JP5835095B2 - Hybrid vehicle and control method of hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle and a hybrid vehicle control method, and more particularly to a hybrid vehicle including a power storage device that stores electric power generated by an electric motor and a hybrid vehicle control method.

  In a hybrid vehicle including a rechargeable power storage device, a technique for limiting the charging power of the power storage device at a high temperature of the power storage device is known from the viewpoint of protecting the power storage device.

  For example, Japanese Patent Laying-Open No. 2011-79447 (Patent Document 1) discloses a hybrid travel system equipped with a rechargeable battery. This hybrid traveling system has a plurality of periods and threshold values corresponding to the charging / discharging current of the rechargeable battery, so that the sum of currents in the period or the sum of squares of currents is equal to or less than the corresponding threshold value. Limit the charge / discharge current of the rechargeable battery. Thereby, the raise of the internal resistance of a rechargeable battery can be controlled (refer to patent documents 1).

JP 2011-79447 A JP 2008-247206 A

  In the hybrid vehicle as described above, the charging power of the power storage device is composed of the generated power generated with the operation of the internal combustion engine and the regenerative power generated with the braking of the hybrid vehicle.

  However, if the generated power and regenerative power are uniformly restricted when the power storage device is at a high temperature, there is a problem that efficient operation of the internal combustion engine is hindered. For example, when the generated power is limited, the internal combustion engine may not be operated at an operating point where the internal combustion engine can efficiently generate power. Further, in a hybrid vehicle that generates power when the internal combustion engine is started, there is a case where the operating range in which the internal combustion engine can be intermittently operated is narrowed due to the generated power being limited.

  Therefore, an object of the present invention is to provide a hybrid vehicle that suppresses the inhibition of the efficient operation of the internal combustion engine when the temperature of the power storage device is high.

  Another object of the present invention is to provide a control method for a hybrid vehicle that suppresses the inhibition of efficient operation of the internal combustion engine when the temperature of the power storage device is high.

  According to this invention, the hybrid vehicle includes an internal combustion engine, at least one electric motor, a power storage device, and a control device. At least one electric motor has a power generation function and a regeneration function. The power generation function is a function that generates electric power as the internal combustion engine operates. The regeneration function is a function for performing power regeneration along with braking of the hybrid vehicle. The power storage device is charged by receiving generated power and regenerative power. The generated power is power generated by the power generation function. The regenerative power is power generated by the regenerative function. The control device is a device for controlling generated power and regenerative power. The control device increases the suppression amount of the regenerative power more than the suppression amount of the generated power at a high temperature of the power storage device where the charging power of the power storage device is suppressed.

  Preferably, the control device increases the difference between the suppression amount of the generated power and the suppression amount of the regenerative power as the temperature of the power storage device is higher.

  Preferably, the hybrid vehicle further includes a three-axis power split device. The triaxial power split device is a device for splitting power from an internal combustion engine. The electric motor includes a first electric motor and a second electric motor. The first electric motor has a power generation function. The second electric motor has a regeneration function. In the power split device, three shafts of the output shaft of the internal combustion engine, the output shaft of the first motor, and the output shaft of the second motor are mechanically coupled. The power split device is configured such that when the hybrid vehicle moves forward, the absolute value of the rotational speed of the first electric motor changes in a decreasing direction as the internal combustion engine starts. The generated electric power is electric power generated by the first electric motor in order to rotate the internal combustion engine when starting the internal combustion engine.

  Preferably, the generated electric power is electric power generated by the electric motor by power generated by the internal combustion engine.

  Preferably, the control device sets a regenerative power limit value based on the temperature of the power storage device. The control device sets a limit value for the regenerative torque output by the motor based on the limit value for the regenerative power and the rotation speed of the motor.

  Preferably, the control device sets a limit value for regenerative power based on the temperature of the power storage device and the temperature of the cooling air for cooling the power storage device. The control device sets a limit value for the regenerative torque output by the motor based on the limit value for the regenerative power and the rotation speed of the motor.

