JP2016063724A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle having a power source system with a high capacity type battery and a high output type battery, the vehicle being able to relieve a decrease in electric energy stored in the vehicle during external charging, which results from deterioration of the high capacity type battery.SOLUTION: The power storage capacity of a PHV battery BB is higher than the power storage capacity of an HV battery BA. The maximum power that the HV battery BA can output is greater than the maximum power that the PHV battery BB can output. The charger 51 externally charges the PHV battery BB and HV battery BA. When the battery capacity of the PHV battery BB exceeds a predetermined value, a control device 30 sets such that only the PHV battery BB is externally chargeable. When the battery capacity of the PHV battery BB is equal to or lower than the predetermined value, the controller sets such that the PHV battery BB and the HV battery BA are externally chargeable.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle, and more particularly to a vehicle equipped with a plurality of storage batteries.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2009-048662), the degree of deterioration of a plurality of secondary batteries is estimated, and the distribution of required charge / discharge power to each secondary battery is changed based on the estimation result. Thus, a technique for improving the battery life is disclosed.

JP 2009-048662 A

  In a vehicle equipped with a power supply system having a high-capacity battery and a high-power battery, conventionally, only a high-capacity battery is used when charging using a power supply external to the vehicle (hereinafter referred to as “external charging”). Was charged.

  However, when a high-capacity battery deteriorates over time, the capacity of the high-capacity battery decreases. As a result, there is a problem that the electric power stored in the vehicle is reduced by the external charging, and the electric power that can be used in the entire vehicle is reduced by executing the external charging.

  Therefore, an object of the present invention is to provide a vehicle having a power supply system having a high capacity type battery and a high output type battery. It is an object of the present invention to provide a vehicle that can alleviate a decrease caused by deterioration.

  The vehicle of the present invention includes a first storage battery and a second storage battery connected to a load, a charging device for externally charging the first storage battery and the second storage battery, and a battery capacity of the first storage battery exceeding a predetermined value. Only the first storage battery is set to be externally chargeable, and when the battery capacity of the first storage battery is equal to or less than a predetermined value, a control device is provided that sets the first storage battery and the second storage battery to be externally chargeable. The storage capacity of the first storage battery is greater than the storage capacity of the second storage battery, and the maximum power that can be output from the second storage battery is greater than the maximum power that can be output from the first storage battery.

  With this configuration, when the deterioration of the first storage battery progresses and the battery capacity becomes a predetermined value or less, both the first storage battery and the second storage battery are set to be externally chargeable. Can be reduced.

  Preferably, when the battery capacity of the first storage battery exceeds a predetermined value, the control device further increases the upper limit SOC at the time of external charging of the first storage battery according to a decrease in the battery capacity due to deterioration of the first storage battery.

  Due to the deterioration of the first storage battery, the battery capacity of the first storage battery after external charging is reduced. With this configuration, the upper limit SOC of the first storage battery is increased, thereby reducing the amount of electricity stored in the first storage battery after external charging. You can avoid it.

  Preferably, when the battery capacity of the first storage battery is equal to or less than a predetermined value, the control device further increases the upper limit SOC at the time of external charging of the second storage battery according to a decrease in the battery capacity due to deterioration of the first storage battery.

  With this configuration, the amount of power stored in the second storage battery is increased by increasing the upper limit SOC of the second storage battery. Therefore, the decrease in the amount of power stored in the entire vehicle after external charging due to deterioration of the first storage battery can be mitigated. .

  Preferably, when the battery capacity of the first storage battery is equal to or less than a predetermined value, the control device further decreases the SOC center of the second storage battery according to a decrease in the battery capacity due to deterioration of the first storage battery.

  With this configuration, since the usable capacity of the second storage battery increases when the vehicle travels due to the decrease in the SOC center of the second storage battery, the usable power of the entire vehicle after external charging due to deterioration of the first storage battery Reduction can be mitigated.

  The vehicle of the present invention includes a first storage battery and a second storage battery connected to a load, a charging device for externally charging the first storage battery and the second storage battery, and a control device. When the battery capacity of the first storage battery exceeds a predetermined value, the control device sets only the first storage battery to be externally chargeable, and at the time of external charging of the first storage battery according to a decrease in battery capacity due to deterioration of the first storage battery. The upper limit SOC is increased. The control device sets the first storage battery and the second storage battery to be externally chargeable when the battery capacity of the first storage battery is equal to or less than a predetermined value, and the second storage battery according to a decrease in the battery capacity due to deterioration of the first storage battery. The upper limit SOC at the time of external charging is increased, and the upper limit SOC at the time of external charging of the first storage battery is fixed.

  With this configuration, as the deterioration of the first storage battery progresses, the upper limit SOC of the first storage battery is increased and the upper limit SOC of the second storage battery is increased stepwise so that it can be used throughout the vehicle after external charging is performed. The electric power to be can be prevented from changing due to deterioration of the first storage battery.

