when the detection device detects an increase in the voltage of the second circuit after implementation of the third control, it is determined that the other external charging contactor has failed in a closed state.

Description

TECHNICAL FIELD

[0001] The present application relates to a contactor failure determination device mounted on a vehicle equipped with a plurality of contactors. BACKGROUND

[0002] In the past, in a vehicle, an inverter and a motor are mounted, and electric power is supplied from a battery to the motor via the inverter, and a disconnection and connection device for disconnecting and connecting the electric connection between a circuit having the inverter and the motor and the battery is provided.

[0003] For example, Patent Literature 1 discloses a structure in which a battery (direct current power supply in Patent Literature 1) and a load circuit are connected in a manner capable of electrically disconnecting and connecting by a plurality of relays. Specifically, in the device of Patent Literature 1, a first main relay is provided between a positive electrode terminal of the battery and the load circuit, a second main relay is provided between a negative electrode terminal of the battery and the load circuit, and a pre-charge relay and a resistor are provided in a state of being connected in parallel to the first main relay and the second main relay. In this way, if a device for disconnecting and connecting the electric connection between the battery and the circuit is provided, unnecessary transfer of electric power between the battery and the circuit can be prevented by control of the device.

[0004] However, in the case of failure of the above-described device, the disconnection and connection of the battery and the circuit cannot be properly performed. Thus, it is necessary to diagnose whether the above-described device is in failure. In this regard, in the device of Patent Literature 1, it is configured to open the first main relay in a state in which the second main relay is closed and the pre-charge relay is open at the time of parking, to determine the failure of the first main relay based on the voltage of the load circuit generated at this time, and then to open the second main relay and close the pre-charge relay, and to determine the failure of the second main relay based on the voltage of the load circuit generated at this time.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent No. 4572168

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] Here, in a vehicle in which a motor is mounted as a drive source or the like, there is a case in which a device capable of charging a battery from an external power supply, that is, an external charging device that connects an external power supply and a battery and supplies output electric power of the power supply to the battery, is mounted. In this case, it is desirable to provide a contactor configured to be capable of disconnecting and connecting the electric connection of the external charging device and a circuit connected thereto so as not to generate unnecessary transfer of electric power between the external charging device and other electrical equipment, the battery, and to properly determine the failure of the contactor. SUMMARY

[0010] The present application has been achieved in view of the above-described circumstances, and has an object to provide a contactor failure determination device for a vehicle which can appropriately determine a failure of a contactor provided in the vehicle.

[0011] Technical means for solving the technical problem

[0012] For the above-described technical problem, the present inventors have studied a structure in which a circuit connected to a battery is connected to an external charging device via a contactor (external charging contactor), the contactor which opens and closes the battery and the above-described circuit at the time of starting of the vehicle is closed, and at the same time, the external charging contactor is closed, and a failure of the external charging contactor is determined based on a change in voltage on the external charging device side at that time. However, it has been found that when the contactor on the battery side and the external charging contactor are closed at the same time, a relatively large noise caused by simultaneous closing of a plurality of contactors is generated. In addition, a structure in which the contactor on the battery side is closed and then the external charging contactor is closed has been studied, but in this structure, there is a concern that a relatively high rush current is introduced from the battery to the external charging device side via the circuit. Through the above-described findings, the present inventors have invented the following contactor failure determination device which can appropriately determine a failure of a contactor.

[0013] That is, in the present application is a contactor failure determination device for a vehicle, mounted on a vehicle, the vehicle having: a battery having a positive terminal and a negative terminal; a first circuit including an inverter and a motor; a first main contactor that opens and closes electrical connection of one of the positive terminal and the negative terminal to the first circuit; a second main contactor that opens and closes electrical connection of the other of the positive terminal and the negative terminal to the first circuit; and a pre-charge contactor that is provided in parallel with the first main contactor and opens and closes electrical connection of the one terminal to the first circuit, characterized by having: a second circuit including an external charging device that can supply power from an external power source to the battery to charge the battery; a pair of external charging contacts that open and close electrical connection of positive side lines of the first circuit and the second circuit to each other and electrical connection of negative side lines to each other; a detection device that can detect increase and decrease in voltage of the second circuit; and a control device that controls the first main contactor, the second main contactor, the pre-charge contactor, and each of the external charging contacts in such a manner that these contactors are opened in parking, the electrical resistance between the terminal and the first circuit via the pre-charge contactor is larger than the electrical resistance between the terminal and the first circuit via the first main contactor, when a vehicle start request is issued as a request to start the vehicle, the control device implements first control that closes one of the external charging contacts, after implementation of the first control, implements second control that closes the pre-charge contactor, after implementation of the second control, implements third control that closes the second main contactor, and after implementation of the third control, detects the voltage of the second circuit, and determines failure of the external charging contact (claimed range 1).

[0014] In the device, when a vehicle start request is issued, the above-described first control, second control, and third control are implemented, and one of the external charging contacts, the pre-charge contactor, and the second main contactor are closed in this order. Therefore, it is possible to avoid closing a plurality of contactors at the same time immediately after a vehicle start request is issued, for example, immediately after an occupant performs an operation to start the vehicle, and thus it is possible to avoid generating a large sound accompanying the closing of a plurality of contactors at the same time. Therefore, it is possible to suppress the occupant from feeling a sense of discomfort at the time of starting the vehicle.

[0015] In addition, in the device, after the one terminal of the battery and the first circuit are connected in a state where the resistance is high via the pre-charge contactor, the other terminal of the battery and the first circuit are electrically connected via the second main contactor. Therefore, when the battery and the first circuit are electrically connected, it is possible to prevent a high rush current from flowing from the battery to the first circuit and even to the second circuit, thereby preventing malfunction of the electrical equipment provided in the first circuit and the external charging device.

[0016] Further, in the device, by determining the malfunction of the external charging contactor based on the increase and decrease of the voltage of the second circuit after the implementation of the third control described above, it is possible to appropriately determine the malfunction of the external charging contactor.

[0017] Specifically, by implementing the second control and the third control, the battery and the first circuit are electrically connected. Therefore, even if the one external charging contactor is closed by implementing the first control, as long as the other external charging contactor is normally opened, the first circuit is electrically cut off from the second circuit, and thus the voltage of the second circuit does not increase. In contrast, in a case where the other external charging contactor malfunctions in a closed state, the battery and the second circuit are electrically connected via the first circuit along with the electrical connection of the battery and the first circuit, and the voltage of the second circuit increases.

[0018] In the device, it is preferable that, when the voltage of the second circuit is detected as increasing after the implementation of the third control by the detection device, the control device determines that the other external charging contactor malfunctions in a closed state (claim 2). Therefore, it is possible to appropriately determine the malfunction of the external charging contactor.

[0019] In the above structure, it is preferable that, when the first control is implemented along with the issuance of the vehicle start request, the control device closes the external charging contactor different from the external charging contactor that was closed when the first control was implemented along with the previous vehicle start request (claim 3).

[0020] According to this structure, it is possible to determine the malfunction of two external charging contactors along with at least two vehicle start requests. In addition, by performing the malfunction determination of only one external charging contactor at a time of a vehicle start request, it is possible to shorten the time from the issuance of the vehicle start request to the start of the travel of the vehicle after the malfunction determination.

[0021] In the above structure, it is preferable that, after the implementation of the third control, the control device closes the first main contactor and opens the pre-charge contactor and the one external charging contactor (claim 4).

[0022] According to this structure, after implementation of the third control, the battery and the first circuit are connected in a state in which the resistance is small via the respective main contactors. In addition, the electrical connection of the battery via the external charging contactor and the first circuit to the second circuit is cut off. Therefore, after implementation of the third control, it is possible to supply higher electric power from the battery to the motor provided in the first circuit. Therefore, in the case where the motor functions as a drive source of the vehicle, it is possible to appropriately travel the vehicle.

