JP2013154706A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent battery voltage from easily reaching below an acceptable lower limit voltage for control.SOLUTION: When warming of purifying catalyst is demanded and the driving power Pdrv* is larger than output limit for control Wout* of high voltage battery, difference power (Pdrv*-Wout*) derived by subtracting the output limit for control Wout* from the driving power Pdrv* is output from an engine, and the engine and a motor are controlled so that a vehicle is driven by the driving power Pdrv*. In case the inter-terminal voltage Vb of the high voltage battery is not higher than a threshold voltage Vbref which is higher than an acceptable lower limit voltage Vbmin (S320), a control current limit Ibmax* and the output limit for control Wout* are made smaller than these before the inter-terminal voltage Vb of high voltage battery is not higher than the threshold voltage Vbref (S360, S370).

Description

  The present invention relates to a hybrid vehicle, and more particularly, an engine in which a purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system and capable of outputting traveling power, and a motor capable of inputting and outputting traveling power. The present invention relates to a hybrid vehicle including a motor and a battery capable of exchanging electric power.

  Conventionally, in this type of hybrid vehicle, an engine in which an exhaust pipe is provided with a catalyst capable of generating a driving force and purifying exhaust gas, a first motor generator, a path for driving the engine to a driving shaft, A power split mechanism that divides the path to one motor generator, a second motor generator that can output power to the drive shaft, and a battery that exchanges power with the first motor generator and the second motor generator. When the warm-up of the vehicle is required, there has been proposed one that performs warm-up running of the vehicle using the driving force from the second motor generator using the electric power from the battery (see, for example, Patent Document 1). . In this hybrid vehicle, in a region where the amount of charge of the battery is below the lower limit of the predetermined reference range, the discharge power of the battery is increased by setting the discharge allowable power during warm-up travel greater than that during normal travel. By satisfying the battery power required for traveling, the driving force required for traveling of the vehicle can be provided only by the driving force from the second motor generator.

JP 2008-285116 A

  In the above-described hybrid vehicle, the discharge allowable power is relatively large although the charge amount of the battery is low, so the battery voltage may reach the control lower limit voltage or less relatively quickly. It is preferable to avoid such a situation as much as possible, because if the battery voltage drops too much, it may lead to accelerated battery deterioration.

  The main purpose of the hybrid vehicle of the present invention is to make it difficult for the battery voltage to reach an allowable lower limit voltage for control.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The first hybrid vehicle of the present invention is
A purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system so as to output driving power, a motor capable of inputting / outputting driving power, and a battery capable of exchanging electric power with the motor And the difference power obtained by subtracting the control output limit from the travel power when the travel power required for travel is greater than the control output limit for the battery. Is output from the engine, and the output power from the battery is equal to or lower than the control output limit, and comprises catalyst warm-up request control means for controlling the engine and the motor so as to run with the running power. In hybrid cars,
When the battery voltage falls below a threshold voltage that is higher than the allowable lower limit voltage for control, the catalyst warm-up request control means limits the control output limit compared to before the battery voltage falls below the threshold voltage. A means to make it smaller,
This is the gist.

  In the first hybrid vehicle of the present invention, when the warm-up request for the purification catalyst is made and the travel power required for travel is greater than the battery control output limit, the control output limit is subtracted from the travel power. The difference power obtained in this way is output from the engine, the output power from the battery is less than the control output limit, and the engine and the motor are controlled to run with the running power. When the voltage becomes lower than the higher threshold voltage, the control output limit is made smaller than before the battery voltage becomes lower than the threshold voltage. As a result, when the battery voltage falls below the threshold voltage, the proportion of the output from the engine is increased and the proportion of the output from the battery is reduced in the driving power compared to before the battery voltage falls below the threshold voltage. Therefore, it is possible to make it difficult for the battery voltage to reach the allowable lower limit voltage or less as compared with the case where the control output limit is not reduced (the time until the battery voltage can be extended). Here, the “allowable lower limit voltage” may be a voltage higher than the protection lower limit voltage that should be strictly observed in order to protect the battery.

  In such a first hybrid vehicle of the present invention, the catalyst warm-up request time control means is configured to perform the step-by-step in order of when the battery voltage falls below the threshold voltage or below the allowable lower limit voltage. It can also be a means for reducing the control output limit.

  Further, in the first hybrid vehicle of the present invention, the catalyst warm-up request control means holds the control output limit when the battery voltage becomes higher than the threshold voltage after becoming lower than the threshold voltage. It can also be a means to do. This is based on the reason that when the battery voltage becomes equal to or lower than the threshold voltage, it is considered that the battery voltage is likely to decrease even if the battery voltage subsequently becomes higher than the threshold voltage.

  Furthermore, in the first hybrid vehicle of the present invention, the catalyst warm-up request time control means is configured such that when the traveling power is larger than the control output limit for the battery, the output power from the battery is the control output limit. And a control means for controlling the output current from the battery to be less than or equal to the control current limit of the battery. Further, the catalyst warm-up request time control means has the battery voltage less than or equal to the threshold voltage. In this case, the control output limit and the control current limit may be made smaller than before the battery voltage becomes equal to or lower than the threshold voltage.

The second hybrid vehicle of the present invention is
A purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system so as to output driving power, a motor capable of inputting / outputting driving power, and a battery capable of exchanging electric power with the motor And the difference power obtained by subtracting the control output limit from the travel power when the travel power required for travel is greater than the control output limit for the battery. Is output from the engine, and the output power from the battery is less than or equal to the control output limit, and the output current from the battery is less than or equal to the control current limit for the battery, so that the engine travels with the travel power. And a catalyst warm-up request control means for controlling the motor,
When the battery voltage falls below a threshold voltage higher than the control allowable lower limit voltage, the catalyst warm-up request control means performs the control current limit compared to before the battery voltage falls below the threshold voltage. A means to make it smaller,
This is the gist.

  In the second hybrid vehicle of the present invention, when the warm-up request for the purification catalyst is made and the travel power required for travel is greater than the battery control output limit, the control output limit is subtracted from the travel power. The difference power obtained in this way is output from the engine, the output power from the battery is less than or equal to the control output limit, and the output current from the battery is less than or equal to the control current limit for the battery so When the battery voltage falls below the threshold voltage higher than the control allowable lower limit voltage, the control current limit is made smaller than before the battery voltage falls below the threshold voltage. As a result, when the battery voltage falls below the threshold voltage, the proportion of the output from the engine is increased and the proportion of the output from the battery is reduced in the driving power compared to before the battery voltage falls below the threshold voltage. Therefore, it is possible to make it difficult for the battery voltage to reach the allowable lower limit voltage or less as compared with the case where the control current limit is not reduced (the time until the battery voltage can be extended). Here, the “allowable lower limit voltage” may be a voltage higher than the protection lower limit voltage that should be strictly observed in order to protect the battery.

  In the first or second hybrid vehicle of the present invention, the catalyst warm-up request time control means is stepwise in the order of when the battery voltage falls below the threshold voltage or below the allowable lower limit voltage. It is also possible to use a means for reducing the control current limit.

  In the first or second hybrid vehicle of the present invention, when the catalyst warm-up request control unit is higher than the threshold voltage after the battery voltage falls below the threshold voltage, the control current It can also be a means of holding a restriction. This is based on the reason that when the battery voltage becomes equal to or lower than the threshold voltage, it is considered that the battery voltage is likely to decrease even if the battery voltage subsequently becomes higher than the threshold voltage.