  According to the vehicle of the present invention, even if the first storage battery is deteriorated, it is possible to alleviate a decrease in power that can be used in the entire vehicle after the external charging is performed.

It is a figure which shows an example of a structure of the vehicle which concerns on embodiment of this invention. It is a figure for demonstrating degradation of PHV battery BB in 1st Embodiment, and control of external charging. It is a flowchart which shows the control procedure of the external charge in 1st Embodiment. It is a figure for demonstrating deterioration of PHV battery BB in 2nd Embodiment, and control of external charging. It is a flowchart which shows the control procedure of the external charge in 2nd Embodiment. It is a figure which shows an example of a structure of the vehicle of a modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating an example of a configuration of a vehicle according to an embodiment of the present invention.

  Referring to FIG. 1, vehicle 1 includes an HV battery BA, a PHV battery BB, boost converters 12A and 12B, smoothing capacitors C1, C2 and CH, voltage sensors 10A and 10B, and current sensors 11A and 11B. Inverters 14 and 22, engine 4, motor generators MG 1 and MG 2, power split mechanism 3, wheels 2, and control device 30.

  The HV battery BA and the PHV battery BB are rechargeable storage batteries. The electric power stored in the HV battery BA and the PHV battery BB is mainly used for generating the driving force of the vehicle 1. As the HV battery BA and the PHV battery BB, for example, a secondary battery such as a lead storage battery, a nickel metal hydride battery, or a lithium ion battery, or a large capacity capacitor such as an electric double layer capacitor can be used.

  The HV battery BA is a high output battery, and the PHV battery BB is a high capacity battery. The maximum power that can be output from the HV battery BA, which is a high-power battery, is greater than the maximum power that can be output from the PHV battery BB, which is a high-capacity battery. The storage capacity of the PHV battery BB, which is a high capacity battery, is larger than the storage capacity of the HV battery BA, which is a high power battery.

  The PHV battery BB can be used, for example, when the vehicle travels in an EV (Electric Vehicle) travel mode. In the EV travel mode, the vehicle 1 travels mainly using the power of the PHV battery BB. However, when the required output of the vehicle 1 is large, the vehicle can travel using the power of the HV battery BA together.

  The HV battery BA can be used, for example, when the vehicle travels in an HV (Hybrid Vehicle) travel mode. In the HV driving mode, the vehicle 1 is driven using the electric energy output from the HV battery BA and the kinetic energy generated by the engine 4, but when the required output of the vehicle 1 is large, the PHV battery BB The vehicle 1 can be run using electric power together.

  Smoothing capacitor C1 is connected between power supply line PL1A and power supply line SL2A. Boost converter 12A boosts voltage VLA across smoothing capacitor C1.

  Smoothing capacitor C2 is connected between power supply line PL1B and power supply line SL2B. Boost converter 12B boosts voltage VLB across smoothing capacitor C2.

  Smoothing capacitor CH smoothes the voltage boosted by boost converters 12A and 12B.

  Inverter 14 converts the DC voltage applied from boost converter 12B or 12A into a three-phase AC voltage, and outputs the three-phase AC voltage to motor generator MG1, for example, to start engine 4. Inverter 14 returns the electric power generated by motor generator MG1 by the power transmitted from engine 4 to boost converters 12A and 12B. At this time, boost converters 12A and 12B are controlled by control device 30 to operate as a step-down circuit, and the electric power generated by motor generator MG1 is supplied as regenerative power to HV battery BA, and HV battery BA is regenerated. Electric power can be stored.

  Inverter 22 converts the DC voltage applied from boost converter 12B or 12A into a three-phase AC voltage, and outputs the three-phase AC voltage to motor generator MG2, for example, to start engine 4. Inverter 22 returns the electric power generated by motor generator MG2 by the power transmitted from engine 4 to boost converters 12A and 12B. At this time, boost converters 12A and 12B are controlled by control device 30 to operate as a step-down circuit, and the electric power generated by motor generator MG1 is supplied as regenerative power to HV battery BA, and HV battery BA is regenerated. Electric power can be stored.

  Power split device 3 is a mechanism that is coupled to engine 4 and motor generators MG1 and MG2 and distributes power between them.

  Vehicle 1 further includes a system main relay SMRB provided on the positive electrode side of HV battery BA, and a system main relay SMRG provided on the negative electrode side of HV battery BA.

  System main relay SMRB is connected between the positive electrode of HV battery BA and power supply line PL1. System main relay SMRG is connected between the negative electrode of HV battery BA and power supply line SL2A. System main relays SMRB and SMRG are controlled to be in a conductive / non-conductive state in accordance with a control signal supplied from control device 30.

  The voltage sensor 10A measures a voltage VBA between terminals of the HV battery BA. The current sensor 11A measures a current IBA flowing through the HV battery BA. Voltage sensor 10A and current sensor 11A are provided for monitoring the state of charge (SOC) of HV battery BA.

