JP2008236985A - Power output unit, drive arrangements, controlling method of these apparatuses, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress degradation of battery outputting DC power to a motor through a boosting circuit on starting an engine by motoring the engine by means of the motor. <P>SOLUTION: A power output apparatus controls the boosting circuit to raise a voltage Vc across the terminal of a smoothing capacitor in a power line from the boosting circuit to a driving circuit for driving the motor to an upper-limit voltage Vmax (S140, S200), gradually lowers the voltage Vc across the terminal to a normal driving voltage Vref of the motor when the voltage Vc reaches the level higher than the upper-limit voltage Vmax (S180, S200), motors the engine by the motor (S180 to S200), and starts ignition control and the like when the rotation Ne of the engine reaches a predetermined rotation Nfire (S210, S220). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power output device, a drive device, a control method thereof, and a vehicle.

Conventionally, this type of power output device includes an engine, a starter motor that motors the engine, a battery that can supply power to the starter motor and a wheel motor that drives the wheels, and boosts the DC power from the battery. There has been proposed one that includes a DC / DC converter that supplies a driving circuit for a wheel motor and a smoothing capacitor provided on the high voltage side of the DC / DC converter (see, for example, Patent Document 1). In this apparatus, when the voltage between the terminals of the battery becomes equal to or lower than a predetermined voltage when starting the engine, the connection between the starter motor and the battery is cut off and the starter motor and the capacitor are connected, and a DC / DC converter is used. After boosting the voltage of the capacitor and charging the capacitor, the operation of the DC / DC converter is stopped, and the starter motor is driven using the discharge power from the capacitor to start the engine.
Japanese Patent Laid-Open No. 11-332012

  In addition to the power output device described above, as a power output device including a motor for motoring the engine, a DC / DC converter that boosts DC power from a battery and supplies the boosted DC power to the motor drive circuit, and a power line of the drive circuit And a smoothing capacitor attached to the. In this apparatus, when the engine is started, a relatively large amount of electric power is required to motor the engine, so that the load on the battery increases and the deterioration of the battery may be promoted.

  It is an object of the present invention to suppress deterioration of a secondary battery that outputs DC power to an electric motor when the internal combustion engine is started by motoring the electric motor. To do.

  In order to achieve the above-described object, the power output device and the drive device, the control method thereof, and the vehicle of the present invention employ the following means.

The power output apparatus of the present invention is
A power output device that outputs power to a drive shaft,
An internal combustion engine;
An electric motor capable of motoring the internal combustion engine;
A drive circuit for receiving the supply of DC power to drive the electric motor;
A secondary battery that outputs DC power;
Voltage conversion means capable of boosting DC power from the secondary battery and supplying the boosted power to the drive circuit;
A capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit;
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady drive voltage, and the internal combustion engine is motored and started. Control means for controlling the drive circuit;
It is a summary to provide.

  In the power output apparatus of the present invention, when the start instruction of the internal combustion engine is given, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady drive voltage at the time of steady driving of the electric motor. As a result, the capacitor is charged. After the voltage between the terminals of the capacitor reaches a predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach a steady drive voltage, and the internal combustion engine is motored and started. The drive circuit is controlled. Since the internal combustion engine is motored by driving the electric motor using the DC power from the secondary battery and the discharge power from the capacitor, the DC power output from the secondary battery can be suppressed. Deterioration can be suppressed.

  In such a power output apparatus of the present invention, the control means is configured such that when an instruction to start the internal combustion engine is given in a state where the output of DC power from the secondary battery is limited to a predetermined power or lower, The voltage conversion means is controlled so that the voltage between the terminals becomes a predetermined voltage higher than the steady driving voltage at the time of steady driving of the electric motor, and the voltage between the terminals of the capacitor after the voltage between the terminals of the capacitor reaches the predetermined voltage. The voltage conversion means, the internal combustion engine, and the drive circuit may be controlled so that the voltage gradually decreases to reach the steady drive voltage and the internal combustion engine is motored and started. it can. Even when the output of DC power from the secondary battery is limited, the internal combustion engine is motored using the discharge power from the capacitor, so that the internal combustion engine can be started more quickly. Here, the “predetermined electric power” includes a lower limit value of electric power required for motoring and starting the internal combustion engine.

  Further, in the power output apparatus of the present invention, the control means may be configured so that the terminal voltage of the capacitor gradually decreases with a predetermined rate of change after the terminal voltage of the capacitor reaches the predetermined voltage, and the steady driving is performed. It can also be a means for controlling the voltage conversion means to reach a voltage.

