JP2013060041A - Hybrid vehicle and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the voltage variation in the power supply system according to the drive force change corresponding to the user operation in battery-less travel of a hybrid vehicle.SOLUTION: The hybrid vehicle turns off the SMR 55 and executes the battery-less traveling at abnormality of the battery 50. The converter 40 controls the dc voltage VL of the power line 56 at the battery-less traveling. The HVECU 70 sets the command value of the output torques of MG1 and MG2 based on both the requested torque for the vehicle traveling and the power control torque to control the dc voltage VH of the power line 54 at the battery-less traveling. In addition, the HVECU 70 sets the voltage command value to the converter 40 to raise the dc voltage VL to respond to the release operation of an accelerator pedal at the battery-less traveling.

Description

  The present invention relates to a hybrid vehicle and a control method therefor, and more specifically to travel control of a hybrid vehicle having a travel mode in which an in-vehicle power storage device is not used.

  In recent years, hybrid vehicles equipped with a motor for driving and an internal combustion engine have attracted attention as environmentally friendly automobiles. As one aspect of a drive system of a hybrid vehicle, an engine, an electric motor, and a generator are known that are mechanically connected via a power split mechanism configured with a planetary gear.

  Japanese Patent Application Laid-Open No. 2007-137373 (Patent Document 1), Japanese Patent Application Laid-Open No. 2010-162996 (Patent Document 2), and Japanese Patent Application Laid-Open No. 2010-247725 (Patent Document 3) disclose a hybrid having such a drive system. In the vehicle, traveling control is described in the case where traveling is performed with the battery disconnected from the electrical system in a state where charging / discharging of the in-vehicle power storage device is prohibited. Hereinafter, such vehicle travel is also referred to as “battery-less travel”.

  In Patent Document 1, when the current rotational speed difference with respect to the target rotational speed of the engine is small during battery-less traveling, the inverter is controlled so that the required torque is output to the drive shaft. It is described that the gate of the inverter is shut off when it exceeds a predetermined value.

  Patent Document 2 describes converter control during battery-less travel in a hybrid vehicle equipped with a power supply system including a converter. Specifically, it is described that the input side voltage (VL) of the converter is controlled to be constant so that overvoltage does not occur in the electric system during battery-less running.

  Further, Patent Document 3 describes control for turning off the system main relay in a non-arcing state when shifting to battery-less traveling.

JP 2007-137373 A JP 2010-162996 A JP 2010-247725 A JP 2002-359929 A JP 2010-173421 A JP-A-6-153495

In battery-less traveling of a hybrid vehicle described in Patent Documents 1 to 3, the power generated by the generator is balanced with the power consumed by the motor so that the DC side voltage (smoothing capacitor voltage) of the inverter does not become excessive. Need to control. For this reason, in Patent Document 2,
It is described that the output torques of the motor and the generator are set based on feedback control for making the smoothing capacitor voltage coincide with the target voltage.

  However, the torques of the electric motor and the generator change due to fluctuations in driving force accompanying pedal operation by the driver. For this reason, when the driving force changes greatly, there is a possibility that the voltage rise cannot be sufficiently suppressed by the feedback control as in Patent Document 2.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a power supply system in a power supply system that accompanies a change in driving force corresponding to a user operation in battery-less traveling of a hybrid vehicle. It is to suppress voltage fluctuation.

  According to an aspect of the present invention, a hybrid vehicle generates power using at least part of the power of an internal combustion engine and an electric motor configured to have a power transmission path between the hybrid vehicle and the drive shaft. A generator, a power storage device, first and second capacitors, a converter, a torque control unit, and a voltage control unit are included. The power storage device is electrically connected to the first power line via a switch. The first capacitor is connected to the first power line. The converter is connected between the first power line and a second power line electrically connected to both the electric motor and the generator, and performs DC voltage conversion between the first and second power lines. Configured as follows. The second capacitor is connected to the second power line. The torque control unit outputs torque of the generator and the motor based on both the required torque for traveling the vehicle and the torque for controlling the voltage of the second power line in the traveling state in which the switch is opened. Set. The voltage control unit controls the operation of the converter so as to control the voltage of the first power line in the traveling state in which the switch is opened. In particular, the voltage control unit controls the converter to increase the voltage of the first power line in response to the accelerator pedal release operation.

  Preferably, in the traveling state in which the switch is opened, the voltage control unit increases the voltage of the first power line from before and after the predetermined period for a predetermined period after detecting the release operation of the accelerator pedal. Control the converter.

  Preferably, the voltage control unit changes a voltage command value of the voltage of the first power line for the converter in accordance with a difference between the voltage of the second power line and the target voltage in a traveling state in which the switch is opened. .

  More preferably, the torque control unit includes a power command calculation unit, first and second torque calculation units, a torque upper / lower limit setting unit, a drive torque setting unit, and a torque setting unit. The power command calculation unit calculates a command value of input / output power of the second power line for controlling the voltage of the second power line to a voltage command value. The first torque calculator is configured to input / output power according to the command value from the generator and the motor to the second power line without affecting the torque acting on the drive shaft. The control torque and the electric power control torque of the motor are calculated. The torque upper / lower limit setting unit sets the torque upper / lower limit range of the drive shaft based on the torque upper / lower limit range of the motor and the torque upper / lower limit range of the generator, from which the power control torque of the motor and the generator is subtracted. The drive torque setting unit sets a torque command value for the drive shaft based on the set upper and lower torque ranges of the drive shaft and the required torque. The second torque calculator is configured to cause the torque command value of the drive shaft to act on the drive shaft without changing the input / output power for the second power line, and the second drive force torque of the generator. Is calculated. The torque setting unit sets torque command values for the generator and the motor according to the sum of the power control torque and the driving force torque of the generator and the motor, respectively.

  Preferably, in the hybrid vehicle, when the rotational speed of any two of the first, second and third rotational elements is determined, the rotational speed of the remaining one rotational element is determined. And a differential device configured to input / output power to the remaining one rotating element based on power input / output to / from any two rotating elements of the first to third rotating elements. . The first rotating element is mechanically connected to the output shaft of the internal combustion engine. The second rotating element is mechanically connected to the output shaft of the generator. The third rotating element is mechanically connected to the drive shaft and the output shaft of the electric motor.

  In another aspect of the present invention, there is provided a method for controlling a hybrid vehicle, wherein the hybrid vehicle has an internal combustion engine configured to have a power transmission path between the hybrid vehicle and at least a part of the power of the internal combustion engine. A generator for generating power using the motor, an electric motor configured to have a power transmission path between the drive shaft, and a power storage device electrically connected to the first power line via a switch , Including a first capacitor connected to the first power line, a converter, and a second capacitor. The converter is connected between the first power line and a second power line electrically connected to both the electric motor and the generator, and performs DC voltage conversion between the first and second power lines. Configured as follows. The second capacitor is connected to the second power line. The control method includes a step of opening the switch when an abnormality of the power storage device is detected during traveling, a required torque for traveling the vehicle in a traveling state in which the switch is opened, and the second power line. A step of setting the output torque of the generator and the motor based on both the torque for controlling the voltage, and a step of controlling the voltage of the first power line by the converter in a traveling state in which the switch is opened; including. The step of controlling includes the step of controlling the converter to increase the voltage of the first power line in response to the accelerator pedal release operation.