  According to the invention, the hybrid vehicle control method is a hybrid vehicle control method including an internal combustion engine, at least one electric motor, and a power storage device. At least one electric motor has a power generation function and a regeneration function. The power generation function is a function that generates electric power as the internal combustion engine operates. The regeneration function is a function for performing power regeneration along with braking of the hybrid vehicle. The power storage device is charged by receiving generated power and regenerative power. The generated power is power generated by the power generation function. The regenerative power is power generated by the regenerative function. The control method includes a step of acquiring the temperature of the power storage device, and controlling the electric motor so that the suppression amount of the regenerative power is larger than the suppression amount of the generated power at a high temperature of the power storage device where the charging power of the power storage device is suppressed. Steps.

  Preferably, the step of controlling includes a step of controlling the electric motor so that the difference between the suppression amount of the generated power and the suppression amount of the regenerative power increases as the temperature of the power storage device increases.

  Preferably, the hybrid vehicle further includes a three-shaft power split device. The triaxial power split device is a device for splitting power from an internal combustion engine. The electric motor has a first electric motor and a second electric motor. The first electric motor has a power generation function. The second electric motor has a regeneration function. In the power split device, three shafts of the output shaft of the internal combustion engine, the output shaft of the first motor, and the output shaft of the second motor are mechanically coupled. The power split device is configured such that when the hybrid vehicle moves forward, the absolute value of the rotational speed of the first electric motor changes in a decreasing direction as the internal combustion engine starts. The generated electric power is electric power generated by the first electric motor in order to rotate the internal combustion engine when starting the internal combustion engine.

  Preferably, the generated electric power is electric power generated by the electric motor by power generated by the internal combustion engine.

  Preferably, the controlling step includes a step of setting a limit value of the regenerative power based on the temperature of the power storage device, and a limit of the regenerative torque output by the motor based on the limit value of the regenerative power and the rotation speed of the motor. Setting a value.

  Preferably, the controlling step includes a step of setting a limit value of the regenerative power based on a temperature of the power storage device and a temperature of cooling air for cooling the power storage device, a limit value of the regenerative power and the rotation speed of the motor And setting a limit value of the regenerative torque output by the electric motor based on the above.

  In this invention, the control device for the hybrid vehicle can brake the hybrid vehicle at a high temperature of the power storage device in which the charging power of the power storage device is suppressed, rather than the suppression amount of the generated power generated by the operation of the internal combustion engine. Increase the amount of regenerative power that is generated. As a result, when the temperature of the power storage device is high, the regenerative power can be selectively limited to ensure an allowable amount of generated power generated with the operation of the internal combustion engine. Therefore, it is possible to suppress the operation of the internal combustion engine from being restricted by the allowable amount of the generated power. Therefore, according to the present invention, it is possible to provide a hybrid vehicle that suppresses inhibition of efficient operation of the internal combustion engine when the temperature of the power storage device is high.

1 is a block diagram showing an overall configuration of a hybrid vehicle according to Embodiment 1 of the present invention. It is a figure which shows the alignment chart of a power split device when starting cranking of an engine. It is a figure which shows the alignment chart of the power split device after the complete explosion of an engine. It is a functional block diagram regarding the regenerative brake torque control of the HVECU shown in FIG. It is the figure which showed the relationship between battery temperature and regenerative brake power limit value. 2 is a flowchart showing a control structure of processing relating to regenerative braking torque control executed by the HVECU shown in FIG. 1. It is a flowchart which shows the control structure of the process regarding the regenerative brake torque control by Embodiment 2 of this invention. It is the figure which showed the relationship between battery temperature, intake air temperature, and regenerative brake power limit value.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a block diagram showing an overall configuration of a hybrid vehicle according to Embodiment 1 of the present invention.

  Referring to FIG. 1, hybrid vehicle 1 includes front wheels 20R and 20L, rear wheels 22R and 22L, engine 2, planetary gear 16, differential gear 18, gears 4 and 6, battery 12, and boosting unit. 32, an inverter 36, a motor generator MG1, and a motor generator MG2.

  Hybrid vehicle 1 further includes a temperature sensor 24, a voltage sensor 26, a current sensor 25, a vehicle speed sensor 33, a cooling fan 13, an intake air temperature sensor 34, and a hybrid electronic control unit 14. Hereinafter, the hybrid electronic control unit 14 is also referred to as “HVECU 14”.

  The engine 2 is an internal combustion engine that outputs power by burning fuel such as a gasoline engine or a diesel engine. The HVECU 14 electrically controls the operating state such as a throttle opening (intake amount), a fuel supply amount, and an ignition timing. It is configured to be controllable.