  Further, in the first or second hybrid vehicle of the present invention, the catalyst warm-up request time control means is configured such that when the battery voltage becomes equal to or lower than the allowable lower limit voltage, the battery voltage is higher than the allowable lower limit voltage. Until the threshold voltage is equal to or higher than the threshold voltage, the power that is greater than the power for traveling is output from the engine and is controlled to travel with the power for traveling. If it carries out like this, the voltage of a battery can be raised more than a 2nd threshold voltage. As described above, in the first or second hybrid vehicle of the present invention, when the battery voltage becomes equal to or lower than the threshold voltage, the driving power from the engine is less than before the battery voltage becomes lower than the threshold voltage. Since the output ratio from the battery is increased and the output ratio from the battery is decreased, the output from the engine can be brought closer to the target power more quickly. As a result, it is possible to suppress the output from the battery to cover the output shortage due to the response delay of the engine, and it is possible to suppress the extent that the battery voltage falls below the allowable lower limit voltage. Here, the “second threshold voltage” may be higher than the threshold voltage.

  Alternatively, in the first or second hybrid vehicle of the present invention, a generator capable of exchanging electric power with the battery, a drive shaft connected to an axle, an output shaft of the engine, and a rotating shaft of the generator. And a planetary gear to which three rotating elements are connected. The motor may be configured such that a rotating shaft is connected to the drive shaft. In addition, the battery pack may include a charger that is connected to an external power source and can charge the battery using electric power from the external power source.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 3 is a flowchart showing an example of a catalyst warm-up request control routine executed by an HVECU 70. 5 is a routine illustrating an example of a limit value setting routine that is executed by a battery ECU 52; It is explanatory drawing which shows an example of the map for request | requirement torque setting. Explanatory drawing which shows an example of the collinear diagram which shows the mechanical relationship between the rotation speed and torque in the rotation element of the planetary gear 30 when driving | running | working, operating the engine 22 at the operating point for warming up of the purification catalyst 134a. It is. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, the target rotational speed Ne *, and the target torque Te * are set. 4 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of the planetary gear 30 when traveling while outputting power from the engine 22. FIG. The inter-terminal voltage Vb, charge / discharge current Ib, and control current of the high voltage battery 50 when the warming-up request of the purification catalyst 134a is made and the traveling power Pdrv * is greater than the control output limit Wout * of the high voltage battery 50 It is explanatory drawing which shows an example of the time change state of restriction | limiting Ibmax *, charging / discharging electric power Wb, the control output restriction | limiting Wout *, the forced charge request | requirement flag Fc, the request | requirement power Pe * of the engine 22, and the real power Pe. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to the crankshaft 26 and a ring gear connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor, for example. Motor MG1 connected to the sun gear of planetary gear 30, for example, a motor MG2 configured as a synchronous generator motor and having a rotor connected to drive shaft 36, inverters 41 and 42 for driving motors MG1 and MG2, Inverters 41 and 42 not shown A system main relay 56 is configured as a motor electronic control unit (hereinafter referred to as a motor ECU) 40 that controls the motors MG1 and MG2 by switching the elements, and a lithium ion secondary battery having a rated voltage of 200V, for example. And a high voltage battery 50 that exchanges electric power with the motors MG1 and MG2 via inverters 41 and 42, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the high voltage battery 50, and each ECU or auxiliary unit. For example, a low voltage battery 58 configured as a lead storage battery having a rated voltage of 12V or the like connected to a power line (hereinafter referred to as a low voltage system power line) 54b to which a machine 59 or the like is connected, inverters 41 and 42, and a high voltage A power line connecting the battery 50 (hereinafter referred to as a high voltage system power line). A DC / DC converter 57 that steps down the power from 54a and supplies it to the low voltage system power line 54b, and a charger 60 that is connected to an external power source such as a household power source and can charge the high voltage battery 50; And a hybrid electronic control unit (hereinafter referred to as HVECU) 70 for controlling the entire vehicle.

  The engine 22 is configured as an internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and the air purified by an air cleaner 122 is passed through a throttle valve 124 as shown in FIG. Inhalation and gasoline are injected from the fuel injection valve 126 to mix the sucked air and gasoline, and this mixture is sucked into the combustion chamber through the intake valve 128 and explosively burned by an electric spark from the spark plug 130. Thus, the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is sent to the outside air through a purification device 134 having a purification catalyst (three-way catalyst) 134a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Discharged.

  The engine ECU 24 is configured as a microprocessor centered on the CPU 24a. In addition to the CPU 24a, the engine ECU 24 includes a ROM 24b for storing processing programs, a RAM 24c for temporarily storing data, an input / output port and a communication port (not shown). Prepare. The engine ECU 24 receives signals from various sensors that detect the state of the engine 22, for example, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a water temperature that detects the temperature of cooling water in the engine 22. A cooling water temperature Tw from the sensor 142, an in-cylinder pressure Pin from a pressure sensor (not shown) attached in the combustion chamber, a cam for detecting the intake valve 128 for intake and exhaust to the combustion chamber and the rotational position of the camshaft for opening and closing the exhaust valve The cam position from the position sensor 144, the throttle position from the throttle valve position sensor 146 for detecting the position of the throttle valve 124, the intake air amount Qa from the air flow meter 148 attached to the intake pipe, and the temperature attached to the intake pipe The intake air temperature Tin from the sensor 149, the catalyst temperature Tc from the temperature sensor 134b that detects the temperature of the purification catalyst 134a, the air-fuel ratio AF from the air-fuel ratio sensor 135a, the oxygen signal Vo from the oxygen sensor 135b, and the like are input via the input port. Have been entered. The engine ECU 24 also integrates various control signals for driving the engine 22, such as a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 140.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and not shown. A phase current applied to the motors MG1 and MG2 detected by the current sensor is input via the input port, and the motor ECU 40 outputs a switching control signal to switching elements (not shown) of the inverters 41 and 42. It is output through the port. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 also calculates the rotational angular velocities ωm1, ωm2 and the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44. ing.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 is connected to a signal necessary for managing the high voltage battery 50, for example, an inter-terminal voltage Vb from a voltage sensor 51 a installed between terminals of the high voltage battery 50 or an output terminal of the high voltage battery 50. The charge / discharge current Ib from the current sensor 51b attached to the connected power line, the battery temperature Tb from the temperature sensor 51c attached to the high voltage battery 50, and the like are input. Data regarding the state is transmitted to the HVECU 70 by communication. Further, in order to manage the high voltage battery 50, the battery ECU 52 is based on the integrated value of the charge / discharge current Ib detected by the current sensor 51b, and the total capacity of the power that can be discharged from the high voltage battery 50 at that time. Or the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the high-voltage battery 50, based on the calculated storage ratio SOC and the battery temperature Tb. It is.

  The charger 60 is connected to the high voltage system power line 54a via a relay 62, and an AC / DC converter 66 that converts AC power from an external power source supplied via a power plug 68 into DC power; A DC / DC converter 64 that converts the voltage of the DC power from the AC / DC converter 66 and supplies the converted voltage to the high voltage system power line 54a.

  The HVECU 70 is configured as a microprocessor centered on the CPU 72, and includes, in addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown). . The HVECU 70 includes a push signal from the power switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, vehicle speed V from the vehicle speed sensor 88, connection from the connection detection sensor 69 that detects connection of the power plug 68 to the external power source A detection signal or the like is input via the input port. From the HVECU 70, a drive signal to the system main relay 56 and the relay 62, a switching control signal to the DC / DC converter 64 and the AC / DC converter 66, a switching control signal to the DC / DC converter 57, and the like are output via an output port. It is output. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 36 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * is output to the drive shaft 36. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. Torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that torque is converted by the MG1 and the motor MG2 and output to the drive shaft 36, and the sum of the required power and the power required for charging and discharging the high voltage battery 50 The engine 22 is operated and controlled so that the power suitable for the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the high-voltage battery 50 is transmitted to the planetary gear 30, the motor MG1, and the motor. The required power is applied to the drive shaft 36 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the motor MG1 is powered, motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the drive shaft 36, etc. There is. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22, the motor MG1, and the motor MG2 are controlled so that the required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no substantial difference in control, both are hereinafter referred to as the engine operation mode.