  Preferably, the step of controlling the converter raises the voltage of the first power line more than before and after the predetermined period for a predetermined period after detecting the release operation of the accelerator pedal in the traveling state in which the switch is opened. To control the converter.

  Preferably, the step of controlling the voltage of the first power line includes the voltage of the first power line with respect to the converter according to a difference between the voltage of the second power line and the target voltage in a traveling state in which the switch is opened. Change the voltage command value.

  More preferably, the setting step affects the torque acting on the drive shaft and the step of calculating the command value of the input / output power of the second power line for controlling the voltage of the second power line to the voltage command value. A step of calculating a power control torque of the generator and a power control torque of the motor for inputting / outputting power according to the command value from the generator and the motor to the second power line without giving the power, and the motor and the power generation Setting the upper and lower torque range of the drive shaft based on the upper and lower torque range of the motor and the upper and lower torque range of the generator, and the set upper and lower torque limits of the drive shaft. A drive torque setting unit for setting a torque command value for the drive shaft based on the range and the required torque, and a torque command value for the drive shaft without changing the input / output power for the second power line According to the step of calculating the driving force torque of the generator and the second driving force torque of the motor for acting on the driving shaft, and the sum of the power control torque and the driving force torque of the generator and the motor, respectively, Setting a torque command value of the electric motor.

  According to the present invention, it is possible to suppress voltage fluctuation in the power supply system accompanying a change in driving force corresponding to a user operation during battery-less traveling of a hybrid vehicle.

1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a circuit diagram of an electric system for driving and controlling the motor generator shown in FIG. 1. FIG. 2 is a collinear diagram when the hybrid vehicle shown in FIG. 1 is running. It is a functional block diagram for battery-less traveling control of the hybrid vehicle according to the first embodiment of the present invention. 4 is a flowchart showing a control process of battery-less travel control according to the first embodiment. FIG. 6 is a schematic waveform diagram showing an operation example during accelerator release operation during battery-less travel in the hybrid vehicle according to the first embodiment of the present invention. It is a functional block diagram for MG torque control in the battery-less traveling control of the hybrid vehicle by Embodiment 2 of this invention. It is a flowchart explaining the process sequence of MG torque control shown in FIG. It is a conceptual diagram which shows the relationship between a system voltage and a torque upper limit. It is a conceptual diagram explaining the setting method of the upper and lower limit range of a driving torque.

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

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention.

  Referring to FIG. 1, hybrid vehicle 20 according to the present embodiment includes an engine 22, a crankshaft 26 as an output shaft of engine 22, a three-shaft power split mechanism 30, and a battery 50. The crankshaft 26 is connected to the power split mechanism 30 via a torsional damper 28.

  Hybrid vehicle 20 further includes an electronic control unit for hybrid (hereinafter referred to as “HVECU”) that controls motor generators MG1 and MG2 (hereinafter simply referred to as MG1 and MG2), transmission 60, and the entire drive system of hybrid vehicle 20. 70).

  MG2 is coupled to power split mechanism 30 via transmission 60. Each of MG1 and MG2 can output both positive torque and negative torque, and can be driven as an electric motor as well as a generator.

  The engine 22 is an “internal combustion engine” that outputs power using a hydrocarbon fuel such as gasoline or light oil. The engine electronic control unit (hereinafter also referred to as “engine ECU”) 24 receives signals from various sensors that detect the operating state of the engine 22 such as the crank angle of the crankshaft 26 from the crank angle sensor 23. The engine ECU 24 communicates with the HVECU 70 and receives a control command for the engine 22 from the HVECU 70. The engine ECU 24 performs fuel injection control, ignition control, intake air amount control, etc. of the engine 22 so that the engine 22 operates in accordance with a control command from the HVECU 70 based on the operation state of the engine 22 based on signals from various sensors. Execute engine control. Furthermore, the engine ECU 24 outputs data relating to the operating state of the engine 22 to the HVECU 70 as necessary.

  The power split mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 disposed 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, and a carrier 34. The carrier 34 is configured to hold the plurality of pinion gears 33 so as to rotate and revolve freely. The power split mechanism 30 is configured as a planetary gear mechanism that performs a differential action with the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements.

  The crankshaft 26 of the engine 22 is connected to the carrier 34, and the output shaft of the MG1 is connected to the sun gear 31 via the sun gear shaft 31a. The ring gear shaft 32 a as a “drive shaft” rotates as the ring gear 32 rotates. The output shaft of MG2 is connected to the ring gear shaft 32a via the transmission 60. Hereinafter, the ring gear shaft 32a is also referred to as a drive shaft 32a.

  The drive shaft 32a is mechanically coupled to the drive wheels 39a and 39b via a gear mechanism 37 and a differential gear 38. Therefore, the power output to the ring gear 32, that is, the drive shaft 32 a by the power split mechanism 30 is output to the drive wheels 39 a and 39 b via the gear mechanism 37 and the differential gear 38.

  Thus, the power split mechanism 30 corresponds to a “differential device”. The carrier 34 corresponds to a “first rotating element”, the sun gear 31 corresponds to a “second rotating element”, and the ring gear 32 corresponds to a “third rotating element”.

  The transmission 60 is configured to give a predetermined reduction ratio Gr between the output shaft 48 of the MG 2 and the drive shaft 32a. The transmission 60 is typically constituted by a planetary gear mechanism. The transmission 60 includes an external gear sun gear 65, an internal gear ring gear 66 arranged concentrically with the sun gear 65, and a plurality of pinion gears 67 that mesh with the sun gear 65 and mesh with the ring gear 66. Since the planetary carrier is fixed to the case 61, the plurality of pinion gears 67 only rotate without revolving. That is, the ratio (reduction ratio) of the rotational speeds of the sun gear 65 and the ring gear 66 is fixed.

  The configuration of the transmission 60 is not limited to the example of FIG. Further, the output shaft of the MG 2 and the ring gear shaft (drive shaft) 32a may be connected without using the transmission 60.

  When MG1 functions as a generator, power from engine 22 input from carrier 34 is distributed to sun gear 31 side and ring gear 32 side according to the gear ratio. On the other hand, when MG 1 functions as an electric motor, the power from engine 22 input from carrier 34 and the power from MG 1 input from sun gear 31 are integrated and output to ring gear 32.

  MG1 and MG2 are typically configured by a three-phase permanent magnet type synchronous motor. MG1 and MG2 exchange power with battery 50 via converter 40 and inverters 41 and 42. Each of inverters 41 and 42 is configured by a general three-phase inverter having a plurality of switching elements.

  The battery 50 is shown as a representative example of the “power storage device”. As the battery 50, a lithium ion secondary battery or a nickel hydride secondary battery is typically applied. However, instead of the battery 50, another power storage device such as an electric double layer capacitor, or a combination of a secondary battery and another power storage device may be used.