  Planetary gear 16 has first to third rotation shafts. The first rotating shaft is connected to the engine 2. The second rotating shaft is connected to motor generator MG1. The third rotating shaft is connected to motor generator MG2.

  A gear 4 is attached to the third rotating shaft. The gear 4 transmits power to the differential gear 18 by driving the gear 6. The differential gear 18 transmits the power received from the gear 6 to the front wheels 20R and 20L. The differential gear 18 transmits the rotational force of the front wheels 20R, 20L to the third rotation shaft of the planetary gear 16 via the gears 6, 4.

  Planetary gear 16 is configured to divide the power of engine 2 into front wheels 20R, 20L and motor generators MG1, MG2. If the rotation of two of the three rotation shafts of the planetary gear 16 is determined, the rotation of the remaining one rotation shaft is naturally determined. In such a configuration, the power generation amount of motor generator MG1 and the driving force of motor generator MG2 are controlled so that engine 2 operates in the most efficient region. In this way, an overall energy efficient vehicle is realized.

  More specifically, planetary gear 16 includes a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear meshes with the sun gear and the ring gear. The carrier supports the pinion gear so that it can rotate. The sun gear is coupled to the rotation shaft of motor generator MG1. The carrier is connected to the crankshaft of the engine 2. The ring gear is coupled to the rotation shaft of motor generator MG2 and gear 4.

  FIG. 2 is a diagram showing a collinear diagram of the planetary gear 16 when cranking of the engine 2 is started. As shown in FIG. 2, the rotational speeds of engine 2 and motor generators MG <b> 1 and MG <b> 2 are connected by a straight line in the alignment chart. Therefore, when engine 2 is stopped and hybrid vehicle 1 moves forward only with the driving force of motor generator MG2, the output shaft speed of motor generator MG2 becomes positive and the output shaft speed of motor generator MG1 becomes negative. Become.

  When starting engine 2, cranking is executed using the driving force of motor generator MG1 so that the rotational speed of engine 2 changes in the positive direction. At this time, the rotational speed of motor generator MG1 changes from negative to positive, and torque of motor generator MG1 acts in the positive direction (the direction of arrow A in FIG. 2). Therefore, motor generator MG1 generates electric power while motor generator MG1 has a negative rotation speed. The electric power generated by the motor generator MG1 when starting cranking of the engine 2 is calculated as the product of the output shaft speed of the motor generator MG1 and torque when starting cranking of the engine 2.

  FIG. 3 is a collinear diagram of the planetary gear 16 after the complete explosion of the engine 2. As shown in FIG. 3, motor generator MG1 outputs a torque for maintaining the output shaft rotational speed of engine 2 at a target rotational speed after complete explosion of engine 2 (after startup). At this time, the rotational speed of motor generator MG1 is positive, and the torque of motor generator MG1 acts in the negative direction (the direction of arrow B in FIG. 3). At this time, motor generator MG1 generates power. The target rotational speed and torque of the engine 2 are selected so that the power output from the engine 2 is output efficiently.

  Referring to FIG. 1 again, the battery 12 is a direct current power source, for example, a secondary battery such as a nickel metal hydride battery or a lithium ion battery. The battery 12 supplies DC power to the boosting unit 32 and is charged by DC power from the boosting unit 32.

  The cooling fan 13 is a fan that blows air to cool the battery 12. The intake air temperature sensor 34 is a sensor that measures the intake air temperature of the cooling fan 13.

  Booster unit 32 boosts the DC voltage received from battery 12 and supplies the boosted DC voltage to inverter 36. The inverter 36 converts the supplied DC voltage into an AC voltage. At the start of engine 2, inverter 36 controls the driving force of motor generator MG1. The AC power generated by motor generator MG1 is converted into DC power by inverter 36. The converted DC power is converted into a voltage suitable for charging the battery 12 by the booster unit 32 in order to charge the battery 12.

  Inverter 36 drives motor generator MG2. Motor generator MG2 generates a driving force for driving front wheels 20R, 20L. On the other hand, at the time of braking of hybrid vehicle 1, motor generator MG2 performs a regenerative operation for converting the rotational energy of front wheels 20R, 20L into electric energy. The battery 12 is charged via the inverter 36 and the booster unit 32 by the electric energy obtained at this time.