  Furthermore, in the power output apparatus of the present invention, the predetermined voltage may be a lower voltage of the breakdown voltage of the switching element of the drive circuit or the breakdown voltage of the capacitor. In this way, the voltage between the terminals of the capacitor can be set to a voltage within the range of the breakdown voltage of the switching element of the drive circuit and the capacitor.

  In the power output apparatus of the present invention, the remaining power is determined based on the power input / output to / from any two of the three shafts including the drive shaft, the output shaft of the internal combustion engine, and the rotation shaft. Three-axis power input / output means for inputting / outputting power to / from the shaft, and a drive motor capable of inputting / outputting power to / from the drive shaft, wherein the motor is connected to the rotary shaft so that power can be input / output. The driving circuit is a circuit for driving the electric motor and the driving electric motor, and the control means outputs a driving force based on a required driving force required for the driving shaft to the driving shaft. The internal combustion engine, the drive circuit, and the voltage conversion unit may be controlled. In this way, it is possible to output a driving force based on the required driving force to the drive shaft while starting the internal combustion engine.

  The vehicle of the present invention is a power output apparatus of the present invention according to any one of the above-described aspects, that is, basically a power output apparatus that outputs power to a drive shaft, and includes an internal combustion engine and the internal combustion engine as a motor. Ringable motor, drive circuit that drives the motor by receiving DC power, a secondary battery that outputs DC power, and boosts DC power from the secondary battery to supply to the drive circuit A voltage conversion means, a capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing the DC power supplied to the drive circuit, and when an instruction to start the internal combustion engine is given, The voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner, and the voltage between the terminals of the capacitor reaches the predetermined voltage. Control means for controlling the voltage conversion means, the internal combustion engine and the drive circuit so that the voltage across the terminals of the capacitor gradually decreases to reach the steady drive voltage and the internal combustion engine is motored and started; The gist of the present invention is that the vehicle is driven with a power output device provided with the axle connected to the drive shaft.

  In such a vehicle of the present invention, since the power output device of the present invention of any one of the above-described aspects is mounted, the effect of the power output device, for example, the effect of suppressing the deterioration of the secondary battery, etc. Similar effects can be achieved.

The drive device of the present invention is
A drive device incorporated in a power output device that outputs power to a drive shaft together with an internal combustion engine and a secondary battery that outputs DC power,
An electric motor capable of motoring the internal combustion engine;
A drive circuit for receiving the supply of DC power to drive the electric motor;
Voltage converting means capable of boosting DC power from the secondary battery and supplying the boosted power to the drive circuit;
A capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit;
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady driving voltage, and the internal combustion engine is motored and started so that the voltage conversion is performed together with the control of the internal combustion engine. Control means for controlling the means and the drive circuit;
It is a summary to provide.

  In such a drive device of the present invention, when the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady drive voltage when the motor is driven in a steady manner. As a result, the capacitor is charged. Then, after the voltage between the terminals of the capacitor reaches a predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach a steady drive voltage, and voltage conversion is performed together with the control of the internal combustion engine so that the internal combustion engine is motored and started. Control means and drive circuit. Since the internal combustion engine is motored by driving the electric motor using the DC power from the secondary battery and the discharge power from the capacitor, the DC power output from the secondary battery can be suppressed. Deterioration can be suppressed.

The method for controlling the power output apparatus of the present invention includes:
An internal combustion engine, an electric motor capable of motoring the internal combustion engine, a drive circuit that receives the supply of DC power to drive the motor, a secondary battery that outputs DC power, and DC power from the secondary battery A voltage conversion means capable of boosting and supplying to the drive circuit, and a capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit. A method for controlling a power output device that outputs power,
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady drive voltage, and the internal combustion engine is motored and started. The drive circuit is controlled.

  In such a control method for a power output apparatus of the present invention, when an internal combustion engine start instruction is issued, the voltage conversion means is provided so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady drive voltage for steady driving of the motor. Control. As a result, the capacitor is charged. After the voltage between the terminals of the capacitor reaches a predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach a steady drive voltage, and the internal combustion engine is motored and started. The drive circuit is controlled. Since the internal combustion engine is motored by driving the electric motor using the DC power from the secondary battery and the discharge power from the capacitor, the DC power output from the secondary battery can be suppressed. Deterioration can be suppressed.