  Further, in the hybrid vehicle 20 of the embodiment, when the system is stopped at home or at a preset charging point, the power plug 68 is connected to an external power source, and the connection detection sensor 69 detects the connection. The relay 55 and the relay 62 are turned on, the charger 60 is controlled, and the high voltage battery 50 is charged with electric power from the external power source. When the system is started after charging the high-voltage battery 50, the storage rate SOC of the high-voltage battery 50 is set to a threshold value Shv (for example, 20% or 30%) set to such an extent that the engine 22 can be started. Until now, the electric travel priority mode in which the electric travel that travels using only the power from the motor MG2 is given priority over the hybrid travel that travels using the power from the engine 22 and the power from the motor MG2. After the power storage ratio SOC of the high voltage battery 50 reaches the threshold value Shv, the vehicle travels in the hybrid travel priority mode in which the hybrid travel is prioritized over the electric travel.

  In the electric travel priority mode, the required torque Tr * required for travel (to be output to the drive shaft 36) is set and set based on the accelerator opening Acc corresponding to the depression amount of the accelerator pedal 83 and the vehicle speed V. Multiplying the required torque Tr * by the rotational speed Nr of the drive shaft 36 (for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor), the travel power Pdrv * required for travel is calculated. To do. When the traveling power Pdrv * is less than or equal to the output limit Wout of the high voltage battery 50, the traveling power Pdrv * is output from the motor MG2 while the operation of the engine 22 is stopped, and the required torque Tr * is applied to the drive shaft 36. The motor MG2 is controlled so as to be output, and the vehicle travels by electric travel. When the traveling power Pdrv * becomes larger than the output limit Wout of the high voltage battery 50, the engine 22 is started and the traveling power Pdrv * is set to the required power Pe * to be output from the engine 22, and the required power from the engine 22 is set. The engine 22 and the motors MG1, MG2 are controlled so that Pe * is output and the required torque Tr * is output to the drive shaft 36, and the vehicle travels by hybrid travel. Thereafter, when the traveling power Pdrv * becomes equal to or lower than the output limit Wout of the high voltage battery 50, the operation of the engine 22 is stopped, the operation of the engine 22 is stopped, and the traveling power Pdrv * is output from the motor MG2. Return to electric running.

  In the hybrid travel priority mode, the charge / discharge required power Pb * (a positive value when discharging from the high voltage battery 50) is set according to the storage ratio SOC of the high voltage battery 50 and the set charge / discharge is set. The required power Pe * to be output from the engine 22 is set by subtracting the required power Pb * from the driving power Pdrv *, and the required power Pe * is determined in advance as the lowest power that can operate the engine 22 relatively efficiently. When the driving threshold value Pop is greater than or equal to the driving threshold value Pop, the engine 22, the motor MG 1, and the motor MG 2 are controlled so that the required power Pe * is output from the engine 22 and the required torque Tr * is output to the drive shaft 36. Travel by. If the required power Pe * is less than the driving threshold value Pop, the engine 22 cannot be operated relatively efficiently. Therefore, the operation of the engine 22 is stopped and the motor MG2 outputs the driving power Pdrv * to shift to electric driving. To do. When the driver depresses the accelerator pedal 83 and the traveling power Pdrv * is increased and the required power Pe * is equal to or higher than the driving threshold value Pop, the engine 22 is started and the engine 22 is started. The vehicle shifts to hybrid traveling that travels by outputting the required power Pe *. The operation threshold value Pop is determined as a value that is considerably smaller than the output limit Wout of the high-voltage battery 50.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the warm-up request for the purification catalyst 134a of the purification device 134 is made will be described. FIG. 3 is a flowchart showing an example of a catalyst warm-up request control routine executed by the HVECU 70. This routine is repeatedly executed every predetermined time (for example, every several msec) when the warm-up request for the purification catalyst 134a is made. The warm-up request for the purification catalyst 134a is less than the activation temperature Tcact (for example, 400 ° C., 420 ° C., 450 ° C., etc.) where the catalyst temperature Tc from the temperature sensor 134b is assumed to be activated. It was supposed to be done at the time. When the warm-up request for the purification catalyst 134a is made, basically, when the engine 22 is started for the first time after the vehicle system is started (when the system is started after the high voltage battery 50 is charged, the electric drive priority mode is usually set). Can be considered when the engine 22 is started while driving.

  When the catalyst warm-up request control routine is executed, first, the CPU 72 of the HVECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speeds Nm1, Nm2 of the motors MG1, MG2. , Data such as the inter-terminal voltage Vb of the high-voltage battery 50, the control current limit Ibmax *, and the control output limit Wout * are input (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The voltage Vb between the terminals of the high voltage battery 50 is detected by the voltage sensor 51a and input from the battery ECU 52 by communication. As the control current limit Ibmax * and the control output limit Wout *, those set by the limit value setting routine illustrated in FIG. 4 are input from the battery ECU 52 by communication. The limit value setting routine of FIG. 4 will be described later.

  When the data is input in this way, the required torque Tr * required for traveling (to be output to the drive shaft 36) is set based on the input accelerator opening Acc and the vehicle speed V, and the drive shaft is set to the set required torque Tr *. The traveling power Pdrv * required for traveling is set by multiplying by the rotation speed Nr of 36 (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. An example of the required torque setting map is shown in FIG. Further, the rotational speed Nr of the drive shaft 36 can be obtained by multiplying the vehicle speed V by a conversion factor, or the rotational speed Nm2 of the motor MG2 can be used.

  Subsequently, the value of the forced charge request flag Fc indicating whether or not the high voltage battery 50 should be forcibly charged is checked (step S120). When the forced charge request flag Fc is 0, the voltage Vb between the terminals of the high voltage battery 50 is determined. Is compared with the allowable lower limit voltage Vbmin for control (step S130). Here, the forced charge request flag Fc is set to 0 as an initial value, and is switched from the value 0 to the value 1 when forced charging of the high voltage battery 50 is to be started, and then the forced charging of the high voltage battery 50 is performed. Is a flag that can be switched from a value of 1 to a value of 0 when the process can be terminated. Further, the allowable lower limit voltage Vbmin is determined in a voltage range higher than a protection lower limit voltage (for example, 120V, 130V, 140V, etc.) that should be strictly observed in order to protect the high voltage battery 50, for example, 150V, 155V, 160V, etc. Can be used. In the embodiment, the allowable lower limit voltage Vbmin is used as a threshold value for determining whether or not forced charging of the high voltage battery 50 should be started.

  When the forced charge request flag Fc is 0 and the inter-terminal voltage Vb of the high voltage battery 50 is higher than the allowable lower limit voltage Vbmin, it is determined that it is not necessary to start the forced charge of the high voltage battery 50, and the traveling power Pdrv * is set. It is compared with the control output limit Wout * of the high voltage battery 50 (step S140).

  When the traveling power Pdrv * is equal to or less than the control output limit Wout * of the high voltage battery 50, the rotational speed Nset and the torque Tset as the operation point for warming up the purification catalyst 134a are used as the target rotational speed Ne of the engine 22. * And target torque Te * are set (step S150). Here, as the rotation speed Nset, for example, a lower limit value (for example, 1000 rpm, 1200 rpm, 1300 rpm) or a slightly larger value when the engine 22 is operated can be used. As the torque Tset, for example, A value of 0 or a value slightly larger than that can be used.

