JP2014087156A - Vehicle, electrical power system and control method of electrical power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time until a vehicle becomes a Ready-On state by improving fault detection efficiency of a relay device.SOLUTION: ECU 30 operates a system main relay SMR2 to connect a second energy storage device BAT2 with a second capacitor C2 and carries out fault detection of the system main relay SMR2 based on voltage of the second capacitor C2. After the fault detection of the system main relay SMR2, ECU 30 operates a system main relay SMR1 to connect a first energy storage device BAT1 with a first capacitor C1 and carries out fault detection of the system main relay SMR1 based on voltage of the second capacitor C1.

Description

    The present invention relates to a vehicle, a power supply system, and a control method for the power supply system, and more particularly to a vehicle having a relay circuit, a power supply system, and a control method for the power supply system.

  A vehicle is equipped with a main battery (hereinafter referred to as a first power storage device) and a sub-battery (hereinafter referred to as a second power storage device). 2. Description of the Related Art A power supply system that is connected in parallel to a motor that receives power supply is known (for example, see Patent Document 1).

  Japanese Patent Laying-Open No. 2011-199934 (Patent Document 1) is connected in parallel with a first high-capacity, high-voltage first secondary battery connected to an inverter unit that drives a motor. Fluctuations in power supplied to the load between the low-voltage, high-output second secondary battery, the boost converter that boosts the voltage output from the second secondary battery, and the positive-side line and the negative-side line The structure provided with the capacitor | condenser which suppresses is disclosed.

  In addition, the power supply system disclosed in Japanese Patent Application Laid-Open No. 2010-252475 (Patent Document 2) performs a capacitor discharging process while a disconnection operation is instructed to the relay device. And it is determined whether the welding of the contact of a relay apparatus has arisen by detecting the voltage of the both ends of the capacitor | condenser at that time.

JP 2011-199934 A JP 2010-252475 A

  In such a vehicle, the failure detection of the relay device may be performed as one of inspection items before the start of traveling. In general, in order to shorten the time from the start of the vehicle to the state where the vehicle can start running (hereinafter referred to as “Ready-ON” state) as much as possible, the welding check of the contact of the relay device can be performed in a short time. desirable.

  In a power supply system in which a relay device provided individually for each power storage device is connected in parallel to the inverter unit, a voltage is applied from a first power storage device and a second power storage device to a common capacitor.

  In such a configuration, when the welding check is first performed at the contact point of the relay device on the first power storage device side when the welding check is performed, if the welding occurs on the relay device on the first power storage device side, the capacitor If it is left as it is, there is a possibility that the welding check of each contact of the relay device on the second power storage device side cannot be performed thereafter.

  For this reason, when performing a welding check on the contact of each relay device in such a case, it is necessary to perform re-separation of the contact and discharge processing of the capacitor after the completion of failure detection, which may reduce the efficiency of failure detection. is there.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a power system in which a relay device for switching between power supply and interruption is interposed between a plurality of power supply devices and a load. Another object of the present invention is to provide a vehicle, a power supply system, and a control method for the power supply system that can improve the efficiency of failure detection of the relay device and shorten the time until the Ready-ON state is reached.

  In short, the present invention is a vehicle including a power supply system, a drive device that is driven by electric power supplied from the power supply system, and a control device that controls the power supply system and the drive device. The power supply system includes a first power storage device capable of supplying power to the drive device, a second power storage device connected in parallel to the first power storage device with respect to the drive device, and the first power storage device and the drive device. A first switch that switches between power supply and cutoff; a converter unit that is connected to a path connecting the first switch and the drive device, converts a voltage output from the first power storage device, and applies the voltage to the drive device; A first capacitor connected in parallel to the first power storage device with respect to the converter unit on a path connecting the first switch and the converter unit, and a second switching between power supply and cutoff from the second power storage device to the drive device The switch includes a second capacitor connected to a path connecting the converter unit and the driving device and to which the voltage of the first power storage device is applied via the converter unit. The control device detects a failure of the second switch based on the voltage of the second capacitor when the second power storage device outputs an operation command for the second switch to be connected to the second capacitor, and the second switch After the failure detection of the first switch, the failure detection of the first switch is performed based on the voltage of the first capacitor when the first power storage device outputs an operation command of the first switch to be connected to the first capacitor. .

  Preferably, when the voltage difference between the first power storage device and the second power storage device is lower than a predetermined threshold, the control device performs failure detection of the second switch and then detects failure of the first switch. Perform detection.

  More preferably, each of the first switch and the second switch has a plurality of contacts, and when the voltage difference exceeds a threshold value, the control device has a plurality of contacts for each of the first switch and the second switch. Failure detection is performed based on the voltage applied to the first capacitor and the second capacitor when an operation command for operating one of the contacts is output.

  More preferably, the control device outputs the operation command for operating one of the plurality of contacts, and the voltage of the second capacitor is the value of the voltage of the second power storage device or the second power storage device If it falls within the range approximating the voltage value, it is determined that welding has occurred in the second switch, and the voltage of the second capacitor is the voltage value of the first power storage device or within the approximating range. If it is within the range, it is determined that welding has occurred in the first switch.

  More preferably, when the voltage of the first capacitor when the operation command for operating one of the plurality of contacts is output is within a range of 0V or close to 0V, When it is determined that the switch is disconnected, and the voltage of the second capacitor is within the range of the voltage value of the first power storage device or the voltage value of the first power storage device, the second switch is disconnected When the voltage of the second capacitor falls within the range of 0V or close to 0V, it is determined that the disconnection has occurred in both the first switch and the second switch.

  More preferably, at least one of the first switch and the second switch has a precharge function that suppresses a rapid increase in the inrush current to the drive device 90.

  More preferably, the control device sets the converter unit to a non-driving state while performing failure detection of the second switch.

  More preferably, the first power storage device includes a high-power battery, and the second power storage device includes a high-capacity battery.

  More preferably, the power supply system includes a control device that adjusts the power supplied to the load. A first power storage device capable of supplying power to the load; a second power storage device connected in parallel to the first power storage device with respect to the load; and supply and interruption of power between the first power storage device and the load. A first switch to be switched, a converter connected to a path connecting the first switch and the load, converting the voltage output from the first power storage device and applying the voltage to the load, and connecting the first switch and the converter A first capacitor connected in parallel with the first power storage device with respect to the converter unit in the path, a second switch for switching supply and interruption of power from the second power storage device to the load, and connecting the converter unit and the load And a second capacitor connected to the path and to which the voltage of the first power storage device is applied via the converter unit. The control device detects a failure of the second switch based on the voltage of the second capacitor when the second power storage device outputs an operation command for the second switch to be connected to the second capacitor, and the second switch After the failure detection of the first switch, the failure detection of the first switch is performed based on the voltage of the first capacitor when the first power storage device outputs an operation command of the first switch to be connected to the first capacitor. .

