JP2020188632A - Vehicle power supply device - Google Patents

Abstract

To determine a failure state of a switch.SOLUTION: A vehicle power supply device comprises: a first power supply system that comprises a first power storage body connected with a generator motor; a second power supply system that comprises a second power storage body having a higher voltage than the first power storage body; power conversion equipment that comprises a low-voltage terminal connected with the first power supply system and a high-voltage terminal connected with the second power supply system; a switch to be controlled to an ON state where the first power supply system and the low-voltage terminal are connected with each other and an OFF state where they are disconnected from each other; and a failure determination unit that determines a failure state of the switch on the basis of a potential difference between the first power supply system and the low-voltage terminal. The failure determination unit outputs an OFF signal to the switch (step S1000), controls the power conversion equipment to a discharge state where discharge from the low-voltage terminal is performed at the first voltage (step S1001), and, under a state where the generator motor is controlled to be in a power generation state where it generates a power at a second voltage different from the first voltage (step S1002), determines that the switch is in the ON state and in such a failure state that it cannot operate in a case where the potential difference becomes lower than a threshold (step S1006).SELECTED DRAWING: Figure 16

Description

The present invention relates to a vehicle power supply device mounted on a vehicle.

The vehicle power supply device mounted on the vehicle is provided with a power storage body such as a lead battery or a lithium ion battery, and is provided with a generator motor such as a motor generator or an ISG (Integrated Starter Generator) (Patent Documents 1 to 1). 3). Further, the vehicle power supply device is provided with a switch made of a semiconductor or the like in order to control the connection state of the power storage body, the generator motor or the like.

Japanese Unexamined Patent Publication No. 2013-189944 International Publication No. 2014/017199 JP-A-2017-103945

By the way, when the switch in the vehicle power supply fails, for example, when the switch is stuck on, which makes it inoperable in the on state, it is difficult to make the vehicle power supply function properly. Therefore, it is required to determine whether or not the switch is in a failed state.

An object of the present invention is to determine a failure state of a switch.

The vehicle power supply device of the present invention is a vehicle power supply device mounted on a vehicle, and is a first power supply system including a power generator connected to an engine and a first power storage body connected to the power generator. A second power supply system including a second power storage body having a voltage higher than that of the first power storage body, a low voltage terminal connected to the first power supply system, and a high voltage terminal connected to the second power supply system. A switch controlled by a power conversion device including the above, an on state for connecting the first power supply system and the low voltage terminal, and an off state for disconnecting the first power supply system and the low voltage terminal. The failure determination unit includes a failure determination unit that determines whether or not the switch is in an inoperable failure state when the switch is on, based on the potential difference between the first power supply system and the low voltage terminal. Outputs an off signal that controls the switch to the off state, controls the power conversion device to a discharge state in which the low voltage terminal discharges the switch at the first voltage, and makes the power generation electric motor different from the first voltage. Under the state controlled to the power generation state in which power is generated by two voltages, when the potential difference is lower than the threshold value, it is determined that the switch is in the on state and is inoperable.

According to the present invention, the power conversion device is controlled to the discharge state in which an off signal for controlling the switch to the off state is output and discharged from the low voltage terminal at the first voltage, and the generator motor is different from the first voltage. When the potential difference between the first power supply system and the low voltage terminal is lower than the threshold value under the state of being controlled to the power generation state in which the voltage is used to generate power, it is determined that the switch is on and the operation is inoperable. Thereby, the failure state of the switch can be determined.

It is the schematic which shows the structural example of the vehicle which mounted the power supply device for a vehicle which is one Embodiment of this invention. (A) and (B) are schematic views which show the execution example of the traveling mode. It is the figure which showed the power circuit and the control system briefly. It is a figure which shows the switching state of each power supply control mode. It is a circuit diagram which shows the power supply situation by the first start mode. It is a circuit diagram which shows the power supply situation by a converter discharge mode. It is a circuit diagram which shows the power supply situation by the ISG power generation mode. It is a circuit diagram which shows the power supply situation by a restart mode. It is a flowchart which shows an example of the execution procedure at the time of switching each power supply control mode. It is a flowchart which shows an example of the execution procedure at the time of switching each power supply control mode. It is a flowchart which shows an example of the switching procedure from the initial start mode to the converter discharge mode. It is a flowchart which shows an example of the switching procedure from the initial start mode to the ISG power generation mode. It is a flowchart which shows an example of the switching procedure from a converter discharge mode to an ISG power generation mode. It is a flowchart which shows an example of the switching procedure from the ISG power generation mode to the converter discharge mode. It is a flowchart which shows an example of the switching procedure from a converter discharge mode to a restart mode. It is a flowchart which shows an example of the execution procedure of ON sticking diagnosis. It is a flowchart which shows an example of the switching procedure from a restart mode to a converter discharge mode. It is a flowchart which shows an example of the switching procedure from a restart mode to a converter discharge mode. It is a flowchart which shows an example of the execution procedure of OFF sticking diagnosis. It is a flowchart which shows an example of the switching procedure from a restart mode to an ISG power generation mode. It is a flowchart which shows an example of the switching procedure from a restart mode to an ISG power generation mode.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Power train]
FIG. 1 is a schematic view showing a configuration example of a vehicle 11 equipped with a vehicle power supply device 10 according to an embodiment of the present invention. As shown in FIG. 1, the power train 12 mounted on the vehicle 11 is provided with an engine 13 and a motor generator 14 as power sources. Further, the power train 12 is provided with a continuously variable transmission 17 including a primary pulley 15 and a secondary pulley 16. The engine 13 is connected to one side of the primary pulley 15 via a forward / backward switching mechanism 18 and a torque converter 19, and the rotor 20 of the motor generator 14 is connected to the other side of the primary pulley 15. Further, the wheels 23 are connected to the secondary pulley 16 via a wheel output shaft 21, a differential mechanism 22, and the like. The forward / backward switching mechanism 18 is composed of a forward clutch 24, a reverse brake, a planetary gear train, and the like.

[Running mode]
2 (A) and 2 (B) are schematic views showing an execution example of the traveling mode. The illustrated vehicle 11 has a motor traveling mode and a parallel traveling mode as traveling modes. The motor running mode is a running mode in which the engine 13 is stopped to drive the motor generator 14, and the parallel running mode is a running mode in which both the engine 13 and the motor generator 14 are driven. As shown in FIG. 2A, when the vehicle 11 is driven in the motor traveling mode, the forward clutch 24 of the forward / backward switching mechanism 18 is released, and the engine 13 is disconnected from the wheels 23. As a result, the motor generator 14 can be driven while the engine 13 is stopped, and the wheels 23 can be driven by the motor power. Further, as shown in FIG. 2B, when the vehicle 11 is driven in the parallel traveling mode, the forward clutch 24 of the forward / backward switching mechanism 18 is engaged, and the engine 13 is connected to the wheels 23. As a result, the wheels 23 can be driven by engine power and motor power.