The method for controlling the drive device of the present invention includes:
Built in a power output device that outputs power to a drive shaft together with an internal combustion engine and a secondary battery that outputs DC power, an electric motor capable of motoring the internal combustion engine, and a drive that drives the electric motor by receiving supply of DC power A circuit, voltage conversion means capable of boosting and supplying DC power from the secondary battery to the drive circuit, and DC supplied from the voltage conversion means to the power line of the drive circuit and supplied to the drive circuit A method of controlling a drive device comprising a capacitor capable of smoothing electric power,
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady driving voltage, and the internal combustion engine is motored and started so that the voltage conversion is performed together with the control of the internal combustion engine. Means and the drive circuit are controlled.

  In such a control method for a driving apparatus according to the present invention, when the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage for steady driving of the motor. To do. As a result, the capacitor is charged. Then, after the voltage between the terminals of the capacitor reaches a predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach a steady drive voltage, and voltage conversion is performed together with the control of the internal combustion engine so that the internal combustion engine is motored and started. The means and the internal combustion engine are controlled. Since the internal combustion engine is motored by driving the electric motor using the DC power from the secondary battery and the discharge power from the capacitor, the DC power output from the secondary battery can be suppressed. Deterioration can be suppressed.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a power output apparatus according to an embodiment of the present invention, and FIG. 2 shows an outline of the configuration of a booster circuit 45 mounted on the hybrid vehicle 20. It is a block diagram. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, A battery 50 that exchanges power via inverters 41 and 42 that drive motors MG1 and MG2 and a booster circuit 45, and a hybrid electronic control unit 70 that controls the entire vehicle are provided.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. 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, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70.

The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 2
2 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  Both the motor MG1 and the motor MG2 are configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via the inverters 41 and 42 and the booster circuit 45. To do. The power line 54 connecting the inverters 41 and 42 and the booster circuit 45 is configured as a positive electrode bus 54a and a negative electrode bus 54b shared by the respective inverters 41 and 42, and generates electric power generated by one of the motors MG1 and MG2. It can be consumed by other motors. A smoothing capacitor 46 is connected to the power line 54. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2, the terminal voltage Vc from the voltage sensor 47 installed between the terminals of the capacitor 46, and the like are input. The motor ECU 40 switches to the inverters 41 and 42. A control signal, a drive signal to the booster circuit 45, and the like are output. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  As shown in FIG. 2, the booster circuit 45 includes two transistors TA and TB, two diodes DA and DB, and a reactor L. The two transistors TA and TB are respectively connected to the positive bus 54a and the negative bus 54b of the power line 54, and the reactor L is connected to the connection point. A positive terminal and a negative terminal of a battery 50 are connected to the reactor L and the negative bus 54 b, and a smoothing capacitor 48 is connected between the terminals of the battery 50. The two transistors TA and TB are each connected in parallel with two diodes DA and DB. Therefore, by controlling the ON / OFF ratio of the transistor TA and the ON / OFF ratio of the transistor TB, the DC voltage of the battery 50 is boosted and output to the inverters 41 and 42, or the positive bus 54a and the negative bus of the inverters 41 and 42 are output. The battery 50 can be charged by stepping down the DC voltage acting on 54b.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature from the temperature sensor (not shown) attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88 that detects the vehicle speed, and the like are input via the input port. . As described above, the hybrid electronic control unit 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. ing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, 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 is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a 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 ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when starting the stopped engine 22 will be described. FIG. 3 is a flowchart showing an example of a start time control routine executed by the hybrid electronic control unit 70. This routine is executed when the engine 22 is instructed to start.

  When the start-up control routine is executed, the CPU 72 of the hybrid electronic control unit 70 firstly has the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1 of the motors MG1, MG2. , Nm2, the rotational speed Ne of the engine 22, the voltage Vc between the terminals of the capacitor 46, and the like are input (step S100). Here, the rotation speed Ne of the engine 22 is calculated based on a signal from a crank position sensor (not shown) attached to the crankshaft 26 and is input from the engine ECU 24 by communication. Further, 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. It was supposed to be. Further, the voltage Vc between the terminals of the capacitor 46 is detected by the voltage sensor 47 and input from the motor ECU 40 by communication.

  When the data is thus input, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V. Is set (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. FIG. 4 shows an example of the required torque setting map.

  Subsequently, the value of the motoring permission flag F is checked (step S120). Here, the motoring permission flag F is a flag that is set to a value of 1 when the engine 22 is being motored by the motor MG1, and a value of 0 is set as an initial value. Therefore, when the process of step S120 is executed for the first time, the motoring permission flag F is set to 0.