  When the SOC of the HV battery BA is lower than the SOC center that determines the switching between the charge control and the discharge control during traveling, the control device 30 outputs the motive power requested by the driver, When the battery BA is charged and the SOC of the current HV battery BA is higher than the SOC center, the HV battery BA is actively discharged.

  Vehicle 1 further includes a system main relay SM1B provided on the positive electrode side of PHV battery BB, and a system main relay SR that is a connection provided on the negative electrode side of PHV battery BB.

  System main relay SM1B is connected between the positive electrode of PHV battery BB and power supply line PL1B. System main relay SR is connected between the negative electrode of PHV battery BB and power supply line SL2B. System main relays SM <b> 1 </ b> B and SR are controlled to be in a conductive / non-conductive state in accordance with a control signal supplied from control device 30.

  Voltage sensor 10B measures voltage VBB between terminals of PHV battery BB. The current sensor 11B measures the current IBB flowing through the PHV battery BB. Voltage sensor 10B and current sensor 11B are provided for monitoring the state of charge (SOC) of PHV battery BB.

  Hereinafter, the state of charge (SOC) represents the “remaining capacity” of the HV battery BA or the PHV battery BB. For example, when the HV battery BA is fully charged, the SOC of the HV battery BA is defined as 100%. The SOC of the HV battery BA is defined as 0% when the HV battery BA is completely discharged. Depending on the electric power stored in the HV battery BA, the SOC of the HV battery BA changes between 0% and 100%.

  Power supply lines SL2A and SL2B extend to inverters 14 and 22 via step-up converters 12A and 12B.

  Control device 30 outputs a control signal for instructing step-up to boost converters 12A and 12B and a control signal for instructing step-down.

  Further, control device 30 outputs a control signal for instructing drive to convert the DC voltage output from boost converters 12A and 12B into an AC voltage for driving motor generator MG1 to inverter 14. Control device 30 converts the AC voltage generated by motor generator MG1 into a DC voltage, and outputs a control signal for instructing regeneration to return the DC voltage to boost converters 12A and 12B. Similarly, control device 30 outputs a control signal for instructing drive to convert the DC voltage, which is the output of boost converters 12A and 12B, into an AC voltage for driving motor generator MG2 to inverter 22. Control device 30 converts the AC voltage generated by motor generator MG2 into a DC voltage and outputs a control signal for instructing regeneration to return the DC voltage to boost converters 12A and 12B.

  Motor generators MG1 and MG2, inverters 14 and 22, boost converters 12A and 12B, and system main relays SMRB, SMRG, SM1B, and SR are powered by electric power stored in HV battery BA and PHV battery BB. A load that generates one driving force is configured.

  The vehicle 1 is configured to be capable of charging (external charging) a storage battery (that is, HV battery BA, PHV battery BB) from a power source external to the vehicle 1. For this purpose, vehicle 1 further includes a power input inlet 50, a charger 51, and a power input channel to which outputs CH1 and CH2 of charger 51 are connected.

  The power input inlet 50 is a terminal for connecting a commercial power source 90 (for example, AC 100 V) outside the vehicle to the vehicle 1. In the vehicle 1, one or both of the HV battery BA and the PHV battery BB can be charged from the commercial power supply 90 external to the vehicle 1 connected to the power input inlet 50.

  The charger 51 receives electric power given from the outside of the vehicle 1 and can supply first and second charging electric power to the HV battery BA and the PHV battery BB simultaneously. The charger 51 includes a first output CH1 that outputs the first charging power to the HV battery BA, and a second output CH2 that outputs the second charging power to the PHV battery BB.

  First output CH1 is connected to HV battery BA via charging relays 91 and 92 on a different path from system main relays SMRB and SMRG between HV battery BA and boost converter 12A.

  Second output CH2 is connected to PHV battery BB via charging relays 93 and 94 on a different path from system main relays SR1B and SR between PHV battery BB and boost converter 12B.

  Charging relays 91, 92, 93, 94 are turned on / off by a control signal from control device 30. When the charging relays 91 and 92 are in the on state, the HV battery BA can be externally charged. When the charging relays 91 and 92 are in the off state, the HV battery BA cannot be externally charged. When the charging relays 93 and 94 are on, the PHV battery BB can be externally charged. When the charging relays 93 and 94 are in the off state, the PHV battery BB cannot be externally charged.

  Here, conventional problems will be described. Conventionally, the control device 30 performs control so that only the high-capacity PHV battery BB having a large storage capacity is charged during external charging. However, when the PHV battery BB deteriorates with time, the battery capacity of the PHV battery BB decreases. As a result, there is a problem that the amount of power stored in the vehicle by external charging is reduced, and the amount of power that can be used in the entire vehicle is reduced by executing external charging.

  Therefore, in the present embodiment, control device 30 performs control so that only PHV battery BB is charged during external charging until deterioration of PHV battery BB proceeds. After the deterioration of the PHV battery BB progresses, the control device 30 performs control so that both the PHV battery BB and the HV battery BA are charged during external charging in order to alleviate the decrease in the amount of power stored by external charging.

