JP5691919B2 - Vehicle power control device - Google Patents

Description

  The present invention relates to a vehicular power control apparatus applied to a hybrid vehicle that can be driven by any of an electric motor for driving and an internal combustion engine.

  In a conventional hybrid vehicle, a main battery that supplies power to a high voltage system load such as a starter motor and a traveling motor that starts an internal combustion engine, and a power to a low voltage system load (auxiliary machine) such as a headlight and an electronic control device And an auxiliary battery to be supplied.

  In Patent Document 1, when the amount of power stored in the main battery decreases and the power supply to the starter motor is insufficient, the main battery is charged from the auxiliary battery, and the charging is sufficiently performed. Later, control for supplying electric power from the main battery to the starting motor will be described.

Japanese Patent Laid-Open No. 11-122824

  However, when the above control is performed, the voltage of the auxiliary battery is suddenly lowered when charging from the auxiliary battery to the main battery is started, so that the operation of the auxiliary machine becomes unstable. For example, problems such as blinking of headlights and stop of operation of the electronic control device occur.

  On the other hand, if the charging power is gradually increased, the voltage of the auxiliary battery can be prevented from rapidly decreasing, and the operation of the auxiliary machine can be stabilized. However, in this case, since the charging time from the auxiliary battery to the main battery is increased by the amount that is gradually increased, the start of power supply to the starter motor is delayed and the start of the internal combustion engine is delayed.

  In addition, when the required power of the motor for traveling increases due to acceleration traveling, uphill traveling, etc., if the suppliable power of the main battery for the required power is insufficient, it may be desired to charge the auxiliary battery from the auxiliary battery. is there. In this case as well, when the charging power is gradually increased to stabilize the operation of the auxiliary machine, there is a problem that the start of power supply with respect to the required power is delayed.

  The present invention has been made to solve the above-mentioned problems, and its purpose is for a vehicle that achieves both the stabilization of the operation of the auxiliary machine and the rapid start of power supply with respect to the required power. It is to provide a power control apparatus.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

In the first aspect of the invention, the main battery that can be driven by any of the traveling electric motor and the internal combustion engine, supplies power to the starting or traveling electric motor for starting the internal combustion engine, and supplies power to the auxiliary machine. It is assumed that the present invention is applied to a hybrid vehicle including an auxiliary battery.

  And when it is determined by the power shortage determining means that determines whether or not the suppliable power of the main battery is insufficient with respect to the required power of the electric motor, and the power shortage determining means, Precharge control means for charging the main battery from an auxiliary battery, the precharge control means performing the charge while limiting the voltage change of the auxiliary battery to be within a predetermined allowable range; and the precharge control means And a simultaneous supply control means for supplying power to the electric motor from both the main battery and the auxiliary battery at the same time after the charging is completed.

  According to this, when charging the main battery from the auxiliary battery, charging is performed while limiting the voltage change of the auxiliary battery to be within a predetermined allowable range, so that the operation of the auxiliary machine becomes unstable. Can be avoided.

  Then, after charging is completed, power is supplied from both the main battery and the auxiliary battery to the electric motor at the same time, so that the burden on the main battery for the required power is reduced. Therefore, the suppliable power required for the main battery is reduced, so that the amount of charge from the auxiliary battery to the main battery can be reduced, and the end timing of the charge can be advanced. Therefore, it is possible to achieve both the stabilization of the auxiliary machine operation and the rapid start of the required power supply to the electric motor.

In a second aspect of the invention, the precharge control means performs gradual change control for starting charging so that charging power from the auxiliary battery gradually increases.

  According to the above-described invention in which the gradual change control is performed in this way, the charging power for the pre-charging is increased stepwise as illustrated in FIG. It can suppress that a voltage falls rapidly. Therefore, stabilization of auxiliary machine operation can be promoted.

According to a third aspect of the present invention, the mode switching timing is switched from a precharge mode in which power discharged from the auxiliary battery is used for charging the precharge control means to a simultaneous supply mode used for power supply in the simultaneous supply control means. When the time is set, the apparatus further comprises schedule setting means for setting the mode switching time on the basis of the storage amounts of the main battery and the auxiliary battery when the power shortage determining means determines that the power is insufficient. .