  System main relays 28 and 30 are provided between the booster unit 32 and the battery 12. System main relays 28 and 30 shut off the high voltage circuit when the vehicle is not in operation. The battery 12 is an assembled battery and includes a plurality of battery units B0 to Bn connected in series.

  The temperature sensor 24 detects the temperature T of the battery 12 and transmits it to the HVECU 14. The voltage sensor 26 detects the inter-terminal voltages V0 to Vn of the battery units B0 to Bn and transmits them to the HVECU 14. Current sensor 25 detects current IB flowing through battery 12 and transmits it to HVECU 14.

  The HVECU 14 controls the engine 2, the inverter 36, and the booster unit 32 according to the outputs of the vehicle speed sensor 33, the intake air temperature sensor 34, the temperature sensor 24, the voltage sensor 26 and the current sensor 25. Note that the control is not limited to processing by software, and processing by dedicated hardware (electronic circuit) is also possible.

  The HVECU 14 sets an upper limit value of charging power input to the battery 12 in order to protect the battery 12. When the temperature T of the battery 12 is high, the upper limit value of the charging power is set to be low. By reducing the upper limit value of the charging power, the charging current can be suppressed, and heat generation of the battery 12 due to the charging current can be suppressed. Thereby, deterioration of the battery 12 due to the battery 12 becoming high temperature can be suppressed. The HVECU 14 controls the generated power generated by the operation of the engine 2 by controlling the start and stop of the engine 2 and the power generation amount of the motor generator MG1 based on the upper limit value of the charging power. When the temperature T of the battery 12 increases, the HVECU 14 decreases the upper limit value of the charging power and suppresses the generated power generated with the operation of the engine 2.

  Specifically, the HVECU 14 sets a vehicle speed threshold value X0 indicating a boundary of a region where the stop of the engine 2 is prohibited. When the vehicle speed detected by the vehicle speed sensor 33 exceeds the vehicle speed threshold value X0, the HVECU 14 prohibits the engine 2 from stopping after the engine 2 is started. Thereby, HVECU 14 can suppress the power generation amount generated by motor generator MG1 when starting engine 2 to be equal to or less than the power generation amount when starting engine 2 when the vehicle speed is vehicle speed threshold value X0.

  HVECU 14 controls the power generation amount of motor generator MG1 based on the SOC (State Of Charge) of battery 12. HVECU 14 sets a target rotational speed and torque at which engine 2 operates efficiently so that motor generator MG1 obtains a desired power generation amount. At this time, the range in which the target rotational speed and torque of engine 2 can be set is limited by the allowable power generation amount of motor generator MG1. Then, the allowable power generation amount of motor generator MG1 is set lower as the upper limit value of the charging power decreases as temperature T of battery 12 increases. Therefore, when temperature T of battery 12 increases, HVECU 14 limits the range in which the target rotational speed and torque of engine 2 can be set based on a decrease in the allowable amount of power generation by motor generator MG1.

  In this way, the HVECU 14 controls the generated power generated by the operation of the engine 2 by controlling the start and stop of the engine 2 and the power generation amount of the motor generator MG1.

  Hybrid vehicle 1 further includes a brake pedal sensor 60 and a brake ECU 65. The brake pedal sensor 60 detects the amount by which the driver has operated the brake pedal. The brake pedal sensor 60 transmits the detected operation amount to the brake ECU 65.

  The brake ECU 65 calculates the total braking force required for the hybrid vehicle 1 based on the operation amount received from the brake pedal sensor 60. Further, the brake ECU 65 calculates a required torque by the hydraulic brake and a required torque by the regenerative brake based on the calculated total braking force. The brake ECU 65 transmits the required torque due to the regenerative brake to the HVECU 14.

  The HVECU 14 executes regenerative brake torque control described below based on the torque requested by the regenerative brake received from the brake ECU 65.

  FIG. 4 is a functional block diagram relating to regenerative braking torque control executed by the HVECU 14 in FIG. Referring to FIG. 4, HVECU 14 includes a limit power calculation unit 110, a torque setting unit 120, and a control unit 130.