When selecting these traveling modes, it is determined based on the required driving force for the vehicle 11 and the SOC of the high voltage battery 50 described later. For example, when the SOC of the high-voltage battery 50 exceeds a predetermined value and the amount of depression of the accelerator pedal is small and the required driving force is small, the motor traveling mode is selected as the traveling mode. On the other hand, when the SOC of the high-voltage battery 50 is less than a predetermined value, or when the amount of depression of the accelerator pedal is large and the required driving force is large, the parallel traveling mode is selected as the traveling mode. In the above description, the parallel traveling mode is exemplified as the traveling mode for driving the engine 13, but the present invention is not limited to this. For example, the engine running mode in which only the engine 13 is driven may be executed by idling the motor generator 14 or disconnecting the motor generator 14 from the primary pulley 15 and stopping the motor generator 14.

[Power supply circuit]
The power supply circuit 30 included in the vehicle power supply device 10 will be described. FIG. 3 is a diagram showing the power supply circuit 30 and the control system briefly. As shown in FIGS. 1 and 3, the power supply circuit 30 has a low voltage system (first power supply system) 41 including a low voltage battery (first storage body) 40 and a higher voltage than the low voltage battery 40. It has a high voltage system (second power supply system) 51 including a voltage battery (second power storage body) 50. As the low voltage battery 40 constituting the low voltage system 41, for example, a lead battery having a terminal voltage of about 12 V can be used, and as the high voltage battery 50 constituting the high voltage system 51, for example, the terminal voltage is about about. A 118V lithium ion battery can be used.

Further, a converter (power conversion device) 60 for supplying power from the high voltage system 51 to the low voltage system 41 is provided between the low voltage system 41 and the high voltage system 51. The converter 60 is provided with a positive electrode terminal (low voltage terminal) 61a and a negative electrode terminal 61b connected to the low voltage system 41, and a positive electrode terminal (high voltage terminal) 62a and a negative electrode connected to the high voltage system 51. The terminal 62b is provided. Further, a low voltage system 41 is connected to the positive electrode terminal 61a of the converter 60 via a switching diode (switch) 63. Further, an electric device group 67 composed of a plurality of electric devices 66 is connected to the positive electrode line 64 that connects the positive electrode terminal 61a of the converter 60 and the switching diode 63 via the positive electrode line 65. The electric device 66 is provided with an electronic stability control device, an electric power steering device, an audio device, and the like.

The low-voltage system 41 of the power supply circuit 30 is composed of a low-voltage battery 40, a starter generator 42, a starter motor 43, and the like. A positive electrode line 44 is connected to the positive electrode terminal 40a of the low voltage battery 40, a positive electrode line 45 is connected to the positive electrode terminal 42a of the starter generator 42, and a positive electrode line 46 is connected to the positive electrode terminal 43a of the starter motor 43. It is connected. These positive electrode lines 44 to 46 are connected to each other, and a starter relay 47 is provided in the positive electrode line 46 of the starter motor 43. Further, a switching diode 63 is connected to the positive electrode lines 44 to 46 of the low voltage system 41 via the positive electrode line 48.

The high-voltage system 51 of the power supply circuit 30 is composed of a high-voltage battery 50, an inverter 52, and the like. A positive electrode line 53 is connected to the positive electrode terminal 50a of the high voltage battery 50, a positive electrode line 54 is connected to the positive electrode terminal 52a of the inverter 52, and a positive electrode line 55 is connected to the positive electrode terminal 62a of the converter 60. ing. These positive electrode lines 53 to 55 are connected to each other. Further, a negative electrode line 56 is connected to the negative electrode terminal 50b of the high voltage battery 50, a negative electrode line 57 is connected to the negative electrode terminal 52b of the inverter 52, and a negative electrode line 58 is connected to the negative electrode terminal 62b of the converter 60. It is connected. These negative electrode lines 56 to 58 are connected to each other.

[Low voltage system]
The starter generator (generator) 42 provided in the low voltage system 41 is connected to the crankshaft 71 of the engine 13 via a belt mechanism 70. The starter generator 42 is a so-called ISG (Integrated Starter Generator) that functions as a generator and an electric motor. The starter generator 42 not only functions as a generator that uses engine power to generate electricity, but also functions as an electric motor that starts and rotates the crankshaft 71. Further, the starter generator 42 has a stator 72 provided with a stator coil and a rotor 73 provided with a field coil. Further, the starter generator 42 is provided with an ISG controller 74 including an inverter, a regulator, a microcomputer, various sensors, and the like in order to control the energized state of the stator coil and the field coil.

By controlling the energized state of the field coil and the stator coil with the ISG controller 74, it is possible to control the power generation voltage, power generation torque, power running torque, etc. of the starter generator 42. That is, the starter generator 42 can be controlled to a power generation state in which power is generated by engine power, a stop state in which power generation is stopped, or a power running state in which the engine 13 is cranked. Further, the ISG controller 74 has a function of detecting the generated current iisg and the generated voltage visg of the starter generator 42. The generated current iisg of the starter generator 42 may be estimated from the exciting current of the stator coil or the field coil, or may be detected by using a current sensor.

Further, the low voltage system 41 is provided with a starter motor 43 for starting and rotating the engine 13. As will be described later, when the push switch 100 is pressed by the occupant, the starter relay 47 of the positive electrode line 46 is switched to the ON state. As a result, the starter motor 43 is energized via the starter relay 47, and the pinion 75 of the starter motor 43 meshes with the ring gear 76 of the torque converter 19 to rotate. By rotating the ring gear 76 by the starter motor 43 in this way, the crankshaft 71 of the engine 13 can be started and rotated.

As described above, the power train 12 is provided with a starter generator 42 and a starter motor 43. When restarting the engine 13 with the switching from the motor running mode to the parallel running mode described above, or when restarting the engine 13 with the idling stop control described later, the engine 13 is used by using the starter generator 42. Starting rotation or cranking is performed. On the other hand, when the control system of the vehicle 11 is started and the engine 13 is started first, that is, when the engine 13 is started by the push switch operation of the occupant or the like, the cranking of the engine 13 is executed by using the starter motor 43. Will be done. The vehicle 11 is provided with an engine controller 77, which is an electronic control unit composed of a microcomputer or the like. When the engine 13 is started by the starter motor 43, the engine controller 77 controls the starter relay 47, and the engine controller 77 controls auxiliary machinery 78 such as injectors and ignitions.

Further, the negative electrode line 80 connected to the negative electrode terminal 40b of the low voltage battery 40 is provided with a battery sensor 81 for detecting the terminal voltage of the low voltage battery 40 and the like. By using this battery sensor 81, it is possible to detect the potential of the positive electrode terminal 40a of the low voltage battery 40, that is, the potential of the positive electrode line 48 connected to the switching diode 63. Further, the battery sensor 81 not only detects the terminal voltage of the low-voltage battery 40, but also has a function of detecting the charge / discharge current of the low-voltage battery 40 and an SOC (State Of Charge) which is a charging state of the low-voltage battery 40. Has a function to detect. The battery sensor 81 is also connected to the positive electrode terminal 40a of the low voltage battery 40 via an energization line (not shown).