  The battery 50 is managed by a battery electronic control unit (hereinafter also referred to as “battery ECU”) 52. A signal necessary for managing the battery 50 is input to the battery ECU 52. For example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, a charge / discharge current of the battery 50 from a current sensor (not shown), a battery temperature from a temperature sensor (not shown) attached to the battery 50, and the like. Is input to the battery ECU 52. The battery ECU 52 outputs data related to the state of the battery 50 to the HVECU 70 by communication as necessary. In addition, in order to manage the battery 50, the battery ECU 52 also calculates a remaining capacity (SOC: State of Charge) based on the integrated value of the charge / discharge current detected by the current sensor.

  The battery 50, the SMR (System Main Relay) 55, the converter 40, and the inverters 41 and 42 constitute an electric system (power supply system) of the hybrid vehicle 20. SMR 55 is arranged between battery 50 and converter 40.

  FIG. 2 is a circuit diagram of an electrical system for driving and controlling MG1 and MG2 shown in FIG.

  Referring to FIG. 2, battery 50 is connected to power line 56 via SMR 55. A capacitor C <b> 1 is connected to the power line 56.

  When SMR 55 is off, battery 50 is disconnected from the electrical system. When SMR 55 is on, battery 50 is connected to the electrical system. The SMR 55 is turned on / off in response to a control signal from the HVECU 70. For example, in a state where the ignition switch 80 is turned on, the user performs an operation for starting operation, thereby instructing activation of the electric system. When the activation of the electric system is instructed, the HVECU 70 turns on the SMR 55. That is, the SMR 55 is turned on during normal travel.

  Converter 40 is provided between power line 56 and power line 54. Converter 40 has a general boost chopper circuit configuration including a reactor and two power semiconductor switching elements (hereinafter also simply referred to as switching elements). As the power semiconductor switching element, a bipolar transistor, a power MOSFET (Metal Oxide Semiconductor Field-Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like can be used. An antiparallel diode is connected to each switching element.

  Inverter 41 connected to MG1 includes a U-phase arm, a V-phase arm, and a W-phase arm. The U-phase arm, V-phase arm and W-phase arm are connected in parallel. Each of the U-phase arm, the V-phase arm, and the W-phase arm has two switching elements connected in series. Each switching element is provided with an antiparallel diode.

  The phase coils (U, V, W) wound around the stator (not shown) of MG1 are alternately connected at the neutral point 112. The connection point of the switching element in each phase arm of inverter 41 is connected to the end of each phase coil of MG1.

  Similarly to the inverter 41, the inverter 42 has a general three-phase inverter configuration. The phase coils (U, V, W) wound around the stator (not shown) of MG2 are alternately connected at the neutral point 122. The connection point of the switching element in each phase arm of inverter 42 is connected to the end of each phase coil of MG2.

  Converter 40 performs bidirectional DC voltage conversion between power line 56 and power line 54. That is, converter 40 has voltage control (hereinafter, also referred to as “VH control”) that matches DC voltage VH of power line 56 with voltage command value VHr, and voltage control that matches DC voltage VL of power line 54 with voltage command value VLr ( Hereinafter, any one of “VL control” can be selectively executed.

  A motor electronic control unit (hereinafter also referred to as “motor ECU”) 45 controls the two switching elements constituting the converter 40 to be turned on and off in a complementary manner in each of the VH control and the VL control. . In VH control, motor ECU 45 controls the duty ratio of converter 40 (the on-period ratio of the two switching elements) based on the detected value of DC voltage VH from voltage sensor 180 and voltage command value VHr. Similarly, in the VL control, motor ECU 45 controls the duty ratio of converter 40 based on the detected value of DC voltage VL by voltage sensor 181 and voltage command value VLr.

  Thus, when the electric power discharged from the battery 50 is supplied to MG1 or MG2, the voltage can be boosted by the converter 40. Conversely, when the battery 50 is charged with the power generated by the MG 1 or MG 2, the voltage can be stepped down by the converter 40. During normal travel, converter 40 performs VH control.

  The inverter 41 converts the DC voltage on the power line 54 into an AC voltage by turning on and off the switching element. The converted AC voltage is supplied to MG1. Further, the inverter 41 converts AC power generated by the regenerative power generation by the MG 1 into DC power. Similarly, the inverter 42 converts the DC voltage on the power line 54 into an AC voltage and supplies it to MG2. Inverter 42 also converts AC power generated by regenerative power generation by MG 2 into DC power.

  As described above, the power line 54 that electrically connects the converter 40 and the inverters 41 and 42 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42. A capacitor C <b> 2 is connected to the power line 54.

  Power line 54 is electrically connected to MG1 and MG2 via inverters 41 and 42. Therefore, the electric power generated by one of MG1 and MG2 can be consumed by the other. During normal travel in which the SMR 55 is in the on state, the battery 50 is charged / discharged by electric power generated from one of MG1 and MG2 or insufficient electric power while the converter 40 executes VH control. Note that the battery 50 is not charged / discharged if the power balance is balanced by MG1 and MG2.

  Both MG1 and MG2 are driven and controlled by the motor ECU 45. Signals necessary for driving and controlling MG1 and MG2 are input to motor ECU 45. For example, signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of MG1 and MG2 and phase currents applied to MG1 and MG2 detected by a current sensor (not shown) are input to the motor ECU 45. Is done. Based on the signals from the rotational position detection sensors 43 and 44, the rotational speeds of the MG1 and MG2 can be detected.

  The motor ECU 45 is in communication with the HVECU 70 and drives and controls the MG1 and MG2 in accordance with an operation command from the HVECU 70. Specifically, motor ECU 45 outputs a switching control signal to inverters 41 and 42 so that the output torques of MG1 and MG2 match torque command values T1r and T2r. For example, motor ECU 45 calculates the output voltage command (AC voltage) of inverters 41 and 42 based on the deviation between the current command value set according to torque command values T1r and T2r and the current detection values of MG1 and MG2. . Then, the switching control signals of the inverters 41 and 42 are generated so that the pseudo AC voltage output from the inverters 41 and 42 approaches each output voltage command, for example, according to pulse width modulation control.

  Motor ECU 45 outputs a switching control signal to converter 40 so as to control DC voltage VH or VL in accordance with voltage command value VHr or VLr. The switching control signal of converter 40 is generated to be a rectangular wave voltage according to the duty ratio for VH control or VL control, for example, according to pulse width modulation control.

  In the configuration of FIG. 2, the power line 56 corresponds to a “first power line”, and the power line 54 corresponds to a “second power line”. The capacitor C1 corresponds to a “first capacitor”, and the capacitor C2 corresponds to a “second capacitor”.

  Referring again to FIG. 1, HVECU 70 is configured as a microprocessor centered on a CPU (Central Processing Unit) 72. The HVECU 70 includes a CPU 72, a ROM (Read Only Memory) 74 that stores processing programs, maps, and the like, a RAM (Random Access Memory) 76 that temporarily stores data, and an input / output port and a communication port (not shown). . The HVECU 70 includes an ignition signal from the ignition 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. The ACC, 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, and the like are input via the input port.