  In another aspect of the present invention, a power supply system control method for supplying power to a load is provided. The power supply system includes a first power storage device capable of supplying power to the load, a second power storage device connected in parallel to the first power storage device with respect to the load, and power supply between the first power storage device and the load. A first switch that switches between switching and shutoff, a converter unit that is connected to a path connecting the first switch and the load, converts the voltage output from the first power storage device and applies the voltage to the load, and the first switch and the converter A first capacitor connected in parallel with the first power storage device with respect to the converter unit in a path connecting the power supply unit, a second switch for switching between supply and interruption of power from the second power storage device to the load, and a converter unit, A second capacitor connected to a path connecting to the load and to which the voltage of the first power storage device is applied via the converter unit. The control method includes a step of outputting an operation command of the second switch such that the second power storage device is connected to the second capacitor, and a voltage of the second capacitor when the operation command of the second switch is output. A step of detecting a failure of the second switch based on the step, a step of outputting an operation command of the first switch such that the first power storage device is connected to the first capacitor after detecting the failure of the second switch; Detecting a failure of the first switch based on the voltage of the first capacitor when an operation command of the first switch is output so that the first power storage device is connected to the first capacitor.

  According to the present invention, in the power supply system configured as described above, the failure of the second switch is detected based on the voltage of the second capacitor when an operation instruction is given to the second switch by the control device. After failure detection of the second switch is performed, failure detection of the first switch is performed based on the voltage of the first capacitor when an operation instruction is given to the first switch.

  For this reason, even when the voltage of the second capacitor rises due to the voltage applied from the second power storage device due to the failure detection of the second switch, the first switch Fault detection can be performed. Accordingly, processing such as discharging of the capacitor charge is not required, so that failure detection can be performed efficiently in a short time before starting running.

1 is an overall block diagram of a hybrid vehicle equipped with a power supply system according to an embodiment of the present invention. It is a figure which shows the structure of the hybrid vehicle carrying the power supply system of a comparative example. It is a time chart which shows the detail of operation | movement at the time of implementing the process of the power supply system of FIG. It is a time chart which shows the detail of operation | movement at the time of implementing the process of the power supply system of embodiment. 5 is a flowchart for explaining a part of a process of performing failure detection in FIG. 4. It is a time chart which shows the detail of operation | movement at the time of implementing a failure detection using the voltage difference of an electrical storage apparatus. It is a flowchart explaining the process of performing the failure detection of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is an overall block diagram of a hybrid vehicle equipped with a power supply system 50 according to an embodiment of the present invention.

[Vehicle configuration]
Referring to FIG. 1, hybrid vehicle 100 includes a power supply system 50, a drive device 90, and an ECU (Electronic Control Unit) 30 as a control device that controls power supply system 50 and drive device 90.

  The power supply system 50 includes a first power storage device BAT1, a second power storage device BAT2, a system main relay SMR1, a system main relay SMR2, a converter unit 10, a first capacitor C1, a second capacitor C2, and a backflow prevention circuit. 35, voltage sensors 42, 44, 46, and 48, and current sensors 52, 54, and 56 are provided.

  As the first power storage device BAT1 and the second power storage device BAT2, a secondary battery such as a lithium ion battery, a nickel hydrogen battery, or a lead storage battery can be used. Further, a chargeable / dischargeable power storage element such as a capacitor may be used.

  First power storage device BAT1 is connected to converter unit 10 serving as a voltage conversion device via system main relay SMR1.

  Voltage VB1 of first power storage device BAT1 is detected by voltage sensor 42, and the value of detected voltage VB1 is output to ECU 30. Current I1 supplied from first power storage device BAT1 to converter unit 10 is detected by current sensor 52, and the detected value is output to ECU 30. The values of the voltage VB1 and the current I1 are used by the ECU 30 for calculating a remaining capacity SOC (SOC: State Of Charge), which will be described later.

  System main relay SMR1 is connected in series with limiting resistor R1 between contact G1 connected between the negative electrode of first power storage device BAT1 and negative electrode line NL1, and between the negative electrode of first power storage device BAT1 and negative electrode line NL1. And a contact B1 connected between the positive electrode of the first power storage device BAT1 and the positive electrode line PL1. The contacts G1, P1, and B1 are individually controlled to be turned on / off according to a control signal SM1 provided from the ECU 30.

  When starting hybrid vehicle 100, ECU 30 conducts contacts B1 and P1 of system main relay SMR1 to precharge first capacitor C1 and second capacitor C2. Thereafter, when the precharge is completed, the ECU 30 opens the contact P1 after making the contact G1 conductive. By switching the contacts G1, P1, and B1 in this order, the system main relay SMR1 can be brought into a state in which power can be supplied to the inverter unit 20 while suppressing an inrush current to the load.

  The first capacitor C1 is provided between the positive electrode line PL1 and the negative electrode line NL1, which are paths connecting the system main relay SMR1 and the converter unit 10, and reduces the voltage fluctuation between the positive electrode line PL1 and the negative electrode line NL1.

  Converter unit 10 includes upper and lower arm switching elements 11 and 12, upper and lower arm diodes 13 and 14, and a reactor 15. Upper and lower arm switching elements 11 and 12 are connected in series between positive electrode line PL3 and negative electrode line NL1 that electrically connect converter unit 10 and driving device 90.

  Upper and lower arm diodes 13 and 14 are connected in reverse parallel to the upper and lower arm switching elements 11 and 12, respectively. Reactor 15 is connected between a connection node of upper and lower arm switching elements 11 and 12 and positive electrode line PL1.

  In the present embodiment, as the upper and lower arm switching elements 11 and 12, for example, an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, or a power bipolar transistor can be used.

  The converter unit 10 is basically controlled such that the upper and lower arm switching elements 11 and 12 are turned on and off in a complementary manner within each switching period. During the boosting operation, converter unit 10 boosts DC power of voltage VL output by first power storage device BAT1 to voltage VH. This step-up operation is performed by applying electromagnetic energy stored in reactor 15 during the ON period of lower arm switching element 12 from upper arm switching element 11 and upper arm diode 13 connected in reverse parallel to positive line PL3. .

  Further, during the step-down operation, converter unit 10 steps down the DC power of voltage VH output by inverter unit 20 in drive device 90 so as to become voltage VL. This step-down operation is performed by applying the electromagnetic energy accumulated in the reactor 15 during the ON period of the upper arm switching element 11 from the lower arm switching element 12 and the lower arm diode 14 connected in reverse parallel to the negative electrode line NL1. It is. The voltage conversion ratio (the ratio of VH and VL) in these step-up and step-down operations is controlled by the on-period ratio (duty ratio) of the upper and lower arm switching elements 11 and 12 in the switching cycle. For example, when the upper arm switching element 11 is turned on and the lower arm switching element 12 is fixed off, VH = VL (voltage conversion ratio = 1.0) can be obtained.

  The second capacitor C2 is connected between the positive electrode line PL3 and the negative electrode line NL1, and reduces voltage fluctuation between the positive electrode line PL3 and the negative electrode line NL1. The voltage sensor 48 detects the voltage across the second capacitor C2, and outputs the detected voltage VH to the ECU 30.