[High voltage system]
The high voltage system 51 is provided with an inverter 52, and the stator 82 of the motor generator 14 is connected to the inverter 52. The inverter 52 is composed of a switching element, a capacitor, and the like, and has a function of mutually converting DC power and AC power. When the motor generator 14 is controlled to the power running state, DC power is converted into AC power via the inverter 52, and power is supplied from the high voltage battery 50 to the motor generator 14. On the other hand, when the motor generator 14 is controlled to the regenerated state, the AC power is converted into DC power via the inverter 52, and the power is supplied from the motor generator 14 to the high voltage battery 50.

Further, the high voltage battery 50 is provided with a battery controller 83 which is an electronic control unit including a microcomputer or the like. Further, the high voltage battery 50 is provided with a battery sensor 84 that detects charge / discharge current, terminal voltage, temperature, and the like. The battery controller 83 provided in the high-voltage battery 50 has a function of calculating the SOC (State Of Charge), which is the state of charge of the high-voltage battery 50, based on the charge / discharge current and the like transmitted from the battery sensor 84. There is. The SOC of the high-voltage battery 50 is a ratio indicating the remaining amount of electricity of the high-voltage battery 50, and is a ratio of the amount of electricity stored to the full charge capacity of the high-voltage battery 50. For example, when the high voltage battery 50 is charged to the upper limit capacity, the SOC is calculated as 100%, and when the high voltage battery 50 is discharged to the lower limit capacity, the SOC is calculated as 0%. Further, the high voltage battery 50 is provided with a main relay 85 controlled by a battery controller 83 in order to disconnect the battery cell from the power supply circuit 30.

[Switching diodes and converters]
As described above, the switching diode 63 and the converter 60 are provided between the low voltage system 41 and the high voltage system 51. By controlling the switching diode 63 in the on state, the low voltage system 41 and the converter 60 can be connected to each other, while by controlling the switching diode 63 in the off state, the low voltage system 41 and the converter 60 can be connected to each other. Can be separated from each other. In the illustrated example, a switching diode 63 composed of a diode is shown as the switch, but the present invention is not limited to this, and a switch composed of another semiconductor element (transistor or the like) may be used. It may be a switch such as a relay that mechanically opens and closes the contacts.

In this way, the converter 60 is connected to the low voltage system 41 via the switching diode 63. The converter 60 composed of a switching element, a capacitor, or the like has a function of stepping down the DC power of the high-voltage battery 50 and outputting it. That is, the converter 60 operates in a discharge state in which the power of the high-voltage battery 50 is discharged toward the electric device group 67 and the like, and a stop state in which the discharge to the electric device group 67 and the like is stopped. That is, when the switching diode 63 is in the ON state and the converter 60 is controlled in the discharge state, power can be supplied from the high voltage battery 50 to both the electric device group 67 and the low voltage system 41. On the other hand, when the switching diode 63 is in the off state and the converter 60 is controlled in the discharge state, electric power can be supplied from the high voltage battery 50 to the electric device group 67. Further, the converter 60 is provided with a voltage sensor 86 for detecting the discharge voltage vcon of the positive electrode terminal 61a, and is provided with a current sensor 87 for detecting the current icon discharged from the positive electrode terminal 61a.

Further, in the present embodiment, when the converter 60 is controlled to the discharged state, the discharge voltage of the converter 60 is controlled to about 13.5 V or about 14.3 V. For example, when the terminal voltage of the low-voltage battery 40 is lower than the predetermined value, or when the required voltage of the electric device group 67 is higher than the predetermined value, the discharge voltage of the converter 60 is controlled to a higher value of about 14.3 V. To. On the other hand, when the terminal voltage of the low voltage battery 40 is higher than the predetermined value and the required voltage of the electric device group 67 is lower than the predetermined value, the discharge voltage of the converter 60 is controlled to a lower value of about 13.5 V. To.

[Control system]
As shown in FIG. 3, the vehicle power supply device 10 has a main controller 90 which is an electronic control unit including a microcomputer or the like in order to control the power train 12, the power supply circuit 30, and the like in coordination with each other. The main controller 90 includes an engine control unit 91 that controls the engine 13, an ISG control unit 92 that controls the starter generator 42, a switch control unit 93 that controls the switching diode 63, a converter control unit 94 that controls the converter 60, and an inverter 52. It has an inverter control unit 95 for controlling the above. Further, the main controller 90 has a traveling mode control unit 96 that controls switching of traveling modes, an idling stop control unit 97 that executes idling stop control, and a failure determination unit 98 that executes failure determination control of the switching diode 63. ing.

The main controller 90 and the above-mentioned controllers 74, 77, and 83 are freely communicated with each other via an in-vehicle network such as CAN or LIN. Further, the main controller 90 includes a push switch 100 operated by an occupant when the control system is started or the engine is first started, a vehicle speed sensor 101 that detects the vehicle speed which is the traveling speed of the vehicle 11, and an accelerator that detects the operation status of the accelerator pedal. A sensor 102, a brake sensor 103 that detects the operating status of the brake pedal, and the like are connected. The main controller 90 controls the starter generator 42 via the ISG controller 74, controls the engine 13 and the starter motor 43 via the engine controller 77, and controls the main relay 85 via the battery controller 83.

Further, the idling stop control unit 97 of the main controller 90 automatically stops and restarts the engine 13 to execute idling stop control. The idling stop control unit 97 stops the engine 13 by cutting fuel or the like when a predetermined stop condition is satisfied during engine operation, and stops the engine 13 when a predetermined start condition is satisfied while the engine is stopped. The generator 42 is rotated to restart the engine 13. The stopping condition of the engine 13 includes, for example, that the vehicle speed falls below a predetermined value and the brake pedal is depressed. Further, as the starting condition of the engine 13, for example, the depression of the brake pedal is released and the depression of the accelerator pedal is started.

[Power control mode]
Subsequently, the control mode of the power supply circuit 30 by the main controller 90 (hereinafter, referred to as a power supply control mode) will be described. The power control modes include an initial start mode executed when the engine is first started, a restart mode executed when the engine is restarted, a converter discharge mode in which power is supplied from the converter 60 to the electrical equipment group 67, and electricity from the starter generator 42. There is an ISG power generation mode that supplies power to the equipment group 67 and the like. Here, FIG. 4 is a diagram showing a switching state of each power supply control mode. Further, FIG. 5 is a circuit diagram showing the power supply status in the initial start mode, FIG. 6 is a circuit diagram showing the power supply status in the converter discharge mode, and FIG. 7 is a circuit diagram showing the power supply status in the ISG power generation mode. FIG. 8 is a circuit diagram showing a power supply status in the restart mode. In FIGS. 5 to 8, in order to clarify the on / off status of the switching diode 63, the switching diode 63 is shown in the same manner as a switch such as a relay. Further, in FIGS. 5 to 8, the power supply status is shown by using arrows.