  Limit power calculation unit 110 calculates a limit value for regenerative brake power output from motor generator MG2 based on temperature T of battery 12. Specifically, the limited power calculation unit 110 receives the temperature T of the battery 12 detected by the temperature sensor 24.

  FIG. 5 is a diagram showing the relationship between the temperature T of the battery 12 and the regenerative brake power limit value. Based on the received temperature T of the battery 12, the limit power calculation unit 110 calculates the limit value of the regenerative brake power by referring to a map in which the relationship between the temperature T of the battery 12 and the regenerative brake power limit value is stored. To do. The relationship between the temperature T of the battery 12 and the regenerative brake power limit value is such that the limit value of the regenerative brake power decreases as the temperature T of the battery 12 increases. For this reason, when the regenerative power generated by the motor generator MG2 is suppressed when the temperature T of the battery 12 is high, the charging power decreases. Note that the relationship between the temperature T of the battery 12 and the regenerative brake power limit value shown in FIG. 5 is an example, and is not limited to the shape.

  At this time, the limited power calculation unit 110 is more effective in braking the hybrid vehicle 1 than the amount of generated power that is suppressed due to the operation of the engine 2 when the battery 12 is at a high temperature where the charging power of the battery 12 is suppressed. The limit value of the regenerative brake power is set so as to increase the amount of suppression of the regenerative power generated accordingly.

  The power generated by the operation of the engine 2 is generated by the motor generator MG1 by the power generated by the motor generator MG1 or the power generated by the engine 2 to rotate the engine 2 when the engine 2 is started. Electric power. The regenerative power generated along with the braking of the hybrid vehicle 1 is power generated by the motor generator MG2 during regenerative braking.

  The limit power calculation unit 110 may set the limit value of the regenerative brake power so that the difference between the suppression amount of the generated power and the suppression amount of the regenerative power increases as the temperature T of the battery 12 increases.

  Referring to FIG. 4 again, torque setting unit 120 sets the regenerative brake torque output from motor generator MG2. Specifically, torque setting unit 120 calculates a regenerative brake torque limit value based on the regenerative brake power limit value received from limit power calculation unit 110 and the rotational speed of motor generator MG2. The torque setting unit 120 sets the regenerative brake torque limit value as the regenerative brake torque when the limit value of the regenerative brake torque is smaller than the required torque by the regenerative brake received from the brake ECU 65. On the other hand, the torque setting unit 120 sets the required torque for the regenerative brake as the regenerative brake torque when the required torque for the regenerative brake received from the brake ECU 65 is less than or equal to the limit value of the regenerative brake torque.

  Control unit 130 transmits a control signal to inverter 36 and boosting unit 32 so that motor generator MG2 outputs the regenerative braking torque set by torque setting unit 120. Control unit 130 transmits the actual regenerative brake torque value output from motor generator MG2 to brake ECU 65. The brake ECU 65 receives the actual regenerative braking torque value received from the control unit 130, and controls the braking force by the hydraulic brake so that the braking force requested by the driver is output. Accordingly, when the regenerative brake torque requested by the brake ECU 65 is not output due to the HVECU 14 limiting the regenerative brake power, the brake ECU 65 can supplement the braking force with the hydraulic brake. Therefore, even when the regenerative brake power is limited, the braking force requested by the driver can be generated.

  FIG. 6 is a flowchart showing a control structure of processing related to regenerative braking torque control executed by HVECU 14 in FIG. The process described below is executed by software, hardware, or cooperation between software and hardware.

  Referring to FIG. 6, when the process is first started, HVECU 14 determines whether or not there is a regenerative brake request from brake ECU 65 at step (hereinafter, step is referred to as S) 10. Specifically, the HVECU 14 determines that there is no regenerative brake request when the required torque by the regenerative brake received from the brake ECU 65 is zero. On the other hand, the HVECU 14 determines that there is a regenerative brake request when the required torque by the regenerative brake received from the brake ECU 65 is not zero. If a negative determination is made in this process (NO in S10), the process proceeds to S20. In S20, HVECU 14 calculates a limit value for regenerative brake power output from motor generator MG2 based on temperature T of battery 12.

  On the other hand, if a positive determination is made in S10 (YES in S10), the process proceeds to S30. At S30, HVECU 14 calculates a regenerative brake torque limit value based on the regenerative brake power limit value calculated and stored at S20 and the rotational speed of motor generator MG2.