  Further, as described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 45, and the battery ECU 52 via the communication port. Accordingly, the HVECU 70 exchanges various control signals and data with other ECUs. Note that the engine ECU 24, the motor ECU 45, and the battery ECU 52 can also be configured by a microprocessor, similar to the HVECU 70. In FIG. 1, the HVECU 70, the engine ECU 24, the motor ECU 45, and the battery ECU 52 are described as separate ECUs, but an ECU in which some or all of these functions are integrated may be arranged. Or you may arrange | position ECU so that the function of each ECU shown in figure may be divided | segmented further.

  The HVECU 70 executes travel control for performing travel suitable for the vehicle state. For example, when starting the vehicle and traveling at a low speed, the hybrid vehicle 20 travels by the output of MG2 with the engine 22 stopped. During steady running, the engine 22 is started, and the hybrid vehicle 20 runs by the outputs of the engine 22 and MG2. In particular, the fuel efficiency of the hybrid vehicle 20 is improved by operating the engine 22 at a highly efficient operating point.

  When engine 22, MG1 and MG2 are connected via power split device 30, the rotational speeds of engine 22, MG1 and MG2 are connected in a collinear diagram as shown in FIG.

  Referring to FIG. 3, during traveling, MG2 mainly operates as a “motor”, and MG1 mainly operates as a “generator”. Hereinafter, the torque and rotation speed of MG2 are also expressed as Tm and Nm, and the torque and rotation speed of MG1 are also expressed as Tg and Ng.

  The engine 22 is controlled by the engine ECU 24 (FIG. 1) so as to operate at an operating point (engine speed Ne and engine torque Te) determined based on the engine required power.

  The torque Tg and the rotational speed Ng of MG1 are controlled so that the engine rotational speed Ne becomes a target rotational speed according to the operating point. As described above, during normal traveling, MG1 outputs negative torque (Tg <0) and enters a state of generating electricity.

  At this time, the direct torque Tep transmitted to the drive shaft 32a by the torque Tg output so as to handle the reaction force of the engine torque Te is expressed as Tep = −Tg × (1 / ρ). Note that ρ is a gear ratio in the power split mechanism 30.

  On the other hand, the torque generated in the drive shaft 32a by the torque Tm of MG2 using the gear ratio (reduction ratio) Gr of the transmission 60 is represented by Tm × Gr. Therefore, the following equation (1) is established for the drive torque Tp acting on the drive shaft 32a (ring gear 32).

Tp = Tm × Gr−Tg × (1 / ρ) (1)
In the hybrid vehicle 20, when an abnormality occurs in the battery 50 and charging / discharging is prohibited, the SMR 55 is turned off, and the battery 50 is disconnected from the electric system, and the vehicle continues to travel according to the alignment chart shown in FIG. 3. To do. Hereinafter, the traveling control at the time of batteryless traveling without using the battery 50 is referred to as “batteryless traveling control”.

  During battery-less travel, the battery 50 cannot be used as a power buffer. For this reason, converter 40 performs VL control instead of VH control. The voltage command value VLr for VL control is set to be equivalent to the output voltage Vb of the battery 50, for example.

  During battery-less traveling, the input / output power ΔP across the MG1 and MG2 directly affects the DC voltage VH of the power line 54 (capacitor C2). ΔP is expressed by the following equation (2). When ΔP <0, power is supplied from MG1 and MG2 to power line 54, and when ΔP> 0, power is supplied from power line 54 to MG1 and MG2.

ΔP = Tm × Nm + Tg × Ng (2)
During battery-less running, the DC voltage VH of the power line 54 changes according to the input / output power ΔP according to the relationship P = (1/2) × C × VH × VH. The capacitance of the capacitor C2 is C. Therefore, the voltage change ΔVH due to ΔP is expressed by the following equation (3). When ΔP <0, where the power generated by MG1 is larger than the power consumed by MG2, ΔVH> 0 and the DC voltage VH increases.

ΔP = − (C / 2) × 2 × VH × ΔVH
= −C × VH × ΔVH (3)
When the DC voltage VH varies, it leads to torque fluctuations of MG1 and MG2, and therefore it is preferable to control the DC voltage VH to the voltage command value VHr even during battery-less traveling.

  Therefore, in the present embodiment, power control based on the output torque of MG1 and MG2 is executed so as to control DC voltage VH by adjusting input / output power of MG1 and MG2 as a whole (that is, input / output power of power line 54) ΔP. To do. That is, during battery-less travel, the output torque of MG1 and MG2 is set reflecting not only the required drive torque but also the torque for power control.

  FIG. 4 is a functional block diagram for batteryless travel control of the hybrid vehicle according to the first embodiment of the present invention. Each functional block shown in FIG. 4 can be realized by hardware processing and / or software processing by the HVECU 70 and / or the motor ECU 45.

  The batteryless travel control unit includes an MG torque control unit 210, an inverter control unit 215, a VL control unit 220, and a converter control unit 225.

  MG torque control unit 210 sets torque command values T1r and T2r for MG1 and MG2 based on required torque Tp0 * for vehicle travel, voltage command value VHr, and DC voltage VH (detected value).

  The required torque Tp * 0 is set based on the vehicle state of the hybrid vehicle 20 (typically, the vehicle speed V and the accelerator opening ACC), and is a drive shaft torque for generating a vehicle driving force corresponding to a user request. It corresponds to.

  On the other hand, based on the voltage command value VHr and the DC voltage VH (detected value), the power command value Pr for controlling the DC voltage VH to the voltage command value VHr can be obtained using ΔP in the equation (3). it can. Specifically, a voltage change ΔVH for controlling the DC voltage VH is obtained, and ΔP when this ΔVH is substituted into Equation (3) can be used as the power command value Pr.

  As a result, the torque command value of MG1 is set so that the drive torque Tp = Tp0 * and the torque for power control are generated using the expression (1) and the expression (2) substituted with ΔP = Pr. The torque command value T2r (Tm) of T1r (Tg) and MG2 can be set.

  The inverter control unit 215 generates the switching control signal Sinv1 of the inverter 41 so that the MG1 generates an output torque according to the torque command value T1r. Similarly, inverter control unit 215 generates switching control signal Sinv2 for inverter 42 so that MG2 generates an output torque in accordance with torque command value T2r.

  The VL control unit 220 sets a voltage command value VLr in VL control based on the accelerator opening ACC from the accelerator pedal position sensor 84. Specifically, the VL control unit 220 detects a release operation of the accelerator pedal 83 (hereinafter, simply referred to as “accelerator release operation”) based on the accelerator opening ACC, and a voltage command in response to the accelerator release operation. The value VLr is increased. For example, in a predetermined period after the accelerator release operation, the voltage command value VLr is changed to a value higher than the voltage command value VLr (normal value) before and after the predetermined period.

  Alternatively, the VL control unit 220 may further set the voltage command value VLr at the time of the accelerator release operation by further reflecting the DC voltage VH. For example, when the voltage deviation (VH−VHr) is large, the voltage command value VLr is preferably set higher so that the charge of the capacitor C2 is controlled to move to the capacitor C1.

  Converter control unit 225 generates switching control signal Scnv for converter 40 based on the detected value of DC voltage VL and voltage command value VLr. Based on switching control signal Scnv, the duty ratio of converter 40 for feedback control of DC voltage VL is realized.

  Next, a control process for realizing the batteryless travel control according to the functional block diagram shown in FIG. 4 will be described with reference to the flowchart of FIG.