[First start mode]
As shown in FIG. 4, when the occupant performs the push switch operation and the main controller 90 receives the initial start request, the main controller 90 executes the initial start mode. Here, as shown in FIG. 5, in the initial start mode, the switching diode 63 is controlled to the on state, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the stopped state, and the starter relay 47 is turned on. Controlled by state. As a result, as shown by the arrow a1, electric power is supplied from the low voltage battery 40 to the starter motor 43, and the engine 13 is cranked by the starter motor 43. Further, since the switching diode 63 is controlled to be in the ON state, power is supplied from the low voltage battery 40 to the electric device group 67 as shown by the arrow a2. After starting the engine using the starter motor 43, the starter relay 47 is controlled to be in the off state.

[Converter discharge mode, ISG power generation mode]
As shown in FIG. 4, when the engine 13 is started by the initial start mode, the converter discharge mode or the ISG power generation mode is executed based on the SOC of the high voltage battery 50. That is, when the SOC of the high-voltage battery 50 is high after the engine is first started, the power supply control mode is switched from the initial start mode to the converter discharge mode in order to supply power from the high-voltage battery 50 to the electric device group 67. On the other hand, when the SOC of the high-voltage battery 50 is low after the engine is first started, the power control mode is switched from the initial start mode to the ISG power generation mode in order to supply electric power from the starter generator 42 to the electric device group 67.

As shown in FIG. 6, in the converter discharge mode (discharge mode), the switching diode 63 is controlled to the on state, the converter 60 is controlled to the discharge state, and the starter generator 42 is controlled to the stop state. As a result, as shown by the arrow b1, electric power is supplied from the converter 60 to the electric device group 67. Further, as shown by the arrow b2, the low voltage battery 40 is charged and discharged according to the discharge state of the converter 60, the operation state of the electric device group 67, and the like. In the converter discharge mode, the engine 13 is stopped when the motor running mode or the idling stop is executed.

As shown in FIG. 7, in the ISG power generation mode (power generation mode), the switching diode 63 is controlled to the on state, the converter 60 is controlled to the stopped state, and the starter generator 42 is controlled to the power generation state. As a result, as shown by the arrow c1, electric power is supplied from the starter generator 42 to the electric device group 67. Further, as shown by the arrow c2, the low voltage battery 40 is charged and discharged according to the power generation status of the starter generator 42, the operating status of the electric device group 67, and the like. In the ISG power generation mode, since the starter generator 42 generates power using the engine power, the execution of the motor running mode and the idling stop accompanied by the engine stop is prohibited.

Further, as shown in FIG. 4, when the SOC of the high-voltage battery 50 drops below a predetermined value during the execution of the converter discharge mode, the power supply control mode is switched from the converter discharge mode to the ISG power generation mode. If the SOC of the high-voltage battery 50 rises and exceeds a predetermined value during the execution of the ISG power generation mode, the power supply control mode is switched from the ISG power generation mode to the converter discharge mode. As a result, the electric power of the high-voltage battery 50, which stores the regenerative electric power when the vehicle is braked, can be positively used, so that the energy efficiency of the vehicle 11 can be improved and the fuel efficiency can be improved. If it is determined that a converter abnormality or the like has occurred during the execution of the converter discharge mode, the power supply control mode is switched from the converter discharge mode to the ISG power generation mode.

[Restart mode]
As shown in FIG. 4, when an engine restart request is made during execution of the converter discharge mode, that is, when it is decided to switch from the motor running mode to the parallel running mode, or when the engine is stopped by idling stop control. When a predetermined start condition is satisfied, the power supply control mode is switched from the converter discharge mode to the restart mode.

As shown in FIG. 8, in the restart mode, the switching diode 63 is controlled to the off state, the converter 60 is controlled to the discharge state, and the starter generator 42 is controlled to the power running state. As a result, as shown by the arrow d1, power is supplied from the low voltage battery 40 to the starter generator 42. Further, as shown by the arrow d2, power is supplied from the converter 60 to the electric device group 67. As described above, in the restart mode in which the power consumption of the starter generator 42 rapidly increases with cranking, the switching diode 63 is controlled to the off state, and the low voltage system 41 and the electric device group 67 are separated from each other. As a result, even when a large current is supplied from the low-voltage battery 40 to the starter generator 42, it is possible to prevent a momentary voltage drop with respect to the electric device group 67, and the electric device group 67 functions normally. be able to.

Further, as shown in FIG. 4, when the engine 13 is restarted by the restart mode, the converter discharge mode or the ISG power generation mode is executed based on the SOC of the high voltage battery 50. That is, when the SOC of the high-voltage battery 50 is high after the engine is restarted, the power control mode is switched from the restart mode to the converter discharge mode in order to supply power from the high-voltage battery 50 to the electric device group 67. On the other hand, when the SOC of the high-voltage battery 50 is low after the engine is restarted, the power control mode is switched from the restart mode to the ISG power generation mode in order to supply power from the starter generator 42 to the electric device group 67. If it is determined that a converter abnormality or the like has occurred after the engine is restarted, the power supply control mode is switched from the restart mode to the ISG power generation mode.

[Switching each power control mode]
Subsequently, switching of each power supply control mode (initial start mode, converter discharge mode, ISG power generation mode, restart mode) by the main controller 90 will be described with reference to the flowchart. 9 and 10 are flowcharts showing an example of an execution procedure when switching each power supply control mode. The flowcharts shown in FIGS. 9 and 10 are connected to each other at the location of reference numeral A. Further, in each flowchart after FIG. 9, the switching diode 63 is described as "diode SW", and the starter generator 42 is described as "ISG".

As shown in FIG. 9, in step S10, it is determined whether or not the accessory mode (Acc mode) is selected by the push switch operation of the occupant. The accessory mode is a mode for using electrical components before the engine is first started. If it is determined in step S10 that the accessory mode is selected, the process proceeds to step S11, and the switching diode 63 is controlled to be in the ON state. Subsequently, when the switching diode 63 is controlled to be in the ON state in step S11, or when it is determined in step S10 that the accessory mode is not selected, the process proceeds to step S12, and the engine is first operated by the occupant's push switch operation. Whether or not there is a start request is determined.

If it is determined in step S12 that there is an engine initial start request, the process proceeds to step S13, the initial start mode is executed as the power control mode, and the engine 13 is started by cranking the starter motor 43. Subsequently, as shown in FIG. 10, in step S14, it is determined whether or not the SOC of the high voltage battery 50 is equal to or higher than the predetermined threshold value S1. If it is determined in step S14 that the SOC of the high-voltage battery 50 is equal to or higher than the threshold value S1, the process proceeds to step S15 in order to supply power from the high-voltage battery 50 to the electrical equipment group 67, and the converter is set as the power control mode. The discharge mode is executed. On the other hand, if it is determined in step S14 that the SOC of the high-voltage battery 50 is less than the threshold value S1, the starter generator 42 proceeds to step S16 to supply power to the electric device group 67, and the power control mode is set. The ISG power generation mode is executed.