  For example, when the amount of power stored in the main battery at the start of the precharge mode is small, the time required for charging the main battery becomes longer, so the mode switching timing needs to be set later. In view of this point, in the above invention, the mode switching time is set based on the storage amount of the main battery and the auxiliary battery, and the precharge mode is switched to the simultaneous supply mode according to the set time (schedule). The mode switching time can be set so that there is no excess or deficiency.

In a fourth aspect of the invention, the schedule setting means has a value that is a sum of the suppliable power of the main battery and the suppliable power of the auxiliary battery during the simultaneous supply mode exceeds the required power. The mode switching time is set so as to match without a shortage.

  According to this, it is possible to prevent a shortage of supply power in the simultaneous supply mode while preventing the charge time in the precharge mode from becoming excessively long. Therefore, it is possible to improve the compatibility between the stabilization of the auxiliary machine operation and the rapid start of the required power supply to the electric motor.

In a fifth aspect of the invention, the simultaneous supply control unit supplies power to the electric motor while limiting the voltage change of the auxiliary battery to be within the allowable range, and from the auxiliary battery to the electric motor. When the discharged electric power is subject to the restriction, the schedule setting means sets the mode switching time in consideration of the fact that the electric power that can be supplied to the auxiliary battery is reduced due to the restriction. .

  According to the above invention, since the voltage change of the auxiliary battery is limited to be within the allowable range at the time of simultaneous supply as in the case of charging, it is possible to avoid the operation of the auxiliary machine becoming unstable during the simultaneous supply. . In addition, when the restriction at the time of simultaneous supply is implemented in this way, the power that can be supplied to the auxiliary battery is reduced during the restriction implementation period, but the charging time is lengthened so that the reduction can be compensated by the main battery. By setting, it is possible to improve the compatibility between the stabilization of the operation of the auxiliary machine and the rapid start of the required power supply to the electric motor.

According to a sixth aspect of the invention, there is provided prediction means for predicting a time when the suppliable power of the main battery becomes insufficient with respect to the required power, and the precharge control means is based on the prediction, the auxiliary battery The charging of the main battery is started.

  According to this, since charging from the auxiliary battery to the main battery can be started at an early stage, it is possible to accelerate the quick start of the required power supply to the electric motor by completing the charging at an early stage. For example, based on the current position information of the host vehicle and the travel route information to the target position that the navigation device has, the prediction can be easily realized, and the required power supply to the electric motor for travel can be started quickly. .

The figure which showed the system configuration | structure concerning 1st Embodiment of this invention. The figure explaining the technical significance of precharging and simultaneous supply in 1st Embodiment. In 1st Embodiment, the time chart explaining the basic concept of precharge and simultaneous supply. The time chart at the time of implementing gradual change control in addition to the pre-charging and simultaneous supply shown in FIG. The flowchart which shows the procedure of the process which implements precharge, gradual change control, and simultaneous supply in 1st Embodiment. The block diagram explaining the setting method of the charging / discharging schedule concerning 1st Embodiment. The time chart at the time of implementing precharge, gradual change control, and simultaneous supply in 2nd Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment in which a vehicle power control apparatus according to the present invention is applied to a parallel series hybrid vehicle will be described with reference to the drawings.

  FIG. 1 is a diagram showing a system configuration according to the present embodiment. As shown in the figure, the vehicle has a traveling engine 10 (internal combustion engine), a first motor generator (first MG11) that functions as a starter motor, and a second motor generator (second MG12) that functions as a traveling drive source. It is installed. These MGs 11 and 12 are three-phase permanent magnet synchronous motors (for example, embedded magnet synchronous motors), and the second MG 12 employs a motor having a higher output than the first MG 11. The first MG 11 corresponds to a “starting electric motor”, and the second MG 12 corresponds to a “traveling electric motor”.

  Further, the vehicle is equipped with a main battery 13 whose terminal voltage is set to a high voltage (for example, several hundreds V or more) and an auxiliary battery 14 which is set to a low voltage (for example, 12 V). For example, a lithium ion storage battery or a nickel hydride storage battery is used for the main battery 13, and a lead storage battery having a lower energy output density than the main battery 13 is used for the auxiliary battery 14.