  When the motoring permission flag F is 0, that is, when motoring of the engine 22 by the motor MG1 is not started, the terminal voltage Vc of the capacitor 46 is compared with the upper limit voltage Vmax (step S130). Here, the upper limit voltage Vax is higher than the steady drive voltage Vref (for example, 300 V) when the motors MG1 and MG2 are driven in a steady manner and slightly lower than the lower one of the withstand voltages of the inverters 41 and 42 and the withstand voltage of the capacitor 46. It is assumed that the voltage is set (for example, 600V).

  When terminal voltage Vc is lower than upper limit voltage Vmax, torque command Tm1 * of motor MG1 is set to 0 (step S140), and target terminal voltage Vc * of capacitor 46 is set to upper limit voltage Vmax (step S150). ), The torque command Tm2 * of the motor MG2 is set by the equation (1) using the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the power distribution and integration mechanism 30 (step S190). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 5 is a collinear diagram showing a dynamic relationship between the number of rotations and torque in the rotating elements of the power distribution and integration mechanism 30. 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 rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque.

  Tm2 * = (Tr * + Tm1 * / ρ) / Gr (1)

  When torque commands Tm1 *, Tm2 * and target terminal voltage Vc * of motors MG1, MG2 are thus set, torque commands Tm1 *, Tm2 * and target terminal voltage Vc are transmitted to motor ECU 40 (step S200). The motor ECU 40 that has received the torque commands Tm1 *, Tm2 * and the target terminal voltage Vc * has the inverters 41, 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. Switching control of the switching element is performed, and switching control of the transistors TA and TB of the booster circuit 45 is performed so that the voltage between the terminals of the capacitor 46 becomes the target terminal voltage Vc *.

  Subsequently, it is determined whether or not the rotational speed Ne of the engine 22 has reached an ignition start rotational speed Nfire for starting ignition control or fuel injection control of the engine 22 (step S210), and the rotational speed Ne is set to the ignition start rotational speed Nf. If not, the process returns to the process of step S100, and the processes of steps S100 to S150 and S190 to S210 are continued until the motoring permission flag F becomes the value 1 or the inter-terminal voltage Vc of the capacitor 46 becomes the upper limit voltage Vmx or more. repeat. Here, in the embodiment, the ignition start rotational speed Nfire is set to a rotational speed larger than the resonance rotational speed band, for example, 1000 rpm or 1200 rpm. When the motoring permission flag F is 0 and the terminal voltage Vc of the capacitor 46 is less than the upper limit voltage Vmax, the torque command Tm1 * is set to the value 0 and the target terminal voltage Vc * of the capacitor 46 is set to the upper limit value. Since it is set to Vmax (steps S140 and S150), control is performed to set the voltage across the terminals of the capacitor 46 to the upper limit voltage Vmax without motoring the engine 22.

  Thus, the control to set the inter-terminal voltage of the capacitor 46 to the upper limit voltage Vmax is executed, and when the inter-terminal voltage Vc of the capacitor 46 becomes equal to or higher than the upper limit voltage Vmax (step S130), motoring of the engine 22 is subsequently started and Control for stepping down the voltage across the capacitor 46 is executed. In such control, first, the motoring permission flag F is set to a value 1, and the elapsed time t from the start of motoring of the engine 22 is started (step S160). And the torque command Tm1 * of the motor MG1 is set using the elapsed time t (step S170). FIG. 6 is an explanatory diagram showing an example of a torque command setting map for setting the torque command Tm1 * of the motor MG1. In the embodiment, the torque command Tm1 * of the motor MG1 is stored as a torque command setting map by predetermining the relationship between the rotational speed Ne of the engine 22 or the elapsed time t from the start of start and the torque command Tm1 * of the motor MG1. In addition, when the rotation speed Ne of the engine 22 and the elapsed time t from the start of the start are given, the corresponding torque command Tm1 * is derived and set from the stored map. In the torque command setting map, as shown in the figure, a relatively large torque is quickly applied to the torque command Tm1 * using rate processing immediately after time t1 when the value 1 is set in the motoring permission flag F in the processing of step S160. And the rotational speed Ne of the engine 22 is rapidly increased. Subsequently, at a time t2 after the time when the rotational speed Ne of the engine 22 has passed the resonant rotational speed band or required for passing through the resonant rotational speed band, the engine 22 is stably stabilized at the ignition start rotational speed Nfire or more. The torque that can be ringed is set in the torque command Tm1 * to reduce the power consumption and the reaction force in the ring gear shaft 32a as the drive shaft. Then, from time t3 when the rotational speed Ne of the engine 22 reaches the ignition start rotational speed Nfire, the torque command Tm1 * is quickly set to the value 0 using rate processing, and the processing ends at time t4 when the complete explosion of the engine 22 is determined. . Immediately after the engine 22 is instructed to start, a large torque is set in the torque command Tm1 * of the motor MG1 and the engine 22 is motored, so that the engine 22 is quickly rotated to the ignition start speed Nfire or more. Can be started.