  Subsequently, as the output torque from the engine 22 using the torque command (previous Tm1 *) of the motor MG1 and the gear ratio ρ of the planetary gear 30 set in the process of step S240 described later when this routine was executed last time. The estimated output torque Test to be estimated is calculated by the following equation (1) (step S230), and the following equation (1) is obtained using the target rotation speed Ne * of the engine 22, the rotation speed Nm2 of the motor MG2, and the gear ratio ρ of the planetary gear 30. 2), the target rotational speed Nm1 * of the motor MG1 is calculated, based on the calculated target rotational speed Nm1 *, the input rotational speed Nm1 of the motor MG1, the estimated output torque Test of the engine 22, and the gear ratio ρ of the planetary gear 30. A torque command Tm1 * of the motor MG1 is calculated from the equation (3) (step S240). FIG. 6 shows an example of a collinear chart showing the dynamic relationship between the rotational speed and torque of the rotating element of the planetary gear 30 when the engine 22 is running while operating at the operating point for warming up the purification catalyst 134a. Show. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotation speed Nr of the ring gear 32, which is a number Nm2, is shown. Note that the two thick arrows on the R axis indicate the torque output from the motor MG1 and acting on the drive shaft 36, and the torque output from the motor MG2 and acting on the drive shaft 36. Expressions (1) and (2) can be easily derived by using this alignment chart. Expression (3) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (3), “k1” in the second term on the right side is a gain of the proportional term. “K2” in the third term on the right side is the gain of the integral term. Since the torque Tset at the warm-up operation point of the purification catalyst 134a is a small value (for example, the value 0 or a value slightly larger than that), the motor MG1 is operated when the engine 22 is operated at the operation point. The torque command Tm1 * is set to a value having a small absolute value. In the alignment chart of FIG. 6, some arrows are exaggerated for the purpose of illustration.

Teest =-(1 + ρ), previous Tm1 * / ρ (1)
Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ・ ρ (2)
Tm1 * =-ρ ・ Teest / (1 + ρ) + k1 ・ (Nm1 * -Nm1) + k2 ・ ∫ (Nm1 * -Nm1) dt (3)

  Then, by adding the torque command Tm1 * divided by the gear ratio ρ of the planetary gear 30 to the required torque Tr *, a temporary torque Tm2tmp that is a temporary value of the torque to be output from the motor MG2 is calculated by the following equation (4). At the same time (step S250), a value obtained by subtracting the consumed power (generated power) of the motor MG1 obtained by multiplying the torque command Tm1 * by the current rotational speed Nm1 from the control output limit Wout * of the high voltage battery 50 is obtained. A torque limit Tm2max1 as an upper limit of the torque that may be output from the motor MG2 by dividing by the number of revolutions Nm2 of the motor MG2 is calculated by the equation (5) (step S260), and as shown in the equation (6), the high voltage A torque limit Tm2max2 is set based on the charging / discharging current Ib of the battery 50 and the control current limit Ibmax * (step S1). Flop S270), as shown in Equation (7), to restrict the tentative torque Tm2tmp calculated by the torque limit Tm2max1, Tm2max2 sets the torque command Tm2 * of the motor MG2 (step S280). Here, equation (4) can be easily derived from the alignment chart of FIG. In the embodiment, the torque limit Tm2ma2 is set to the control output limit Wout * of the high voltage battery 50 when the charge / discharge current Ib of the high voltage battery 50 is equal to or less than the control current limit Ibmax *. When the charge / discharge current Ib is larger than the control current limit Ibmax *, a value that tends to be smaller than the control output limit Wout * is set as the charge / discharge current Ib increases. Considering that the torque Tset at the warm-up operation point of the purification catalyst 134a is small and the magnitude of the torque command Tm1 * of the motor MG1 is also small, if the torque command Tm1 * is 0, the temporary motor torque Tm2tmp is required. Torque Tr * is set. Then, considering that the traveling power Pdrv * is equal to or less than the control output limit Wout * of the high voltage battery 50, the temporary motor torque Tm2tmp is set in the torque command Tm2 * of the motor MG2.

Tm2tmp = Tr * + Tm1 * / ρ (4)
Tm2max1 = Wout * -Tm1 * ・ Nm1 / Nm2 (5)
Tm2max2 = f (Ib, Ibmax) (6)
Tm2 * = min (Tm2tmp, Tm2max1, Tm2max2) (7)

  When the target rotational speed Ne * of the engine 22 and the target torque Te * and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set in this way, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S290), and this routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * controls the intake air amount in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as fuel injection control and ignition control. At this time, in order to further promote the warming-up of the purification catalyst 134a, the ignition timing of the engine 22 is later than the ignition timing for efficiently operating the engine 22 (hereinafter referred to as fuel efficiency ignition timing) and the catalyst warm-up time is increased. The ignition timing suitable for the engine (hereinafter referred to as catalyst warm-up ignition timing) was used. The reason why the ignition timing is made later than the ignition timing for fuel consumption is to promote warm-up of the purification catalyst 134a by increasing the energy discharged to the exhaust system as thermal energy out of the combustion energy by making the combustion slow. . The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do. By such control, it is possible to travel with the traveling power Pdrv * while promoting warming up of the purification catalyst 134a. For motor MG2, as described above, a value obtained by limiting temporary torque Tm2tmp by torque limit Tm2max1 based on control output limit Wout * and torque limit Tm2max2 based on control current limit Ibmax * is set as a torque command. Since Tm2 * is set and used for control, the charging / discharging current Ib of the high voltage battery 50 becomes equal to or less than the control current limit Ibmax *, and the charging / discharging power Wb (= Vb × Ib) of the high voltage battery 50 is the control output. It can be considered that the control is performed so that the limit Wout * or less.

  When the traveling power Pdrv * is larger than the control output limit Wout * for the high voltage battery 50 in step S140, a value obtained by subtracting the control output limit Wout * for the high voltage battery 50 from the traveling power Pdrv * (hereinafter referred to as differential power). (Pdrv * −Wout *)) is set as the required power Pe * to be output from the engine 22 (step S160), and the engine 22 is efficiently operated as a restriction between the rotational speed Ne of the engine 22 and the torque Te. The target rotational speed Ne * and the target torque Te * of the engine 22 are set using the operation line and the required power Pe * (step S170), and the torques of the motors MG1 and MG2 are processed by the processing of steps S230 to S280 described above. The commands Tm1 * and Tm2 * are set, and the target engine speed Ne * of the engine 22 is set. The engine ECU24 for target torque Te * city, the torque command Tm1 * of the motor MG1, MG2, and sends each motor ECU40 for Tm2 * (step S290), and terminates this routine. FIG. 7 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained by the intersection of the operating line and a curve with a constant required power Pe * (Ne * × Te *). FIG. 8 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque of the rotating elements of the planetary gear 30 when traveling while outputting power from the engine 22. In this case, the deterioration of the emission can be suppressed as compared with the case where the traveling power Pdrv * is output from the engine 22.

  In steps S120 and S130, when the forced charge request flag Fc is 0 and the inter-terminal voltage Vb of the high voltage battery 50 is equal to or lower than the allowable lower limit voltage Vbmin, it is determined that the forced charge of the high voltage battery 50 should be started, and the forced charge request is made. A value 1 is set in the flag Fc (step S180). Then, a value obtained by subtracting a predetermined negative power Pc for charging the high voltage battery 50 (a positive value when discharging from the high voltage battery 50) from the traveling power Pdrv * (hereinafter, forced charging traveling power (Pdrv *). -Pc) is set as the required power Pe * of the engine 22 (step S190), the operation line for efficiently operating the engine 22 as a restriction between the rotational speed Ne of the engine 22 and the torque Te, and the required power Pe The target rotational speed Ne * and the target torque Te * of the engine 22 are set using * and (step S170), and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set by the processing of steps S230 to S280 described above. The target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. Motor MG1, MG2 torque command Tm1 *, and Tm2 * to the motor ECU 40 (step S290), and terminates this routine. By such control, the high voltage battery 50 can be charged and the terminal voltage Vb of the high voltage battery 50 can be raised.