  Main battery 13 supplies power to first MG 11 and second MG 12 via inverter 15. The auxiliary battery 14 supplies electric power to auxiliary ECUs 16 such as various ECUs 18 to 20 described later, headlights, and air conditioners. The discharge power of auxiliary battery 14 can be boosted by DCDC converter 17 and input to inverter 15 to be supplied to first MG 11 and second MG 12.

  The three-phase alternating current power generated by the first MG 11 and the second MG 12 is rectified to direct current by the inverter 15 and charged to the main battery 13, and is stepped down by the DCDC converter 17 and charged to the auxiliary battery 14. The inverter 15 includes three sets of series connection bodies of a pair of switching elements (for example, IGBT) (not shown), and the connection points of these series connection bodies are respectively connected to the U, V, and W phases of the first MG 11 and the second MG 12. It is connected.

  The motor control device (MG ECU 18) is a control device that controls the operation of the switching elements of the inverter 15 so as to control the control amounts of the first MG 11 and the second MG 12 as desired.

  The engine control device (ENGECU 19) is a control device that operates various actuators necessary for combustion control of the engine 10 and the like. The ENG ECU 19 sequentially inputs an air flow meter for detecting the amount of intake air supplied to the combustion chamber of the engine 10, a detection signal of a crank angle sensor, and the like. Based on these input signals, the engine 10 performs fuel injection control by a fuel injection valve, etc. The combustion control is performed. Specifically, the ENGECU 19 calculates an engine torque (command engine torque) based on the engine rotational speed, the engine load, and the like, and performs the combustion control to control the torque.

  The hybrid control device (HVECU 20) is a control device higher than the MGECU 18 and the ENGECU 19 (upstream side in view of a user request input from a user interface such as an accelerator pedal). The HVECU 20 calculates command values for control amounts of the engine 10, the first MG 11 and the second MG 12 based on a detection signal such as an operation amount of the accelerator pedal of the user.

  In the present embodiment, the command value for the control amount of MG 11, 12 is the command value for the generated torque of MG 11, 12 (command motor torque), and the command value for the control amount of engine 10 is the command engine torque. Then, the command motor torque is output to the MGECU 18 and the command engine torque is output to the ENGECU 19. By such a command signal, for example, while the main driving power source of the vehicle is the engine 10, the second MG 12 is used as an auxiliary driving power source, or only the engine 10 is used as the driving power source.

  Further, the HVECU 20 determines the SOC (State of charge: the ratio of the actual charge amount to the full charge amount) of the auxiliary battery 14 and the main voltage so that the voltage step-up amount and step-down amount by the DCDC converter 17 become desired values. The operation of the DCDC converter 17 is controlled according to the SOC of the battery 13 or the like. The HVECU 20 is capable of bidirectional communication with each of the MGECU 18 and the ENGECU 19.

  In the normal travel mode, the engine power is divided into two paths by the power split mechanism 21. One is a path for generating power by driving the first MG 11, and the second MG 12 is driven by this electric power. The other is a path for directly driving the drive wheels 22. Then, control is performed so that the ratio of these routes is maximized.

  In the rapid acceleration mode, power is supplied from the main battery 13 in addition to the generated power from the first MG 11. By adding the driving force of the second MG 12 together with the engine driving force, the smooth power performance with good response is exhibited and the acceleration performance is improved. Incidentally, the driving force of the second MG 12 is transmitted to the driving wheel 22 via the reduction gear 23 and the differential gear 24.

  In the deceleration braking mode, the second MG 12 is operated as a generator by the rotational force of the drive wheels 22 to regenerate the braking energy of the vehicle and charge the main battery 13. If the SOC of main battery 13 is less than the predetermined value, engine 10 is started and power is generated by first MG 11 to start charging (charging mode). In addition, when charging is started when traveling is stopped, the first MG 11 is operated as a starter and the engine 10 is started, and then the first MG 11 is operated as a generator and charged.