  When charging only the PHV battery BB during external charging, the control device 30 turns off the charging relays 91 and 92, turns on the charging relays 93 and 94, and outputs the second output of the charger 51. The second charging power is output from CH2. In this case, all the electric power supplied from the outside of the vehicle 1 becomes the second charging electric power. Control device 30 stops the output of the second charging power from charger 5 when the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB.

  When charging both the HV battery BA and the PHV battery BB at the time of external charging, the control device 30 first turns on the charging relays 91 and 92, turns off the charging relays 93 and 94, and charges them. The first charging power is output from the first output CH1 of the container 51. In this case, all of the electric power supplied from the outside of the vehicle 1 becomes the first charging electric power. Control device 30 stops the output of the first charging power from charger 5 when the SOC of HV battery BA reaches the upper limit SOC of HV battery BA. After the charging of the HV battery BA is completed, the control device 30 turns on the charging relays 93 and 94, turns off the charging relays 91 and 92, and performs the second charging from the second output CH2 of the charger 51. Output power. In this case, all of the electric power given from the outside of the vehicle 1 becomes the second charging electric power. Control device 30 stops the output of the second charging power from charger 5 when the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB.

  Instead of this, when charging both the HV battery BA and the PHV battery BB during external charging, the control device 30 turns on the charging relays 91, 92, 93, 94 and The first charging power may be output from the first output CH1, and the second charging power may be output from the second output CH2 of the charger 51. In this case, the electric power given from the outside of the vehicle 1 is distributed to the first charging power and the second charging power.

  FIG. 2 is a diagram for explaining deterioration of the PHV battery BB and control of external charging in the first embodiment.

As shown in FIG. 2, the battery capacity of the PHV battery BB decreases with time.
When the battery capacity of PHV battery BB exceeds TH1 (kWh), upper limit SOC during external charging of PHV battery BB is maintained at a fixed value yb1 (for example, 80%). That is, the PHV battery BB is charged to yb1 in a fully charged state. In this range, the fixed value yb1 is maintained in this way because the amount of decrease in the battery capacity of the PHV battery BB accompanying the deterioration of the PHV battery BB is small, and thus the amount of decrease in the amount of electricity stored in the vehicle during external charging is ignored. This is because it is as few as possible.

  When the battery capacity of the PHV battery BB becomes equal to or lower than TH1, the upper limit SOC when the PHV battery BB is externally charged by an amount corresponding to the decrease in the battery capacity of the PHV battery BB so as not to decrease the storage amount of the PHV battery BB. Increase. Thereby, even if the PHV battery BB is deteriorated, the charged amount of the PHV battery BB after the external charging is performed, that is, the usable power can be kept constant. As a result, the usable electric power of the entire vehicle after execution of external charging can be kept constant.

  Let TH2 (kWh) be the battery capacity of the PHV battery BB when the upper limit SOC at the time of external charging of the PHV battery BB is yb2 (for example, 100%).

  In order to compensate for the decrease in the amount of electricity stored in the PHV battery BB, the HV battery BA is set to be externally chargeable when the battery capacity of the PHV battery BB becomes equal to or less than TH2.

  The upper limit SOC at the time of external charging of the HV battery BA when the battery capacity of the PHV battery BB is TH2 is defined as ya1. When the battery capacity of the PHV battery BB decreases from TH2, the upper limit SOC when the HV battery BA is externally charged is increased by an amount corresponding to the decrease in the battery capacity of the PHV battery BB in order to compensate for the decrease in the charged amount of the PHV battery BB. increase. As a result, even if the PHV battery BB deteriorates, the amount of electricity stored in the HV battery BA after the external charging is performed, that is, the usable power increases. As a result, the usable electric power of the entire vehicle after execution of external charging can be kept constant.

  The upper limit SOC at the time of external charging of the HV battery BA when the battery capacity of the PHV battery BB reaches TH3 (kWh) is assumed to be ya2 (for example, 100%).

  When the upper limit SOC of the HV battery BA is larger than ya2, the deterioration of the HB battery BA is accelerated due to overcharge. Therefore, the upper limit SOC at the time of external charging of the HV battery BA when the battery capacity of the PHV battery BB is TH3 or less is fixed to ya2. To do. That is, priority is given to protection of the HV battery BA, and a reduction in the amount of usable electric power of the entire vehicle after external charging is allowed.

  In the above description, when the battery capacity of the PHV battery BB is larger than TH2, the HV battery BA is set to be non-externally chargeable only by externally charging only the PHV battery BB. This is because, for example, a desired travel distance) can be ensured. Further, there are cases where it is preferable to keep the amount of usable electric power of the entire vehicle after external charging as constant as possible throughout the year and to keep the performance of the vehicle constant.