  If the value 1 is set in the forced charge request flag Fc in this way, the forced charge request flag Fc is determined to be the value 1 in step S120 when this routine is executed next time, and the inter-terminal voltage of the high voltage battery 50 is determined. Vb is compared with a threshold voltage Vbcstop higher than the allowable lower limit voltage Vbmin (step S210). Here, the threshold voltage Vbcstop is determined as a voltage at which forced charging of the high voltage battery 50 may be terminated, and for example, 190V, 200V, 210V, or the like can be used. In this embodiment, the threshold voltage Vbcstop is higher than the threshold voltage Vbcstop described above.

  When the inter-terminal voltage Vb of the high-voltage battery 50 is less than the threshold voltage Vbcstop, it is determined that the forced charging of the high-voltage battery 50 should be continued, and the processing from step S190 is executed. On the other hand, when the inter-terminal voltage Vb of the high voltage battery 50 is equal to or higher than the threshold voltage Vbcstop, it is determined that the forced charging of the high voltage battery 50 may be terminated, and a value 0 is set in the forced charging request flag Fc (step S220). Then, the processing after step S140 is executed. When the value 0 is set in the forced charge request flag Fc in this way, the next time this routine is executed, it is determined in step S120 that the forced charge request flag Fc is 0, and the processes after step S130 are executed. .

  The catalyst warm-up request control routine in FIG. 3 has been described above. Next, the limit value setting routine of FIG. 4 will be described. When the limit value setting routine is executed, the battery ECU 52 first executes a process of inputting the inter-terminal voltage Vb, the current limit Ibmax, and the output limit Wout of the high voltage battery 50 (step S300). Here, the voltage Vb between the terminals of the high voltage battery 50 is input as detected by the voltage sensor 51a. In addition, the rated value of the high voltage battery 50 is input as the current limit Ibmax. Further, the output limit Wout of the high voltage battery 50 is input based on the battery temperature Tb of the high voltage battery 50 and the storage rate SOC.

  When data is input in this way, the values of the history flags Fh1 and Fh2 are checked (step S310). Here, the history flag Fh1 is set to a value 0 as an initial value at the start of the warm-up request of the purification catalyst 134a, and the inter-terminal voltage Vb of the high-voltage battery 50 decreases and is higher than the allowable lower limit voltage Vbmin by a predetermined voltage α. This is a flag in which a value of 1 is set when the threshold voltage is lower than Vbref. Further, the history flag Fh2 is set to a value 0 as an initial value at the start of the warm-up request for the purification catalyst 134a, and is set when the inter-terminal voltage Vb of the high voltage battery 50 decreases to become the allowable lower limit voltage Vbmin or less. 1 is a flag to be set. For example, 5V, 10V, 15V, or the like can be used as the predetermined voltage α.

  When the history flags Fc1 and Fc2 are both 0, the inter-terminal voltage Vb of the high-voltage battery 50 is compared with the threshold voltage Vbref (step S320), and when the inter-terminal voltage Vb of the high-voltage battery 50 is higher than the threshold voltage Vbref, The current limit Ibmax of the high voltage battery 50 is set to the control current limit Ibmax * (step S330), and the output limit Wout of the high voltage battery 50 is set to the control output limit Wout * (step S340). Exit. In this case, when the traveling power Pdrv * is larger than the control output limit Wout * (= Wout) of the high voltage battery 50, the differential power (Pdrv * −Wout *) is output from the engine 22 and the high voltage battery 50 is charged. The discharge current Ib becomes equal to or less than the control current limit Ibmax *, the charge / discharge power Wb (= Vb × Ib) of the high voltage battery 50 becomes equal to or less than the control output limit Wout *, and the traveling power Pdrv * is output to the drive shaft 36. Thus, the engine 22 and the motors MG1, MG2 are controlled to travel.

  On the other hand, when the inter-terminal voltage Vb of the high voltage battery 50 is equal to or lower than the threshold voltage Vbref in step S320, the history flag Fh1 is set to 1 (step S350), and the predetermined value ΔIb1 is subtracted from the current limit Ibmax of the high voltage battery 50. Is set to the control current limit Ibmax * (step S360), and a value obtained by subtracting the predetermined value ΔW1 from the output limit Wout of the high voltage battery 50 is set to the control output limit Wout * (step S370). This routine ends. Here, as the predetermined value ΔIb1, for example, 55A, 60A, 65A or the like can be used when the current limit Ibmax is 200A, 210A, 220A, or the like. Further, as the predetermined value ΔW1, for example, 13 kW, 14 kW, 15 kW, or the like can be used when the output limit Wout is 39 kW, 41 kW, 43 kW, or the like. In this case, when the traveling power Pdrv * is larger than the control output limit Wout *, before the terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the threshold voltage Vbref (the history flags Fh1 and Fh2 are both 0 and Compared to the case where the voltage Vb between terminals of the high voltage battery 50 is higher than the threshold voltage Vbref), the ratio of the output from the engine 22 and the ratio of the output from the high voltage battery 50 are small in the traveling power Pdrv *. Become. Accordingly, the terminals of the high voltage battery 50 are compared with those for setting the control current limit Ibmax * and the control output limit Wout * as before the inter-terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the threshold voltage Vbref. The decrease in the inter-voltage Vb can be moderated. As a result, the inter-terminal voltage Vb of the high-voltage battery 50 can be made difficult to reach the allowable lower limit voltage Vbmin or less (the time until it can be extended).

  When the value 1 is set in the history flag Fh1, the next time this routine is executed, it is determined in step S310 that the history flag Fh1 is the value 1 and the history flag Fh2 is the value 0. 50 inter-terminal voltage Vb is compared with allowable lower limit voltage Vbmin (step S380). When the inter-terminal voltage Vb of the high voltage battery 50 is higher than the allowable lower limit voltage Vbmin, a value obtained by subtracting the predetermined value ΔIb1 from the current limit Ibmax of the high voltage battery 50 is set as the control current limit Ibmax * (step S360). ), A value obtained by subtracting the predetermined value ΔW1 from the output limit Wout of the high-voltage battery 50 is set as the control output limit Wout * (step S370), and this routine ends.

  On the other hand, when the inter-terminal voltage Vb of the high voltage battery 50 is equal to or lower than the allowable lower limit voltage Vbmin in step S380, the history flag Fh2 is set to a value 1, and the current limit Ibmax of the high voltage battery 50 is greater than the predetermined value ΔIb1. Is set to the control current limit Ibmax * (step S400), and the value obtained by subtracting the predetermined value ΔW2 larger than the predetermined value ΔW1 from the output limit Wout of the high-voltage battery 50 is set to the control output limit Wout *. (Step S410), and this routine is finished. Here, as the predetermined value ΔIb2, for example, 85A, 90A, 95A or the like can be used when the current limit Ibmax is 200A, 210A, 220A or the like and the predetermined value ΔIb1 is 55A, 60A, 65A, or the like. Further, as the predetermined value ΔW2, for example, 19W, 20W, 21W or the like can be used when the output limit Wout is 39 kW, 41 kW, 43 kW, or the like and the predetermined value ΔW1 is 13 kW, 14 kW, 15 kW, or the like.