  Subsequently, at S40, the HVECU 14 sets the limit value of the regenerative brake torque as the regenerative brake torque when the limit value of the regenerative brake torque calculated at S30 is smaller than the required torque by the regenerative brake received from the brake ECU 65. . On the other hand, when the required torque by the regenerative brake received from the brake ECU 65 is equal to or less than the limit value of the regenerative brake torque calculated in S30, the HVECU 14 sets the required torque by the regenerative brake as the regenerative brake torque.

  Subsequently, at S50, the HVECU 14 controls the inverter 36 and the boosting unit 32 so that the motor generator MG2 outputs the regenerative braking torque set at S40.

  Subsequently, at S60, the HVECU 14 transmits the actual regenerative brake torque value output from the motor generator MG2 to the brake ECU 65.

  As described above, the HVECU 14 calculates the regenerative brake power limit value when the regenerative brake request is not received from the brake ECU 65, and based on the regenerative brake power limit value calculated when the regenerative brake request is received from the brake ECU 65. Set the regenerative brake torque. Thereby, while the regenerative brake request is received from the brake ECU 65, the regenerative brake power limit value is not updated, so that fluctuations in the regenerative brake torque when the regenerative brake power is limited can be suppressed. Therefore, the regenerative braking torque can be limited without impairing drivability.

  As described above, in the first embodiment, the HVECU 14 is more hybrid than the suppression amount of the generated power generated by the operation of the engine 2 when the battery 12 at which the charging power of the battery 12 is suppressed is high. The amount of suppression of regenerative power generated as the vehicle 1 is braked is increased. Thereby, when the temperature T of the battery 12 is high, the regenerative electric power can be selectively limited to ensure an allowable amount of generated electric power generated with the operation of the engine 2. Therefore, it is possible to suppress the operation of the engine 2 from being restricted by the allowable amount of generated power. Therefore, according to this Embodiment 1, when the temperature of the battery 12 is high, it can suppress that the efficient driving | operation of the engine 2 is inhibited.

  In Embodiment 1, HVECU 14 controls motor generators MG1 and MG2 so that the difference between the suppression amount of generated power and the suppression amount of regenerative power increases as temperature T of battery 12 increases. Thereby, regenerative electric power can be suppressed, so that the temperature T of the battery 12 is high. Therefore, when the temperature T of the battery 12 is high, it is possible to suppress a reduction in the allowable amount of generated power generated with the operation of the engine 2.

  In the first embodiment, hybrid vehicle 1 includes a planetary gear 16 for dividing the power from engine 2, motor generator MG1 having a power generation function, and motor generator MG2 having a regeneration function. Planetary gear 16 is mechanically coupled to three axes of the output shaft of engine 2, the output shaft of motor generator MG1, and the output shaft of motor generator MG2. Planetary gear 16 is configured such that when hybrid vehicle 1 moves forward, the absolute value of the rotational speed of motor generator MG1 changes in a decreasing direction as engine 2 is started. The generated power is power generated by the motor generator MG1 to rotate the engine 2 when the engine 2 is started. Therefore, the HVECU 14 suppresses the regenerative power generated by the braking of the hybrid vehicle 1 rather than the suppression amount of the generated power when the engine 2 is started when the battery 12 is at a high temperature where the charging power of the battery 12 is suppressed. Increase the amount. For this reason, the allowable amount of generated power when starting the engine 2 can be ensured. Therefore, it can suppress that the opportunity which can stop the driving | operation of the engine 2 reduces.

  In the first embodiment, the generated power is the power generated by motor generator MG1 by the power generated by engine 2. Therefore, the HVECU 14 generates regenerative power accompanying the braking of the hybrid vehicle 1 rather than the power generated by the motor generator MG1 by the power generated by the engine 2 when the battery 12 is at a high temperature at which the charging power of the battery 12 is suppressed. Increase the amount of suppression. For this reason, it can suppress that the output range of the engine 2 is restrict | limited by the restriction | limiting of the electric power which motor generator MG1 produces | generates. Therefore, the engine 2 can be operated at an efficient operating point.