  Subsequently, the target inter-terminal voltage Vc * is gradually decreased from the upper limit voltage Vmax with the time change rate k, and the elapsed time t from the start of the motoring of the engine 22 is used to reach the steady drive voltage Vref at time t4. Setting is made according to equation (2) (step S180). Here, in the embodiment, the time change rate k is set as a change rate for reducing the target terminal voltage Vc * from the upper limit voltage Vmax to the steady drive voltage Vref between times t1 and t4. The target terminal voltage Vc * is set in this way because the discharge power of the capacitor 46 obtained by gradually decreasing the terminal voltage Vc of the capacitor 46 (the square of the difference between the upper limit voltage Vmax and the steady drive voltage Vref). This is because the energy based on this is used to drive the motors MG1 and MG2.

  Vc * = max (Vmax-k ・ t, Vref) (2)

  When the torque command Tm1 * of the motor MG1 and the target terminal voltage Vc * of the capacitor 46 are set in this way, the processing of steps S190 to S210 is executed, and when the rotational speed Ne of the engine 22 has not reached the ignition start rotational speed Nfire, step is performed. The process returns to S100. Here, since the motoring permission flag F is set to the value 1 in the process of step S140, after returning to the process of step S100, the process of steps S130 and S160 is not executed, but steps S100 to S120, The processes of steps S170 to S210 are executed. As described above, when the inter-terminal voltage Vc of the capacitor 46 becomes equal to or higher than the upper limit voltage Vmax, the rotational speed Ne of the engine 22 is increased to the ignition start rotational speed Nfire and the inter-terminal voltage Vc of the capacitor 46 is gradually decreased. Control to make the steady drive voltage Vref is executed.

  When the engine 22 is motored in this way and the engine speed Ne is equal to or greater than the ignition start engine speed Nfire (step S210), fuel injection control and ignition control are started (step S220), and the engine 22 is completely exploded. It is determined whether or not (step S230). When the engine 22 has not completely exploded, the process returns to step S100 to continue motoring of the engine 22, and when the engine 22 has completely exploded, the start time control routine is terminated.

  FIG. 7 is an explanatory diagram showing an example of how the torque command Tm1 * of the motor MG1 and the rotation speed Ne of the engine 22 and the inter-terminal voltage Vc of the capacitor 46 change over time after the start instruction of the engine 22 is given. Here, for the sake of explanation, it is assumed that the inter-terminal voltage Vc of the capacitor 46 before the start instruction of the engine 22 is the steady driving voltage Vref. When the engine 22 is instructed to start, the inter-terminal voltage Vc of the capacitor 46 is boosted from the steady drive voltage Vref to the upper limit voltage Vmax as shown in the figure. As a result, the capacitor 46 is charged. At this time, since the torque command Tm1 of the motor MG1 is set to the value 0, the engine 22 is not motored and the rotational speed of the engine 22 does not increase. When the inter-terminal voltage Vc of the capacitor 46 reaches the upper limit voltage Vmax (time t1), the torque command Tm1 * of the motor MG1 is set using the torque command setting map illustrated in FIG. As a result, the rotational speed Ne of the engine 22 increases. At this time, the inter-terminal voltage Vc of the capacitor 46 is gradually reduced, so that discharge power is output from the capacitor 46, and the motors MG1 and MG2 are driven using the power output from the battery 50 and the discharge power of the capacitor 46. Will be. In this way, when the engine 22 is motored by the motor MG1, the power output from the battery 50 and the discharged power of the capacitor 46 can be used, so the load on the battery 50 is reduced and the deterioration of the battery 50 is suppressed. Can do.

  According to the hybrid vehicle 20 of the embodiment described above, the engine 22 is motored while gradually decreasing the inter-terminal voltage Vc of the capacitor 46 after boosting the inter-terminal voltage Vc of the capacitor 46. Therefore, the engine 22 is driven by the motor MG1. When motoring, the discharge power of the capacitor 46 can be used together with the discharge power of the battery 50, and the load of the battery 50 can be reduced to suppress the deterioration of the battery 50.