Further, when the converter discharge mode is executed in step S15, the process proceeds to step S17, and it is determined whether or not there is a motor running request or an idling stop request. That is, in step S17, switching from the parallel traveling mode to the motor traveling mode is determined by depressing the accelerator pedal or the like, and if it is determined that there is a motor traveling request, the process proceeds to step S18 and the engine 13 is stopped. The motor drive mode is executed. Further, in step S17, when a predetermined stop condition in the idling stop control is satisfied and it is determined that there is an idling stop request, the process proceeds to step S18 and the idling stop for stopping the engine 13 is executed.

In the following step S19, it is determined whether or not there is an engine restart request. In step S19, when the switch from the motor running mode to the parallel running mode is determined by depressing the accelerator pedal or the like and it is determined that there is an engine restart request, the process proceeds to step S20 and the restart mode is set as the power control mode. Is executed. Further, in step S19, when a predetermined start condition is satisfied during idling stop and it is determined that there is an engine restart request, the process proceeds to step S20, the restart mode is executed as the power control mode, and the starter generator is executed. The engine 13 is started by the cranking of 42. As described above, when the engine 13 is restarted, the process proceeds to step S14 again, and the power supply control mode is switched from the restart mode to the converter discharge mode or the ISG power generation mode based on the SOC of the high voltage battery 50.

[From initial start mode to converter discharge mode]
The procedure for switching from the initial start mode to the converter discharge mode will be described with reference to the flowchart shown in FIG. FIG. 11 is a flowchart showing an example of the procedure for switching from the initial start mode to the converter discharge mode.

As shown in FIG. 11, in step S30, the initial start mode is executed as the power control mode. In the initial start mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the stopped state, and the switching diode 63 is controlled to the on state. In the following step S31, the starter relay 47 is controlled to be in the ON state, and the engine 13 is cranked by the starter motor 43. Then, the process proceeds to step S32, and it is determined whether or not the engine start is completed.

If it is determined in step S32 that the engine start has not been completed, the process returns to step S30, and the cranking of the engine 13 in the initial start mode is continued. On the other hand, if it is determined in step S32 that the engine start is completed, the process proceeds to step S33, the starter relay 47 is controlled to the off state, and cranking by the starter motor 43 is stopped. As described above, when the engine 13 is started by the initial start mode, the process proceeds to step S34, and the power supply control mode is switched from the initial start mode to the converter discharge mode. In the converter discharge mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the stop state, and the switching diode 63 is controlled to the on state.

[From initial start mode to ISG power generation mode]
The procedure for switching from the initial start mode to the ISG power generation mode will be described with reference to the flowchart shown in FIG. FIG. 12 is a flowchart showing an example of the procedure for switching from the initial start mode to the ISG power generation mode.

As shown in FIG. 12, in step S40, the initial start mode is executed as the power control mode. In the initial start mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the stopped state, and the switching diode 63 is controlled to the on state. In the following step S41, the starter relay 47 is controlled to be in the ON state, and the engine 13 is cranked by the starter motor 43. Then, the process proceeds to step S42, and it is determined whether or not the engine start is completed.

If it is determined in step S42 that the engine start has not been completed, the process returns to step S40, and the cranking of the engine 13 in the initial start mode is continued. On the other hand, if it is determined in step S42 that the engine start is completed, the process proceeds to step S43, the starter relay 47 is controlled to the off state, and cranking by the starter motor 43 is stopped. As described above, when the engine 13 is started by the initial start mode, the process proceeds to step S44, and the power control mode is switched from the initial start mode to the ISG power generation mode. In the ISG power generation mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the power generation state, and the switching diode 63 is controlled to the on state.

[From converter discharge mode to ISG power generation mode]
The procedure for switching from the converter discharge mode to the ISG power generation mode will be described with reference to the flowchart shown in FIG. FIG. 13 is a flowchart showing an example of the procedure for switching from the converter discharge mode to the ISG power generation mode.

As shown in FIG. 13, in step S50, the converter discharge mode is executed as the power supply control mode. In the converter discharge mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the stop state, and the switching diode 63 is controlled to the on state. In the following step S51, it is determined whether or not the engine is running. If it is determined in step S51 that the engine is stopped, the process proceeds to step S52, and the engine 13 is started using the starter generator 42.

On the other hand, if it is determined in step S51 that the engine is running, the process proceeds to step S53, the starter generator 42 is switched from the stopped state to the power generation state, and the power generation voltage of the starter generator 42 is controlled to about 14.3V. Will be done. Subsequently, in step S54, the discharge state of the converter 60 is maintained, and the discharge voltage of the converter 60 is controlled to about 13.5V. That is, in the converter discharge mode, when the discharge voltage of the converter 60 is about 13.5V, the discharge voltage is maintained at about 13.5V, and when the discharge voltage of the converter 60 is about 14.3V. The discharge voltage is reduced to about 13.5V.

In the following step S55, it is determined whether or not the discharge current icon of the converter 60 is below a predetermined threshold value i1 (for example, 0.5 A). If it is determined in step S55 that the discharge current icon is below the threshold value i1, the process proceeds to step S56, the converter 60 is switched from the discharged state to the stopped state, the process proceeds to step S57, and the ISG power generation mode is set as the power control mode. Will be executed. In the ISG power generation mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the power generation state, and the switching diode 63 is controlled to the on state.

[From ISG power generation mode to converter discharge mode]
The procedure for switching from the ISG power generation mode to the converter discharge mode will be described with reference to the flowchart shown in FIG. FIG. 14 is a flowchart showing an example of a procedure for switching from the ISG power generation mode to the converter discharge mode.

As shown in FIG. 14, in step S60, the ISG power generation mode is executed as the power supply control mode. In the ISG power generation mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the power generation state, and the switching diode 63 is controlled to the on state. In the following step S61, the converter 60 is switched from the stopped state to the discharged state, and the discharge voltage of the converter 60 is controlled to about 14.3 V. Next, in step S62, the power generation voltage of the starter generator 42 is gradually lowered, and in step S63, it is determined whether or not the power generation current iisg of the starter generator 42 falls below a predetermined threshold value i2 (for example, 0.5 A). If it is determined in step S63 that the generated current iisg is below the threshold value i2, the process proceeds to step S64, the starter generator 42 is switched from the power generation state to the stopped state, the process proceeds to step S65, and the converter discharge mode is used as the power control mode. Is executed. In the converter discharge mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the stop state, and the switching diode 63 is controlled to the on state.