[0023] In the above structure, it is preferable to provide a second detection device capable of detecting increase and decrease of the voltage of the first circuit, and when the increase of the voltage of the first circuit after implementation of the second control is detected by the second detection device, the control device determines that the second main contactor has failed in a closed state (claim 5).

[0024] If the second contactor normally opens, even if the second control is implemented to close the pre-charge contactor, the battery and the first circuit are electrically cut off. In contrast to this, when the second main contactor has failed in a closed state, the battery and the first circuit are electrically connected by implementation of the second control, and thus the voltage of the first circuit increases. With these, in this structure, when the voltage of the first circuit increases after implementation of the second control, it is determined that the second contactor has failed in a closed state. Therefore, in addition to the external charging contactor, it is possible to appropriately determine whether the second main contactor has failed.

[0025] In the above structure, it is preferable that, when the voltage of the first circuit does not increase after implementation of the third control is detected by the second detection device capable of detecting increase and decrease of the voltage of the first circuit, the control device determines that at least one of the pre-charge contactor and the second main contactor has failed in an open state (claim 6).

[0026] If both the pre-charge contactor and the second main contactor are normal, as long as the third control is implemented and controlled in such a manner that they are closed together, the battery and the first circuit are electrically connected and the voltage of the first circuit increases. In contrast to this, when at least one of the pre-charge contactor and the second main contactor has failed in an open state, even if the third control is implemented, the battery and the first circuit are maintained in an electrically cut-off state, and thus the voltage of the first circuit does not increase. With these, in this structure, when the voltage of the first circuit does not increase after implementation of the third control, it is determined that at least one of the pre-charge contactor and the second main contactor has failed in an open state. Therefore, it is possible to appropriately determine the failure of these contactors.

[0027] In the above structure, it is preferable that the control device, after the implementation of the third control, implement a fourth control that closes the first main contactor, after the implementation of the fourth control, implement a fifth control that opens the pre-charge contactor, and when a decrease in the voltage of the first circuit after the implementation of the fifth control is detected by the second detection device that is capable of detecting an increase or decrease in the voltage of the first circuit, determine that the first main contactor has failed in an open state (claim 7).

[0028] If the first main contactor is normal, because the battery is electrically connected to the first circuit via the first main contactor by the implementation of the fourth control, even if the pre-charge contactor is opened in conjunction with the implementation of the fifth control, the voltage of the first circuit does not decrease. In contrast, when the first main contactor has failed in an open state, the electrical connection of the battery to the first circuit is cut when the pre-charge contactor is opened in conjunction with the implementation of the fifth control, and thus the voltage of the first circuit decreases. With these, in this structure, when the voltage of the first circuit decreases after the implementation of the fifth control, it is determined that the first main contactor has failed in an open state. Thus, the failure of the first main contactor can be appropriately determined.

[0029] In the above structure, it is preferable that the time from the implementation of the second control to the implementation of the third control be shorter than the time from the implementation of the third control to the implementation of the fourth control (claim 8).

[0030] In the above structure, it is preferable that the time from the implementation of the third control to the implementation of the fourth control be longer than the time from the implementation of the fourth control to the implementation of the fifth control (claim 9).

[0031] In the above structure, it is preferable that the time from the implementation of the fourth control to the implementation of the fifth control be longer than the time from the implementation of the first control to the implementation of the second control (claim 10).

[0032] According to such a time setting described above, the failure of the contactors can be further appropriately determined.

[0033] In the above structure, it is preferable that the control device, after the implementation of the third control, in a state in which the first circuit is electrically connected to the battery, implement a sixth control that opens the external charging contactor that was closed at the time of the implementation of the first control, and in the case where it is determined that the other external charging contactor has failed in a closed state, when the voltage of the second circuit is not detected to have decreased by the detection device after the implementation of the sixth control, determine that each of the external charging contactors has failed in a closed state (claim 11).

[0034] Even in the case where the external charging contactor of one side fails in the closed state, as long as the external charging contactor of the other side is normal, when the external charging contactor of the other side is opened in the state where the first circuit is electrically connected to the battery, the electrical connection of the battery to the second circuit is cut off, and thus the voltage of the second circuit drops. In contrast, in the case where the external charging contactor of the other side also fails in the closed state, even if the control is performed in such a manner that the external charging contactor of the other side is opened in the state where the first circuit is electrically connected to the battery, the electrical connection of the battery to the second circuit is maintained, and thus the drop in the voltage of the second circuit does not occur. With these, in the structure in which the control is performed in such a manner that the external charging contactor of the other side is opened, the voltage of the second circuit does not increase or decrease at this time, and in the case where it has been determined that the external charging contactor of one side fails in the closed state, it is determined that the external charging contactor of the other side also fails in the closed state. Thus, the failure of the external charging contactors of both sides can be appropriately determined.

[0035] In the above structure, as the external charging device, a structure can be exemplified in which an AC / DC converter that converts an alternating current into a direct current is provided, and an alternating current power source outside the vehicle is converted into a direct current and supplied to the battery (claim 12).

[0036] In the above structure, it is preferable that the time from when the first control is implemented until when the second control is implemented is shorter than the time from when the second control is implemented until when the third control is implemented (claim 13).

[0037] According to the above time setting, the failure of the contactor can be further appropriately determined.

[0038] Effects of the Invention

[0039] As described above, according to the contactor failure determination device of the vehicle of the present application, the failure of the contactor provided to the vehicle can be appropriately determined. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a diagram schematically showing the structure of a vehicle on which the contactor failure determination device according to the embodiment of the present application is mounted.

[0041] Figure 2 is a block diagram showing the relationship of each controller.

[0042] Figure 3 is a block diagram showing the control system related to the contactor failure determination.

[0043] Figure 4is a flowchart showing a part of the step of contactor failure determination performed when a start request of the vehicle is issued.

[0044] Figure 5 is a flowchart showing a continuation of the step shown in Figure 4

[0045] Figure 6 is a flowchart showing a continuation of the step shown in Figure 5

[0046] Figure 7 is a flowchart showing a step of contactor failure determination performed when the vehicle is stopped.

[0047] Figure 8 is a graph showing a time change of a parameter when a start request of the vehicle is issued, (a) is a graph in a case where the contactor is normal, (b) is a graph of a main voltage in a case where the P-side main contactor is stuck on, (c) is a graph of a main voltage in a case where at least one of the P-side main contactor and the pre-contactor is stuck off, and (d) is a graph of a main voltage in a case where the N-side main contactor is stuck off.

[0048] Figure 9 is a graph showing a time change of a parameter when a start request of the vehicle is issued, (a) is a graph in a case where the contactor is normal, (b) is a graph of an OBC voltage in a case where the subject OBC contactor is stuck on, and (c) is a graph of an OBC voltage in a case where both of the OBC contactors are stuck on.

[0049] Figure 10 is a graph showing a time change of a parameter when the vehicle is stopped.

[0050] Symbol explanation

[0051] 2 high-voltage battery (battery)

[0052] 2a positive terminal

[0053] 2b negative terminal

[0054] 3 low-voltage battery

[0055] 4 electric motor

[0056] 6 inverter

[0057] 30 high-voltage circuit (first circuit)

[0058] 40 OBC circuit (second circuit)

[0059] 41 OBC (external charging device)

[0060] 43 AC / DC converter ​​

[0061] 71 P-side main contact (second main contact, main contact)

[0062] 72 N-side main contact (first main contact, main contact)

[0063] 73 pre-contact (pre-charge contact)

[0064] 81 P-side OBC contact (external charge contact)

[0065] 82 N-side OBC contact (external charge contact)

[0066] 201 PCM (control device)

[0067] SN1 main voltage sensor (detection device)

[0068] SN2 OBC voltage sensor (second detection device) DETAILED DESCRIPTION

[0069] (1) Overall structure of vehicle

[0070] A contact failure determination device of an embodiment of the present application will be described. Figure 1 is a diagram schematically showing the structure of a vehicle 1 on which a contact failure determination device 100 of the present embodiment is mounted. The vehicle 1 is, for example, a four-wheel automobile.