  Second power storage device BAT2 is connected to drive device 90 in parallel with first power storage device BAT1. Second power storage device BAT2 is connected to drive device 90 through positive electrode line PL2 and negative electrode line NL2. A system main relay SMR2 is provided between second power storage device BAT2 and power lines PL2 and NL2. System main relay SMR2 switches between supply and interruption of power from second power storage device BAT2 to drive device 90.

  System main relay SMR2 has contact G2 connected between the negative electrode of second power storage device BAT2 and negative electrode line NL2, contact B2 connected between the positive electrode of second power storage device BAT2 and positive electrode line PL2, A contact P2 connected in parallel to the contact B2 and connected in series to the limiting resistor R2. The contacts G2, B2, and P2 are individually controlled to be turned on / off according to a signal SM2 provided from the ECU 30.

  A limiting resistor R2 is provided at the contact P of the system main relay SMR2 of this embodiment. Therefore, the system main relay SMR2 can be connected to the drive device 90 while protecting the second capacitor C2 and the voltage sensor 48 without causing an inrush current to the load. The limiting resistors R1 and R2 are only required to include at least the system main relay SMR2 of the system main relay SMR1 and the system main relay SMR2.

  The backflow prevention circuit 35 is provided in the positive electrode line PL2. The backflow prevention circuit 35 is configured by a diode D3, for example, and is connected with the direction flowing from the positive line PL2 to the positive line PL3 as the forward direction.

  When the voltage VH exceeds the voltage VB2, the ECU 30 outputs a control signal SM2 that causes the connection operation to be performed, and the contacts B2 and G2 are connected. In this way, the second power storage device BAT2 can be connected to the inverter unit 20 in a so-called no-load state where no current flows from the second power storage device BAT2.

  A voltage sensor 44 is connected to both ends of the second power storage device BAT2. Voltage sensor 44 detects the value of voltage VB2 of second power storage device BAT2 and outputs the detected value to ECU 30. Current sensor 54 detects the value of current I2 supplied from second power storage device BAT2, and outputs the value to ECU 30. Then, ECU 30 compares the value of voltage VB2 with the value of voltage VH detected by voltage sensor 48, and switches first power storage device BAT1 and second power storage device BAT2.

  First power storage device BAT1 includes a high-power battery, and the other second power storage device BAT2 includes a high-capacity battery. For example, for the first power storage device BAT1, a secondary battery having a maximum output power that is higher than that of the second power storage device BAT2 can be used. The first power storage device BAT1 is adapted to HV traveling, which will be described later, and is constituted by a secondary battery capable of supplying a relatively large current, thereby providing sufficient output and charging performance during acceleration / deceleration traveling. it can.

  As the second power storage device BAT2, a secondary battery having a larger power storage capacity than the first power storage device BAT1 can be used. In addition, by supplying power directly to the inverter unit 20 without interposing a power conversion device such as the converter unit 10, power conversion loss is small during constant speed traveling with little speed change when cruising on a highway, for example. In addition, the power energy efficiency can be improved.

  As described above, a high-power and large-capacity DC power supply can be configured by appropriately using the two first power storage devices BAT1 and second power storage devices BAT2.

  Drive device 90 includes engine 2, motor generators MG1 and MG2 as rotating electric machines, inverter unit 20 that supplies electric power to motor generators MG1 and MG2, and power split that connects engine 2 and motor generators MG1 and MG2. It includes a mechanism 4 and a wheel 6 that is connected to power split mechanism 4 and is rotatable by power from engine 2 and motor generators MG1, MG2.

  Motor generators MG1, MG2 are controlled by ECU 30. Hybrid vehicle 100 travels by driving force from at least one of engine 2 and motor generator MG2.

  That is, hybrid vehicle 100 of this embodiment performs so-called HV traveling that travels using engine 2 and motor generator MG2, and so-called EV traveling that travels by the rotational driving force of motor generator MG2, depending on the driving state. It is possible to travel while automatically selecting.

  Motor generator MG <b> 1 and motor generator MG <b> 2 are rotationally driven by power supply from inverter unit 20. Inverter unit 20 is controlled by control signal PWI from ECU 30 to adjust the rotational torque of motor generators MG1, MG2.

  During the HV traveling, the rotational driving force of motor generator MG2 and the rotational driving force of engine 2 are torque-distributed by power split mechanism 4. Torque-distributed rotational driving force is divided into wheels 6 or motor generator MG1 to rotate wheels 6 or motor generator MG1. Thereby, the hybrid vehicle 100 can be run. Further, the rotational electromotive force of motor generator MG1 can be obtained by inverter control.

  Further, even during EV traveling, when the rotational torque to be generated by motor generator MG2 is insufficient, engine 2 is started and the insufficient rotational torque is compensated using the rotational driving force from engine 2.

  In addition, hybrid vehicle 100 of the present embodiment is provided with external charging device 60 that charges second power storage device BAT2 using electric power from a power supply external to the vehicle. External charging device 60 includes a charger side relay switch CHR, a vehicle body side charging port 61, a charger 62, and a voltage sensor 63.

  The charger 62 is connected to the vehicle body side charging port 61 and is connected to the second power storage device BAT2 from the charger side relay switch CHR. The charger 62 receives AC power transmitted from the external power source 70 to the vehicle body side charging port 61 using the charging cable 80. Then, the received AC power is converted to DC power, and charging power is supplied to the second power storage device BAT2.

  Among these, one end 65 of the contact BC of the charger side relay switch CHR is connected to the positive electrode of the second power storage device BAT2, and the other end 67 is connected to the output terminal of the charger 62. Further, one end 66 of the contact GC is connected to the negative electrode of the second power storage device BAT2, and the other end 68 is connected to the output terminal 68 of the charger 62. A contact PC connected in series with the limiting resistor is provided in parallel with the contact GC on the negative electrode side.

  Voltage sensor 63 measures the voltage at output terminals 67 and 68 of charger 62 and outputs the measured value VCH to ECU 30.

  The charging cable 80 corresponds to EVSE (Electric Vehicle Supply Equipment) in the SAE standard, and includes a connector portion 81. Connector portion 81 of charging cable 80 is connected to vehicle body side charging port 61 provided in hybrid vehicle 100, and electric power from external power supply 70 is transmitted to hybrid vehicle 100.

  In FIG. 1, a hybrid vehicle 100 including the engine 2 is shown and described as an electric vehicle. However, the configuration of the vehicle is not limited to this, and for example, an electric vehicle that runs only by a motor or an external charging device 60 may be a vehicle body The vehicle may be an electric vehicle that is not equipped with. Further, it may be a hybrid vehicle using a fuel cell together with the engine 2 or in place of the engine. Thus, the shape, type, and quantity of the drive source are not particularly limited, and a so-called series / parallel type that includes the power split mechanism 4 and distributes the power of the engine 2 to the motor generator MG1 and the wheels 6 is provided. A plug-in hybrid vehicle, a so-called series-type hybrid vehicle that uses the power of the engine 2 only for power generation by the motor generator MG1 and generates the driving force of the vehicle using only the motor generator MG2, or other types of hybrid vehicles It is also applicable to.