  By the way, when the first MG 11 is operated as a starter and the engine 10 is started, the SOC of the main battery 13 is remarkably reduced, and sufficient power cannot be supplied from the main battery 13 to operate the first MG 11 as a starter. Supplies power to the first MG 11 also using the power of the auxiliary battery 14.

  Describing in more detail with reference to FIG. 2, the power that can be supplied from the main battery 13 is insufficient with respect to the required power of the first MG 11 (starter motor) because the SOC of the main battery 13 is significantly reduced. 2 (see FIG. 2A), the pre-charging shown in FIG. 2B is performed, and then the simultaneous supply shown in FIG. 2C is performed.

  That is, in the pre-charging, the auxiliary battery 14 supplies power to the auxiliary machine 16, and boosts a part of the discharged power by the DCDC converter 17 and supplies it to the main battery 13. Thereby, the main battery 13 is charged from the auxiliary battery 14 (pre-charge), and the SOC of the main battery 13 increases. Thereafter, power is supplied (simultaneously supplied) from both the main battery 13 and the auxiliary battery 14 to the first MG 11 to operate the first MG 11 as a starter motor. The auxiliary battery 14 at the time of simultaneous supply is discharged to the auxiliary machine 16 simultaneously with the discharge to the first MG 11.

  FIG. 3 is a time chart for explaining the basic concept of the above-described precharging and simultaneous supply. The symbol PBreq in the figure represents the required power of the first MG 11 and is calculated from the command motor torque. Moreover, each of the codes | symbols PBmain and PBsub in a figure shows the electric power which can be supplied of the main battery 13 and the auxiliary | assistant battery 14 when not performing a precharge. Each of PBmain 'and PBsub' indicates a change in charge / discharge power when pre-charging is performed.

  The example shown in FIG. 3A shows a situation where PBmain + PBsub <PBreq as shown in FIG. In this case, pre-charging is started at time t0 and simultaneous supply is started at time t1. That is, auxiliary battery 14 starts discharging (charging main battery 13) at time t0 prior to time t1 when simultaneous supply is started. Note that the time (mode switching time) for switching from the mode in which pre-charging is performed (pre-charging mode) to the mode in which simultaneous supply is performed (simultaneous supply mode) corresponds to the time t1 in FIG.

  In the example of (d), the discharge power is set constant both at the time of pre-charging and at the same time of simultaneous supply. On the other hand, the main battery 13 is charged by the discharge power PBsub 'from the auxiliary battery 14 from the time t0 to the time t1, and starts discharging together with the auxiliary battery 14 from the time t1.

  The power that can be supplied from the main battery 13 is increased by the amount of increase in the SOC of the main battery 13 due to pre-charging (see arrow in (c)). As a result, in the simultaneous supply after the pre-charging, as shown in (e), PBmain '+ PBsub' = PBreq, and the engine can be started by driving the motor of the first MG11.

  However, when starting the discharge from the auxiliary battery 14 at time t0, if the discharge power PBsub ′ is raised stepwise as shown in (d), the terminal voltage of the auxiliary battery 14 is temporarily greatly reduced. As a result, there is a concern that the operation of the auxiliary machine 16 becomes unstable. For example, there is a concern that various ECUs 18 to 20 (auxiliary equipment) may be reset or the headlight (auxiliary equipment) may blink.

  Therefore, in the present embodiment, the control shown in FIG. 4 is implemented by further improving the control shown in FIG. That is, gradual change control is performed to start charging so that the discharge power from the auxiliary battery 14 (charging power to the main battery 13) gradually increases. Specifically, the rising change rate ΔPB of the discharge power PBsub ′ shown in FIG. 4B is limited to be less than a predetermined value.

  In the example of FIG. 4, the discharge power PBsub 'does not reach the target value even at time t1 when simultaneous supply is started. For this reason, the discharge power PBsub 'continues to increase until the time t2 when the target value is reached. The target value is set to a value obtained by subtracting the power supplied to the auxiliary machine 16 from the power that can be supplied from the auxiliary battery 14.