[0071] The vehicle 1 (contact failure determination device 100) has: a high-voltage battery 2; a low-voltage battery 3 having a lower output voltage than the high-voltage battery 2; a high-voltage circuit 30 having a plurality of electrical devices and electrically connected to the high-voltage battery 2; an OBC circuit 40 electrically connected to the high-voltage circuit 30; and a plurality of contacts. In addition, the vehicle 1 has a plurality of controllers including a microprocessor or the like that control each part of the vehicle 1. Furthermore, the high-voltage battery 2 corresponds to the "battery" in the scope of claim, the high-voltage circuit 30 corresponds to the "first circuit" in the scope of claim, and the OBC circuit 40 corresponds to the "second circuit" in the scope of claim.

[0072] (battery)

[0073] The high-voltage battery 2 has a pair of terminals (positive terminal 2a, negative terminal 2b). In the present embodiment, a Li battery (lithium battery) is mounted as the high-voltage battery 2 on the vehicle 1. For example, the high-voltage battery 2 has a plurality of battery assemblies each composed of 12 battery cells connected in 2 rows by 6 columns, and is configured by connecting these battery assemblies in series. In addition, in the present embodiment, a lead battery is mounted as the low-voltage battery 3 on the vehicle 1. For example, the nominal voltage of the high-voltage battery 2 is 24 V, and the nominal voltage of the low-voltage battery 3 is 12 V.

[0074] (High-voltage circuit)

[0075] The high-voltage circuit 30 includes the electric motor 4, the generator 5, the inverter 6, the converter 7, the DC / DC converter 8, the PTC heater 9, the electric compressor 10, and the like as electric devices. In addition, the high-voltage circuit 30 has a P-side high-voltage line 31a as a line of a positive electrode side connected to the positive electrode terminal 2a of the high-voltage battery 2 and an N-side high-voltage line 31b as a line of a negative electrode side connected to the negative electrode terminal 2b of the high-voltage battery 2. Hereinafter, the P-side high-voltage line 31a and the N-side high-voltage line 31b are appropriately collectively referred to as a high-voltage line 31.

[0076] The inverter 6, the converter 7, the DC / DC converter 8, the PTC heater 9, and the electric compressor 10 are connected to the high-voltage line 31, respectively. The electric motor 4 is connected to the high-voltage line 31 via the inverter 6. The generator 5 is connected to the high-voltage line 31 via the converter 7.

[0077] The electric motor 4 is rotated by the electric power supply from the high-voltage battery 2. The electric motor 4 is mounted on the vehicle 1 as a drive source of the vehicle 1, and the output of the electric motor 4 is transmitted to a wheel (not shown) via a drive force transmission device 20.

[0078] The generator 5 is a power generation device for charging the high-voltage battery 2. The vehicle 1 of the present embodiment is a series type hybrid vehicle. That is, an engine 22 that drives the generator 5 is mounted on the vehicle 1, and the generator 5 is driven to rotate by the engine 22 to generate electric power, and the electric power generated by the generator 5 is supplied to the high-voltage battery 2. The engine 22 is, for example, a rotor engine. In addition, the generator 5 is connected to the wheel via the drive force transmission device 20, and the vehicle 1 is capable of regenerating energy at the time of deceleration thereof.

[0079] The inverter 6 is a device that converts direct current into alternating current, and direct current from the high-voltage battery 2 is converted into alternating current and supplied to the electric motor 4. The converter 7 is a device that converts alternating current into direct current, and alternating current generated by the generator 5 is converted into direct current and supplied to the high-voltage battery 2.

[0080] The DC / DC converter 8 is a device that steps down and outputs input electric power, and steps down the output voltage of the high-voltage battery 2 and supplies it to the low-voltage battery 3. A main voltage sensor SN1 that can detect the voltage of the electric power input to the DC / DC converter 8 via the high-voltage line 31, that is, the voltage of the high-voltage circuit 30 is provided to the DC / DC converter 8. The main voltage sensor SN1 corresponds to the "second detection device" in the claimed scope.

[0081] The PTC heater 9 and the electric compressor 10 constitute a refrigeration and heating device 11 of the vehicle 1. Specifically, the PTC heater 9 is a device for heating the interior of the vehicle 1, and the electric compressor 10 is a device for cooling the interior of the vehicle 1. Further, in the present embodiment, a cooling plate (not shown) for cooling the high-voltage battery 2 is provided, and the electric compressor 10 also cools the cooling plate.

[0082] (OBC circuit)

[0083] The OBC circuit 40 includes an OBC (On Board Charger) 41 and an AC charging port 42, and the like. In addition, the OBC circuit 40 has a P-side OBC line 43a as a line on the positive side connected to the P-side high-voltage line 31a, and an N-side OBC line 43b as a line on the negative side connected to the N-side high-voltage line 31b.

[0084] The OBC 41 is a device for charging the high-voltage battery 2 by supplying electric power from the power supply 300 outside the vehicle to the high-voltage battery 2. In the present embodiment, the OBC 41 charges the high-voltage battery 2 by electric power from the alternating-current power supply 300 outside the vehicle. Thus, the OBC 41 has an AC / DC converter 43 as a device for converting alternating current to direct current. The AC charging port 42 is a device for electrically connecting a cable connected to the alternating-current power supply 300 outside the vehicle to the OBC 41. The AC charging port 42 is electrically connected to the OBC 41, and is configured so that a connector provided at the end of the above-described cable is inserted and fitted thereto. The OBC voltage sensor SN2 capable of detecting the voltage of the OBC circuit 40 is provided in the OBC 41. The above-described OBC 41 corresponds to the "external charging device" in the scope of claim, and the OBC voltage sensor SN2 corresponds to the "detection device" in the scope of claim.

[0085] Further, in the present embodiment, the high-voltage battery 2 can also be charged by electric power from a direct-current power supply outside the vehicle. Specifically, the DC charging port 50 is provided in the vehicle 1, the DC charging port 50 is connected to the high-voltage circuit 30 via contactors 51, 52, and is fitted to a connector of a cable connected to a direct-current power supply outside the vehicle to electrically connect the direct-current power supply outside the vehicle to the high-voltage circuit 30.

[0086] (Controller)

[0087] Figure 2is a block diagram showing the relationship of the controllers mounted on the vehicle 1 to each other. The vehicle 1 is mounted with the C-BCM (Center-Body Control Module) 200, the PCM (Power Control Module) 201, the ECM (Engine Control Module) 202, the DMCM (Driver Moor Control Module) 203, the SGCM (Starter Generator Control Module) 204, the BCCM (Battery Charger Control Module) 205, the BECM (Battery Energy Control Module) 206, and the ESU (Electric Supply Unit) 207 as controllers. These controllers 200 to 207 are connected to the low-voltage battery 3 and act by receiving electric power from the low-voltage battery.

[0088] Each of the controllers 200 to 207 mainly performs the following control. The C-BCM 200 controls doors, windows, and the like. The PCM 201 controls devices of the drive system of the vehicle 1. The ECM 202 controls the engine 22. The DMCM 203 controls the inverter 6. The SGCM 204 controls the converter 7. The BCCM 205 controls the OBC 41. The BECM 206 controls the high-voltage battery 2. The ESU 207 controls the refrigeration and heating device 11. These controllers 200 to 207 transfer signals to each other. For example, these controllers 200 to 207 perform CAN (Controller Area Network) communication to each other.

[0089] Here, Figure 2 The HMI device 208 shown is a device that performs display of various information and the like, including a display and the like. In addition, HMI is an abbreviation for Human Machine Interface.