FIG. 3 is a flowchart showing a control procedure of external charging in the first embodiment.
First, in step S100, the control device 30 detects the battery capacity of the PHV battery BB. For example, the battery capacity of the PHV battery BB can be detected using the charge current integrated value when the PHV battery BB is discharged until the charging rate reaches 0% and then fully charged.

  When the capacity of the PHV battery BB exceeds the threshold value TH1 (step S101: YES), the process proceeds to step S102.

  In step S102, control device 30 sets upper limit SOC at the time of external charging of PHV battery BB to fixed value yb1.

  In step S103, control device 30 sets PHV battery BB to be externally chargeable.

  In step S104, control device 30 sets HV battery BA to be externally chargeable.

  On the other hand, when the capacity of the PHV battery BB exceeds a threshold value TH2 (a value obtained in advance as the capacity of the PHV battery BB when the upper limit SOC of the PHV battery BB is yb2) and is equal to or less than the threshold value TH1 (step S101: NO, step In S105: YES, the process proceeds to step S106.

  In step S106, the control device 30 increases the upper limit SOC at the time of external charging of the PHV battery BB according to the decrease in the capacity of the PHV battery BB, so that the storage amount of the PHV battery BB after the external charging is performed, that is, the usage Keep the possible power constant.

  Specifically, the control device 30 includes the usable power P1 after external charging of the PHV battery BB when the capacity of the PHV battery BB is TH1, and the capacity of the PHV battery BB is x (TH1 ≦ x ≦ TH2). The upper limit SOC at the time of external charging of the PHV battery BB with respect to the current capacity of the PHV battery BB is obtained using the map 1 determined so that the available power Px after the external charging of the PHV battery BB is the same. .

  In step S107, control device 30 sets PHV battery BB to be externally chargeable.

  In step S108, control device 30 sets HV battery BA to be externally chargeable.

  On the other hand, when the capacity of the PHV battery BB exceeds the threshold value TH3 (a value obtained in advance as the capacity of the PHV battery BB when the upper limit SOC of the HV battery BA is ya2) and is equal to or less than the threshold value TH2 (step S101: NO, step In S105: NO, step S109: YES, the process proceeds to step S110.

  In step S110, control device 30 determines upper limit SOC at the time of external charging of PHV battery BB as upper limit value yb2 (the PHV battery BB when the capacity of PHV battery BB is TH2, which can be obtained using map 1 described above). To the upper limit SOC at the time of external charging.

  In step S111, control device 30 sets PHV battery BB to be externally chargeable.

  In step S112, control device 30 sets HV battery BA to be externally chargeable.

  In step S113, control device 30 increases upper limit SOC at the time of external charging of HV battery BA according to the decrease in capacity of PHV battery BB.

  Specifically, the control device 30 determines the usable power after external charging of the PHV battery BB when the capacity of the PHV battery BB is x (TH2 ≦ x ≦ TH3) and the capacity of the PHV battery BB is TH2. The difference db between the usable power after external charging of the PHV battery BB and the usable power PA after external charging of the HV battery BA when the capacity of the PHV battery BB is x are determined to be the same. Using map 2, the upper limit SOC at the time of external charging of HV battery BA with respect to the current capacity of PHV battery BB is obtained.

  When the capacity of the PHV battery BB is equal to or less than the threshold value TH3 (step S101: NO, step S105: NO, step S109: NO), the process proceeds to step S114.

  In step S114, control device 30 sets upper limit SOC at the time of external charging of PHV battery BB to upper limit value yb2.

  In step S115, control device 30 sets PHV battery BB to be externally chargeable.

  In step S116, control device 30 sets HV battery BA to be externally chargeable.

  In step S117, control device 30 determines upper limit SOC at the time of external charging of HV battery BA as upper limit value ya2 (HV battery BA when capacity of PHV battery BB is TH3, which can be obtained using map 2 described above. To the upper limit SOC at the time of external charging.

  In step S118, control device 30 controls charger 51 to execute external charging. When only the PHV battery BB is set to be externally chargeable, the control device 30 turns off the charging relays 91 and 92, turns on the charging relays 93 and 94, and turns on the second of the charger 51. The first charging power is output from the output CH2. When the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB, control device 30 ends the external charging.

  When both HV battery BA and PHV battery BB are set to be externally chargeable, control device 30 turns charging relays 91 and 92 on, turns charging relays 93 and 94 off, and charges The first charging power is output from the first output CH1 of the container 51. When the SOC of the HV battery BA reaches the upper limit SOC of the HV battery BA, the control device 30 ends the external charging to the HV battery BA. Thereafter, control device 30 turns charging relays 93 and 94 on, turns charging relays 91 and 92 off, and outputs second charging power from second output CH <b> 2 of charger 51. When the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB, control device 30 ends the external charging.