[Converter discharge mode to restart mode]
The procedure for switching from the converter discharge mode to the restart mode will be described with reference to the flowchart shown in FIG. FIG. 15 is a flowchart showing an example of the procedure for switching from the converter discharge mode to the restart mode.

As shown in FIG. 15, in step S70, the converter discharge mode is executed as the power supply control mode. In the converter discharge mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the stop state, and the switching diode 63 is controlled to the on state. In the following step S71, it is determined whether or not there is a motor running request or an idling stop request. If it is determined in step S71 that there is a motor running request or an idling stop request, the process proceeds to step S72, and ON sticking diagnosis for diagnosing ON sticking of the switching diode 63 is executed. Note that the ON sticking of the switching diode 63 is a failure state in which the switching diode 63 cannot operate in the ON state.

In step S71 described above, the situation where it is determined that there is a motor running request or idling stop request means that the engine restart is required after the motor running mode or idling stop is executed, and the power supply control mode is changed from the converter discharge mode to the restart mode. It is a situation where it is necessary to switch to. That is, since it is necessary to switch the switching diode 63 to the off state when switching the power supply control mode to the restart mode, the switching diode is set in step S72 before the motor running mode or idling stop accompanied by the engine stop is executed. 63 ON sticking diagnosis is being executed.

Here, FIG. 16 is a flowchart showing an example of the execution procedure of the ON sticking diagnosis. As shown in FIG. 16, in step S1000, an OFF signal (off signal) for controlling the switching diode 63 to the off state is output from the main controller 90 toward the switching diode 63. Next, in step S1001, the discharge voltage vcon of the converter 60 is maintained, and in the subsequent step S1002, the generated voltage visg of the starter generator 42 is raised above the discharge voltage vcon.

As described above, in the ON sticking diagnosis, the discharge voltage (first voltage) vcon of the converter 60 controlled to the discharge state and the power generation voltage (second voltage) visg of the starter generator 42 controlled to the power generation state are determined. The voltage values are controlled to be different from each other. For example, when the discharge voltage vcon of the converter 60 is controlled to about 13.5 V (first voltage) in the converter discharge mode, the generated voltage visg of the starter generator 42 is raised to about 14.3 V (second voltage). Be done. Further, when the discharge voltage vcon of the converter 60 is controlled to about 14.3 V (first voltage) in the converter discharge mode, the generated voltage visg of the starter generator 42 is raised to about 15.3 V (second voltage). Be done.

Subsequently, in step S1003, it is determined whether or not the terminal voltage Vsw of the switching diode 63 exceeds a predetermined threshold value V1 (for example, 0.5V). The terminal voltage Vsw of the switching diode 63 is a potential difference between the terminal 63a on the low voltage system 41 side and the terminal 63b on the converter 60 side in the switching diode 63, and in the present embodiment, the generated voltage visg and the discharge voltage vcon The absolute value of the difference is calculated as the terminal voltage Vsw. That is, the terminal voltage Vsw of the switching diode 63 means the potential difference between the low voltage system 41 (first power supply system) and the positive electrode terminal (low voltage terminal) 61a. When it is determined in step S1003 that the terminal voltage Vsw exceeds the threshold value V1, a predetermined potential difference is generated between both terminals 63a and 63b of the switching diode 63, so the process proceeds to step S1004 and the switching diode It is determined that 63 is normally controlled to the off state.

On the other hand, if it is determined in step S1003 that the terminal voltage Vsw is equal to or less than the threshold value V1, the process proceeds to step S1005, and whether or not the terminal voltage Vsw is equal to or less than the threshold value V1 for a predetermined time (for example, 1 second). Is determined. Then, in step S1005, if it is determined that the terminal voltage Vsw is equal to or less than the threshold value V1 for a predetermined time, the process proceeds to step S1006, and it is determined that the switching diode 63 has a failure state (ON sticking). Will be done. That is, in the ON sticking diagnosis of the present embodiment, an OFF signal is output to the switching diode 63, the converter 60 is controlled to the discharge state at the first voltage, and the starter generator 42 generates power at the second voltage higher than the first voltage. Controlled by state. In this way, when the terminal voltage Vsw of the switching diode 63 is equal to or less than the threshold value V1 under the state where the potential difference is intentionally generated between both terminals 63a and 63b of the switching diode 63, the switching diode 63 Since it is presumed that the switching diode 63 is not operating in the ON state, it is determined that the switching diode 63 is stuck ON.

As described above, when the ON sticking diagnosis is executed in step S72 shown in FIG. 15, the process proceeds to step S73, and it is determined whether or not the switching diode 63 is normal. If it is determined in step S73 that the switching diode 63 has failed, it is difficult to switch the power supply control mode to the restart mode. Therefore, the process proceeds to step S74 to execute the motor running mode and the idling stop. Prohibited, the process proceeds to step S75, and a warning light for notifying the occupant of the abnormality of the power supply circuit 30 is turned on.

On the other hand, if it is determined in step S73 that the switching diode 63 is normal, the process proceeds to step S76, and the motor running mode or idling stop is executed. In the following step S77, it is determined whether or not there is an engine restart request. If it is determined in step S77 that there is an engine restart request, the process proceeds to step S78, and the switching diode 63 is controlled to the off state. Then, the process proceeds to step S79, and the restart mode is executed as the power control mode. In the restart mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the power running state, and the switching diode 63 is controlled to the off state.

As described above, the failure determination unit 98 of the main controller 90 outputs an OFF signal to the switching diode 63, controls the converter 60 to be discharged at the first voltage, and controls the starter generator 42 to the first voltage. When the terminal voltage Vsw is lower than the threshold voltage V1 under the state of being controlled to the power generation state in which the power is generated at the second voltage different from the above, it is determined that the switching diode 63 is stuck ON. Thereby, when the power supply control mode is switched from the converter discharge mode to the restart mode, the switching diode 63 can be appropriately controlled to the off state. Further, the main controller 90 appropriately adjusts the restart mode in which the switching diode 63 is controlled to the ON state in order to diagnose ON sticking of the switching diode 63 in the process of switching the power supply control mode from the converter discharge mode to the restart mode. Can be executed.

Further, in the above description, in the ON sticking diagnosis, the power generation voltage (second voltage) visg of the starter generator 42 controlled to the power generation state is obtained from the discharge voltage (first voltage) vcon of the converter 60 controlled to the discharge state. Is also increasing. As a result, a potential difference can be generated between both terminals 63a and 63b of the switching diode 63 without being affected by the low voltage battery 40 provided in the low voltage system 41. Further, in the above description, the generated voltage (second voltage) visg is higher than the discharge voltage (first voltage) vcon, but the present invention is not limited to this, and between both terminals 63a and 63b of the switching diode 63. The generated voltage (second voltage) visg may be lower than the discharge voltage (first voltage) vcon if the potential difference can be appropriately generated.