[0090] (Contactors)

[0091] The vehicle 1 is provided with a pair of main contactors 71, 72 (P-side main contactor 71, N-side main contactor 72) as contactors, a pre-charge contactor 73, and a pair of OBC contactors 81, 82 (P-side OBC contactor 81, N-side OBC contactor 82). The contactors are electromagnetic openers including electromagnets, and open and close the electrical connection of two contacts to each other in accordance with the electric power supplied. When the contactors are closed, the two contacts are electrically connected to become a state of being energized, and when the contactors are opened, the two contacts are electrically disconnected to become a state of not being energized.

[0092] (Main contactor)

[0093] The P-side main contactor 71 opens and closes the electrical connection of the positive terminal 2a of the high-voltage battery 2 and the high-voltage circuit 30. Specifically, the two contacts of the P-side main contactor 71 are connected to the positive terminal 2a of the high-voltage battery 2 (specifically, the positive terminal 2a via the positive-side battery line 2d) and the P-side high-voltage line 31a, respectively, and the P-side main contactor 71 opens and closes the electrical connection of the positive terminal 2a of the high-voltage battery 2 and the P-side high-voltage line 31a.

[0094] The N-side main contactor 72 opens and closes the electrical connection of the negative terminal 2b of the high-voltage battery 2 and the high-voltage circuit 30. Specifically, the two contacts of the N-side main contactor 72 are connected to the negative terminal 2b of the high-voltage battery 2 (specifically, the negative terminal 2b via the negative-side battery line 2e) and the N-side high-voltage line 31b, respectively, and the N-side main contactor 72 opens and closes the electrical connection of the negative terminal 2b of the high-voltage battery 2 and the N-side high-voltage line 31b.

[0095] The pre-charge contactor 73 is provided in parallel with one of the main contactors, and opens and closes one of the terminals of the high-voltage battery 2 and the high-voltage circuit 30. Specifically, the two contacts of the pre-charge contactor 73 are connected to one of the terminals of the high-voltage battery 2 and the high-voltage line 31 corresponding thereto, and they are opened and closed by the pre-charge contactor in addition to the main contactor. However, the electrical resistance between one of the terminals of the high-voltage battery 2 and the high-voltage line 31 via the pre-charge contactor 73 is larger than the electrical resistance between one of the terminals of the high-voltage battery 2 and the high-voltage line 31 via the main contactor provided in parallel with the pre-charge contactor 73. Therefore, in a state where both the pre-charge contactor 73 and the main contactor in parallel therewith are closed, current does not flow through the line on the pre-charge contactor 73 side, but flows through the line on the main contactor side which has smaller resistance.

[0096] In the present embodiment, the pre-charge contactor 73 is provided between the negative terminal 2b of the high-voltage battery 2 and the N-side high-voltage line 31b and opens and closes the electrical connection therebetween. The resistance 74 is provided between the pre-charge contactor 73 and the N-side high-voltage line 31b. Hereinafter, the pre-charge contactor 73 will be appropriately referred to as a pre-contactor 73.

[0097] Further, in the present embodiment, the pre-contactor 73 is provided in a manner of opening and closing the negative terminal 2b and the N-side high-voltage line 31b, and in conjunction therewith, the N-side main contactor 72 provided in parallel with the pre-contactor 73 corresponds to the "first main contactor" in the scope of the claims, and the P-side main contactor 71 corresponds to the "second main contactor" in the scope of the claims.

[0098] (OBC contactor)

[0099] The P-side OBC contactor 81 and the N-side OBC contactor 82 open and close the electrical connection of the high-voltage circuit 30 and the OBC circuit 40.

[0100] Specifically, the two contacts of the P-side OBC contactor 81 are connected to the P-side OBC line 43a and the P-side high-voltage line 31a, respectively, and the P-side OBC contactor 81 opens and closes the electrical connection of the P-side OBC line 43a and the P-side high-voltage line 31a. The two contacts of the N-side OBC contactor 82 are connected to the N-side OBC line 43b and the N-side high-voltage line 31b, respectively, and the N-side OBC contactor 82 opens and closes the electrical connection of the N-side OBC line 43b and the N-side high-voltage line 31b.

[0101] The P-side OBC contactor 81 and the N-side OBC contactor 82 correspond to the "external charging contactor" in the scope of the claims.

[0102] (Control structure of contactors)

[0103] Figure 3 is a block diagram showing the control structure of the contactors. Each contactor is mainly controlled by the PCM 201. Specifically, the PCM 201 is supplied with electric power from the low-voltage battery 3. The PCM 201 opens and closes each contactor by switching the supply and stop of electric power from the low-voltage battery 3 to each contactor. The PCM 201 corresponds to the "control device" in the scope of the claims.

[0104] The detection information of various sensors and the operation signals of various switches are input to the PCM 201. Specifically, the detection signals of the main voltage sensor SN1 and the OBC voltage sensor SN2 are input to the PCM 201. Hereinafter, the voltage of the high-voltage circuit 30 detected by the main voltage sensor SN1 will be appropriately referred to as the main voltage, and the voltage of the OBC circuit 40 detected by the OBC voltage sensor SN2 will be appropriately referred to as the OCB voltage.

[0105] The vehicle 1 is provided with a start switch SW1 for an occupant to perform start / stop of the vehicle 1, and an operation signal of the start switch SW1 is also input to the PCM 201. The start switch SW1 is turned off at the time of parking, and when turned on, the PCM 201 determines that a start request of the vehicle 1 (a request for start of the vehicle 1) is issued. When the start request is determined to be issued, the PCM 201 starts the vehicle 1. That is, the PCM 201 starts energization to the controllers 200 to 207 to start them, and becomes a state in which various devices can be operated. Subsequently, driving of the motor 4 is started in accordance with an operation of the driver.

[0106] In addition, when the start switch SW1 is switched from off to on, the PCM 201 opens and closes the contactors in such a manner that the state of each contactor at the time when a prescribed time elapses (in which no contactor failure is determined in the contactor failure determination described later and after the end of the determination) becomes a state in which each main contactor 71, 72 is closed and the precontactor 73 and each OBC contactor 81, 82 are open. In addition, when the start switch SW1 is switched from on to off, the PCM 201 opens and closes the contactors in such a manner that the state of each contactor at the time when a prescribed time elapses becomes a state in which each main contactor 71, 72, the precontactor 73, and each OBC contactor 81, 82 is closed.

[0107] (Contactor failure determination)

[0108] Next, the failure determination of each contactor 71, 72, 73, 81, 82 by the PCM 201 will be described. The failure determination is performed at the time when the start request of the vehicle 1 is issued (when the start switch SW1 is switched from off to on) and at the time of stop of the vehicle 1 (when the start switch SW1 is switched from on to off).

[0109] The PCM 201 performs the failure determination of one of the two OBC contactors 81, 82 (the OBC contactor 81 (82)) at the time when the start request of the vehicle 1 is issued. Then, when the next start request of the vehicle 1 is issued, the failure determination of the other OBC contactor 82 (81) is performed by switching the OBC contactor as the object of the failure determination. That is, the PCM 201 alternately performs the failure determination of the P-side OBC contactor 81 and the failure determination of the N-side OBC contactor 82 at the time when the start request of the vehicle 1 is issued each time.

[0110] Figures 4-6 is a flowchart showing the steps of the failure determination of the contactors at the time when the start request of the vehicle 1 is issued. Figure 7 is a flowchart showing the steps of the failure determination of the contactors at the time of stop of the vehicle 1. Figure 8 and Figure 9It is a graph showing the time changes of various parameters when a start-up request is issued. Figure 10 This is a graph showing the time-varying parameters of vehicle 1 when it comes to a stop. Hereinafter, the contactor being in the closed state will be referred to as "on," and the contactor being in the open state will be referred to as "off." Furthermore, a fault occurring when the contactor is in the closed state will be called "on-sticking," and a fault occurring when the contactor is in the open state will be called "off-sticking."