  As described above, according to the present embodiment, when the battery capacity of the PHV battery exceeds a predetermined value (TH2), only the PHV battery is set to be externally chargeable, and the battery capacity is reduced due to deterioration of the PHV battery. Accordingly, the upper limit SOC during external charging of the PHV battery is increased. In addition, when the battery capacity of the PHV battery is equal to or less than a predetermined value (TH2), the PHV battery and the HV battery are set to be externally chargeable, and at the time of external charging of the HV battery according to the decrease in the battery capacity due to deterioration of the PHV battery. Increase the upper limit SOC. As a result, the power that can be used in the entire vehicle after the external charging is performed can be prevented from changing due to deterioration of the PHV battery.

[Second Embodiment]
In the first embodiment, when the PHV battery capacity is equal to or lower than TH2, the PHV battery capacity is decreased in order to prevent the electric power that can be used in the entire vehicle after the external charging is performed due to the deterioration of the PHV battery. Accordingly, the configuration for increasing the upper limit SOC of the HV battery BA has been described. In contrast, in the present embodiment, the upper limit SOC of HV battery BA is assumed to be a constant value, and instead, a configuration in which the SOC center of HV battery BA is reduced will be described.

  FIG. 4 is a diagram for explaining deterioration of the PHV battery BB and control of external charging in the second embodiment.

As shown in FIG. 4, the battery capacity of the PHV battery BB decreases with time.
When the battery capacity of PHV battery BB exceeds TH1 (kWh), upper limit SOC during external charging of PHV battery BB is maintained at a fixed value yb1 (for example, 80%). That is, the PHV battery BB is charged to yb1 in a fully charged state. In this range, the fixed value yb1 is maintained in this way because the amount of decrease in the battery capacity of the PHV battery BB accompanying the deterioration of the PHV battery BB is small, and thus the amount of decrease in the amount of electricity stored in the vehicle during external charging is ignored. This is because it is as few as possible.

  When the battery capacity of the PHV battery BB becomes equal to or lower than TH1, the upper limit SOC when the PHV battery BB is externally charged by an amount corresponding to the decrease in the battery capacity of the PHV battery BB so as not to decrease the storage amount of the PHV battery BB. Increase. Thereby, even if the PHV battery BB is deteriorated, the charged amount of the PHV battery BB after the external charging is performed, that is, the usable power can be kept constant. As a result, the usable electric power of the entire vehicle after execution of external charging can be kept constant.

  Let TH2 (kWh) be the battery capacity of the PHV battery BB when the upper limit SOC at the time of external charging of the PHV battery BB is yb2 (for example, 100%).

  The upper limit SOC at the time of external charging of the PHV battery BB when the battery capacity of the PHV battery BB is equal to or less than TH2 is fixed to yb2. Then, in order to compensate for the decrease in the charged amount of the PHV battery BB, the HV battery BA is set to be externally chargeable when the battery capacity of the PHV battery BB becomes equal to or less than TH2.

  The SOC center of the HV battery BA when the battery capacity of the PHV battery BB is TH2 is yc1. When the battery capacity of the PHV battery BB decreases from TH2, the SOC center of the HV battery BA is decreased by an amount corresponding to the decrease in the battery capacity of the PHV battery BB in order to compensate for the decrease in the charged amount of the PHV battery BB. As a result, even if the PHV battery BB deteriorates, the usable power of the HV battery BA after the external charging is performed increases. As a result, the usable electric power of the entire vehicle after execution of external charging can be kept constant.

  It is assumed that the SOC center of the HV battery BA is yc2 (for example, 40%) when the battery capacity of the PHV battery BB reaches TH3 (kWh).

  If the SOC center of the HV battery BA is made smaller than yc2, regenerative electric power is difficult to accumulate during traveling. Therefore, the SOC center of the HV battery BA when the battery capacity of the PHV battery BB is TH3 or less is fixed to yc2. That is, priority is given to regeneration to the HV battery BA, and a reduction in the amount of usable electric power of the entire vehicle after external charging is allowed.

FIG. 5 is a flowchart showing a control procedure of external charging in the second embodiment.
First, in step S200, control device 30 detects the battery capacity of PHV battery BB. For example, the battery capacity of the PHV battery BB can be detected using the charge current integrated value when the PHV battery BB is discharged until the charging rate reaches 0% and then fully charged.

  When the capacity of the PHV battery BB exceeds the threshold value TH1 (step S201: YES), the process proceeds to step S202.

  In step S202, control device 30 sets upper limit SOC at the time of external charging of PHV battery BB to fixed value yb1.

  In step S203, control device 30 sets PHV battery BB to be externally chargeable.

  In step S204, control device 30 sets HV battery BA to be externally chargeable.

  On the other hand, when the capacity of the PHV battery BB exceeds the threshold value TH2 (a value obtained in advance as the capacity of the PHV battery BB when the upper limit SOC of the PHV battery BB is yb2) and is equal to or less than the threshold value TH1 (step S201: NO, step In S205: YES, the process proceeds to step S206.

  In step S206, the control device 30 increases the upper limit SOC at the time of external charging of the PHV battery BB according to the decrease in the capacity of the PHV battery BB, so that the storage amount of the PHV battery BB after the external charging is performed, that is, the usage Keep the possible power constant.