  In the embodiment, as described above, after the inter-terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the allowable lower limit voltage Vbmin, the inter-terminal voltage Vb is larger than the traveling power Pdrv * until the inter-terminal voltage Vb becomes equal to or higher than the threshold voltage Vbcstop. By driving the engine 22 and the motors MG1, MG2 so that the forced charging travel power (Pdrv * -Pc) is output from the engine 22 and travels with the travel power Pdrv *, the travel is performed while charging the high voltage battery 50. . As a previous step, when the inter-terminal voltage Vb of the high voltage battery 50 becomes lower than the threshold voltage Vbref, compared to before the threshold voltage Vbref becomes lower, the control current limit Ibmax *, control of the high voltage battery 50 is controlled. The output limit Wout * is reduced to increase the output ratio from the engine 22 and the output ratio from the high-voltage battery 50 in the traveling power Pdrv *, so that the output ratio from the high-voltage battery 50 is reduced. When the voltage Vb becomes equal to or lower than the allowable lower limit voltage Vbmin, the output from the engine 22 can be brought closer to the required power Pe * (= Pdrv * −Pc) quickly. As a result, it is possible to suppress the output from the high voltage battery 50 to cover the output shortage due to the response delay of the engine 22, and to suppress the extent that the inter-terminal voltage Vb of the high voltage battery 50 is below the allowable lower limit voltage Vbmin. Can do. Moreover, at this time, the control current limit Ibmax * and the control output limit Wout * of the high voltage battery 50 are made smaller than before the inter-terminal voltage Vb of the high voltage battery 50 reaches the allowable lower limit voltage Vbmin or less. Further, the degree to which the inter-terminal voltage Vb of the high voltage battery 50 is lower than the allowable lower limit voltage Vbmin can be further suppressed. The terminal voltage Vb of the high voltage battery 50 reaches the allowable lower limit voltage Vbmin or less after the terminal voltage Vb of the high voltage battery 50 reaches the threshold voltage Vbref or less and before the allowable lower limit voltage Vbmin or less. By setting large values (Ibmax−ΔIb1) and (Wout−ΔW1) to the control current limit Ibmax * and the control output limit Wout * as compared to the following, it is possible to suppress the deterioration of the emission to some extent.

  When the history flag Fh2 is set to 1 in this way, the next time this routine is executed, it is determined in step S310 that both the history flags Fh1 and Fh2 are 1 and the current limit Ibmax of the high-voltage battery 50 is determined. A value obtained by subtracting the predetermined value ΔIb2 is set as the control current limit Ibmax * (step S400), and a value obtained by subtracting the predetermined value ΔW2 from the output limit Wout of the high-voltage battery 50 is set as the control output limit Wout *. (Step S410), this routine is finished.

  Here, the reason why the history flags Fh1 and Fh2 are used for setting the control current limit Ibmax * and the control output limit Wout * will be described. In the embodiment, when the inter-terminal voltage Vb of the high-voltage battery 50 becomes higher than the threshold voltage Vbref after the threshold voltage Vbref or less (the history flag Fh1 is the value 1, the history flag Fh2 is the value 0, and the high-voltage battery 50 When the terminal-to-terminal voltage Vb is higher than the threshold voltage Vbref), the control current limit Ibmax * and the control output limit Wout * are not restored to the current limit Ibmax and the output limit Wout, and the value (Ibmax−ΔIb1), It is held at (Wout−ΔW1). Further, when the inter-terminal voltage Vb of the high voltage battery 50 becomes lower than the allowable lower limit voltage Vbmin after the terminal voltage Vb becomes equal to or lower than the allowable lower limit voltage Vbmin (the history flags Fh1, Fh2 are both 1 and the inter-terminal voltage of the high voltage battery 50 is When Vb is higher than the allowable lower limit voltage Vbmin), the control current limit Ibmax * and the control output limit Wout * are returned to the current limit Ibmax, the output limit Wout, and the values (Ibmax−ΔIb1) and (Wout−ΔW1). Instead, they are held at values (Ibmax−ΔIb2) and (Wout−ΔW2). This is because, when the inter-terminal voltage Vb of the high-voltage battery 50 falls below the threshold voltage Vbref and the allowable lower limit voltage Vbmin, the inter-terminal voltage Vb decreases relatively steeply even if the inter-terminal voltage Vb subsequently increases to some extent. It is based on the reason that it is thought that it is in the state which is easy to do (it has not recovered | restored from the state after becoming easy to deteriorate). Therefore, when the inter-terminal voltage Vb of the high-voltage battery 50 rises after decreasing, the control current limit Ibmax * and the control output limit Wout * are not restored (not increased), so that the inter-terminal voltage Vb subsequently increases. It is possible to suppress a sharp drop.

  FIG. 9 shows the inter-terminal voltage Vb and charge / discharge current Ib of the high-voltage battery 50 when the warm-up request for the purification catalyst 134a is made and the travel power Pdrv * is larger than the control output limit Wout * of the high-voltage battery 50. FIG. 6 is an explanatory diagram showing an example of changes over time of control current limit Ibmax *, charge / discharge power Wb and control output limit Wout *, forced charge request flag Fc, required power Pe * of engine 22 and actual power Pe. . In the drawing, the left side shows the time change of the embodiment in which the control current limit Ibmax * and the control output limit Wout * are set according to the inter-terminal voltage Vb of the high voltage battery 50, and the right side shows the high voltage battery 50. A time-change state of a comparative example in which the current limit Ibmax and the output limit Wout are set to the control current limit Ibmax * and the control output limit Wout * regardless of the terminal voltage Vb is shown. The charge / discharge power Wb can be calculated, for example, by the product of the inter-terminal voltage Vb of the high voltage battery 50 and the charge / discharge current Ib. Further, the actual power Pe of the engine 22 can be calculated, for example, by multiplying the estimated output torque Test by the rotational speed Ne of the engine 22.

  In both the example and the comparative example, similarly, the differential power (Pdrv * −Wout *) of the engine 22 before the voltage Vb between the terminals of the high voltage battery 50 reaches the allowable lower limit voltage Vbmin or less (before time t12, t22). After setting the required power Pe * to control the engine 22, the inter-terminal voltage Vb of the high-voltage battery 50 reaches the allowable lower limit voltage Vbmin and the forced charging flag Fc is switched from the value 0 to the value 1 (time t12, t22) Thereafter, the forced charging power (Pdrv * −Pc) is set to the required power Pe * of the engine 22 to control the engine 22. In the figure, times t11 and t21 are times when the inter-terminal voltage Vb of the high voltage battery 50 is equal to or lower than the threshold voltage Vbref in the examples and comparative examples.

  As shown on the right side of the figure, in the comparative example, when the inter-terminal voltage Vb of the high-voltage battery 50 reaches the allowable lower limit voltage Vbmin (time t22), the control output limit Wout * is relatively large (output limit Wout). Therefore, the difference between the forced charging power (Pdrv * −Pc) and the differential power (Pdrv * −Wout *) is relatively large, and the required power Pe * changes relatively large. Therefore, in order to cover the response delay of the engine 22, until the actual power Pe from the engine 22 approaches the required power Pe * (= Pdrv * −Pc) to some extent (time t22 to t23), the comparison is made from the high voltage battery 50. Large current and power (current and power close to the current limit Ibmax and output limit Wout) are output, and the inter-terminal voltage Vb of the high-voltage battery 50 is lowered to some extent relative to the allowable lower limit voltage Vbmin. Then, after the actual power Pe * has approached the required power Pe * to some extent (after time t23), the current and power from the high voltage battery 50 are reduced and the voltage Vb between the terminals of the high voltage battery 50 is increased.