[From restart mode to converter discharge mode]
The procedure for switching from the restart mode to the converter discharge mode will be described with reference to the flowcharts shown in FIGS. 17 and 18. 17 and 18 are flowcharts showing an example of the procedure for switching from the restart mode to the converter discharge mode. The flowcharts shown in FIGS. 17 and 18 are connected to each other at the reference numeral B.

As shown in FIG. 17, in step S80, the restart mode is executed as the power control mode. In the restart mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the power running state, and the switching diode 63 is controlled to the off state. When the engine 13 is restarted by cranking the starter generator 42 in step S81, the discharge voltage vcon of the converter 60 is maintained in the following step S82, and the generated voltage visg of the starter generator 42 is the discharge voltage in step S83. Raised towards vcon. That is, when the discharge voltage vcon of the converter 60 is controlled to about 13.5 V, the generated voltage visg of the starter generator 42 is raised to about 13.5 V. Further, when the discharge voltage vcon of the converter 60 is controlled to about 14.3 V, the generated voltage visg of the starter generator 42 is raised to about 14.3 V.

Next, in step S84, it is determined whether or not the terminal voltage Vsw of the switching diode 63 is below a predetermined threshold value V2 (for example, 0.5V). If it is determined in step S84 that the terminal voltage Vsw is equal to or higher than the threshold value V2, the process proceeds to step S85, and the generated voltage visg of the starter generator 42 is adjusted toward the discharge voltage vcon. On the other hand, if it is determined in step S84 that the terminal voltage Vsw is below the threshold value V2, the process proceeds to step S86, and the switching diode 63 is controlled to be in the ON state.

Subsequently, as shown in FIG. 18, in step S87, the generated voltage of the starter generator 42 is gradually lowered, and in step S88, the generated current iisg of the starter generator 42 falls below a predetermined threshold value i3 (for example, 0.5 A). Whether or not it is determined. If it is determined in step S88 that the generated current iisg is below the threshold value i3, the process proceeds to step S89, the starter generator 42 is switched from the power generation state to the stopped state, the process proceeds to step S90, and the switching diode 63 is fixed to OFF. Be diagnosed. Note that the OFF sticking of the switching diode 63 is a failure state in which the switching diode 63 cannot operate in the OFF state.

Here, FIG. 19 is a flowchart showing an example of the execution procedure of the OFF sticking diagnosis. As shown in FIG. 19, in step S2000, an ON signal (ON signal) for controlling the switching diode 63 in the ON state is output from the main controller 90 toward the switching diode 63. Next, in step S2001, it is determined whether or not the terminal voltage Vsw of the switching diode 63 is lower than a predetermined threshold value V3 (for example, 0.5V). When it is determined in step S2001 that the terminal voltage Vsw is lower than the threshold value V3, the potential difference between both terminals 63a and 63b in the switching diode 63 has been eliminated, so the process proceeds to step S2002 and the switching diode 63 Is normally controlled to be on.

On the other hand, if it is determined in step S2001 that the terminal voltage Vsw is equal to or higher than the threshold value V3, the process proceeds to step S2003, and whether or not the terminal voltage Vsw is equal to or higher than the threshold value V3 for a predetermined time (for example, 1 second). Is determined. Then, in step S2003, when it is determined that the terminal voltage Vsw is equal to or higher than the threshold value V3 for a predetermined time, the process proceeds to step S2004, and it is determined that the switching diode 63 has a failure state (OFF fixed). Will be done. That is, in the OFF sticking diagnosis of the present embodiment, the ON signal is output to the switching diode 63, the converter 60 is controlled to the discharged state, and the starter generator 42 is controlled to the stopped state. In this way, when the terminal voltage Vsw of the switching diode 63 is equal to or higher than the threshold value V3 under the state where the potential difference is intentionally generated between both terminals 63a and 63b of the switching diode 63, the switching diode 63 Since it is presumed that the switching diode 63 is not operating in the OFF state, it is determined that the switching diode 63 is stuck OFF.

As described above, when the OFF sticking diagnosis is executed in step S90 shown in FIG. 18, the process proceeds to step S91, and it is determined whether or not the switching diode 63 is normal. If it is determined in step S91 that the switching diode 63 is stuck OFF, it is difficult to switch the power supply control mode to the converter discharge mode. Therefore, the process proceeds to step S92 to proceed to the motor running mode or idling stop. Is prohibited, the process proceeds to step S93, and the warning light for notifying the occupant of the abnormality of the power supply circuit 30 is turned on. On the other hand, if it is determined in step S91 that the switching diode 63 is normal, the process proceeds to step S94, and the converter discharge mode is executed as the power supply control mode. In the converter discharge mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the stop state, and the switching diode 63 is controlled to the on state.

In this way, the failure determination unit 98 of the main controller 90 outputs an ON signal to the switching diode 63 in the process of switching the power supply control mode from the restart mode to the converter discharge mode, and the terminal voltage Vsw exceeds the threshold value V3. In addition, it is determined that OFF sticking has occurred in the switching diode 63. Thereby, when the power supply control mode is switched from the restart mode to the converter discharge mode, the switching diode 63 can be appropriately controlled to the on state.

[From restart mode to ISG power generation mode]
The procedure for switching from the restart mode to the ISG power generation mode will be described with reference to the flowcharts shown in FIGS. 20 and 21. 20 and 21 are flowcharts showing an example of the procedure for switching from the restart mode to the ISG power generation mode. The flowcharts shown in FIGS. 20 and 21 are connected to each other at the reference numeral C.

As shown in FIG. 20, in step S100, the restart mode is executed as the power control mode. In the restart mode, the converter 60 is controlled to the discharge state, the starter generator 42 is controlled to the power running state, and the switching diode 63 is controlled to the off state. When the engine 13 is restarted by cranking the starter generator 42 in step S101, the discharge voltage vcon of the converter 60 is maintained in the following step S102, and the generated voltage visg of the starter generator 42 is the discharge voltage in step S103. Raised towards vcon. That is, when the discharge voltage vcon of the converter 60 is controlled to about 13.5 V, the generated voltage visg of the starter generator 42 is raised to about 13.5 V. Further, when the discharge voltage vcon of the converter 60 is controlled to about 14.3 V, the generated voltage visg of the starter generator 42 is raised to about 14.3 V.

Next, in step S104, it is determined whether or not the terminal voltage Vsw of the switching diode 63 is below a predetermined threshold value V4 (for example, 0.5V). If it is determined in step S104 that the terminal voltage Vsw is equal to or higher than the threshold value V4, the process proceeds to step S105, and the generated voltage visg of the starter generator 42 is adjusted toward the discharge voltage vcon. On the other hand, if it is determined in step S104 that the terminal voltage Vsw is below the threshold value V4, the process proceeds to step S106 and the switching diode 63 is controlled to be in the ON state.