  In the first embodiment, HVECU 14 sets a limit value for regenerative power based on temperature T of battery 12. HVECU 14 sets a limit value for the regenerative torque output from motor generator MG2 based on the limit value for regenerative power and the rotational speed of motor generator MG2. Thereby, when the battery 12 becomes high temperature, the regenerative power can be limited in accordance with the amount of heat generated by the current flowing through the battery 12. Therefore, the protection against the temperature rise of the battery 12 can be appropriately performed.

[Embodiment 2]
The second embodiment of the present invention differs from the first embodiment in the method for calculating the regenerative brake power limit value. Specifically, in the second embodiment, the regenerative brake power limit value is calculated based on the temperature T of the battery 12 and the temperature of the cooling air for cooling the battery 12. Thereby, it can prevent that regenerative electric power is restrict | limited too much.

  FIG. 7 is a flowchart showing a control structure of processing relating to regenerative braking torque control according to Embodiment 2 of the present invention.

  Referring to FIG. 7, S10 and S30 to S60 are the same as those in the first embodiment, and therefore description thereof will not be repeated.

  In S120, HVECU 14 calculates a limit value for the regenerative brake power output from motor generator MG2 based on temperature T of battery 12 and the temperature of the cooling air for cooling battery 12. The HVECU 14 receives the temperature detected by the intake air temperature sensor 34. The temperature detected by the intake air temperature sensor 34 is the temperature of the cooling air for cooling the battery 12.

  FIG. 8 is a diagram showing the relationship among the temperature T of the battery 12, the intake air temperature, and the regenerative brake power limit value. As shown in FIG. 8, when the temperature of the cooling air is low, the map is set so that the regenerative brake power limit value becomes higher when the temperature T of the battery 12 is the same as when the temperature of the cooling air is high. Yes. The HVECU 14 calculates the limit value of the regenerative brake power by referring to this map.

  As described above, in the second embodiment, the HVECU 14 sets the regenerative power limit value based on the temperature T of the battery 12 and the temperature of the cooling air for cooling the battery 12. Thereby, even when the temperature T of the battery 12 is high, when the temperature of the cooling air is low and the cooling capacity of the battery 12 is high, the restriction of the regenerative brake power can be suppressed. Therefore, according to the second embodiment, it is possible to prevent the regenerative power from being excessively limited with respect to the state of the battery 12.

  In the above embodiment, the hybrid vehicle 1 including the boosting unit 32 has been described. However, a configuration without the boosting unit 32 may be used.

  In the above embodiment, the battery 12 has been described, but a capacitor may be used instead of the battery 12.

  In the above embodiment, the series / parallel type hybrid vehicle has been described in which the power of the engine 2 can be divided and transmitted to the front wheels 20R, 20L and the motor generators MG1, MG2 by the planetary gear 16. Can be applied to other types of hybrid vehicles. That is, for example, a so-called series-type hybrid vehicle that uses the engine 2 only to drive the motor generator MG1 and generates the driving force of the vehicle only by the motor generator MG2, or regenerative energy among the kinetic energy generated by the engine 2 The present invention can also be applied to a hybrid vehicle in which only the electric energy is recovered, a motor assist type hybrid vehicle in which a motor assists the engine as the main power if necessary.

  Also in this case, when the temperature T of the battery 12 is high, it is possible to selectively limit the regenerative power and to secure an allowable amount of generated power generated with the operation of the engine 2. Therefore, it is possible to suppress the operation of the engine 2 from being restricted by the allowable amount of generated power. Therefore, when the temperature of the battery 12 is high, it can suppress that the efficient driving | operation of the engine 2 is inhibited.

  In the above description, engine 2 corresponds to an embodiment of “internal combustion engine” in the present invention, and the motor generator corresponds to an embodiment of “electric motor” in the present invention. Motor generator MG1 corresponds to an example of “first electric motor” in the present invention, and motor generator MG2 corresponds to an example of “second electric motor” in the present invention. Battery 12 corresponds to an example of “power storage device” in the present invention, and HVECU 14 corresponds to an example of “control device” in the present invention. Planetary gear 16 corresponds to an embodiment of “power split device” in the present invention.

  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 Hybrid vehicle, 2 engine, 4, 6 gear, 12 battery, 13 cooling fan, 14 HVECU, 16 planetary gear, 18 differential gear, 20R, 20L front wheel, 24 temperature sensor, 28, 30 system main relay, 32 boost unit, 33 Vehicle speed sensor, 34 Intake air temperature sensor, 36 Inverter, 60 Brake pedal sensor, 65 Brake ECU.