  As shown on the left side in the figure, in the embodiment, when the inter-terminal voltage Vb of the high voltage battery 50 reaches the threshold voltage Vbref or less (time t11), the control current limit Ibmax * and the control output limit of the high voltage battery 50 are shown. Wout * is reduced to values (Ibmax−ΔIb1) and (Wout−ΔW1). Thereby, the inter-terminal voltage Vb of the high-voltage battery 50 can be made equal to or lower than the allowable lower limit voltage Vbmin. After that, when the inter-terminal voltage Vb of the high voltage battery 50 reaches the allowable lower limit voltage Vbmin or less (time t12), since the control output limit Wout * is smaller than that of the comparative example, the forced charging power ( The difference between Pdrv * -Pc) and the differential power (Pdrv * -Wout *) is reduced, and the amount of change in the required power Pe * is reduced. In addition, at this time, the control current limit Ibmax * and the control output limit Wout * of the high-voltage battery 50 are reduced by the values (Ibmax−ΔIb2) and (Wout−ΔW2). As a result, the actual power Pe from the engine 22 approaches the required power Pe * relatively quickly, and a large current or power is not output from the high voltage battery 50, so that the inter-terminal voltage Vb of the high voltage battery 50 is allowed. The degree below the lower limit voltage Vbmin can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, when the warm-up request for the purification catalyst 134a is made and the travel power Pdrv * is larger than the control output limit Wout * of the high voltage battery 50, the travel power Pdrv *. The difference power (Pdrv * −Wout *) obtained by subtracting the control output limit Wout * from the engine is output from the engine 22, and the engine 22 and the motors MG1, MG2 are controlled so as to travel by the traveling power Pdrv *. When the inter-terminal voltage Vb of the high-voltage battery 50 falls below the threshold voltage Vbref, which is higher than the allowable lower limit voltage Vbmin, the control voltage is higher than that before the inter-terminal voltage Vb of the high-voltage battery 50 falls below the threshold voltage Vbref. Whether to reduce current limit Ibmax * and control output limit Wout * In addition, the ratio of the output from the engine 22 can be increased and the ratio of the output from the high voltage battery 50 can be decreased in the traveling power Pdrv *, and the inter-terminal voltage Vb of the high voltage battery 50 is equal to or lower than the allowable lower limit voltage Vbmin. (Time until reaching the allowable lower limit voltage Vbmin or less) can be lengthened.

  Further, in the hybrid vehicle 20 of the embodiment, when the inter-terminal voltage Vb of the high voltage battery 50 reaches the allowable lower limit voltage Vbmin or less, the forced charging traveling power (Pdrv * −Pc) larger than the traveling power Pdrv * is the engine 22. Since the engine 22 and the motors MG1, MG2 are controlled so as to travel with the traveling power Pdrv *, the high voltage battery 50 can be charged to increase the voltage Vb between the terminals of the high voltage battery 50. . Moreover, as described above, when the inter-terminal voltage Vb of the high-voltage battery 50 becomes equal to or lower than the threshold voltage Vbref higher than the allowable lower limit voltage Vbmin, the inter-terminal voltage Vb of the high-voltage battery 50 becomes lower than the threshold voltage Vbref. Since the ratio of the output from the engine 22 is increased and the ratio of the output from the high-voltage battery 50 is decreased in the traveling power Pdrv * as compared with the driving power Pdrv *, * -Pc), the output from the high voltage battery 50 to cover the output shortage due to the response delay of the engine 22 can be suppressed, and the voltage Vb between the terminals of the high voltage battery 50 is the allowable lower limit. The degree below the voltage Vbmin can be suppressed.

  In the hybrid vehicle 20 according to the embodiment, when the inter-terminal voltage Vb of the high-voltage battery 50 is equal to or lower than the threshold voltage Vbref, the control is performed as compared with before the inter-terminal voltage Vb of the high-voltage battery 50 is equal to or lower than the threshold voltage Vbref. Although the current limit Ibmax * and the control output limit Wout * are reduced, only one of them may be reduced.

  In the hybrid vehicle 20 of the embodiment, the control output limit Wout * of the high voltage battery 50 is set to the output limit Wout before the terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the threshold voltage Vbref. A value (Wout−ΔW1) is set after the inter-terminal voltage Vb becomes equal to or less than the allowable lower limit voltage Vbmin after the inter-terminal voltage Vb becomes equal to or lower than the threshold voltage Vbref, and the inter-terminal voltage Vb of the high-voltage battery 50 falls below the allowable lower limit voltage Vbmin. After that, the value (Wout−ΔW2) is set, but after the inter-terminal voltage Vb of the high-voltage battery 50 becomes lower than the threshold voltage Vbref, before the lower limit voltage Vbmin or lower Regardless of the value, the value (Wout−ΔW1) or the value (Wout−ΔW2) may be set.

  In the hybrid vehicle 20 of the embodiment, the control current limit Ibmax * of the high voltage battery 50 is set to the current limit Ibmax before the inter-terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the threshold voltage Vbref. A value (Ibmax−ΔIb1) is set after the inter-terminal voltage Vb becomes equal to or lower than the threshold voltage Vbref and before it becomes lower than the allowable lower limit voltage Vbmin, and the inter-terminal voltage Vb of the high voltage battery 50 becomes lower than the allowable lower limit voltage Vbmin. After that, the value (Ibmax−ΔIb2) is set to the control current limit Ibmax *. However, after the inter-terminal voltage Vb of the high voltage battery 50 becomes equal to or lower than the threshold voltage Vbref, the allowable lower limit voltage Vbmin or lower is set. Value (Ibmax−ΔIb1) or value (Ibmax−ΔIb2) It may be set to.

  In the hybrid vehicle 20 of the embodiment, when setting the control current limit Ibmax * and the control output limit Wout * of the high voltage battery 50, the history flags Fh1, Fh2 (the voltage Vb between the terminals of the high voltage battery 50 is equal to or lower than the threshold voltage Vbref). , Information indicating whether or not there is a history of lower than the allowable lower limit voltage Vbmin) is used, but these may not be used. In this case, the control current limit Ibmax * and the control output limit Wout * of the high voltage battery 50 are simply the current limit Ibmax of the high voltage battery 50 when the inter-terminal voltage Vb of the high voltage battery 50 is higher than the threshold voltage Vbref. The output limit Wout is set, and when the inter-terminal voltage Vb of the high voltage battery 50 is lower than the threshold voltage Vbref and higher than the allowable lower limit voltage Vbmin, values (Ibmax−ΔIb1) and (Wout−ΔW1) are set. When the inter-terminal voltage Vb is less than or equal to the allowable lower limit voltage Vbmin, values (Ibmax−ΔIb2) and (Wout−ΔW2) may be set.

  In the hybrid vehicle 20 of the embodiment, when the inter-terminal voltage Vb of the high-voltage battery 50 becomes equal to or lower than the allowable lower limit voltage Vbmin, the forced charging travel power (until the inter-terminal voltage Vb of the high-voltage battery 50 becomes equal to or higher than the threshold voltage Vbcstop. (Pdrv * −Pc) is output from the engine 22 and the engine 22 and the motors MG1 and MG2 are controlled so that the engine 22 travels with the traveling power Pdrv * (so that the high voltage battery 50 travels while being charged). The engine 22 and the motors MG1, MG2 are controlled so that the traveling power Pdrv * is output from the engine 22 and travels by the traveling power Pdrv * (so that the high voltage battery 50 travels without being charged / discharged). It is good.

  Although not specifically described in the hybrid vehicle 20 of the embodiment, when the warming-up request for the purification catalyst 134a is made, the output is about several kW larger than the output limit Wout when the warming-up request for the purification catalyst 134a is not made. The control output limit Wout * may be set using the limit Wout. In this case, before the purification catalyst 134a is requested to warm up and before the terminal voltage Vb of the high voltage battery 50 reaches the threshold voltage Vbref or lower, the output limit Wout when the purification catalyst 134a is not requested to warm up. A large output limit Wout of about several kW is set as the control output limit Wout *.

  In the hybrid vehicle 20 of the embodiment, the temperature sensor 134b attached to the purification device 134 detects the temperature of the purification catalyst 134a as the catalyst temperature Tc. However, the temperature sensor 134b is not provided and the integrated value of the intake air amount Qa is provided. Alternatively, the temperature of the purification catalyst 134a may be estimated based on the intake air temperature Tin, the cooling water temperature Tw, and the like.