Subsequently, as shown in FIG. 21, in step S107, the discharge voltage of the converter 60 is gradually lowered, and in step S108, whether or not the discharge current icon of the converter 60 falls below a predetermined threshold value i4 (for example, 0.5 A). Is judged. If it is determined in step S108 that the discharge current icon is below the threshold value i4, the process proceeds to step S109, the converter 60 is switched from the discharged state to the stopped state, the process proceeds to step S110, and the switching diode 63 is diagnosed as being stuck OFF. Will be done.

As shown in FIG. 19 described above, in step S2000, an ON signal (ON signal) for controlling the switching diode 63 in the ON state is output from the main controller 90 toward the switching diode 63. Next, in step S2001, it is determined whether or not the terminal voltage Vsw of the switching diode 63 is lower than a predetermined threshold value V3 (for example, 0.5V). When it is determined in step S2001 that the terminal voltage Vsw is lower than the threshold value V3, the potential difference between both terminals 63a and 63b in the switching diode 63 has been eliminated, so the process proceeds to step S2002 and the switching diode 63 Is normally controlled to be on.

On the other hand, if it is determined in step S2001 that the terminal voltage Vsw is equal to or higher than the threshold value V3, the process proceeds to step S2003, and whether or not the terminal voltage Vsw is equal to or higher than the threshold value V3 for a predetermined time (for example, 1 second). Is determined. Then, in step S2003, when it is determined that the terminal voltage Vsw is equal to or higher than the threshold value V3 for a predetermined time, the process proceeds to step S2004, and it is determined that the switching diode 63 has a failure state (OFF fixed). Will be done. That is, in the OFF sticking diagnosis of the present embodiment, the ON signal is output to the switching diode 63, the converter 60 is controlled to the discharged state, and the starter generator 42 is controlled to the stopped state. In this way, when the terminal voltage Vsw of the switching diode 63 is equal to or higher than the threshold value V3 under the state where the potential difference is intentionally generated between both terminals 63a and 63b of the switching diode 63, the switching diode 63 Since it is presumed that the switching diode 63 is not operating in the OFF state, it is determined that the switching diode 63 is stuck OFF.

As described above, when the OFF sticking diagnosis is executed in step S110 shown in FIG. 21, the process proceeds to step S111, and it is determined whether or not the switching diode 63 is normal. If it is determined in step S111 that the switching diode 63 is stuck OFF, it is difficult to switch the power supply control mode to the ISG power generation mode. Therefore, the process proceeds to step S112 to proceed to the motor running mode or idling stop. Is prohibited, the process proceeds to step S113, and a warning light for notifying the occupant of the abnormality of the power supply circuit 30 is turned on. On the other hand, if it is determined in step S111 that the switching diode 63 is normal, the process proceeds to step S114, and the ISG power generation mode is executed as the power supply control mode. In the ISG power generation mode, the converter 60 is controlled to the stopped state, the starter generator 42 is controlled to the power generation state, and the switching diode 63 is controlled to the on state.

In this way, the failure determination unit 98 of the main controller 90 outputs an ON signal to the switching diode 63 in the process of switching the power supply control mode from the restart mode to the ISG power generation mode, and the terminal voltage Vsw exceeds the threshold value V3. In addition, it is determined that OFF sticking has occurred in the switching diode 63. Thereby, when the power supply control mode is switched from the restart mode to the ISG power generation mode, the switching diode 63 can be appropriately controlled to be in the ON state.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof. In the above description, the terminal voltage Vsw of the switching diode 63 is obtained based on the discharge voltage vcon detected by the voltage sensor 86 and the generated voltage visg detected by the ISG controller 74, but the present invention is limited to this. There is no. If it is possible to obtain the potential difference between the terminal 63a on the low voltage system 41 side and the terminal 63b on the converter 60 side of the switching diode 63, use the voltage value detected by a voltage sensor, controller, etc. provided in another part. You may. Further, the power train mounted on the vehicle 11 is not limited to the power train 12 illustrated in FIG. 1, and may be another type of power train.

10 Vehicle power supply 11 Vehicle 13 Engine 40 Low-voltage battery (first storage unit)
41 Low voltage system (first power supply system)
42 Starter generator (motor generator)
50 High voltage battery (second storage body)
51 High voltage system (second power supply system)
60 converter (power conversion equipment)
61a Positive electrode terminal (low voltage terminal)
62a Positive electrode terminal (high voltage terminal)
63 Switching diode (switch)
90 Main controller 98 Failure determination unit vcon Discharge voltage (first voltage)
visg power generation voltage (second voltage)
Threshold V1
Threshold V3

Claims (5)

It is a vehicle power supply installed in a vehicle.
A first power supply system including a generator motor connected to an engine and a first power storage body connected to the generator motor.
A second power supply system including a second storage body having a voltage higher than that of the first storage body,
A power conversion device including a low voltage terminal connected to the first power supply system and a high voltage terminal connected to the second power supply system.
A switch controlled to an on state for connecting the first power supply system and the low voltage terminal and an off state for disconnecting the first power supply system and the low voltage terminal.
A failure determination unit that determines whether or not the switch is in an inoperable failure state when the switch is on, based on the potential difference between the first power supply system and the low voltage terminal.
Have,
The failure determination unit outputs an off signal for controlling the switch to the off state, controls the power conversion device to the discharge state of discharging from the low voltage terminal at the first voltage, and controls the generator motor to the first. Under the state controlled to the power generation state in which power is generated by a second voltage different from the voltage, when the potential difference is lower than the threshold value, it is determined that the switch is in the on state and the operation is inoperable.
Vehicle power supply. In the vehicle power supply device according to claim 1,
The second voltage is higher than the first voltage.
Vehicle power supply. In the vehicle power supply device according to claim 1 or 2.
As a power supply control mode, there is a discharge mode in which the switch is controlled to the on state, the power conversion device is controlled to the discharge state, and the generator motor is controlled to the stop state.
As a power control mode, there is a restart mode in which the switch is controlled to the off state, the power conversion device is controlled to the discharge state, and the generator motor is controlled to the power running state.
In the process of switching the power supply control mode from the discharge mode to the restart mode, the failure determination unit determines whether or not the switch is in an inoperable failure state in the on state.
Vehicle power supply. In the vehicle power supply device according to claim 3.
In the process of switching the power supply control mode from the restart mode to the discharge mode, the failure determination unit outputs an on signal for controlling the switch to the on state, and when the potential difference exceeds the threshold value, the switch causes the switch. Judge that it is an inoperable failure state in the off state,
Vehicle power supply. In the vehicle power supply device according to claim 3 or 4.
As a power generation control mode, there is a power generation mode in which the switch is controlled to the on state, the power conversion device is controlled to the stopped state, and the power generation motor is controlled to the power generation state.
The failure determination unit outputs an on signal for controlling the switch to the on state in the process of switching the power supply control mode from the restart mode to the power generation mode, and when the potential difference exceeds the threshold value, the switch causes the switch. Judge that it is an inoperable failure state in the off state,
Vehicle power supply.

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