[0111] Figure 8 (a) indicates the status of the start switch SW1 from top to bottom, the command of PCM201 for the P-side main contactor 71, the N-side main contactor 72, the pre-contactor 73, the OBC contactor 81(82) (object OBC contactor) which is the object of fault determination, and the OBC contactor 82(81) (non-object OBC contactor) which is not the object of fault determination, the main voltage, and the OBC voltage. Figure 8 The curve of the main voltage in (a) is the curve under the condition that the contactor is not faulty. Figure 8 The curve (solid line) in (b) is the curve of the main voltage when the P-side main contactor 71 is determined to be connected and stuck after performing step S7 described later. Figure 8 The curve (solid line) of (c) is the curve of the main voltage when at least one of the P-side main contactor 71 and pre-contactor 73 is disconnected and stuck after implementing step S14 described later. Figure 8 The curve (d) (solid line) represents the main voltage curve when the N-side main contactor 72 is determined to be disconnected due to the implementation of step S26 described later. Figure 8 In (b) to (c), all are represented by a single-dot dash. Figure 8 Part of the main voltage of (a).

[0112] Figure 9 (a) is with Figure 8 The same diagram as (a). On the other hand, Figure 9 The curve (solid line) of (b) is the curve of the OBC voltage when the OBC contactor 81 (82) is determined to be connected and stuck after performing step S16 described later. Figure 9 The curve (c) (solid line) represents the OBC voltage curve when the connection adhesion between both sides of the OBC contactors 81 and 82 is determined by performing step S28 described later. Figure 9 In (b) and (c), a single-dot dash is used to represent the line. Figure 9 The OBC voltage of (a).

[0113] Figure 10 Indicates and Figure 8 (a) and Figure 9 (a) Curves with the same parameters. Furthermore, in Figure 10In the graph of the main voltage, the solid line is a graph in the case where the contactor is not faulty, the one-dot chain line is a graph in the case where at least one of the N-side main contactor 72 and the precontactor 73 is determined to be stuck on by implementing the step S34 described later, and the broken line is a graph in the case where the P-side main contactor 71 is determined to be stuck on by implementing the step S38 described later.

[0114] (Fault determination processing at startup)

[0115] Figure 4 The flowchart is implemented in a state where the startup switch SW1 is off, an instruction to turn off each contactor is issued from the PCM 201, and the high-voltage battery 2 and the high-voltage circuit 30 are electrically cut off, and the main voltage is around 0.

[0116] First, the PCM 201 determines whether the startup switch SW1 is switched from off to on and a startup request of the vehicle 1 is issued (step S1). This determination is implemented on the basis of a signal from the startup switch SW1. In the case where the determination is YES in the step S1, the process proceeds to the step S2. Figure 8 and Figure 9 In the example of FIG. 6, the startup switch SW1 is switched from off to on at time tl.

[0117] The PCM 201 determines one of the P-side OBC contactor 81 and the N-side OBC contactor 82 as the object OBC contactor when the determination in the step S1 is YES (when the startup switch SW1 is switched from off to on) (step S2). Specifically, the PCM 201 determines the OBC contactor 81 (82) different from the OBC contactor 82 (81) determined as the object of the fault determination in the step S2 implemented last time in conjunction with the startup switch SW1 being switched to on as the new object of the fault determination.

[0118] Next, the PCM 201 switches an instruction to the non-object OBC contactor 82 (81) different from the OBC contactor 81 (82) determined as the object OBC contactor in the step S2 from off to on. In the example of FIG. 6, the instruction to the non-object OBC contactor 82 (81) is switched to on at time t2. Figure 8 and Figure 9 In the example of FIG. 6, the instruction to the non-object OBC contactor 82 (81) is switched to on at time t2.

[0119] Next, the PCM 201 waits for a predetermined first time to elapse (the determination of the step S4 becomes YES) after implementing the step S3, and switches an instruction to the precontactor 73 from off to on (step S5). In the example of FIG. 6, the instruction to the precontactor 73 is switched to on at time t3. Figure 8 and Figure 9 In the example of FIG. 6, the instruction to the precontactor 73 is switched to on at time t3.

[0120] During step S5, the command issued from PCM201 to the P-side main contactor 71 is to disconnect. Therefore, if the P-side main contactor 71 is functioning correctly, even if the pre-contactor 73 is activated in step S5, the high-voltage battery 2 and the high-voltage circuit 30 remain electrically disconnected. Therefore, in this case, as... Figure 8 As shown in (a), after time t3 (after the implementation of step S5), the main voltage also remains near 0. In contrast, with the P-side main contactor 71 closed and stuck, when the pre-contactor 73 is closed in step S5, the electrical connection between the high-voltage battery 2 and the high-voltage circuit 30 begins. Therefore, in this case, as... Figure 8 As shown in (b), the main voltage rises (increases) after time t3 (after the implementation of step S5).

[0121] Therefore, after step S5, PCM201 determines whether the main voltage has increased (step S6). Then, if the determination is yes, i.e., the main voltage has increased, PCM201 determines that the P-side main contactor 71 is stuck (step S7). In addition, PCM201 causes the HMI device 208 to display an abnormality notification to inform the occupants of the abnormality, and then ends the fault determination.

[0122] On the other hand, if the determination in step S6 is negative, i.e., the main voltage does not rise, PCM201 enters... Figure 5 Step S11. In step S11, PCM201 determines whether a predetermined second time has elapsed since step S5 was implemented. Then, PCM201 waits for the determination to be yes (waiting for the second time to elapse since step S5) and implements step S12. In step S12, PCM201 switches the command to the P-side main contactor 71 from open to closed. Figure 8 and Figure 9 In the example, at time t4, the command to the P-side main contactor 71 is switched from disconnected to connected.

[0123] If neither the pre-contact 73 nor the P-side main contactor 71 is disconnected and stuck, then by implementing step S12, both the pre-contact 73 and the P-side main contactor 71 are connected, thereby initiating the electrical connection between the high-voltage circuit 30 and the high-voltage battery 2. Therefore, in this case, as... Figure 8 As shown in (a), after time t4 (after the implementation of step S12), the main voltage rises (increases). Conversely, even when step S12 is implemented, the high-voltage circuit 30 remains electrically disconnected from the high-voltage battery 2 when at least one of the pre-contact 73 and the P-side main contactor 71 is disconnected from the contactor. Therefore, as... Figure 8 As shown in (c), around time t4 (before and after the implementation of step S12), the main voltage does not change and remains near 0.

[0124] Thus, after the execution of step S12, the PCM 201 determines whether the main voltage has not risen (increased) (step S13). Then, in the case where the determination in step S13 is YES, i.e., the main voltage has not risen, the PCM 201 determines that at least one of the precontactor 73 and the P-side main contactor 71 is stuck open (step S14). In addition, the PCM 201 causes the HMI device 208 to perform display of a notification of abnormality or the like to inform the occupant of the abnormality, and then ends the failure determination.