  In the hybrid vehicle 20 of the embodiment, after the inter-terminal voltage Vc of the capacitor 46 reaches the upper limit voltage Vmax, the target inter-terminal voltage Vc * is decreased from the upper limit voltage Vmax with the time change rate k to reach the steady drive voltage Vref. Although the target terminal voltage Vc * may be gradually decreased from the upper limit voltage Vmax to the steady driving voltage Vref, the target terminal voltage Vc * may be reduced from the upper limit voltage Vmax to a curved line, or may be stepped. It is good also as what falls.

  In the hybrid vehicle 20 of the embodiment, after the inter-terminal voltage Vc of the capacitor 46 reaches the upper limit voltage Vmax, the time during which the target terminal voltage Vc * is decreased from the upper limit voltage Vmax to the steady drive voltage Vmax between times t1 and t4. Although it is set with the rate of change k, the driving state of the motors MG1 and MG2 and the operating state of the battery so that the power obtained by subtracting the power that can be output from the battery from the power consumed by the motors MG1 and MG2 is discharged from the capacitor 46 The time change rate k may be set based on the above. In this case, it is desirable that the upper limit value (in the embodiment, the upper limit voltage Vmax) of the target terminal voltage Vc * is appropriately set based on the driving state of the motors MG1 and MG2 and the operating state of the battery.

  In the hybrid vehicle 20 of the embodiment, the upper limit voltage Vmax is set as a voltage slightly lower than the lower one of the withstand voltage of the switching elements of the inverters 41 and 42 and the withstand voltage of the capacitor 46, but from the steady drive voltage Vref. The voltage may be any voltage as long as it is within the lower voltage range of the withstand voltage of the switching elements of inverters 41 and 42 and the withstand voltage of capacitor 46, and the power that can be output from the battery from the power consumed by motors MG1 and MG2. The upper limit voltage Vmax may be set so that the power obtained by reducing the power can be covered by the discharge power of the capacitor 46.

  In the hybrid vehicle 20 of the embodiment, the start time control routine illustrated in FIG. 3 is executed when the start instruction of the engine 22 is given, but the temperature of the battery 50, the remaining capacity (SOC) of the battery 50, and the like 3 may be executed when the engine 22 is instructed to start in a state where the electric power that can be output from the battery 50 is limited to a predetermined electric power or less. Here, the “predetermined power” includes a lower limit value of power necessary for motoring the engine 22. In this case, when the power that can be output from the battery 50 is not limited to a predetermined power or less, the processing of steps S120 to S160 and S180 is omitted, the terminal voltage Vc of the capacitor 46 is set to the upper limit voltage Vmax, and the steady state is started from the upper limit voltage Vmax. The torque command Tm1 * of the motor MG1 is set using the torque command setting map illustrated in FIG. 6 immediately after the start instruction of the engine 22 is performed without executing the process of reducing the drive voltage Vref, and the required torque Tr It is desirable to execute processing for controlling the motor MG2 so that torque based on * is output to the ring gear shaft 32a.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be connected to an axle (an axle connected to the drive wheels 64a and 64b in FIG. 8) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  In the embodiments, the case where the present invention is applied to a hybrid vehicle including an engine and a motor as a power source for traveling is illustrated, but the present invention is applied to a normal engine vehicle including only an engine as a power source for traveling. It may be a thing. In this case, it is desirable to motor the engine using a starter motor that can motor the engine.