  The control process according to the flowchart shown in FIG. 5 is executed at predetermined control cycles during battery-less travel control. Note that the control process shown in FIG. 5 is repeatedly executed at a predetermined cycle.

  Referring to FIG. 5, HVECU 70 determines in step S100 whether or not use (charging / discharging) of battery 50 is prohibited due to battery abnormality. When charging / discharging is prohibited (YES in S100), the HVECU 70 turns off the SMR 55 in step S105. Further, subsequent steps S110 to S150 for batteryless travel control are executed.

  On the other hand, HVECU 70 skips subsequent steps S105 to S150 for batteryless travel control when battery 50 can be used (NO in S100), that is, during normal travel.

  During battery-less traveling, the HVECU 70 calculates a power command value Pr for power control for controlling the DC voltage VH to the voltage command value VHr in step S110.

  Further, HVECU 70 sets torque command values T1r and T2r based on the required torque (Tp0 *) for vehicle travel and the torque for power control in step S120. That is, the processing in steps S110 and S120 corresponds to the function of MG torque control unit 210 in FIG.

  Further, HVECU 70 executes VL control by converter 40 in steps S130 to S150. In step S130, the HVECU 70 determines whether an accelerator release operation has been executed based on the accelerator opening ACC. For example, an accelerator release operation is detected when ACC> ACC * in the previous cycle and ACC <ACC * in the current cycle with respect to a predetermined determination value ACC *. Then, during a predetermined period starting from detection of the accelerator release operation, step S130 is determined as YES. Hereinafter, the period in which step S130 is determined to be YES is also referred to as “accelerator release operation”.

  The HVECU 70 proceeds to step S140 and sets the voltage command value VLr = V1 (normal value) during the non-accelerator release operation (NO determination in S130). For example, V 1 is a value corresponding to the output voltage Vb of the battery 50.

  On the other hand, the HVECU 70 proceeds to step S150 and sets the voltage command value VLr = V2 (V2> V1) during the accelerator release operation (when YES is determined in S130). Thereby, the voltage command value VLr is set so as to increase the DC voltage VL during the accelerator release operation. As a result, the converter 40 operates so that the electric charge of the power line 54 (capacitor C2) moves the power line 56 (capacitor C1), thereby generating a force for reducing the DC voltage VH.

  In step S150, as described above, the voltage command value VLr during the accelerator release operation may be set by further reflecting the DC voltage VH and the voltage command value VHr. For example, when the voltage deviation (VH−VHr) is large, it is preferable to increase voltage command value VLr.

  FIG. 6 shows an operation example during accelerator release operation during battery-less traveling in the hybrid vehicle according to the first embodiment of the present invention.

  In the operation example of FIG. 6, at time t1, an accelerator release operation is detected as the accelerator opening ACC decreases. And the predetermined period (time t1-t2) from the time t1 is recognized as the time of accelerator release operation.

  During the accelerator operation, MG2 consumes electric power to output drive torque. When the accelerator release operation is performed from this state, the power consumption of MG2 decreases rapidly, and thus a force for increasing the DC voltage VH works.

  In FIG. 6, an example of an operation waveform when the voltage command value VHr for VL control is set to a constant value is indicated by a dotted line for comparison. In this case, the accelerator release operation corresponds to the above voltage increase by power control using the MG1 and MG2 torques fed back to the DC voltage VH.

  However, during battery-less traveling, the torque of MG2 affects the vehicle driving force, so the range in which the torques of MG1 and MG2 can be changed is limited in consideration of the required torque. As described above, since it is difficult to change the torques of MG1 and MG2 from the viewpoint of only power control, there is a certain limit to the control response of the DC voltage VH by only power control. As a result, the direct-current voltage VH greatly increases in response to the accelerator release operation and then fluctuates relatively large for a certain period. When this amount of fluctuation increases, there is a risk of overvoltage occurring in the electrical system.

  On the other hand, according to the first embodiment, as indicated by a solid line in the figure, the DC voltage VL rises during time t1 to t2 as the voltage command value VLr becomes higher than normal. That is, converter 40 operates so as to lower DC voltage VH by the electric charge of power line 54 (capacitor C2) moving power line 56 (capacitor C1). Thereby, the fluctuation | variation (especially increase side) of the DC voltage VH can be suppressed.

  When a predetermined period elapses after the accelerator release operation is detected, the voltage command value is gradually returned to the normal value (V1), so that the DC voltage VL gradually returns to the normal level. By making the DC voltage VL gentle at this time, fluctuations in the DC voltage VH can be suppressed. Further, the length of the predetermined period (time t1 to t2) during which the DC voltage VL is increased is determined in advance in accordance with a period necessary for stabilizing the behavior of the DC voltage VH based on actual machine experiments and the like. Can do.

  As described above, in the battery-less traveling of the hybrid vehicle according to the first embodiment, by changing the converter control according to the accelerator release operation, the driving force change by the user operation, in particular, the increase of the DC voltage VH accompanying the accelerator release operation. Can be suppressed.

  The voltage command value VLr at the time of the accelerator release operation further reflects the DC voltage VH (more specifically, the deviation (VH−VHr) from the voltage command value), thereby further suppressing fluctuations in the DC voltage VH. It is possible.

  On the contrary, when the accelerator pedal 83 is depressed, there is a possibility that the DC voltage VH decreases due to an increase in power consumption of MG2. Therefore, the converter 40 may be controlled so as to promote the charge transfer from the capacitor C1 to the capacitor C2 by reducing the DC voltage VL for a predetermined period in response to the accelerator depression operation. That is, by changing the DC voltage VL by the converter 40 in at least one of the accelerator release operation and the accelerator stepping operation described above, the voltage fluctuation in the power supply system due to the driving force change corresponding to the user operation is suppressed. be able to.

[Embodiment 2]
As described above, the torque setting of MG1 and MG2 in battery-less traveling needs to be set according to the required torque (Tp0 *) for vehicle traveling while performing power feedback control. Therefore, in the second embodiment, a preferred mode for ensuring power controllability and vehicle travelability will be described for MG torque control in battery-less travel control.

  FIG. 7 is a functional block diagram for MG torque control in battery-less travel control of a hybrid vehicle according to Embodiment 2 of the present invention. Each functional block shown in FIG. 7 can be realized by hardware processing and / or software processing by the HVECU 70.

  7, MG torque control unit 210 shown in FIG. 4 includes power command calculation unit 510, MG torque conversion unit 520, MG torque upper / lower limit setting unit 530, and drive torque upper / lower limit setting unit 540. Drive torque setting unit 550, MG torque conversion unit 560, and MG torque setting unit 570.

  The power command calculation unit 510 calculates a power correction command value ΔPr based on the DC voltage VH and the voltage command value VHr of the DC voltage, and calculates a power command value Pr based on this ΔPr. The power correction command value ΔPr indicates the amount of change in input / output power of the power line 54 for bringing the DC voltage VH closer to the voltage command value VHr. The power correction command value ΔPr is set to a negative value (ΔPr <0) when the power of the power line 54 is insufficient, and is set to a positive value (ΔPr> 0) when the power of the power line 54 is excessive.