  Specifically, the control device 30 includes the usable power P1 after external charging of the PHV battery BB when the capacity of the PHV battery BB is TH1, and the capacity of the PHV battery BB is x (TH1 ≦ x ≦ TH2). The upper limit SOC at the time of external charging of the PHV battery BB with respect to the current capacity of the PHV battery BB is obtained using the map 1 determined so that the available power Px after the external charging of the PHV battery BB is the same. .

  In step S207, control device 30 sets PHV battery BB to be externally chargeable.

  In step S208, control device 30 sets HV battery BA to be externally chargeable.

  On the other hand, when the capacity of the PHV battery BB exceeds a threshold value TH3 (a value obtained in advance as the capacity of the PHV battery BB when the upper limit SOC of the HV battery BA is yc2) and is equal to or less than the threshold value TH2 (step S201: NO, step In S205: NO, step S209: YES, the process proceeds to step S210.

  In step S210, control device 30 determines upper limit SOC at the time of external charging of PHV battery BB as upper limit value yb2 (PHV battery BB when the capacity of PHV battery BB is TH2 can be obtained using map 1 described above. To the upper limit SOC at the time of external charging.

  In step S211, control device 30 sets PHV battery BB to be externally chargeable.

  In step S212, control device 30 sets HV battery BA to be externally chargeable.

  In step S213, control device 30 decreases the SOC center of HV battery BA in accordance with the decrease in the capacity of PHV battery BB.

  Specifically, the control device 30 determines the usable power after external charging of the PHV battery BB when the capacity of the PHV battery BB is x (TH2 ≦ x ≦ TH3) and the capacity of the PHV battery BB is TH2. The difference db between the usable power after external charging of the PHV battery BB and the usable power PA after external charging of the HV battery BA when the capacity of the PHV battery BB is x are determined to be the same. Map 2 is used to determine the SOC center of HV battery BA with respect to the current capacity of PHV battery BB.

  When the capacity of the PHV battery BB is equal to or less than the threshold value TH3 (step S201: NO, step S205: NO, step S209: NO), the process proceeds to step S214.

  In step S214, control device 30 sets upper limit SOC at the time of external charging of PHV battery BB to upper limit value yb2.

  In step S215, control device 30 sets PHV battery BB to be externally chargeable.

  In step S216, control device 30 sets HV battery BA to be externally chargeable.

  In step S217, control device 30 determines the SOC center of HV battery BA as lower limit value yc2 (the center of SOC of HV battery BA when the capacity of PHV battery BB is TH3, which can be obtained using map 2 described above). Set to.

  In step S218, control device 30 controls charger 51 to execute external charging.

  When only the PHV battery BB is set to be externally chargeable, the control device 30 turns off the charging relays 91 and 92, turns on the charging relays 93 and 94, and turns on the second of the charger 51. The first charging power is output from the output CH2. When the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB, control device 30 ends the external charging.

  When both HV battery BA and PHV battery BB are set to be externally chargeable, control device 30 turns charging relays 91 and 92 on, turns charging relays 93 and 94 off, and charges The first charging power is output from the first output CH1 of the container 51. When the SOC of the HV battery BA reaches the upper limit SOC of the HV battery BA, the control device 30 ends the external charging to the HV battery BA. Thereafter, control device 30 turns charging relays 93 and 94 on, turns charging relays 91 and 92 off, and outputs second charging power from second output CH <b> 2 of charger 51. When the SOC of PHV battery BB reaches the upper limit SOC of PHV battery BB, control device 30 ends the external charging.

  After the external charging is completed, when the SOC of the HV battery BA is lower than the SOC center during driving, the control device 30 charges the HV battery BA when there is a margin after outputting the power required by the driver. When the SOC of the current HV battery BA is higher than the SOC center, the HV battery BA is actively discharged. Here, in steps S213 and S217 of FIG. 5, when the battery capacity of the PHV battery BB is equal to or lower than TH2, the SOC center of the HV battery is set low, so that the discharge amount of the HV battery BA increases. As a result, the PHV When the battery capacity of the battery BB deteriorates to the threshold value TH2 or less, it is possible to mitigate a decrease in the amount of power that can be used by the entire vehicle after execution of external charging.

  As described above, according to the present embodiment, when the battery capacity of the PHV battery exceeds a predetermined value (TH2), only the PHV battery is set to be externally chargeable, and the battery capacity is reduced due to deterioration of the PHV battery. Accordingly, the upper limit SOC during external charging of the PHV battery is increased. In addition, when the battery capacity of the PHV battery is equal to or less than a predetermined value (TH2), the PHV battery and the HV battery are set to be externally chargeable, and the SOC center of the HV battery is reduced according to the decrease in the battery capacity due to the deterioration of the PHV battery. Let As a result, the power that can be used in the entire vehicle after the external charging is performed can be prevented from changing due to deterioration of the PHV battery.