  The ECU 30 controls the power supply system 50 and the inverter unit 20 to adjust the driving force for traveling. When the value of voltage VH detected by voltage sensor 48 exceeds the value of voltage VB2, ECU 30 outputs a control signal SM2 to system main relay SMR2 to connect the contact.

  In addition, a notification device 40 is connected to the ECU 30. The notification device 40 performs notification output using characters and figures through a monitor output display unit (not shown) provided in the passenger compartment. The ECU 30 transmits an output signal that causes the notification device 40 to perform notification output including non-detection of welding. Based on the input of the display output, the notification device 40 notifies the user that the vehicle is ready to travel by sound output and lighting of an indicator lamp, etc., audibly and / or visually.

  The vehicle ECU (not shown) generates an output request PR required for the engine 2, the motor generator MG1, and the motor generator MG2. ECU 30 generates control signal PWC for driving converter unit 10 based on voltages VB1, VB2, and voltages VL, VH according to the accelerator pedal opening, vehicle speed, output request PR, and the like, and the generated control The signal PWC is output to the converter unit 10.

  ECU 30 also generates control signal PWI based on the rotational speed and current of motor generators MG1, MG2 and voltage VH. By outputting the generated control signal PWI to the inverter unit 20, the inverter unit 20 adjusts the rotational driving force of the motor generators MG1 and MG2.

  ECU 30 further outputs a remaining capacity SOC indicating the remaining capacity of first power storage device BAT1 and second power storage device BAT2 based on voltages VB1, VB2 and current values I1, I2 detected by current sensors 52, 54. A power upper limit value WOUT (unit: watts) is obtained. The value indicating the remaining capacity SOC is defined by the ratio of the actual charge capacity to the rated capacity, for example, defined as 100% when the power storage device is fully charged, and defined as 0% when the power storage device is completely discharged. Is done.

[Comparative example]
FIG. 2 is a diagram showing a configuration of a hybrid vehicle 200 equipped with a power supply system 150 of a comparative example. The same parts as those in the embodiment are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIG. 2, in hybrid vehicle 200 of this comparative example, as compared with the configuration of power supply system 50 in FIG. Similarly, a second converter unit 110 that converts the voltage of power supplied to the inverter unit 20 is provided.

  In the hybrid vehicle 200 of the comparative example configured as described above, in so-called EV traveling that travels using only the driving force of the motor generators MG1 and MG2, the first power storage device BAT1 supplies power alone or independently. The electric power of the second power storage device BAT <b> 2 boosted by the two converter unit 110 is supplied to the inverter unit 20.

  FIG. 3 is a time chart showing changes in voltage VH due to connection and disconnection of system main relays SMR1 and SMR2 when power supply system 50 is activated in this comparative example.

  Referring to FIG. 3, in hybrid vehicle 200, when the vehicle is started at time t1, control signals SM1 and SM2 that connect contact B1 of system main relay SMR1 and contact B2 of system main relay SMR2 are output. .

  From time t1, preparation for starting the control operation required for each part is completed, and by time t4 when the vehicle becomes ready-ON, the welding check of each contact point of system main relays SMR1, SMR2 is performed. . In the welding check performed by the ECU 30, for example, by switching the connection state and the non-connection state of each contact and detecting the voltage VH that varies depending on the charge accumulated or discharged in the first capacitor C1 and the second capacitor C2, It is determined whether a failure such as contact welding or wire breakage has occurred.

  When the relay is normal, no voltage is applied from the first power storage device BAT1 and the second power storage device BAT2 to the first capacitor C1 and the second capacitor C2 by the connection operation command by the control signals SM1 and SM2. As indicated by a two-dot chain line f1 in FIG. 3, when the voltage VH increases, it is determined that there is welding at any one of the contacts G1, G2 or P1, P2.

  When the contacts G1, G2 or P1, P2 are normal without welding, the voltage VH increases when the contacts P1, P2 are connected at time t2, as indicated by the solid line. Then, precharge is completed at time t3.

  At time t <b> 4, inverter unit 20 is in a state where it can start traveling by receiving power supply and rotating motor generators MG <b> 1 and MG <b> 2.

  In the power supply system 150 of this comparative example, the converter unit 10 is provided on the first power storage device BAT1 side, and the second converter unit 110 is further provided on the second power storage device BAT2 side. Therefore, each of the first capacitor C11 and the second capacitor C12 can be precharged, and both the first power storage device BAT1 side and the second power storage device BAT2 side connected in parallel to the drive device 90 are parallel. It can be activated at the same time.

  As in this comparative example, a first capacitor C11 and a converter unit 10 are provided corresponding to the system main relay SMR1, and a second capacitor C12 and a second converter unit 110 are provided corresponding to the system main relay SMR2. In this configuration, the first capacitor C11 and the second capacitor C12 are individually precharged and discharged, so that the failure of each contact point of both system main relays SMR1 and SMR2 can be detected.

  However, a vehicle equipped with another power supply system having a simplified configuration in which the second capacitor C12 or the second converter unit 110 is not provided as in the power supply system shown in this comparative example is also conceivable. In such a vehicle power supply system, both the system main relays SMR1 and SMR2 are welded, or a failure or a path disconnection (hereinafter referred to as a disconnection is collectively referred to as a disconnection state) where the contact is in an open state. May not be detected efficiently.

  For example, in the power supply system 50 of FIG. 1, the voltage applied from the first power storage device BAT1 to the first capacitor C1 is also applied to the second capacitor C2 through the upper arm diode 13 connected in antiparallel with the converter unit 10. The

  For this reason, when the welding detection of the system main relay SMR1 is performed first, the system main relay SMR1 on the first power storage device BAT1 side is disconnected, the discharge processing of the second capacitor C2 is performed, and then the system main relay SMR2 is restarted. It is necessary to make a connection. Therefore, in a power supply system with a simplified configuration, there may be a case where failure detection efficiency of each contact cannot be improved.

  Moreover, even if the contact of the system main relay SMR2 on the second power storage device BAT2 side is disconnected, the value of the voltage VH has already increased. For this reason, there may arise a problem that the disconnection cannot be detected on the second power storage device BAT2 side.

  In such a simplified power supply system, when the system main relay SMR1 is welded, the voltage VH of the second capacitor C2 also increases due to the application of the voltage VB1 from the first power storage device BAT1 side. Therefore, at least a failure of the system main relay SMR1 can be detected, but there may occur a case where it is not possible to specify which of the system main relays SMR1, SMR2 is welded or disconnected.

  Therefore, in the present embodiment, prior to the operation of connecting system main relay SMR1 on the first power storage device BAT1 side, the operation of connecting system main relay SMR2 on the second power storage device BAT2 side to the load is performed. The welding check of the contact B2 is performed using the voltage VH applied to the second capacitor C2. Thereafter, the operation of connecting the system main relay SMR1 using the first capacitor C1 is performed to check the welding. Thereby, in the power supply system 50 of this embodiment, while being able to perform a welding check efficiently, a failure location can be pinpointed, the power efficiency is favorable, and the power supply system 50 with a simple structure is provided.