[0125] In addition, at the time of the execution of step S12, the command issued from the PCM 201 to the non-target OBC contactor 82 (81) is ON, and the command issued to the target OBC contactor 81 (82) is OFF. Therefore, if the target OBC contactor 81 (82) is stuck open, even if the high-voltage circuit 30 and the high-voltage battery 2 are electrically connected in conjunction with the execution of step S12, the OBC voltage is maintained around 0. That is, in this case, as shown in (a) of FIG. 10, the OBC voltage does not change around the time t4 (before and after the execution of step S12). Figure 9

[0126] On the other hand, in the case where the target OBC contactor 81 (82) is stuck closed, the high-voltage circuit 30 and the OBC circuit 40 are electrically connected at the time point of the execution of step S12. Therefore, in this case, when the high-voltage circuit 30 and the high-voltage battery 2 are electrically connected in conjunction with the execution of step S12, the OBC voltage rises (increases). That is, in this case, as shown in (b) of FIG. 10, the OBC voltage rises after the time t4 (after the execution of step S12). Figure 9

[0127] Thus, in the case where the determination in step S13 is NO, i.e., the main voltage rises (increases) after the execution of step S12, i.e., in the case where the high-voltage circuit 30 and the high-voltage battery 2 are electrically connected in conjunction with the execution of step S12, the PCM 201 proceeds to step S15. Then, in step S15, the PCM 201 determines whether the OBC voltage rises (increases) in conjunction with the execution of step S12. Then, in the case where the determination in step S15 is YES, i.e., the OBC voltage rises, the PCM 201 determines that the target OBC contactor 81 (82) is stuck closed (step S16). In addition, the PCM 201 causes the HMI device 208 to perform display of a notification of abnormality or the like to inform the occupant of the abnormality.

[0128] In the case where the determination in step S15 is NO, then after step S16, the PCM 201 proceeds to step S21 of FIG. 11. Figure 6

[0129] ​​​In step S21, the PCM 201 determines whether or not a prescribed third time has elapsed from the implementation of step S12. Then, the PCM 201 waits for the determination to be affirmative (waits for the third time to elapse from the implementation of step S12), and switches the command to the N-side main contactor 72 from off to on (step S22). In the example of FIG. 10, Figure 8 and Figure 9 the command to the N-side main contactor 72 is switched to on at time t5. Next, the PCM 201 waits for a prescribed fourth time to elapse from the implementation of step S22 (waits for the determination of step S23 to be affirmative), and switches the command to both the precontactor 73 and the non-object OBC contactor 82 (81) from on to off (step S24). In the example of FIG. 11, Figure 8 and Figure 9 the command to the precontactor 73 and the non-object OBC contactor 82 (81) is switched to off at time t6.

[0130] At the implementation time point of step S24, the command from the PCM 201 to the P-side main contactor 71 and the N-side main contactor 72 is on. Therefore, if the N-side main contactor 72 is normal, at the implementation time of step S24, the electric power between the high-voltage battery 2 and the high-voltage circuit 30 does not flow through the precontactor 73 but flows through the N-side main contactor 72. Therefore, if the N-side main contactor 72 is normal, even if step S24 is implemented and the command to the precontactor 73 is switched to off, the path of the current does not change, and as shown in (a) of FIG. 12, after time t6 (after the implementation of step S24), the main voltage does not drop. In contrast, in the case where the N-side main contactor 72 is stuck open, at the time point just before step S24 is implemented, the electric power between the high-voltage battery 2 and the high-voltage circuit 30 does not flow through the N-side main contactor 72 but flows through the precontactor 73. Therefore, in this case, when step S24 is implemented and the command to the precontactor 73 is switched to off, the high-voltage battery 2 and the high-voltage circuit 30 are electrically cut off, and as shown in (d) of FIG. 12, after time t6 (after the implementation of step S24), the main voltage drops (decreases). Figure 8 Figure 8

[0131] Thus, the PCM 201 makes a determination as to whether or not the main voltage drops (decreases) after the implementation of step S24 (step S25). Then, in the case where the determination is affirmative, that is, the main voltage drops (decreases), the PCM 201 determines that the N-side main contactor 72 is stuck open (step S26). In addition, the PCM 201 causes the HMI device 208 to perform display of a notification of the abnormality or the like, and notifies the occupant of the abnormality, and then ends the failure determination.

[0132] ​​Further, at the timing immediately before the execution of the step S24, the instruction issued from the PCM 201 to the non-target OBC contactor 82 (81) is ON. Thus, assuming that the target OBC contactor 81 (82) is stuck ON (i.e., in the case where the step S15 is determined YES and the step S16 is executed), at the timing immediately before the execution of the step S24, the OBC circuit 40 is electrically connected to the high-voltage circuit 30. Further, if the N-side main contactor 72 is normal and the main voltage does not decrease after the execution of the step S24, the electrical connection between the high-voltage battery 2 and the high-voltage circuit 30 is also maintained after the execution of the step S24. Therefore, in the case where the main voltage does not decrease after the execution of the step S24 and the target OBC contactor 81 (82) is stuck ON, the OBC circuit 40 is electrically connected to the high-voltage battery 2 via the high-voltage circuit 30 at the timing immediately before the execution of the step S24.

[0133] Therefore, in the case where the main voltage does not decrease after the execution of the step S24, in the case where the target OBC contactor 81 (82) is stuck ON but the non-target OBC contactor 82 (81) is not stuck ON, as shown in (b) of FIG. 10, when the step S24 is executed at the time t6 and the instruction to the non-target OBC contactor 82 (81) is switched to OFF, the OBC circuit 40 is electrically disconnected from the high-voltage circuit 30 in conjunction therewith, and thus the OBC voltage decreases. Figure 9

[0134] On the other hand, in the case where the main voltage does not decrease after the execution of the step S24, in the case where both the target OBC contactor 81 (82) and the non-target OBC contactor 82 (81) are stuck ON, even if the step S24 is executed and the instruction to the non-target OBC contactor 82 (81) is switched to OFF, the electrical connection between the OBC circuit 40 and the high-voltage circuit 30 is maintained, and as a result, as shown in (c) of FIG. 10, after the time t6 (after the execution of the step S24), the OBC voltage does not decrease (decrease). Figure 9

[0135] ​​Thus, in a case where the determination in step S25 is NO, i.e., the main voltage does not decrease after the execution of step S24, the PCM 201 proceeds to step S27 to determine whether or not the following condition is satisfied: the closing sticking of the subject OBC contactor 81 (82) has been determined (i.e., step S16 has been executed) and the OBC voltage does not decrease (decrease) in association with the execution of step S24. Then, in a case where the determination in step S27 is YES, i.e., the above condition is satisfied, it is determined that both the subject OBC contactor 81 (82) and the non-subject OBC contactor 82 (81) are stuck (step S28). In addition, the PCM 201 causes the HMI device 208 to perform display of a notification of an abnormality or the like to inform the occupant of the abnormality, and then ends the failure determination. On the other hand, in a case where the determination in step S27 is NO, i.e., the above condition is not satisfied, the PCM 201 determines that the subject OBC contactor 81 (82) is normal (not stuck), and ends the failure determination.

[0136] Here, in the present embodiment, the above first to fourth times are set as follows. That is, the first time (time t2 to time t3) is set to be shorter than the second time (time t3 to time t4). The second time (time t3 to time t4) is set to be shorter than the third time (time t4 to time t5). The third time (time t4 to time t5) is set to be longer than the fourth time (time t5 to time t6). The fourth time (time t5 to time t6) is set to be longer than the first time (time t2 to time t3). Further, the lengths of the times are not limited to the above, but if set as above, the change in voltage accompanying the opening and closing of each contactor can be appropriately detected, the failure of the contactor can be further appropriately determined, and the time required for the failure determination can be shortened.

[0137] (Failure determination process at the time of parking)

[0138] Figure 7 The flowchart of FIG. 10 is executed in a state where the PCM 201 issues an instruction to close the N-side main contactor 72 and the P-side main contactor 71, and issues an instruction to open the precontactor 73 and each OBC contactor 81, 82 from the PCM 201 in a state where the start switch SW1 is closed.

[0139] First, the PCM 201 determines whether or not the start switch SW1 is switched from closed to open (step S31). This determination is executed on the basis of a signal from the start switch SW1. In the example of FIG. 10, the start switch SW1 is switched from closed to open at time t11. Figure 10

[0140] ​When the determination of step S1 becomes YES at the time when the start switch SW1 is switched from ON to OFF, the PCM 201 switches the command to the N-side main contactor 72 from ON to OFF (step S32). In the example of Fig. 10, the command to the N-side main contactor 72 is switched from ON to OFF at time tl 2. Figure 10 In the example of Fig. 10, the command to the N-side main contactor 72 is switched from ON to OFF at time tl 2.