  As described above, when the simultaneous supply is started, the discharge power from the auxiliary battery 14 is gradually increased in the same manner as when the precharge is started. Therefore, the period from time t1 when simultaneous supply is started to time t2 when the discharge power PBsub ′ reaches the target value is compared with the case where the supply to the first MG 11 is performed as compared with the case where discharge is performed stepwise as shown in FIG. There is a concern that the electric power PBmain + PBsub ′ is reduced by the amount of halftone dots in FIG.

  Therefore, in the present embodiment, when the power discharged from the auxiliary battery 14 to the first MG 11 is restricted, the precharge is performed in consideration of the fact that the suppliable power of the auxiliary battery 14 is reduced due to the restriction. A period Ta is set. Specifically, the precharge period is set so that the charged amount (halftone dot area shown in FIGS. 4D and 4E) charged from the auxiliary battery 14 to the main battery 13 coincides with the halftone dot area shown in FIG. Ta is set. As a result, as shown in FIG. 4 (f), PBmain '+ PBsub' = PBreq can be established, and the concern that the supply power PBmain + PBsub 'is insufficient from the time point t1 to the time point t2 can be solved.

  FIG. 5 is a flowchart showing a processing procedure by the microcomputer included in the HVECU 20, and the above-described precharging, gradual change control, and simultaneous supply are performed by the processing.

  First, when it is determined in step S10 shown in FIG. 5 that an engine start request has occurred, the motor drive power (required power PBreq) of the first MG 11 required for engine start is calculated in the next step S11. In the subsequent step S12, the suppliable power PBmain of the main battery 13 is calculated based on the SOC and temperature of the main battery 13.

  In subsequent step S13 (power shortage determining means), it is determined whether or not the power PBmain that can be supplied from the main battery 13 is insufficient with respect to the required power PBreq, and when it is determined that there is no shortage (S13: NO). In step S14, power is supplied from the main battery 13 to the first MG 11 to drive the motor without starting precharging and simultaneous supply, and the engine 10 is started.

  On the other hand, when it is determined that PBmain is insufficient with respect to PBreq (S13: YES), the power that can be supplied from auxiliary battery 14 is determined based on the SOC and temperature of auxiliary battery 14 in the next step S15. PBsub is calculated.

  In subsequent step S16 (schedule setting means), a charge / discharge schedule is set based on the respective electric powers PBreq, PBmain, PBsub calculated in steps S11 to S15. Specifically, the mode switching time t1 or the precharge period Ta described in FIG. 4 is set, the charge / discharge power of both the batteries 13, 14 in the precharge mode, and the both batteries 13, 14 in the simultaneous supply mode are set. Set the charge / discharge power.

  This charging / discharging schedule is set so that the suppliable power PBmain '+ PBsub' from both batteries 13 and 14 during the simultaneous supply mode coincides with PBreq without excess or deficiency. In the example of FIG. 4, the precharge period Ta is set so that Ta = (1/2) × (PBsub / ΔPB). Note that PBsub in the equation represents the target value of PBsub 'described above. The rising change rate ΔPB is a fixed value set in advance, and is a value set so that the change in the terminal voltage of the auxiliary battery is within a predetermined allowable range.

  In a succeeding step S17, it is determined whether or not the elapsed time from the time point t0 at which the precharge is started has reached the precharge period Ta set in the step S16. If the precharge period Ta has not been reached (S17: NO), the discharge power of the auxiliary battery 14 is increased at the rising change rate ΔPB and the main battery 13 is charged in the next step S18 (precharge control means). The electric power is increased at the rising change rate ΔPB.

  When the precharge period Ta is reached (S17: YES), in step S19, the suppliable power PBmain '(discharge power) from the main battery 13 is calculated. In detail, the power charged from the auxiliary battery 14 is added to the suppliable power PBmain of the main battery 13 before the start of precharging.

  In the subsequent step S20 (simultaneous supply control means), the shortage of the required power PBreq of PBmain 'calculated in step S19 is discharged from the auxiliary battery 14. In subsequent step S21, the precharge mode is switched to the simultaneous supply mode by switching the discharge destination of the electric power discharged from the auxiliary battery 14 from the main battery 13 to the first MG 11. As a result, the first MG 11 can be driven by a motor with sufficient torque, and the engine can be started.