  In the hybrid vehicle 20 of the embodiment, the charger 60 is provided, but the charger 60 may not be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 10, the drive shaft 36 transmits the power from the motor MG2. It may be connected to an axle (an axle connected to the wheels 39a and 39b in FIG. 10) different from the connected axle (the axle to which the drive wheels 38a and 38b are connected).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, but is exemplified in the hybrid vehicle 220 of the modification of FIG. As described above, the inner rotor 232 connected to the crankshaft of the engine 22 and the outer rotor 234 connected to the drive shaft 36 that outputs power to the drive wheels 38a and 38b have a part of the power from the engine 22. A counter-rotor motor 230 that transmits power to the drive shaft 36 and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 320 of the modification of FIG. 12, the motor MG is attached to the drive shaft 36 connected to the drive wheels 38a and 38b via the transmission 330, and the clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 36 via the rotation shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 13, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 39a, 39b in FIG. 13). In other words, any type of hybrid vehicle may be used as long as it includes an engine and an electric motor that inputs and outputs driving power.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “engine”, the motor MG2 corresponds to the “motor”, the high voltage battery 50 corresponds to the “battery”, and the HVECU 70 executes the catalyst warm-up request control routine of FIG. 4, the battery ECU 52 that executes the limit value setting routine of FIG. 4, the engine ECU 24 that controls the engine 22 based on the data from the HVECU 70, and the motor ECU 40 that controls the motor MG2 based on the data from the HVECU 70 This corresponds to “control means for catalyst warm-up request”.

  Here, the “engine” is not limited to the engine 22 that outputs power using gasoline, light oil, or the like as fuel, and a purification device having a purification catalyst for purifying exhaust, such as a hydrogen engine, is attached to the exhaust system. Any type of engine may be used as long as it can output power for traveling. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output driving power, such as an induction motor. . The “battery” is not limited to the battery 50 configured as a lithium ion secondary battery, but can exchange power with the motor, such as a nickel hydride secondary battery, a nickel cadmium secondary battery, and a lead storage battery. Any type of battery may be used. The “control means” is not limited to the combination of the HVECU 70, the engine ECU 24, the motor ECU 40, and the battery ECU 52, and may be configured by a single electronic control unit. Further, as the “control means”, when the warm-up request for the purification catalyst 134a is made and the travel power Pdrv * is larger than the control output limit Wout * of the high-voltage battery 50, the control output is derived from the travel power Pdrv *. A differential voltage (Pdrv * −Wout *) obtained by subtracting the limit Wout * is output from the engine 22 and controls the engine 22 and the motors MG1 and MG2 so as to travel with the traveling power Pdrv *. When the inter-terminal voltage Vb of the battery 50 falls below the threshold voltage Vbref higher than the allowable lower limit voltage Vbmin, the control current limit Ibmax * is greater than before the inter-terminal voltage Vb of the high voltage battery 50 falls below the threshold voltage Vbref. And the control output limit Wout * are not limited to those that are reduced. When the warming-up request for the purification catalyst is made and the travel power required for travel is greater than the battery control output limit, the differential power obtained by subtracting the control output limit from the travel power is output from the engine. When the output power from the battery is less than or equal to the control output limit, and the engine and the motor are controlled to run with the running power, when the battery voltage falls below the threshold voltage higher than the allowable lower limit voltage for control, The control output limit is made smaller than before the battery voltage falls below the threshold voltage, or the travel power required for running when the purification catalyst is warmed up is greater than the battery control output limit Sometimes, the difference power obtained by subtracting the control output limit from the driving power is output from the engine and output from the battery. When the power is below the control output limit and the output current from the battery is below the battery control current limit, and the engine and motor are controlled to run with the running power, the battery voltage is the lower limit for control. When the voltage becomes lower than the threshold voltage higher than the voltage, any voltage can be used as long as the control current limit is made smaller than before the battery voltage becomes lower than the threshold voltage.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20, 120, 220, 320, 420 Hybrid vehicle, 22 engine, 24 electronic control unit for engine (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b Wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 High voltage battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Electronic control unit for battery ( Battery ECU), 54a High voltage system power line, 54b Low voltage system power line, 56 System main relay, 57 DC / DC converter, 58 Low voltage battery, 59 Auxiliary equipment, 60 Charger, 62 Relay, 64 DC / DC converter, 66 AC / DC converter, 68 power plug, 69 connection detection sensor, 70 electronic control unit for hybrid (HVECU), 72 CPU, 74 ROM, 76 RAM, 80 power switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 122 air cleaner, 124 throttle valve, 126 fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 134 purification device 134a purification catalyst, 134b temperature sensor, 135a air-fuel ratio sensor, 135b oxygen sensor, 136, throttle motor, 138 ignition coil, 140 Rank position sensor, 142 Water temperature sensor, 143 Pressure sensor, 144 Cam position sensor, 146 Throttle valve position sensor, 148 Air flow meter, 149 Temperature sensor, 150 Variable valve timing mechanism, 230 Counter rotor motor, 232 Inner rotor, 234 Outer rotor, 329 clutch, 330, 430 transmission, MG, MG1, MG2 motor.

Claims (8)

A purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system so as to output driving power, a motor capable of inputting / outputting driving power, and a battery capable of exchanging electric power with the motor And the difference power obtained by subtracting the control output limit from the travel power when the travel power required for travel is greater than the control output limit for the battery. Is output from the engine, and the output power from the battery is equal to or lower than the control output limit, and comprises catalyst warm-up request control means for controlling the engine and the motor so as to run with the running power. In hybrid cars,
When the battery voltage falls below a threshold voltage that is higher than the allowable lower limit voltage for control, the catalyst warm-up request control means limits the control output limit compared to before the battery voltage falls below the threshold voltage. A means to make it smaller,
Hybrid car. The hybrid vehicle according to claim 1,
The catalyst warm-up request control means is means for gradually reducing the control output limit in the order of when the battery voltage is less than or equal to the threshold voltage and when the battery voltage is less than or equal to the allowable lower limit voltage.
Hybrid car. A hybrid vehicle according to claim 1 or 2,
The catalyst warm-up request control means is means for holding the output limit for control when the battery voltage becomes higher than the threshold voltage after becoming lower than the threshold voltage.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 3,
The catalyst warm-up request control means, when the driving power is greater than the control output limit of the battery, the output power from the battery is less than the control output limit and the output current from the battery is It is a means to control to be below the current control limit of the battery,
Furthermore, the catalyst warm-up request control means, when the battery voltage falls below the threshold voltage, compared to before the battery voltage falls below the threshold voltage, the control output limit and the control A means to reduce the current limit,
Hybrid car. A purification device having a purification catalyst for purifying exhaust gas is attached to an exhaust system so as to output driving power, a motor capable of inputting / outputting driving power, and a battery capable of exchanging electric power with the motor And the difference power obtained by subtracting the control output limit from the travel power when the travel power required for travel is greater than the control output limit for the battery. Is output from the engine, and the output power from the battery is less than or equal to the control output limit, and the output current from the battery is less than or equal to the control current limit for the battery, so that the engine travels with the travel power. And a catalyst warm-up request control means for controlling the motor,
When the battery voltage falls below a threshold voltage higher than the control allowable lower limit voltage, the catalyst warm-up request control means performs the control current limit compared to before the battery voltage falls below the threshold voltage. A means to make it smaller,
Hybrid car. A hybrid vehicle according to claim 4 or 5,
The catalyst warm-up request control means is means for gradually reducing the control current limit in the order of when the battery voltage is lower than the threshold voltage, and when the battery voltage is lower than the allowable lower limit voltage.
Hybrid car. A hybrid vehicle according to any one of claims 4 to 6,
The catalyst warm-up request control means is means for holding the control current limit when the battery voltage becomes higher than the threshold voltage after becoming lower than the threshold voltage.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 7,
The catalyst warm-up request control means, when the battery voltage falls below the allowable lower limit voltage, the power greater than the driving power until the battery voltage becomes equal to or higher than a second threshold voltage higher than the allowable lower limit voltage. Is a means for controlling the vehicle to travel with the traveling power while being output from the engine.
Hybrid car.

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