  The MG torque conversion unit 520 calculates necessary torques (hereinafter also referred to as power control torque) T1p and T2p for MG1 and MG2 for inputting / outputting electric power according to the electric power command value Pr to the electric power line 54. The MG torque conversion unit 520 corresponds to a “first torque calculation unit”.

  MG torque upper / lower limit setting unit 530 sets torque upper limit value T1max and torque lower limit value T1min of MG1, and torque upper limit value T2max and torque lower limit value T2min of MG2 in the control cycle.

  For example, as shown in FIG. 9, the torque upper limit value is determined by the DC voltage and the rotation speed of the motor generator in the control cycle.

  Referring to FIG. 9, the upper limit torque that can be output by each of MG1 and MG2 varies according to the MG rotation speed and the DC voltage. Under the same MG speed, the lower the DC voltage VH, the lower the upper limit torque that can be output. On the other hand, under the same DC voltage, the upper limit torque that can be output decreases as the rotational speed increases.

  Even when the torque and / or the rotational speed are in a negative range, the same relationship as described above is established among the absolute value of the MG torque, the absolute value of the MG rotational speed, and the DC voltage VH. Accordingly, in each control cycle, the torque upper limit values T1max and T2max and / or the torque lower limit values T1min and T2min can be set in light of the DC voltage VH and the rotational speed (Ng, Ne).

  Alternatively, torque upper limit values T1max, T2max and / or torque lower limit values are used in order to limit the increase in torque (absolute value) from the viewpoint of component / equipment protection from excessive rotation of the rotating elements and excessive temperatures of MG1 and MG2. Values T1min and T2min may be set.

  Further, in order to suppress steep torque fluctuations, the torque upper and lower limits T1max and T1min of MG1 and the torque upper and lower limits T2max of MG2 are limited so as to limit the amount of change from the output torque in the previous control cycle to a predetermined value or less. , T2min may be set.

  Referring to FIG. 7 again, MG torque upper and lower limit setting unit 530 comprehensively considers the above viewpoints, and in each control cycle, torque upper limit values T1max and T2max and torque lower limit values T1min and T2min in the control cycle. Set.

  The drive torque upper and lower limit setting unit 540 sets the upper and lower limits of the drive torque Tp by correcting the torque upper and lower limit range set by the MG torque upper and lower limit setting unit 530 with the power control torques T1p and T2p.

  The drive torque upper / lower limit setting unit 540 is calculated by the MG1 torque upper / lower limit values T1max and T1min and the MG2 torque upper / lower limit values T2max and T2min set by the MG torque upper / lower limit setting unit 530 and the MG torque conversion unit 520. A torque upper limit value Tpmax and a torque lower limit value Tpmin that can be output to the drive shaft 32a are set based on the power control torques T1p and T2p. As will be described in detail later, the torque upper limit value Tpmax and the torque lower limit value Tpmin are determined by the MG torque upper and lower limit setting unit 530 after the power control torques T1p and T2p by MG1 and MG2 are secured. It defines the upper and lower limit range of the drive shaft torque when it is within the upper and lower limit range. Thus, the functions of the MG torque upper / lower limit setting unit 530 and the drive torque upper / lower limit setting unit 540 correspond to the “torque upper / lower limit setting unit”.

  The drive torque setting unit 550 sets the torque closest to the required torque Tp * 0 within the upper and lower limit range (Tpmax to Tpmin) of the drive torque set by the drive torque upper / lower limit setting unit 540 to the drive torque command value Tp *. Set.

  As described above, the required torque Tp * 0 generates a vehicle driving force corresponding to a user request that is set based on the vehicle state of the hybrid vehicle 20 (typically, the vehicle speed V and the accelerator opening ACC). This corresponds to the drive shaft torque for

  MG torque conversion unit 560 converts drive torque command value Tp * set by drive torque setting unit 550 into the output torque of MG1 and MG2. Thereby, driving force control torques T1d and T2d of MG1 and MG2 are calculated. The MG torque conversion unit 560 corresponds to a “second torque calculation unit”.

  The MG torque setting unit 570 is based on the sum of the driving force control torques T1d and T2d set by the MG torque conversion unit 560 and the power control torques T1p and T2p set by the MG torque conversion unit 520. Command values T1r and T2r are set.

  Next, a control process for realizing the MG torque control in the batteryless travel control according to the functional block diagram shown in FIG. 7 will be described using the flowchart of FIG.

  The control processing according to the flowchart shown in FIG. 8 corresponds to the details of step S120 shown in FIG. In other words, the control process shown in FIG. 8 is executed at a predetermined cycle during battery-less traveling in accordance with the execution of the control process shown in FIG.

  Referring to FIG. 8, HVECU 70 sets the upper and lower limit values of MG1 torque and MG2 torque in step S121. The processing in step S121 corresponds to the function of the MG torque upper / lower limit setting unit 530 in FIG. Thus, the original torque upper limit values T1max and T2max and torque lower limit values T1min and T2min in the current control cycle are set.

  Further, HVECU 70 calculates power command value Pr for controlling DC voltage VH to voltage command value VHr in step S122. The processing in step S122 corresponds to the function of the power command calculation unit 510 in FIG. For example, the power command value Pr is set according to the following equation (4).

Pr = ΔPr + Ploss + Pax (4)
In Expression (4), the power correction command value ΔPr indicates a control calculation value obtained by performing the PID control calculation on the voltage deviation (VH−VHr). Ploss is power loss due to MG1 and MG2. For example, Ploss can be set as a function of the rotational speed for each of MG1 and MG2. Pax is the power consumption of the auxiliary load that operates using the power of the power line 54.

  When VHr> VH, since the power of the power line 54 is insufficient, the power command value Pr changes in the negative direction by the PID control calculation. On the other hand, when VHr <VH, since the power of the power line 54 is excessive, the power command value Pr changes in the positive direction by the PID control calculation.

  In step S123, the HVECU 70 calculates the power control torques T1p and T2p of the MG1 and MG2 based on the power command value Pr. The processing in step S123 corresponds to the function of the MG torque conversion unit 520 in FIG.

  The power control torques T1p and T2p correspond to the output torques of MG1 and MG2 for inputting / outputting power according to the power command value Pr to / from the power line 54 without affecting the drive shaft torque. The power control torques T1p and T2p can be obtained as follows.

  First, in equation (1), Tp = 0 is set, and Tm = T2p and Tg = T1p are substituted to obtain the following equation (5).

0 = T2p × Gr−T1p × (1 / ρ) (5)
From the equation (5), it is understood that the relationship of the following equation (6) is established between the power control torques T1p and T2p.

T1p = T2p × ρ × Gr (6)
Further, in the equation (2), ΔP = Pr, Tm = T2p, and T1p of the equation (6) is substituted for Tg, the following equation (7) is obtained.

Pr = T2p × Nm + T2p × ρ × Gr × Ng
= T2p × (Nm + (ρ × Gr × Ng)) (7)
From the equation (7), it is understood that the power control torque T2p of MG2 is represented by the following equation (8).

T2p = Pr / (Nm + (ρ × Gr × Ng)) (8)
Further, from the equations (8) and (6), the power control torque T1p of MG1 is expressed by the following equation (9).