  FIG. 4 is a time chart showing details of the operation when the processing of the power supply system 50 of this embodiment is performed.

  Referring to FIG. 4, when hybrid vehicle 100 is activated at time t1, control signal SM2 is output from ECU 30 to cause connection operation to contact B2 of system main relay SMR2. At this time, since the control signal SM2 outputs an operation command to the contact B2, the contact G2 and the contact P2 do not perform the connection operation. At this time, if the contact G2 and the contact P2 are normal, no voltage is applied to the second capacitor C2 even when the contact B2 is connected, so the value of the voltage VH should remain as it is. Therefore, when the voltage VH increases as indicated by a two-dot chain line f2 in FIG. 4, it can be determined that welding has occurred at least one of the contacts G2 and P2.

  More specifically, ECU 30 first places converter unit 10 in a non-driven state while detecting a failure of system main relay SMR2. This prevents charge transfer from the second capacitor C2 to the first capacitor C1.

  Next, in order to precharge the second capacitor C2, at time t2, the ECU 30 outputs a control signal SM2 as a command for causing the contact P2 of the system main relay SMR2 to perform a connection operation. At this time, if the voltage VH does not increase, the contact P2 and / or the contact B2 may be disconnected.

  After boosting by precharging the second capacitor C2, there is no welding at any of the contacts G2, P2, and when normal, the contact G2 is connected and the contact P2 is disconnected at time t3. Then, the system main relay SMR2 advances the connection of the contacts B2 and G2 while performing failure detection (also referred to as self-diagnosis), and establishes a state where electricity can be supplied.

  If the voltage VH does not rise to the value of the voltage VB2 at time t3 even if the second capacitor C2 is precharged, the contact P2 and / or the contact B2 may be disconnected. When this is combined with the detection result at time t2, the voltage VH does not increase at time t2, and if the voltage VH does not increase at time t3 as shown by the broken line in FIG. 4, the contact B2 may be disconnected. is there. Further, when the voltage VH does not increase at time t2, and the voltage VH increases at time t3, the contact P2 may be disconnected.

  Further, when the voltage VH does not increase at time t3, the contact G2 and / or the contact B2 may be disconnected. In this case, when the voltage VH has increased at time t2, the contact B2 Is likely to be normal, the contact G2 may be disconnected.

  Thus, following the detection of the welding of the contact P2, it is possible to detect whether the contact P2, the contact B2, or the contact G2 is disconnected.

  After the connection of the system main relay SMR2 is established, the ECU 30 outputs the control signal SM1 to the system main relay SMR1 to perform the welding check and connect the system main relay SMR1.

  At time t4, control signal SM1 is output from ECU 30 to cause connection operation to contact B1 of system main relay SMR1. At this time, the connection operation of the contact G1 and the contact P1 is not performed by the output control signal SM1. Therefore, if the contact G1 and the contact P1 are normal, the value of the voltage VL should remain as it is. Therefore, when the voltage VL rises as indicated by the alternate long and short dash line f3 in FIG. 4, it can be determined that at least one of the contact G1 and the contact P1 is welded.

  Thus, even when the second capacitor C2 is charged, the welding check of the contacts P1 and G1 can be performed by the change of the voltage VH of the first capacitor C1 in the state where only the contact B1 is connected.

  Next, in order to precharge the first capacitor C1, at time t5, the ECU 30 outputs a control signal SM1 that causes a connection operation to be performed on the contact P1 of the system main relay SMR1.

  At this time, if the voltage VL is not boosted, it can be determined that the contact B1 and / or the contact P1 may be disconnected. When boosting is performed by precharging the first capacitor C1, and no contact is made at any of the contacts G1 and P1, the contact G1 is connected and the contact P1 is disconnected at time t6. Then, the system main relay SMR1 can establish a connection while performing failure detection, and can be brought into a Ready-ON state.

  In this way, the power supply system 50 establishes the connection while detecting the failure of the system main relay SMR2, and subsequently establishes the connection while the system main relay SMR1 detects the failure, and both the system main relays SMR1, SMR1. After the connection of SMR2 is established, the Ready-ON state can be set at time t7, and the time from the start of the vehicle to Ready-ON can be shortened.

FIG. 5 is a flowchart for explaining the failure detection process of FIG.
Referring to FIG. 5, ECU 30 detects a failure of system main relay SMR2 in steps S1 to S8. First, when failure detection is started as the vehicle starts in step S1, the ECU 30 outputs a control signal SM2 for connecting the contact B2 of the system main relay SMR2 in step S2.

  In step S3, ECU 30 determines whether voltage VH is voltage VB2 of second power storage device BAT2. When voltage VH is the same value as voltage VB2 (YES in step S3), the process proceeds to step S5, determines that contact P2 and / or contact G2 is welded, and proceeds to step S9. Note that. The case where the voltage VH is the same value as the voltage VB2 includes the case where the value of the voltage VB2 matches the value of the voltage VH, or the value of the voltage VH falls within a predetermined approximate range. It is. “To be within the approximate range” means that a predetermined width obtained from a detection error or the like is provided above and below the value of the reference voltage VB2, and the value of the voltage VH within the range of the width is detected. Show.

  The predetermined width may be set in any manner as long as it falls within the predetermined width range that can be estimated as welding or disconnection above and below the reference voltage value. Hereinafter, in the description of the determination of other voltage values, the meaning of the same value is provided when the voltage values match, and above and below the reference voltage value within the approximate range. It will be described as including the case where it falls within the range of the predetermined width.

  When voltage VH is different from voltage VB2 (NO in step S3), the process proceeds to step S4, and ECU 30 outputs control signal SM2 for connecting contact P2 of system main relay SMR2. In step S6, the ECU 30 determines whether or not the voltage VH is 0V. In step S6, if voltage VH remains at 0V and does not increase (YES in step S6), ECU 30 determines in step S7 that contact B2 and / or P2 is disconnected, and the process proceeds to step S9. Proceed. In step S6, when voltage VH changes to other than 0 V (NO in step S6), the process proceeds to step S8. In step S8, the ECU 30 outputs the control signal SM2 so as to connect the contact G2, and outputs the control signal SM2 so that the contact P2 is disconnected.

  The ECU 30 detects a failure of the system main relay SMR1 in steps S9 to S17. In step S9, the ECU 30 outputs a control signal SM1 for connecting the contact B1 of the system main relay SMR1. In step S10, ECU 30 determines whether or not the value of voltage VL of first capacitor C1 detected by voltage sensor 46 is equal to the value of voltage VB1 of first power storage device BAT1. If the value of voltage VL is the same as voltage VB1 (YES in step S10), the process proceeds to step S11, and ECU 30 determines that contact P1 and / or contact G1 is welded, and the process Return to the main routine. If the value of voltage VL is not the same as voltage VB1 (NO in step S10), ECU 30 advances the process to step S12. In step S12, the ECU 30 outputs a control signal SM1 so as to connect the contact P1 of the system main relay SMR1. Next, the ECU 30 proceeds to step S13 and determines whether or not the voltage VL of the first capacitor C1 is 0V. If voltage VL is 0 V (YES in step S13), ECU 30 determines in step S14 that contact P1 and / or contact B1 is disconnected, and returns the process to the main routine.