  FIG. 6 is a block diagram for explaining a method for setting a charge / discharge schedule according to the present embodiment. The contents of processing executed mainly by the HVECU 20 will be described below.

  The HVECU 20 includes various units 201 to 209 described below. The means 201 detects the presence or absence of a request for starting the engine based on information of a driver request such as an ignition switch operation or an engine start switch.

  Means 202 calculates suppliable power PBmain from main battery 13 based on the SOC and temperature of main battery 13. The means 203 calculates the suppliable power PBsub from the auxiliary battery 14 based on the SOC and temperature of the auxiliary battery 14.

  The means 204 calculates the discharge schedule of the auxiliary battery 14. Specifically, a value obtained by subtracting the power supplied to the auxiliary machine 16 (for example, the current auxiliary machine supplied power) from the suppliable power PBsub is calculated as the power used for the precharging and the simultaneous supply. The discharge schedule is calculated by limiting the change rate of the discharge so as not to exceed ΔPB so that the terminal voltage change of the auxiliary battery 14 falls within a predetermined allowable range. Then, the means 205 calculates a command value of the discharge power PBsub 'from the auxiliary battery 14 at the current time according to the discharge schedule of the auxiliary battery 14.

  The means 206 charges the main battery 13 based on the discharge schedule of the auxiliary battery 14 calculated by each means 201, 202, 204, the supplyable power PBmain from the main battery 13, and the predicted required power PBreq. Calculate the discharge schedule.

  Specifically, it is predicted to determine that the suppliable power PBmain is insufficient with respect to the required power PBreq, and to perform pre-charging before the time when it is predicted to be insufficient (time t1 in the example of FIG. 4). The battery 13 is charged. In addition, the precharge period Ta is set so that the total value of the powers PBmain and PBsub that can be supplied during the simultaneous supply mode coincides with the required power PBreq without excess or deficiency. That is, the time when the precharge period Ta has elapsed (time t1 in the example of FIG. 4) from the time when the engine start request is detected (time t0 in the example of FIG. 4) is the mode switching time (time t1 in the example of FIG. 4). ).

  The means 207 calculates the command value of the charge / discharge power PBmain 'from the main battery 13 at the current time according to the discharge schedule of the main battery 13. In the means 208, the current power (required power PBreq) required for vehicle travel, the current charge / discharge power PBmain 'of the main battery 13 calculated by the respective means 201, 205, and 207, the auxiliary battery 14 The command values (corresponding to command motor torque) to the first MG 11 and the second MG 12 and the command value for starting the engine 10 are calculated based on the current discharge power PBsub ′. The command value calculated in this way is output to MGECU 18 and ENGECU 19.

  The means 209 calculates a step-up ratio command value for the DCDC converter 17 based on the current discharge power PBsub 'of the auxiliary battery 14 calculated by the means 205. The step-up ratio command value calculated in this way is output to the DCDC converter 17.

  Next, the effect by this embodiment explained in full detail above is demonstrated below.

  In short, if only the precharge is performed without performing the gradual change control and the simultaneous supply, the terminal voltage fluctuation of the auxiliary battery 14 at the time of starting the precharge becomes large, and the operation of the auxiliary machine 16 becomes unstable. On the other hand, if the pre-charging is performed while performing the gradual change control, the operation of the auxiliary machine 16 can be stabilized. However, if the simultaneous supply is not performed, the time required for the pre-charging becomes remarkably long. It takes a long time to drive the first MG 11 after it is requested, and the engine cannot be started quickly.

  Therefore, in the present embodiment, simultaneous supply is performed in addition to performing pre-charging while performing gradual change control. According to this, it is possible to set the amount of charge for precharging the main battery 13 as much as the power is supplied from the auxiliary battery 14 to the first MG 11. Therefore, it is possible to shorten the time required for precharging while stabilizing the operation of the auxiliary machine 16.

(Second Embodiment)
In the first embodiment, power shortage to the starter motor (first MG11) at the time of starting the engine is solved, whereas in this embodiment, power shortage to the traveling electric motor (second MG12) is solved. Is intended.