  Here, 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 an “internal combustion engine”, the motor MG1 corresponds to a “motor”, the inverter 41 corresponds to a “drive circuit”, the battery 50 corresponds to a secondary battery, and the booster circuit 45 includes Corresponding to “voltage converting means”, the capacitor 46 corresponds to “capacitor”, and when the engine 22 is instructed to start, the target terminal voltage Vc * of the capacitor 46 is set to the upper limit voltage Vmax, and the capacitor 46 is connected between the terminals. After the voltage Vc * reaches the upper limit voltage Vmax, the target terminal voltage Vc * is set so that the target terminal voltage Vc * of the capacitor 46 gradually decreases to reach the steady drive voltage Vref, and the engine 22 is motored. The torque command Tm1 * of the motor MG1 is set to be started and transmitted to the motor ECU 40, and the ignition control and fuel injection control of the engine 22 are performed. The switching element of the inverter 41 is controlled on the basis of the hybrid electronic control unit 70 that executes the processing of steps S120 to S220 of the start time control routine of FIG. 3 for transmitting the start instruction to the engine ECU 24 and the torque command Tm1 * of the motor MG1. The motor ECU 40 that controls the booster circuit 45 based on the target inter-terminal voltage Vc * and the engine ECU 24 that starts ignition control and fuel injection control in the engine 22 correspond to “control means”. The power distribution and integration mechanism 30 corresponds to a “3-axis power input / output unit”, and the motor MG2 corresponds to a “drive motor”. Further, the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 and the target terminal difficulty voltage Vc * are set so that the required torque Tr * required for the ring gear shaft 32a as the drive shaft is output to the ring gear shaft 32a. Based on torque control commands Tm1 *, Tm2 * and target terminal voltage Vc * of hybrid electronic control unit 70, motors MG1, MG2 for executing the processes of steps S190 and S200 of the start-up control routine of FIG. A combination of the motor ECU 40 that controls the inverters 441 and 42 and the booster circuit 45 and the engine ECU 24 also corresponds to a “control unit”, and a combination of the inverter 41 and the inverter 42 also corresponds to a “drive circuit”. Further, the anti-rotor motor 230 corresponds to an “electric motor”. Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. 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 power to the drive shaft, such as an induction motor. . The “drive circuit” may be any type of drive circuit as long as it receives DC power and drives the motor. The “voltage converting means” is not limited to the booster circuit 45 using the reactor L, but boosts the DC power from the secondary battery to the drive circuit, such as a charge pump booster circuit using a capacitor. Any type of voltage conversion group may be used as long as it can supply voltage conversion means. The “control means” is not limited to the combination of the hybrid electronic control unit 70, the engine ECU 24, and the motor ECU 40, and may be configured by a single electronic control unit. As the “control means”, when the engine 22 is instructed to start, the target terminal voltage Vc * of the capacitor 46 is set to the upper limit voltage Vmax, and the terminal voltage Vc * of the capacitor 46 reaches the upper limit voltage Vmax. Thereafter, the target terminal voltage Vc * of the capacitor 46 is gradually decreased to reach the steady driving voltage Vref, the target terminal voltage Vc * is set and the booster circuit 45 is controlled or the engine 22 is motored and started. Thus, it is not limited to controlling the switching element of the inverter 41 based on the torque command Tm1 * of the motor MG1 or starting the ignition control or fuel injection control of the engine 22, but an instruction to start the internal combustion engine was made. Sometimes the voltage is converted so that the voltage between the terminals of the capacitor is higher than the steady drive voltage when the motor is driven steady Voltage conversion means for controlling the stage so that after the voltage across the capacitor reaches a predetermined voltage, the voltage across the capacitor gradually decreases to a steady drive voltage and the internal combustion engine is motored and started As long as it controls the internal combustion engine and the drive circuit, it may be anything. The “three-axis power input / output means” is not limited to the power distribution / integration mechanism 30 described above, but includes four or more shafts using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. Such as a gear connected to the motor or a gear having an operating action different from that of the planetary gear, such as a differential gear, which has three axes of a drive shaft, an output shaft of an internal combustion engine, and a rotary shaft, and any two of the three shafts As long as the power is input / output to / from the remaining shafts based on the power input / output to / from the power source, any method may be used. The “drive motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of generator as long as it can input and output power to the drive shaft, such as an induction motor. Absent. 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. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. In other words, the interpretation of the invention described in the column of means for solving the problem 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 problem. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in a power output device, a vehicle manufacturing industry, and the like.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. FIG. 3 is a configuration diagram showing an outline of a configuration of a booster circuit 45. It is a flowchart which shows an example of the starting time control routine performed by the electronic control unit for hybrid 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the alignment chart for demonstrating the power distribution integration mechanism 30 dynamically. It is explanatory drawing which shows an example of the map for torque command setting. It is explanatory drawing which shows an example of the time change state of torque command Tm1 * of motor MG1 after engine 22 start instruction | indication, the rotational speed Ne of the engine 22, and the voltage Vc between the terminals of the capacitor | condenser 46. FIG. 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.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 320 Electric vehicle, 22 engine, 24 Engine electronic control unit (engine ECU), 26 Crankshaft, 28
Damper, 30 Power distribution and integration mechanism, 31 Sun gear, 32 Ring gear, 32a Ring gear shaft, 33 Pinion gear, 34 Carrier, 35, Reduction gear, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position Detection sensor, 45 Booster circuit, 46, 48 Capacitor, 47 Voltage sensor, 50 Battery, 52 Battery electronic control unit (battery ECU), 54 Power line, 60 Gear mechanism, 62 Differential gear, 63a, 63b, 64a, 64b Drive Wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake Key pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 230 Rotor motor, 232 Inner rotor 234 Outer rotor, D1, D2 diode, L reactor, MG1, MG2 motor, TA, TB transistor.