[0141] At the implementation point of step S32, the P-side main contactor 71 remains ON. Therefore, if the N-side main contactor 72 is normally switched to OFF or the precontactor 73 is normally OFF, the high-voltage battery 2 and the high-voltage circuit 30 are electrically disconnected by the N-side main contactor 72 being switched to OFF. Therefore, as shown by the solid line of Fig. 10, the main voltage drops after time tl 2 at which step S32 is implemented. In contrast to this, when the N-side main contactor 72 or the precontactor 73 is ON stuck, the electrical connection of the high-voltage battery 2 and the high-voltage circuit 30 is maintained. Therefore, in this case, as shown by the one-dot chain line of Fig. 10, the main voltage does not drop after time tl 2 at which step S32 is implemented. Figure 10 Figure 10

[0142] Thus, after the implementation of step S32, the PCM 201 determines whether the main voltage has not dropped (step S33). Then, in the case where the determination of step S33 is YES, i.e., the main voltage has not dropped, the PCM 201 determines that at least one of the N-side main contactor 72 and the precontactor 73 is ON stuck (step S34). On the other hand, in the case where the determination of step S33 is NO, i.e., the main voltage has dropped, the PCM 201 proceeds to step S39.

[0143] After step S34, the PCM 201 waits for a prescribed fifth time to elapse from the implementation of step S32 (waits for the determination of step S35 to become YES), and switches the command to the P-side main contactor 71 from ON to OFF (step S36). In the example of Fig. 10, the command to the P-side main contactor 71 is switched from ON to OFF at time tl 3. Figure 10

[0144] At this time, in the case where the determination of step S34 is that at least one of the N-side main contactor 72 and the precontactor 73 is ON stuck, the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected at the point of time just before step S36 is implemented. Therefore, if the P-side main contactor 71 is not ON stuck, when the command to the P-side main contactor 71 is switched to OFF at step S36, the high-voltage battery 2 and the high-voltage circuit 30 are electrically disconnected. Thus, as shown by the broken line of Fig. 10, the main voltage drops after time tl 3 (after the implementation of step S36). On the other hand, when the P-side main contactor 71 is ON stuck, even if the command to the P-side main contactor 71 is switched to OFF at step S36, the electrical connection of the high-voltage battery 2 and the high-voltage circuit 30 is maintained. Thus, in this case, as shown by the one-dot chain line of Fig. 10, the main voltage does not drop after time tl 3 at which step S36 is implemented. Figure 10 Figure 10 ​​​​The main voltage does not decrease after the time t13 at which the step S36 is implemented, as indicated by a single-dot chain line.

[0145] Thus, after implementation of the step S36, the PCM 201 determines whether the main voltage has not decreased (step S37). Then, when the determination of the step S37 is YES, i.e., in the case where the main voltage has not decreased, the PCM 201 determines that the P-side main contactor 71 is stuck in ON (step S38). In addition, the PCM 201 causes the HMI device 208 to perform display of notification of abnormality or the like and informs the occupant of the abnormality, and then ends the failure determination.

[0146] On the other hand, when the determination of the step S37 is NO, i.e., in the case where the main voltage has decreased, the PCM 201 ends the processing without determining that the P-side main contactor 71 is stuck in ON.

[0147] Returning to the step S33, in the case where the determination of the step S33 is NO, i.e., in the case where the main voltage has decreased in association with implementation of the step S32, the PCM 201 waits for a prescribed fifth time to elapse from implementation of the step S32 (waits for the determination of the step S39 to be YES), and switches the command to the P-side main contactor 71 from ON to OFF (step S40). Then, in this case, the processing is directly ended. Furthermore, although illustration and the like are omitted, in the present embodiment, the PCM 201 also performs discharge processing of the high-voltage circuit 30 after the above-described step S32.

[0148] Here, the above-described step S3 corresponds to the "first control" in the scope of claim, the above-described step S5 corresponds to the "second control" in the scope of claim, and the above-described step S12 corresponds to the "third control" in the scope of claim. In addition, the above-described step S22 corresponds to the "fourth control" in the scope of claim, the step of switching the precontactor 73 to OFF in the above-described step S24 corresponds to the "fifth control" in the scope of claim, and the step of switching the non-object OBC contactor 82 (81) to OFF in the above-described step S24 corresponds to the "sixth control" in the scope of claim.

[0149] (Action and the like)

[0150] As described above, in the above-described embodiment, the PCM 201 implements the steps S3, S5, and S12 when it is determined that a request to start the vehicle 1 has been made upon switching of the start switch SW1 from OFF to ON, and sequentially turns ON the non-object OBC contactor 82 (81), the precontactor 73, and the P-side main contactor 71. Thus, it is possible to avoid turning ON these contactors at the same time immediately after the ON operation of the start switch SW1, and thus it is possible to avoid generation of a large sound in association with simultaneous ON of a plurality of contactors. Therefore, it is possible to suppress a feeling of strangeness that the occupant feels at the time of starting of the vehicle 1.

[0151] In addition, in a state where the precontactor 73 is on and the N-side main contactor 72 is off, the P-side main contactor 71 is made on. That is, in a state where the negative terminal 2b of the high-voltage battery 2 and the high-voltage circuit 30 are connected in a state of high resistance via the precontactor 73, the positive terminal 2a of the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected. Therefore, when the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected, a higher rush current from the high-voltage battery 2 to the high-voltage circuit 30 can be prevented, and thus a failure of an electrical device provided in the high-voltage circuit 30 can be prevented. In addition, in a case where the high-voltage circuit 30 and the OBC circuit 40 are electrically connected, the above-described rush current to the OBC circuit 40 can also be prevented, and thus a failure of the OBC 41 can be prevented.

[0152] Then, in the above-described embodiment, when the subject OBC contactor 81 (82) is stuck on, the determination of step S15 is performed using a rise in the OBC voltage after the execution of step S12 (after the P-side main contactor 71 is switched on), and in a case where the OBC voltage rises after the execution of step S12 (in a case where the determination of step S15 is Yes), it is determined that the subject OBC contactor 81 (82) is stuck on. Therefore, whether or not the subject OBC contactor 81 (82) is stuck on, that is, whether or not a failure occurs in a closed state, can be appropriately determined.

[0153] In addition, in the above-described embodiment, the PCM 201 alternately performs the failure determination of the P-side OBC contactor 81 and the failure determination of the N-side OBC contactor 82 each time a start request of the vehicle 1 is issued. Therefore, with at least two start requests issued, the failures of the two OBC contactors 81, 82 can be determined. In addition, by suppressing the number of OBC contactors 81, 82 for which the failure determination is performed at the time of one start request issuance to one, the time required for the failure determination is shorter than a case where the failure determination is performed for each of the two OBC contactors 81, 82. Therefore, after a start request is issued, the travel of the vehicle 1 can be started early.

[0154] In addition, in the above-described embodiment, after step S12, step S22 of switching the N-side main contactor 72 to on is performed, and then step S24 of switching the precontactor 73 and the non-subject OBC contactor 82 (81) to off is performed. That is, after step S12, the high-voltage battery 2 and the high-voltage circuit 30 are connected in a state of low resistance, and the electrical connection of the high-voltage battery 2 and the OBC circuit 40 via the high-voltage circuit 30 is cut off. Therefore, the electric motor 4 provided in the high-voltage circuit 30 can be supplied with higher power immediately after step S24 is performed. Therefore, the appropriate travel of the vehicle 1 can be started early.

[0155] In addition, in the above-described embodiment, when the N-side main contactor 72 is stuck open, the determination of step S25 is performed using the decrease in the main voltage after the execution of step S24 (after the precontactor 73 is switched to open), and in the case where the main voltage decreases after the execution of step S24 (in the case where the determination of step S25 is YES), it is determined that the N-side main contactor 72 is stuck open. Thus, it is possible to appropriately determine whether the N-side main contactor 72 is stuck open.