  FIG. 7 is a time chart illustrating precharging, gradual change control, and simultaneous supply according to the present embodiment. The HVECU 20 always obtains the current position information of the host vehicle and the travel route information to the target position that the navigation device has, and predicts that the required power PBreq of the second MG 12 will suddenly increase due to the rapid acceleration mode or the like. To do. In the example of FIG. 7, as a result of performing the prediction at the time point t3 while the vehicle is traveling, the main battery suppliable power PBmain with respect to the required power PBreq is determined to be traveling on the uphill road from the time point t4. Predicted to be insufficient at time t4.

  That is, the dotted line in FIG. 7A represents the suppliable power PBmain of the main battery, and the PBmain is insufficient with respect to the required power PBreq indicated by the solid line. Therefore, in this embodiment, pre-charging is started at time t3 and simultaneous supply is started at time t4 (mode switching time). That is, auxiliary battery 14 starts discharging (charging main battery 13) at time t3 before time t4 when simultaneous supply is started.

  Moreover, as shown in FIG.7 (c), gradual change control is implemented also in this embodiment. That is, the discharge power from auxiliary battery 14 in the precharge mode and the simultaneous supply mode is limited so that the change rate of the discharge power is less than a predetermined value. Thereby, as shown in FIG.7 (d), the voltage change of the terminal voltage VBsub of the auxiliary battery 14 is in a predetermined allowable range. Therefore, the operation of the auxiliary machine 16 can be stabilized.

  However, when the gradual change control is performed as described above, the discharge power of the auxiliary battery 14 may not reach the maximum value immediately after the simultaneous supply mode is started. In this case, the discharge power from the main battery 13 (power supplied to the second MG 12) is increased during the period from t4 to t5 until the maximum value is reached (see FIG. 7B). The precharge period Ta is set so that this increase is possible.

In the example of FIG. 7, the simultaneous supply mode is terminated at time t6. Even at this termination, the gradual change control is performed so that the voltage change of the terminal voltage VBsub of the auxiliary battery 14 is within a predetermined allowable range. We are carrying out. Therefore, it is possible to suppress the terminal voltage VBsub from rapidly increasing with the end of the simultaneous supply mode. Therefore, for example, problems such as temporarily increasing the brightness of the headlight can be suppressed, and the operation of the auxiliary machine 16 can be stabilized even when the simultaneous supply mode ends.
In the present embodiment, as indicated by the one-dot chain line in FIG. 6, the means 201 according to the first embodiment also functions as a prediction means. That is, the means 201 (prediction means) is based on navigation information such as the current position information of the host vehicle and the travel route information to the target position, and information on the driver request such as the accelerator pedal depression amount. The current power required for traveling (required power PBreq) is calculated, and the transition of the required power PBreq when traveling on the travel route is predicted.
Further, in the present embodiment, the means 206 of FIG. 6 predicts and determines that the suppliable power PBmain is insufficient with respect to the required power PBreq, and before the time when it is predicted to be insufficient (time t4 in the example of FIG. 7). The main battery 13 is charged so as to perform pre-charging. In addition, the precharge period Ta is set so that the total value of the powers PBmain and PBsub that can be supplied during the simultaneous supply mode coincides with the required power PBreq without excess or deficiency. That is, a time point (t3 time point in the example of FIG. 7) that is a precharge period Ta before the time point t4 predicted to be insufficient is set as the precharge start time.

  Further, in the means 208, the current power (required power PBreq) required for vehicle travel, the current charge / discharge power PBmain 'of the main battery 13 and the auxiliary battery 14 calculated by the respective means 201, 205, and 207 are calculated. The command value (corresponding to the command motor torque) to the first MG 11 and the second MG 12 and the command value (corresponding to the command engine torque) to the engine 10 are calculated based on the current discharge power PBsub ′. The command value calculated in this way is output to MGECU 18 and ENGECU 19.