Claims (9)

A power output device that outputs power to a drive shaft,
An internal combustion engine;
An electric motor capable of motoring the internal combustion engine;
A drive circuit for receiving the supply of DC power to drive the electric motor;
A secondary battery that outputs DC power;
Voltage conversion means capable of boosting DC power from the secondary battery and supplying the boosted power to the drive circuit;
A capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit;
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady drive voltage, and the internal combustion engine is motored and started. Control means for controlling the drive circuit;
A power output device comprising:   The control means is configured to drive the electric motor in a steady state when the voltage across the capacitor is instructed to start the internal combustion engine in a state where the output of DC power from the secondary battery is limited to a predetermined power or less. The voltage conversion means is controlled to be a predetermined voltage higher than a steady driving voltage at the time of the operation, and after the voltage between the terminals of the capacitor reaches the predetermined voltage, the voltage between the terminals of the capacitor is gradually decreased to the steady voltage. 2. A power output apparatus according to claim 1, wherein the power output device is a means for controlling the voltage conversion means, the internal combustion engine and the drive circuit so that the internal combustion engine is motored and started when the drive voltage is reached.   The control means controls the voltage conversion means so that the terminal voltage of the capacitor gradually decreases at a predetermined rate of change and reaches the steady driving voltage after the terminal voltage of the capacitor reaches the predetermined voltage. The power output apparatus according to claim 1, wherein the power output apparatus is a means for performing the operation.   4. The power output apparatus according to claim 1, wherein the predetermined voltage is a lower one of a withstand voltage of a switching element of the drive circuit or a withstand voltage of the capacitor. The power output device according to any one of claims 1 to 4,
Three axes that have three axes of the drive shaft, the output shaft of the internal combustion engine, and a rotary shaft, and that input / output power to the remaining shaft based on power input / output to / from any two of the three axes Power input / output means,
A drive motor capable of inputting and outputting power to the drive shaft;
With
The electric motor is connected to the rotating shaft so that power can be input and output,
The drive circuit is a circuit that drives the electric motor and the driving electric motor,
The control means is means for controlling the internal combustion engine, the drive circuit, and the voltage conversion means so that a drive force based on a required drive force required for the drive shaft is output to the drive shaft. .   A vehicle on which the power output apparatus according to claim 1 is mounted and an axle is connected to the drive shaft. A drive device incorporated in a power output device that outputs power to a drive shaft together with an internal combustion engine and a secondary battery that outputs DC power,
An electric motor capable of motoring the internal combustion engine;
A drive circuit for receiving the supply of DC power to drive the electric motor;
Voltage converting means capable of boosting DC power from the secondary battery and supplying the boosted power to the drive circuit;
A capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit;
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady driving voltage, and the internal combustion engine is motored and started so that the voltage conversion is performed together with the control of the internal combustion engine. Control means for controlling the means and the drive circuit;
A drive device comprising: An internal combustion engine, an electric motor capable of motoring the internal combustion engine, a drive circuit that receives the supply of DC power to drive the motor, a secondary battery that outputs DC power, and DC power from the secondary battery A voltage conversion means capable of boosting and supplying to the drive circuit, and a capacitor attached to the power line of the drive circuit from the voltage conversion means and capable of smoothing DC power supplied to the drive circuit. A method for controlling a power output device that outputs power,
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady drive voltage, and the internal combustion engine is motored and started. A control method for a power output apparatus, wherein the drive circuit is controlled. Built in a power output device that outputs power to a drive shaft together with an internal combustion engine and a secondary battery that outputs DC power, an electric motor capable of motoring the internal combustion engine, and a drive that drives the electric motor by receiving supply of DC power A circuit, voltage conversion means capable of boosting and supplying DC power from the secondary battery to the drive circuit, and DC supplied from the voltage conversion means to the power line of the drive circuit and supplied to the drive circuit A method of controlling a drive device comprising a capacitor capable of smoothing electric power,
When the internal combustion engine is instructed to start, the voltage conversion means is controlled so that the voltage between the terminals of the capacitor becomes a predetermined voltage higher than the steady driving voltage when the electric motor is driven in a steady manner. After the voltage reaches the predetermined voltage, the voltage between the terminals of the capacitor gradually decreases to reach the steady driving voltage, and the internal combustion engine is motored and started so that the voltage conversion is performed together with the control of the internal combustion engine. A control method for a driving apparatus, characterized in that: means and the driving circuit are controlled.

Images