T1p = Pr × (ρ × Gr) / (Nm + (ρ × Gr × Ng)) (9)
When MG1 and MG2 output power control torques T1p and T2p, the power value according to the power command value Pr is input to and output from the power line 54 without changing the torque acting on the drive shaft 32a (Tp = 0). be able to.

  In step S124, the HVECU 70 corrects the torque upper and lower limit ranges of MG1 and MG2 set in step S121 in order to ensure the output of the power control torques T1p and T2p. Further, in step S125, the HVECU 70 sets the torque upper and lower limit values Tpmax and Tpmin of the drive shaft 32a based on the torque upper and lower limit values of MG1 and MG2 obtained in step S124. That is, the processes in steps S124 and S125 correspond to the function of the drive torque upper / lower limit setting unit 540 shown in FIG.

  In step S124, corrected torque upper limit value T1max # and torque lower limit value T1min # for MG1 are obtained by subtracting power control torque T1p from original torque upper limit value T1max and torque lower limit value T1min. Similarly, the corrected torque upper limit value T2max # and torque lower limit value T2min # for MG2 are obtained by subtracting the power control torque T2p from the original torque upper limit value T2max and torque lower limit value T2min.

  Torque range in which MG1 can output to secure driving torque so that power control torque T1p is secured by torque upper limit value T1max # and torque lower limit value T1min # and is within the original torque upper / lower limit range T1max to T1min. Is shown. Similarly, the torque upper limit value T2max # and the torque lower limit value T2min # indicate a torque range in which MG2 can be output for securing the drive torque after securing the power control torque T2p.

  In step S125, the upper and lower limit values of the drive torque output to the drive shaft 32a are calculated based on the torque upper and lower limit values corrected in step S124.

  Here, the relationship between the torques Tg and Tm of MG1 and MG2 for generating the drive torque Tp while maintaining the power balance, that is, ΔPr = 0, is expressed as follows by setting ΔP = 0 in the equation (2). It is shown by the equation (10).

Tg = − (Nm / Ng) × Tm (10)
By substituting the equation (10) into the equation (1) and deleting Tg, the relationship between the drive torque Tp and the torque Tm of MG2 when ΔP = 0 is expressed by the equation (11).

Tp = Tm × Gr + (1 / ρ × Nm / Ng) × Tm
= (Gr + (1 / ρ × Nm / Ng)) × Tm (11)
By substituting the torque upper limit values T2max # and T2min # for MG2 into the equation (11), the upper and lower limit values Tpmax2 and Tpmin2 of the drive torque Tp from the MG2 torque limit are obtained.

  Similarly, the relationship between the drive torque Tp and the torque Tg of MG1 when ΔP = 0 is obtained by substituting the equation (10) into the equation (1) to eliminate Tm, and is expressed by the equation (12). .

Tp = − (Ng / Nm × Gr) × Tg− (1 / ρ) × Tg
=-(1 / ρ + Gr × Ng / Nm) × Tg (12)
Therefore, by substituting the torque upper limit values T1max # and T1min # for MG1 into the equation (12), the upper and lower limit values Tpmax1, Tpmin1 of the drive torque Tp from the MG1 torque limit can be obtained.

  Referring to FIG. 10, the range in which the upper and lower limit ranges (Tpmax1 to Tpmin1) of the drive torque from the MG1 torque limit and the upper and lower limit ranges (Tpmax2 to Tpmin2) of the drive torque from the MG2 torque limit overlap The upper and lower limits are set. That is, the drive torque upper limit value Tpmax = min (Tpmax1, Tpmax2), and the drive torque lower limit value Tpmin = max (Tpmin1, Tpmin2). As a result, the upper and lower limit range (Tpmax to Tpmin) of the drive torque Tp that can be output to the drive shaft 32a, that is, the settable range of the drive torque command value Tp *, is ensured while ensuring the output of the power control torques T1p and T2p Determined.

  Referring to FIG. 8 again, HVECU 70 sets drive torque command value Tp # based on drive torque upper and lower limit values Tpmax, Tpmin and user requested torque Tp * 0 in step S126. The process of step S126 corresponds to the function of the drive torque setting unit 550 in FIG.

  In step S126, the drive torque command value Tp * is set to a value closest to the required torque Tp * 0 within the upper and lower limit range (Tpmax to Tpmin) of the drive torque Tp set in step S125. Specifically, when Tp * 0> Tpmax, Tp * = Tpmax is set. Similarly, when Tp * 0 <Tpmin, Tp * = Tpmin is set. When Tpmin <Tp * 0 <Tpmax, Tp * = Tp * 0 is set.

  In step S127, the HVECU 70 calculates the driving force control torques T1d and T2d of the MG1 and MG2 from the driving torque command value Tp * set in step S126. The driving force control torques T1d and T2d correspond to the output torques of MG1 and MG2 for generating driving torque according to the driving torque command value Tp * after executing power control. The processing in step S127 corresponds to the function of the MG torque conversion unit 560 in FIG.

  The driving force control torque T1d is obtained by Expression (13) by setting Tp = Tp * and Tg = T1d in Expression (12).

T1d = −Tp * / (1 / ρ + Gr × Ng / Nm) (13)
Similarly, the driving force control torque T2d is obtained by Expression (14) by setting Tp = Tp * and Tm = T2d in Expression (11).

T2d = Tp * / (Gr + (1 / ρ × Nm / Ng)) (14)
HVECU 70 sets torque command values T1r and T2r for MG1 and MG2 in step S128. The processing in step S128 corresponds to the function of the MG torque setting unit 570 in FIG.

  In step S128, final torque command values T1r and T2r are calculated based on the following equations (15) and (16).

T1r = T1p + T1d (15)
T2r = T2p + T2d (16)
Then, the output torque of MG1 and MG2 is controlled according to the torque command values T1r and T2r by the electric system shown in FIG.

  As described above, in the battery-less travel control of the hybrid vehicle according to the second embodiment, the power control torques T1p and T2p for controlling the DC voltage VH are limited to a range that can ensure the MG1, The output torque of MG2 can be set. For this reason, even in battery-less running where converter 40 cannot be used, DC voltage VH is stable, and fluctuations in output torque of MG1 and MG2 are suppressed. As a result, vehicle running performance is improved.

  Furthermore, since power control is performed using both MG1 and MG2 torques, the range of torque that can be output from MG1 and MG2 is widened after realizing power control. As a result, in addition to the effects of the first embodiment, the vehicle driving force in battery-less traveling can be easily ensured, thereby improving traveling performance.

  It should be noted that the configuration of the hybrid vehicle to which the present invention is applied is described in terms of points that are not limited to the illustration of FIG. Specifically, an internal combustion engine, a generator that generates power using at least part of the power of the internal combustion engine, and an electric motor that outputs torque to the drive shaft by the power of the power line to which the generated power of the generator is supplied are used. If the converter controls DC voltage in a configuration capable of executing battery-less travel, the output torque of the generator and motor is appropriately set according to the battery-less travel control described in this embodiment. can do.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied to travel control of a hybrid vehicle having a travel mode in which the on-vehicle power storage device is not used.