  As described above, according to the present embodiment, when power shortage to the electric motor for traveling (second MG 12) is predicted, in addition to performing pre-charging while performing gradual change control, simultaneous supply is performed. To do. According to this, it is possible to set the amount of charge for precharging the main battery 13 as much as power is supplied from the auxiliary battery 14 to the second MG 12. Therefore, it is possible to shorten the time required for precharging while stabilizing the operation of the auxiliary machine 16.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In FIG. 4 (b) and FIG. 7 (c), the gradual change control for gradually changing the PBsub is implemented, but the PBsub is limited so that the voltage change of the auxiliary battery is within a predetermined allowable range. If the change is made, the gradual change control may be abolished and the PBsub may be changed stepwise as shown in FIG. However, in this case, the gradual change control is more advantageous in that the voltage of the auxiliary battery 14 can be prevented from rapidly decreasing and the stabilization of the auxiliary machine operation can be promoted.

  As described above, when raising the PBsub stepwise, the PBsub may be stepped up only once as shown in FIG. 3D, or the PBsub may be raised by stepping up multiple times. Thus, if the step is raised in multiple steps, the voltage of the auxiliary battery 14 can be prevented from abruptly decreasing compared to the case where the step is raised in one step.

  In each of the above embodiments, the present invention is applied to a parallel series type hybrid vehicle. However, for example, the engine may be used only for power generation and may be applied to a series type in which traveling is performed only by an electric motor. May be applied to a parallel type in which the engine is the main body and the electric motor supports the engine output at the time of start or high load operation.

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 11 ... 1st MG (electric motor for starting), 12 ... 2nd MG (electric motor for driving), 13 ... Main battery, 14 ... Auxiliary battery, 16 ... Auxiliary machine, 201 ... Prediction means, S13 ... power shortage determination means, S16 ... schedule setting means, S18 ... pre-charge control means, S20 ... simultaneous supply control means, t1 ... mode switching timing.

Claims (6)

A main battery that can be driven by either an electric motor for traveling or an internal combustion engine and that supplies power to a starting or traveling electric motor for starting the internal combustion engine, and an auxiliary battery that supplies electric power to an auxiliary machine Applied to hybrid vehicles,
Power shortage determining means for determining whether or not the power that can be supplied from the main battery is insufficient with respect to the required power of the electric motor;
A means for charging the main battery from the auxiliary battery when the electric power shortage determining means determines that the electric power is insufficient. A voltage change of the auxiliary battery can stabilize the operation of the auxiliary machine. Pre-charging control means for performing the charging while limiting to be within a predetermined allowable range;
In order to discharge from the auxiliary battery the shortage of the required power of the main battery that can be supplied after charging by the precharge control means, after the completion of charging by the precharge control means, Simultaneous supply control means for supplying power to the electric motor simultaneously from both the main battery and the auxiliary battery while limiting the voltage change of the auxiliary battery to be within the allowable range;
A vehicle power control device comprising:   The vehicular power control apparatus according to claim 1, wherein the precharge control unit performs gradual change control for starting charging so that charging power from the auxiliary battery gradually increases. In the case where the time to switch from the precharge mode used for charging the precharge control means to the electric power discharged from the auxiliary battery to the simultaneous supply mode used for power supply of the simultaneous supply control means is a mode switching time,
The schedule setting means for setting the mode switching time based on the storage amounts of the main battery and the auxiliary battery when the power shortage determining means determines that the power is insufficient is provided. The power control apparatus for vehicles as described.   The schedule setting means is configured so that a value obtained by combining the suppliable power of the main battery and the suppliable power of the auxiliary battery during the simultaneous supply mode matches the required power without excess or deficiency. The vehicle power control device according to claim 3, wherein the mode switching time is set. When the electric power discharged from the front Kiho battery to the electric motor is subject to the restriction, in consideration of the available power of the auxiliary battery by the restriction is lower, the schedule setting means the mode The vehicle power control device according to claim 4, wherein a switching time is set. Comprising prediction means for predicting a time when the suppliable power of the main battery becomes insufficient with respect to the required power,
The vehicular power control apparatus according to any one of claims 1 to 5, wherein the precharge control unit starts charging the auxiliary battery from the auxiliary battery based on the prediction.

Images