  In step S13, if voltage VL is not equal to voltage VB1 (NO in step S13), ECU 30 advances the process to step S15. In step S15, the ECU 30 outputs the control signal SM1 so as to connect the contact G1, and outputs the control signal SM1 so that the contact P1 is disconnected. ECU 30 advances the process to step S16 to determine whether or not the value of voltage VL detected by voltage sensor 48 is equal to the value of voltage VB1 of first power storage device BAT1. If the value of voltage VL is equal to the value of voltage VB1 (YES in step S16), ECU 30 determines that ECU 30 is normal in step S17, and if the value of voltage VL is not the value of voltage VB1. The processing is returned to the main routine on the assumption that there is a possibility that the contact G1 is disconnected.

  Here, as shown in FIG. 4, by making the timings of the control signals SM1 and SM2 output from the ECU 30 different, the operation of connecting both the system main relays SMR1 and SMR2 is performed in parallel, and the connection is started. After connecting the contact point P2, the contact point P1 is connected. Thus, the ECU 30 can detect whether the voltage VH and / or the voltage VL increases or does not increase, and can determine whether or not each contact is disconnected or welded. In addition, about each step S5, S7, S11, S14, and S17 shown in FIG. 5, you may make it alert | report using the alerting | reporting apparatus 40 with determination of a failure.

  In the vehicle power supply system according to the first embodiment, the ECU 30 connects the second power storage device BAT2 to the second capacitor C2 through the system main relay SMR2, and thus the system main is based on the voltage VH of the second capacitor C2. After failure detection of relay SMR2 is performed, failure detection of the contact of system main relay SMR1 is performed based on the voltage of first capacitor C1 to which first power storage device BAT1 is connected by system main relay SMR1.

  For this reason, even if the second capacitor C2 rises at the voltage VH applied from the second power storage device BAT2, the voltage of the first capacitor C1 is not affected, and later, based on the voltage VL of the first capacitor C1, It is possible to detect a failure of the system main relay SMR1. This eliminates the need for capacitor discharge processing and reconnection of the relay device, so that the failed part can be identified efficiently.

[Embodiment 2]
In the first embodiment described above, the failure of the contact of the system main relay SMR1 is detected after the failure of the contact of the system main relay SMR2 is performed, so that the failure can be detected efficiently and the startup time is reduced. A vehicle equipped with a power system that can be described has been described. In addition to these functions and effects, when the voltage VB2 of the second power storage device BAT2 is higher than the voltage VB1 of the first power storage device BAT1 and has a voltage difference (VB2-VB1), the Ready-ON state from the start of the vehicle A power supply system capable of detecting a failure while both the system main relay SMR1 and the system main relay SMR2 are connected in parallel and substantially simultaneously will be described in the second embodiment below. .

  FIG. 6 is a time chart showing details of the operation when failure detection is performed using the voltage difference between first power storage device BAT1 and second power storage device BAT2 of the second embodiment. The first power storage device BAT1 of the second embodiment is configured by a high output battery having a voltage VB1, and the second power storage device BAT2 is configured by a high capacity battery having a voltage VB2 higher than the voltage VB1. Therefore, it has a predetermined voltage difference (VB2-VB1).

  First, at time t10, when the control signal SM1 and the control signal SM2 are output from the ECU 30 so that the contacts B1 and B2 of the system main relay SMR1 and the system main relay SMR2 are connected, the contacts P1, G1, P2, and G2 In the normal case, the voltage VL across the first capacitor C1 and / or the voltage VH across the second capacitor C2 does not increase.

  If the connection and disconnection operation of system main relay SMR1 and / or system main relay SMR2 does not function in response to control signals SM1 and SM2 from ECU 30, and is not normal, the connection operation of contacts B1 and / or B2 VL and / or voltage VH increases. Specifically, when the voltage VL across the first capacitor C1 increases to the voltage VB1 of the first power storage device BAT1, and / or the voltage VH across the second capacitor C2 reaches the voltage VB1 of the first power storage device BAT1. When it rises, it can be determined that either the contact P1 or the contact G1 is welded.

  On the other hand, when the voltage VH across the second capacitor C2 rises to the same value as the voltage VB2 of the second power storage device BAT2, it can be determined that the contact P2 of the system main relay SMR2 is welded. In this case, whether or not contact P1 or contact G1 of system main relay SMR1 is welded can be determined by whether or not the value of voltage VL increases to the same value as voltage VB1 of first power storage device BAT1.

  Next, at time t11, the control signals SM1 and SM2 are output from the ECU 30. The control signals SM1 and SM2 are commands for causing the contacts P1 and P2 to be connected. The contact P1 of the system main relay SMR1 and the contact P2 of the system main relay SMR2 are connected in parallel, and Precharging of the capacitor C1 and the second capacitor C2 is started.

  In the case of this embodiment, voltage VB2 of second power storage device BAT2 is set in advance higher than voltage VB1 of first power storage device BAT1, so that voltage of second capacitor C2 is normal when system main relay SMR2 is normal. VH rises to the same value as voltage VB2 of second power storage device BAT2 by precharging. On the other hand, when the contact B2 of the system main relay SMR2 is disconnected, the voltage VB2 is not applied from the second power storage device BAT2, so that when the system main relay SMR1 is normal, the voltage VH of the second capacitor C2 is the first power storage. The voltage rises to the same value as the voltage VB1 of the device BAT1.

  Further, when the contact B1 of the system main relay SMR1 is disconnected, the voltage VL of the first capacitor C1 does not increase. Note that if both the contact B1 of the system main relay SMR1 and the contact B2 of the system main relay SMR2 are disconnected, the voltage VH does not increase as shown by the broken line in FIG. If normal, the contacts G1 and G2 are connected at time t12, and the contacts P1 and P2 are simultaneously disconnected at time t13. Thereby, the connection of the system main relay SMR1 and the system main relay SMR2 is completed, and a Ready-ON state is set.

The process of performing the failure detection in FIG. 6 will be described using the flowchart shown in FIG.
Referring to FIG. 7, in step S20, ECU 30 determines whether or not the absolute value of the voltage difference between first power storage device BAT1 and second power storage device BAT2 is greater than a predetermined threshold value α. Is done.

  If the voltage difference is smaller than predetermined threshold value α (NO in step S20), the process proceeds to step S1 in FIG.

  If the voltage difference is larger than predetermined threshold value α (YES in step S20), ECU 30 proceeds to the next step S21, and contacts B1, B2 on only one side of both system main relays SMR1, SMR2. Control signals SM1 and SM2 are output so as to perform the operation of connecting the two.