Claims (10)

An internal combustion engine;
At least one electric motor having a power generation function for generating electric power with the operation of the internal combustion engine and a regeneration function for performing electric power regeneration with braking of the hybrid vehicle;
A power storage device charged by receiving the generated power generated by the power generation function and the regenerative power generated by the regenerative function;
A control device for controlling the generated power and the regenerative power;
The control device is configured to increase the suppression amount of the regenerative power more than the suppression amount of the generated power at a high temperature of the power storage device in which charging power of the power storage device is suppressed .
The control device is a hybrid vehicle that increases a difference between the suppression amount of the generated power and the suppression amount of the regenerative power as the temperature of the power storage device is higher . A three-shaft power split device for splitting power from the internal combustion engine;
The motor is
A first electric motor having the power generation function;
A second electric motor having the regeneration function,
In the power split device, the output shaft of the internal combustion engine, the output shaft of the first electric motor, and the output shaft of the second electric motor are mechanically connected, and when the hybrid vehicle moves forward, The absolute value of the rotational speed of the first electric motor changes in a decreasing direction as the internal combustion engine starts,
The hybrid vehicle according to claim 1, wherein the generated electric power is electric power generated by the first electric motor to rotate the internal combustion engine when starting the internal combustion engine. The hybrid vehicle according to claim 1, wherein the generated power is power generated by the electric motor by power generated by the internal combustion engine. The control device sets a limit value of the regenerative power based on the temperature of the power storage device, and limits the regenerative torque output by the motor based on the limit value of the regenerative power and the rotation speed of the motor. The hybrid vehicle according to any one of claims 1 to 3 , wherein a value is set. The control device sets a limit value of the regenerative power based on a temperature of the power storage device and a temperature of cooling air for cooling the power storage device, and sets the limit value of the regenerative power and the rotation speed of the motor. The hybrid vehicle according to any one of claims 1 to 3 , wherein a limit value of the regenerative torque output by the electric motor is set based on A control method for a hybrid vehicle,
The hybrid vehicle
An internal combustion engine;
At least one electric motor having a power generation function for generating electric power with the operation of the internal combustion engine and a regeneration function for performing electric power regeneration with braking of the hybrid vehicle;
A power storage device charged by receiving the generated power generated by the power generation function and the regenerative power generated by the regenerative function;
The control method is:
Obtaining a temperature of the power storage device;
At a high temperature of the power storage device is charging power is suppressed of the electric storage device, it viewed including the steps of controlling the motor so that the amount of suppression of the regenerative power is larger than the suppression quantity of the generated power,
The control step includes a step of controlling the electric motor such that a difference between the suppression amount of the generated power and the suppression amount of the regenerative power increases as the temperature of the power storage device increases. . The hybrid vehicle further includes a three-shaft power split device for splitting power from the internal combustion engine,
The motor is
A first electric motor having the power generation function;
A second electric motor having the regeneration function,
In the power split device, the output shaft of the internal combustion engine, the output shaft of the first electric motor, and the output shaft of the second electric motor are mechanically connected, and when the hybrid vehicle moves forward, The absolute value of the rotational speed of the first electric motor changes in a decreasing direction as the internal combustion engine starts,
The hybrid vehicle control method according to claim 6 , wherein the generated electric power is electric power generated by the first electric motor to rotate the internal combustion engine when starting the internal combustion engine. The hybrid vehicle control method according to claim 6 , wherein the generated electric power is electric power generated by the electric motor using power generated by the internal combustion engine. The controlling step includes
Setting a limit value of the regenerative power based on the temperature of the power storage device;
The hybrid vehicle according to any one of claims 6 to 8 , further comprising a step of setting a limit value of a regenerative torque output by the electric motor based on a limit value of the regenerative electric power and a rotation speed of the electric motor. Control method. The controlling step includes
Setting a limit value for the regenerative power based on the temperature of the power storage device and the temperature of cooling air for cooling the power storage device;
The hybrid vehicle according to any one of claims 6 to 8 , further comprising a step of setting a limit value of a regenerative torque output by the electric motor based on a limit value of the regenerative electric power and a rotation speed of the electric motor. Control method.

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