  20 hybrid vehicle, 22 engine, 23 crank angle sensor, 24 engine ECU, 26 crankshaft, 28 torsional damper, 30 power split mechanism, 31, 65 sun gear, 31a sun gear shaft, 32, 66 ring gear, 32a ring gear shaft (drive shaft) ), 33, 67 Pinion gear, 34 carrier, 37 gear mechanism, 38 differential gear, 39a, 39b drive wheel, 40 converter, 41, 42 inverter, 43, 44 rotational position detection sensor, 45 motor ECU, 48 output shaft (MG2) , 50 battery, 52 battery ECU, 54, 56 power line, 60 transmission, 61 case, 70 HVECU, 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 pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 112, 122 neutral point, 180, 181 voltage sensor, 210 MG torque control unit, 215 inverter control unit 220 VL control unit, 225 converter control unit, 510 power command calculation unit, 520, 560 MG torque conversion unit, 530 MG torque upper / lower limit setting unit, 540 drive torque upper / lower limit setting unit, 550 drive torque setting unit, 570 MG torque Setting unit, ACC accelerator opening, C1, C2 condenser, MG1 motor generator (generator), MG2 motor generator (electric motor), Ne engine speed, Ng MG1 speed, Nm MG2 speed, Pr power command value, Scnv, Sinv1, Sinv2 switching control signal, T1r, T2r torque command value, T1p, T2p power control torque, T1max, T2max MG torque upper limit value (original), T1min, T2min torque lower limit value (original), T1d, T2d driving force control Torque, Te engine torque, Tep direct delivery torque, Tg MG1 torque, Tm MG2 torque, Tp * 0 required torque, Tp * drive torque command value, Tpmax drive torque upper limit value, Tpmin drive torque lower limit value, Vb output voltage (battery), VH, VL DC voltage, VHr, VLr Voltage command value.

Claims (9)

An internal combustion engine configured to have a power transmission path between the drive shaft,
A generator for generating electricity using at least part of the power of the internal combustion engine;
An electric motor configured to have a power transmission path between the drive shaft,
A power storage device electrically connected to the first power line via a switch;
A first capacitor connected to the first power line;
Connected between the first power line and a second power line electrically connected to both the motor and the generator, and performs DC voltage conversion between the first and second power lines. A converter configured to
A second capacitor connected to the second power line;
Based on both the required torque for vehicle travel and the torque for controlling the voltage of the second power line in the travel state in which the switch is opened, the output torque of the generator and the motor is A torque control unit for setting;
A voltage control unit for controlling the operation of the converter so as to control the voltage of the first power line in a traveling state in which the switch is opened;
The voltage control unit is a hybrid vehicle that controls the converter to increase the voltage of the first power line in response to an accelerator pedal release operation.   The voltage control unit raises the voltage of the first power line more than before and after the predetermined period for a predetermined period after detecting the release operation of the accelerator pedal in a traveling state in which the switch is opened. The hybrid vehicle according to claim 1, wherein the converter is controlled as follows.   The voltage control unit changes a voltage command value of the voltage of the first power line with respect to the converter according to a difference between the voltage of the second power line and a target voltage in a traveling state in which the switch is opened. The hybrid vehicle according to claim 1. The torque control unit
A power command calculation unit that calculates a command value of input / output power of the second power line for controlling the voltage of the second power line to a voltage command value;
Power control torque of the generator for inputting / outputting electric power according to the command value from the generator and the motor to the second power line without affecting the torque acting on the drive shaft And a first torque calculator for calculating a power control torque of the electric motor,
Torque for setting a torque upper and lower limit range of the drive shaft based on a torque upper and lower limit range of the motor and a torque upper and lower limit range of the generator from which the power control torque of the motor and the generator is subtracted Upper and lower limit setting section,
A drive torque setting unit for setting a torque command value of the drive shaft based on the set torque upper and lower limit range of the drive shaft and the required torque;
The driving force torque of the generator and the second driving force torque of the motor are calculated so that the torque command value of the driving shaft is applied to the driving shaft without changing the input / output power to the second power line. A second torque calculator for
The torque setting part for setting the torque command value of the said generator and the said motor according to the sum of the said electric power control torque and the said driving force torque of each of the said generator and the said motor of Claims 1-3 The hybrid vehicle of any one of Claims. When the rotation speed of any two of the first, second and third rotation elements is determined, the rotation speed of the remaining one rotation element is determined, and the first to third rotation elements are determined. A differential device configured to input / output power to / from the remaining one rotating element based on power input / output to / from any two rotating elements of the rotating elements;
The first rotating element is mechanically coupled to an output shaft of the internal combustion engine;
The second rotating element is mechanically coupled to an output shaft of the generator;
The hybrid vehicle according to claim 1, wherein the third rotating element is mechanically connected to the drive shaft and the output shaft of the electric motor. A power transmission path between the internal combustion engine configured to have a power transmission path between the drive shaft, a generator for generating power using at least part of the power of the internal combustion engine, and the drive shaft A power storage device electrically connected to the first power line via a switch, a first capacitor connected to the first power line, and the first power line. One power line and a second power line electrically connected to both the motor and the generator so as to perform DC voltage conversion between the first and second power lines. A control method for a hybrid vehicle comprising a converter configured as described above and a second capacitor connected to the second power line,
The control method is:
When an abnormality of the power storage device is detected during traveling, opening the switch; and
Based on both the required torque for vehicle travel and the torque for controlling the voltage of the second power line in the travel state in which the switch is opened, the output torque of the generator and the motor is Steps to set,
In a running state in which the switch is opened, the step of controlling the voltage of the first power line by the converter,
The control step includes a step of controlling the converter so as to increase the voltage of the first power line in response to an accelerator pedal release operation.   The step of controlling the converter includes, in a traveling state in which the switch is opened, the voltage of the first power line more than before and after the predetermined period for a predetermined period after detecting the release operation of the accelerator pedal. The method for controlling a hybrid vehicle according to claim 6, wherein the converter is controlled to be raised.   The step of controlling the voltage of the first power line includes the step of controlling the voltage of the first power line with respect to the converter according to a difference between the voltage of the second power line and a target voltage in a traveling state in which the switch is opened. The method for controlling a hybrid vehicle according to claim 6 or 7, wherein the voltage command value of the voltage is changed. The setting step includes:
Calculating a command value of input / output power of the second power line for controlling the voltage of the second power line to a voltage command value;
Power control torque of the generator for inputting / outputting electric power according to the command value from the generator and the motor to the second power line without affecting the torque acting on the drive shaft And calculating a power control torque of the electric motor,
Setting a torque upper and lower limit range of the drive shaft based on a torque upper and lower limit range of the motor and a torque upper and lower limit range of the generator, from which the power control torque of the motor and the generator is subtracted;
A drive torque setting unit for setting a torque command value of the drive shaft based on the set torque upper and lower limit range of the drive shaft and the required torque;
The driving force torque of the generator and the second driving force torque of the motor are calculated so that the torque command value of the driving shaft is applied to the driving shaft without changing the input / output power to the second power line. Steps,
A step of setting a torque command value of the generator and the motor according to a sum of the power control torque and the driving force torque of each of the generator and the electric motor. Control method.

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