  In the embodiment of the present invention, the PHV battery capacity is used (TH1 ≧ PHV battery capacity> TH2) in the determination of S105 of the flowchart of FIG. 3 and the flowchart S205 of FIG. Instead, the upper limit SOC of the PHV battery may be used. That is, instead of TH1 ≧ PHV battery capacity> TH2, yb1 ≦ PHV battery upper limit SOC <yb2 may be used.

  Similarly, in the embodiment of the present invention, the PHV battery capacity is used in the determination of S109 in the flowchart of FIG. 3 (TH2 ≧ PHV battery capacity> TH3). Instead, the upper limit SOC of the HV battery may be used. That is, instead of TH2 ≧ PHV battery capacity> TH3, ya1 ≦ HV battery upper limit SOC <ya2 may be used.

  Similarly, in the embodiment of the present invention, the battery capacity of PHV is used in the determination of S209 in the flowchart of FIG. 5 (TH2 ≧ PHV battery capacity> TH3). Instead, the SOC center of the HV battery may be used. That is, instead of TH2 ≧ PHV battery capacity> TH3, yc2 <HV SOC center ≦ yc1 may be used.

  In the embodiment of the present invention, power can be supplied from the charger to both the HV battery BA and the PHV battery BB. However, the present invention is not limited to this.

FIG. 6 is a diagram illustrating a configuration of a vehicle according to a modification.
As shown in FIG. 6, as in the embodiment, when charging the PHV battery BB, the charge relays 93 and 94 are turned on, and power is supplied from the charger 551 to the PHV battery BB.

  On the other hand, when charging HV battery BA, charging relays 93 and 94 and system main relays SM1B, SR, SMRB, and SMRG are turned on, and HV battery is sequentially passed from charger 551 through boost converter 12-B and boost converter 12A. Boost converters 12A and 12B operate so that power flows to BA.

  In the present embodiment, when the capacity of the PHV battery BB is equal to or less than the threshold value TH1, the upper limit SOC at the time of external charging of the PHV battery BB is set to the fixed value yb1, but this is not limitative. is not. Even when the capacity of the PHV battery BB is equal to or less than the threshold value TH1, the storage of the PHV battery BB after the external charging is performed by increasing the upper limit SOC at the time of external charging of the PHV battery BB according to the decrease in the capacity of the PHV battery BB. The amount, i.e. the available power, may be kept constant.

  The embodiments disclosed this time are also scheduled to be implemented in appropriate combinations. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  1 vehicle, 2 wheels, 3 power split mechanism, 4 engine, 10A, 10B voltage sensor, 11A, 11B current sensor, 12A, 12B boost converter, 14, 22 inverter, 30 control device, 50 power input inlet, 51,551 charging 91-94 charging relay, BA HV battery, BB PHV battery, C1, C2, CH smoothing capacitor, MG1, MG2 motor generator, PL1A, PL1B, PL2 power line, SL2A, SL2B power line, SMRB, SMRG, SM1B , SR System main relay.

Claims (5)

A first storage battery and a second storage battery connected to a load;
A charging device for externally charging the first storage battery and the second storage battery;
When the battery capacity of the first storage battery exceeds a predetermined value, only the first storage battery is set to be externally chargeable, and when the battery capacity of the first storage battery is less than the predetermined value, the first storage battery and the second storage battery A control device for setting the storage battery to be externally chargeable,
The storage capacity of the first storage battery is greater than the storage capacity of the second storage battery, and the maximum power that can be output from the second storage battery is greater than the maximum power that can be output from the first storage battery.   When the battery capacity of the first storage battery exceeds the predetermined value, the control device further increases the upper limit SOC during external charging of the first storage battery according to a decrease in battery capacity due to deterioration of the first storage battery. The vehicle according to claim 1.   When the battery capacity of the first storage battery is less than or equal to the predetermined value, the control device further increases the upper limit SOC at the time of external charging of the second storage battery according to a decrease in battery capacity due to deterioration of the first storage battery. The vehicle according to claim 1.   The control device further reduces the SOC center of the second storage battery when the battery capacity of the first storage battery is less than or equal to the predetermined value, according to a decrease in battery capacity due to deterioration of the first storage battery. The vehicle according to 1. A first storage battery and a second storage battery connected to a load;
A charging device for externally charging the first storage battery and the second storage battery;
A control device,
The controller is
When the battery capacity of the first storage battery exceeds a predetermined value, only the first storage battery is set to be externally chargeable, and when the first storage battery is externally charged according to a decrease in battery capacity due to deterioration of the first storage battery. When the battery capacity of the first storage battery is less than or equal to the predetermined value, the first storage battery and the second storage battery are set to be externally chargeable, and the battery capacity due to deterioration of the first storage battery is set. A vehicle that increases the upper limit SOC during external charging of the second storage battery and fixes the upper limit SOC during external charging of the first storage battery according to a decrease.

Images