  In step S22, the ECU 30 determines whether or not the voltage VH of the second capacitor C2 has increased.

  If voltage VH has not increased (NO in step S22), ECU 30 advances the process to step S24. In step S24, ECU 30 outputs control signals SM1 and SM2 that issue a command to connect contacts P1 and P2.

  In step S25, the ECU 30 determines whether or not the value of the voltage VL is the same as the value of the voltage VB1, and the value of the voltage VH is the same as the value of the voltage VB2. When the value of voltage VL is the same as the value of voltage VB1 and the value of voltage VH is the same as the value of voltage VB2 (YES in step S25), ECU 30 proceeds to step S26 and proceeds to system main relay. It is determined that SMR1 and system main relay SMR2 are normal.

  If the value of voltage VL is not the same as the value of voltage VB1 or the value of voltage VH is not the same as the value of voltage VB2 (NO in step S25), ECU 30 determines that a disconnection has occurred and proceeds to step S30. To identify the location of which contacts are broken.

  Specifically, when the value of voltage VL is 0 V and the value of voltage VH is 0 V, ECU 30 determines that contact B1 of system main relay SMR1 and contact B2 of system main relay SMR2 are both disconnected. To do. When only the voltage VL is 0 V, the ECU 30 determines that the contact B1 of the system main relay SMR1 is disconnected. Further, when the value of voltage VH is equal to the value of voltage VB1 of first power storage device BAT1 and is not 0 V, ECU 30 determines that contact B2 is disconnected.

  On the other hand, when voltage VH increases in step S22 (YES in step S22), ECU 30 proceeds to step S27 and determines whether or not voltage VL is 0V. If voltage VL is 0 V (YES in step S27), ECU 30 proceeds to step S33 and determines that contact P2 is welded. If voltage VL is not 0 V (NO in step S27), ECU 30 proceeds to step S28 and determines whether voltage VH is equal to voltage VB2.

  When voltage VH is the same value as VB2 (YES in step S28), ECU 30 advances the process to step S31, and both contact point P1 of system main relay SMR1 and contact point P2 of system main relay SMR2 are welded. Is determined. If the value of voltage VH is not the same value as voltage VB2 (NO in step S28), ECU 30 proceeds to step S32 and determines that contact P1 is welded. In each step S31, S32, and S33, the identified failure location is notified to the user by the notification device 40 connected to the ECU 30.

  As described above, in the power supply system of the second embodiment, as shown in FIGS. 6 and 7, the system main relay SMR1 and the system main relay SMR2 can detect the fault location in parallel, so that it is efficient. The vehicle can be started in a short time while detecting the failure of each contact.

  Therefore, in an electric power system including system main relays SMR1 and SMR2 for switching between supply and interruption of electric power between a plurality of power storage devices and drive device 90, the efficiency of failure detection is improved, and connection is started from the start of the vehicle. It is possible to shorten the time from completion to the Ready-ON state.

The embodiment described above will be summarized with reference to the drawings again.
As shown in FIG. 1, this hybrid vehicle 100 includes a power supply system 50, a drive device 90 that is driven by electric power supplied from the power supply system 50, and an ECU 30 that controls the power supply system 50 and the drive device 90. The power supply system 50 includes a first power storage device BAT1 that can supply power to the drive device 90, a second power storage device BAT2 that is connected to the drive device 90 in parallel with the first power storage device BAT1, and a first power storage device BAT1. Connected to a path connecting system main relay SMR1 and drive device 90, and the voltage output from first power storage device BAT1 is connected to a path connecting system main relay SMR1 and drive device 90. A converter unit 10 that converts and applies the drive unit 90; a first capacitor C1 that is connected to the converter unit 10 in parallel with the first power storage device BAT1 through a path connecting the system main relay SMR1 and the converter unit 10; A system main relay SMR2 that switches between supply and interruption of power from the second power storage device BAT2 to the drive device 90; It is connected to a path connecting the motor unit 10 and drive unit 90, and a second capacitor C2 the voltage of the first power storage device BAT1 is applied through the converter unit 10. The ECU 30 controls the system main relay SMR2 based on the voltage of the second capacitor C2 when the control signal SM2 that is the operation command of the second switch that causes the second power storage device BAT2 to be connected to the second capacitor C2 is output. After detecting the failure and detecting the failure of the system main relay SMR2, the first capacitor C1 when the operation command of the system main relay SMR1 such that the first power storage device BAT1 is connected to the first capacitor C1 is output. The failure of the system main relay SMR1 is detected based on the voltage of.

  Preferably, ECU 30 detects a failure of system main relay SMR2 when the voltage difference (VH−VL) between first power storage device BAT1 and second power storage device BAT2 is lower than a predetermined threshold value α. After that, the system main relay SMR1 is performed.

  More preferably, each of system main relay SMR1 and system main relay SMR2 has a plurality of contacts, and when voltage difference (VH−VL) exceeds threshold value α, ECU 30 determines system main relay SMR1 and system main relay SMR1. For each of the main relays SMR2, failure detection is performed based on voltages applied to the first capacitor C1 and the second capacitor C2 when an operation command for operating one of the plurality of contacts is output.

  More preferably, ECU 30 outputs the operation command for operating one of the plurality of contacts, the voltage of second capacitor C2 is the value of voltage of second power storage device BAT2, or the second power storage device. Is within the range that approximates the voltage value of the power supply, it is determined that welding has occurred in the system main relay SMR2, and the voltage of the second capacitor C2 is equal to or approximates the voltage value of the first power storage device BAT1. If it falls within the range, it is determined that welding has occurred in the system main relay SMR1.

  More preferably, when the voltage of the first capacitor C1 when the operation command for operating one of the plurality of contacts is output is within a range of 0V or close to 0V, the ECU 30 When it is determined that disconnection has occurred in relay SMR1, and the voltage of second capacitor C2 falls within the value of voltage VB1 of first power storage device BAT1 or in a range that approximates the value of voltage VB1, the system main relay SMR2 When it is determined that a disconnection has occurred and the voltage of the second capacitor C2 falls within the range of 0V or close to 0V, it is determined that a disconnection has occurred in both the system main relay SMR1 and the system main relay SMR2. To do.

  More preferably, at least one of system main relay SMR1 and system main relay SMR2 has a precharge function that suppresses a sudden increase in inrush current.

  More preferably, ECU 30 sets converter unit 10 in a non-driven state while detecting a failure of system main relay SMR2.

  More preferably, first power storage device BAT1 includes a high-power battery, and second power storage device BAT2 includes a high-capacity battery.