[0156] In addition, in the above-described embodiment, when the P-side main contactor 71 is stuck closed, the determination of step S6 is performed using the increase in the main voltage after the execution of step S5 (after the precontactor 73 is switched to closed), and in the case where the main voltage increases after the execution of step S5 (in the case where the determination of step S6 is YES), it is determined that the P-side main contactor 71 is stuck closed. Thus, it is possible to appropriately determine whether the P-side main contactor 71 is stuck closed.

[0157] In addition, in the above-described embodiment, when at least one of the P-side main contactor 71 and the precontactor 73 is stuck open, the determination of step S13 is performed using the non-increase in the main voltage after the execution of step S12 (after the P-side main contactor 71 is switched to closed), and in the case where the main voltage does not increase after the execution of step S12 (in the case where the determination of step S13 is YES), it is determined that at least one of the P-side main contactor 71 and the precontactor 73 is stuck open. Thus, it is possible to appropriately determine the failure of the P-side main contactor 71 and the precontactor 73.

[0158] In addition, in the above-described embodiment, when both of the OBC contactors 81 and 82 are stuck closed, the determination of step S27 is performed using the non-decrease in the OBC voltage after the execution of step S24 (after the non-target OBC contactor 82 (81) is switched to open), and in the case where the OBC voltage does not decrease after the execution of step S24 (in the case where the determination of step S27 is YES), it is determined that both of the OBC contactors 81 and 82 are stuck closed. Thus, it is possible to appropriately determine the failure of these OBC contactors 81 and 82.

[0159] (Modified Example)

[0160] In the above-described embodiment, although the case where the main voltage sensor SN1 for detecting the voltage of the high-voltage circuit 30 is provided to the DC / DC converter 8 is described, the position where the main voltage sensor SN1 is provided is not limited thereto. In addition, the sensor for detecting the increase and decrease of the voltage of the high-voltage circuit 30 is not limited thereto. For example, the increase and decrease of the voltage of the high-voltage circuit 30 can be detected using a current sensor or the like. Similarly, the increase and decrease of the voltage of the OBC circuit 40 can be detected using a current sensor or the like instead of the OBC voltage sensor SN2.

[0161] In the above-described embodiment, although the case where the precontactor 73 is provided in parallel with the N-side main contactor 72 is described, the precontactor 73 can be provided in parallel with the P-side main contactor 71. Further, in the case where the precontactor 73 is provided in parallel with the P-side main contactor 71, the "P-side main contactor" and the "N-side main contactor" in the above-described flowchart of the failure determination ( Figures 4-7 ) can be replaced.

[0162] In the above-described embodiment, although the case where, when the instruction to the non-object OBC contactor 82 (81) is switched from off to on (step S3) and the instruction to the precontactor 73 is switched from off to on (step S5), only the determination of whether the P-side main contactor 71 is on-stuck is performed (steps S6, S7) is described, in addition to this determination, the determination of whether the OBC voltage rises can be performed, and in the case where the OBC voltage rises, it can be determined that the object OBC contactor 81 (82) is on-stuck. In addition, the external charging device can be a structure in which the high-voltage battery is charged with electric power from a direct-current power supply outside the vehicle.

Claims

1. A contactor failure determination device of a vehicle, mounted on a vehicle that has: a battery that has a positive terminal and a negative terminal; a first circuit that includes an inverter and a motor; a first main contactor that turns on and off electrical connection of one of the positive terminal and the negative terminal to the first circuit; and a second main contactor that turns on and off electrical connection of the other of the positive terminal and the negative terminal to the first circuit. and a pre-charge contactor provided in parallel with the first main contactor and opening and closing the electrical connection of the one terminal to the first circuit, characterized by comprising: an on-vehicle charger circuit including an on-vehicle charger capable of supplying electric power from a power source outside a vehicle to the battery to charge the battery; a pair of external charging contactors opening and closing the electrical connection of positive-side lines and the electrical connection of negative-side lines of the first circuit and the on-vehicle charger circuit to each other, respectively; a detection device capable of detecting an increase and decrease in voltage of the on-vehicle charger circuit; and a control device controlling the first main contactor, the second main contactor, the pre-charge contactor, and each of the external charging contactors so as to be opened at parking, the resistance between the one terminal and the first circuit via the pre-charge contactor is greater than the resistance between the one terminal and the first circuit via the first main contactor, when a vehicle start request as a request to start the vehicle is issued, the control device implements a first control to close one of the external charging contactors, implements a second control to close the pre-charge contactor after implementation of the first control, implements a third control to close the second main contactor after implementation of the second control, and detects the voltage of the on-vehicle charger circuit after implementation of the third control, determines a failure of the external charging contactor, the time from implementation of the first control to implementation of the second control is shorter than the time from implementation of the second control to implementation of the third control.

2. The contactor failure determination device for a vehicle according to claim 1, characterized in that when the voltage of the on-vehicle charger circuit is detected by the detection device to increase after implementation of the third control, the control device determines that the other of the external charging contactors fails in the closed state.

3. The contactor failure determination device for a vehicle according to claim 1, characterized in that the control device closes a different external charging contactor from the external charging contactor closed at the time of implementation of the first control in association with the issuance of the vehicle start request.

4. The contactor failure determination device for a vehicle according to claim 1, characterized in that the control device closes the first main contactor and opens the pre-charge contactor and one of the external charging contactors after implementation of the third control.

5. The contactor failure determination device for a vehicle according to claim 1, characterized in that a second detection device capable of detecting an increase and decrease in voltage of the first circuit is further included, when the voltage of the first circuit is detected by the second detection device to increase after implementation of the second control, the control device determines that the second main contactor fails in the closed state.

6. The contactor failure determination device of the vehicle according to claim 1, characterized in that, when it is detected by the second detection device capable of detecting increase and decrease of the voltage of the first circuit that the voltage of the first circuit does not increase after the implementation of the third control, the control device determines that at least one of the pre-charge contactor and the second main contactor has failed in the open state.

7. The contactor failure determination device of the vehicle according to claim 1, characterized in that, the control device, implements the fourth control that closes the first main contactor after the implementation of the third control, implements the fifth control that opens the pre-charge contactor after the implementation of the fourth control, when it is detected by the second detection device capable of detecting increase and decrease of the voltage of the first circuit that the voltage of the first circuit decreases after the implementation of the fifth control, determines that the first main contactor has failed in the open state.

8. The contactor failure determination device of the vehicle according to claim 7, characterized in that, the time from the implementation of the second control to the implementation of the third control is shorter than the time from the implementation of the third control to the implementation of the fourth control.

9. The contactor failure determination device of the vehicle according to claim 7, characterized in that, the time from the implementation of the third control to the implementation of the fourth control is longer than the time from the implementation of the fourth control to the implementation of the fifth control.

10. The contactor failure determination device of the vehicle according to claim 7, characterized in that, the time from the implementation of the fourth control to the implementation of the fifth control is longer than the time from the implementation of the first control to the implementation of the second control.

11. The contactor failure determination device of the vehicle according to claim 1, characterized in that, the control device, after the implementation of the third control, in a state in which the first circuit and the battery are electrically connected, implements the sixth control that opens the external charging contactor that was closed at the time of the implementation of the first control, in the case where it is determined that the other external charging contactor has failed in the closed state, when it is detected by the detection device that the voltage of the on-board charger circuit does not decrease after the implementation of the sixth control, determines that each of the external charging contactors has failed in the closed state, respectively.

12. The contactor failure determination device of the vehicle according to claim 1, characterized in that, the on-board charger has an AC / DC converter that converts alternating current into direct current, converts an alternating current power source outside the vehicle into direct current, and supplies the battery.

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