  More preferably, the power supply system 50 is for supplying power to the driving device 90. First power storage device BAT1 capable of supplying power to drive device 90, second power storage device BAT2 connected in parallel with first power storage device BAT1 to drive device 90, first power storage device BAT1, and drive device 90 Connected to the path connecting system main relay 1 and drive device 90, and converting the voltage output from first power storage device BAT1 to drive device 90, the first capacitor C1 connected in parallel with the first power storage device BAT1 with respect to the converter unit 10 on the path connecting the system main relay SMR1 and the converter unit 10 to the converter 90, and the second power storage device BAT2 System main relay SMR2 that switches between supply and interruption of electric power to the drive device 90 from the converter, the converter unit 10, the drive device 90, It is connected to a path connecting, and a second capacitor C2 the voltage of the first power storage device BAT1 is applied through the converter unit 10. The ECU 30 detects a failure of the system main relay SMR2 based on the voltage of the second capacitor C2 when the second power storage device BAT2 outputs an operation command for the second switch such that the second power storage device BAT2 is connected to the second capacitor C2. After detecting the failure of the system main relay SMR2, based on the voltage of the first capacitor C1 when the operation command of the system main relay SMR1 is output such that the first power storage device BAT1 is connected to the first capacitor C1. Failure detection of system main relay SMR1 is performed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  2 engine, 4 power split mechanism, 6 wheels, 10 converter section, 11, 12 upper, lower arm switching element, 13, 14 upper, lower arm diode, 15 reactor, 20 inverter section, 30 ECU, 35 backflow prevention circuit, 40 Notification device, 42, 44, 46, 48 Voltage sensor, 50 Power supply system 63 Voltage sensor, 52, 54, 56 Current sensor, 60 External charging device, 61 Car body side charging port, 62 Battery charger, 65 One end, 66 Other end, 70 External power supply, 80 connection cable, 100 hybrid vehicle, 110 second converter section, BAT1 first power storage device, BAT2 second power storage device, C1, C2 first and second capacitors, CHR charger side relay switch, D3 diode , MG1, MG2 Motor generator, NL1, NL2 Negative line, PL1, PL2, PL3 Positive line, PR request output, SMR1, SMR2 system main relay, R1, R2 limiting resistor.

Claims (10)

A vehicle comprising: a power supply system; a drive device that is driven by electric power supplied from the power supply system; and a control device that controls the power supply system and the drive device,
The power supply system includes:
A first power storage device capable of supplying electric power to the drive device;
A second power storage device connected in parallel to the first power storage device with respect to the drive device;
A first switch that switches between supply and interruption of power between the first power storage device and the drive device;
A converter unit connected to a path connecting the first switch and the driving device, converting a voltage output from the first power storage device and applying the voltage to the driving device;
A first capacitor connected in parallel with the first power storage device with respect to the converter unit in a path connecting the first switch and the converter unit;
A second switch for switching between supply and interruption of power from the second power storage device to the drive device;
A second capacitor connected to a path connecting the converter unit and the drive device, to which the voltage of the first power storage device is applied via the converter unit;
The control device detects a failure of the second switch based on a voltage of the second capacitor when the second power storage device outputs an operation command for the second switch such that the second power storage device is connected to the second capacitor. And after the failure detection of the second switch is performed, the voltage of the first capacitor when the first power storage device outputs an operation command for the first switch to be connected to the first capacitor. A vehicle that detects a failure of the first switch based on   When the voltage difference between the first power storage device and the second power storage device is lower than a predetermined threshold, the control device performs failure detection of the second switch and then performs the first switch The vehicle according to claim 1, wherein fault detection is performed. Each of the first switch and the second switch has a plurality of contacts,
When the voltage difference exceeds the threshold value, the control device outputs an operation command for operating one of the plurality of contacts for each of the first switch and the second switch. The vehicle according to claim 2, wherein failure detection is performed based on a voltage applied to the first capacitor and the second capacitor.   The control device is configured such that a voltage of the second capacitor when an operation command for operating one of the plurality of contacts is output is a voltage value of the second power storage device or the second power storage device. If it falls within the approximate range, it is determined that welding has occurred in the second switch, and the voltage of the second capacitor is equal to the voltage value of the first power storage device or the voltage of the first power storage device. The vehicle according to claim 3, wherein it is determined that welding has occurred in the first switch when it falls within a range that approximates to.   When the voltage of the first capacitor when the operation command for operating one of the plurality of contacts is output is within a range of 0V or close to 0V, the control device If the voltage of the second capacitor falls within the range of the voltage value of the first power storage device or a voltage approximate to the voltage of the first power storage device, the second switch When it is determined that a disconnection has occurred and the voltage of the second capacitor falls within the range of 0V or close to 0V, it is determined that a disconnection has occurred in both the first switch and the second switch. The vehicle according to claim 3 or 4.   6. The vehicle according to claim 1, wherein at least one of the first switch and the second switch has a precharge function that suppresses a rapid increase in an inrush current to the driving device. .   The vehicle according to any one of claims 1 to 6, wherein the control device sets the converter unit to a non-driven state while performing failure detection of the second switch. The first power storage device includes a high-power battery,
The vehicle according to any one of claims 1 to 7, wherein the second power storage device includes a high-capacity battery. A power supply system including a control device for adjusting power supplied to a load,
A first power storage device capable of supplying power to the load;
A second power storage device connected in parallel to the first power storage device with respect to the load;
A first switch that switches between supply and interruption of power between the first power storage device and the load;
A converter unit connected to a path connecting the first switch and the load, converting a voltage output from the first power storage device and applying the voltage to the load;
A first capacitor connected in parallel with the first power storage device with respect to the converter unit in a path connecting the first switch and the converter unit;
A second switch that switches between supply and interruption of power from the second power storage device to the load;
A second capacitor connected to a path connecting the converter unit and the load, to which the voltage of the first power storage device is applied via the converter unit;
The control device detects a failure of the second switch based on a voltage of the second capacitor when the second power storage device outputs an operation command for the second switch such that the second power storage device is connected to the second capacitor. And after the failure detection of the second switch is performed, the voltage of the first capacitor when the first power storage device outputs an operation command for the first switch to be connected to the first capacitor. A power supply system that detects a failure of the first switch based on A control method of a power supply system for supplying power to a load,
The power supply system includes:
A first power storage device capable of supplying power to the load;
A second power storage device connected in parallel to the first power storage device with respect to the load;
A first switch that switches between supply and interruption of power between the first power storage device and the load;
A converter unit connected to a path connecting the first switch and the load, converting a voltage output from the first power storage device and applying the voltage to the load;
A first capacitor connected in parallel with the first power storage device with respect to the converter unit in a path connecting the first switch and the converter unit;
A second switch that switches between supply and interruption of power from the second power storage device to the load;
A second capacitor connected to a path connecting the converter unit and the load, to which the voltage of the first power storage device is applied via the converter unit;
The control method includes a step of outputting an operation command of the second switch such that the second power storage device is connected to the second capacitor, and an operation command of the second switch is output. A step of detecting a failure of the second switch based on a voltage of the second capacitor; and the first storage device is connected to the first capacitor after detecting the failure of the second switch. A step of outputting an operation command of one switch, and a voltage of the first capacitor when the operation command of the first switch is output such that the first power storage device is connected to the first capacitor. And detecting the failure of the first switch.

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