JP7013885B2 - automobile - Google Patents

Description

The present invention relates to an automobile, and more particularly to an automobile including a motor, an inverter, and a power storage device.

Conventionally, as a vehicle of this type, in a vehicle equipped with a traveling motor, an inverter for driving the motor, and a battery connected to the inverter via a power line, braking is performed by regenerative driving of the motor when the accelerator is off. (For example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 3-261306

In such an automobile, when the storage ratio of the battery is large when the accelerator is off, the regenerative drive of the motor is limited in order to protect the battery. Therefore, at that time, the problem is how to apply the braking torque to the vehicle while suppressing the increase in the storage ratio of the power storage device.

The main object of the automobile of the present invention is to apply braking torque to the vehicle while suppressing an increase in the storage ratio of the power storage device when the storage ratio of the power storage device is large when the accelerator is off.

The automobile of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The automobile of the present invention
With a driving motor
The inverter that drives the motor and
A power storage device connected to the inverter via a power line,
A control device that controls the inverter so that the motor is regeneratively driven when the accelerator is off.
It is a car equipped with
When the storage ratio of the power storage device is equal to or higher than the predetermined ratio when the accelerator is off, the control device turns on the inverter in three phases.
The gist is that.

In the automobile of the present invention, the inverter is controlled so that the motor is regeneratively driven when the accelerator is off. Then, when the storage ratio of the power storage device is equal to or higher than the predetermined ratio when the accelerator is off, the inverter is turned on in three phases. Here, "three-phase on" means turning on all of the switching elements of the upper arm or all of the switching elements of the lower arm of the inverter. When the inverter is turned on in three phases, braking torque is applied from the motor to the vehicle. Therefore, when the storage ratio of the power storage device is equal to or higher than the predetermined ratio when the accelerator is off, the braking torque can be applied to the vehicle while suppressing the increase in the storage ratio of the power storage device by turning on the three-phase inverter.

In such an automobile of the present invention, a second motor for traveling and a second inverter for driving the second motor and connected to the power line are further provided, and the control device is provided with the accelerator off when the accelerator is off. Occasionally, when the power storage ratio is equal to or higher than the predetermined ratio, at least one of the inverter and the second inverter may be turned on in three phases.

Further, the automobile of the present invention may further include a second and third motors for traveling and a second and third inverters that drive the second and third motors and are connected to the power line. good. In this case, the control device may control the inverter so that the motor is regeneratively driven by the required braking torque when the storage ratio is less than the first ratio when the accelerator is off. In the control device, when the storage ratio is the first ratio or more when the accelerator is off, the storage ratio is larger than the first ratio and less than the second ratio, or the absolute value of the required braking torque is the said. When the absolute value of the first braking torque acting on the vehicle when the second inverter is turned on in three phases or less, the second inverter is turned on in three phases and the motor has the required braking torque and the first braking torque. The inverter may be controlled so as to be regeneratively driven by a torque based on the difference. When the accelerator is off, the control device has the second storage ratio when the storage ratio is equal to or higher than the second ratio and the absolute value of the required braking torque is larger than the absolute value of the first braking torque. When it is less than the third ratio, which is larger than the ratio, or when the absolute value of the required braking torque is equal to or less than the absolute value of the second braking torque acting on the vehicle when the second and third inverters are turned on in three phases, the first 2. The third inverter may be turned on in three phases and the inverter may be controlled so that the motor is regeneratively driven by a torque based on the difference between the required braking torque and the second braking torque. In addition, the control device has the required braking torque when the storage ratio is equal to or higher than the third ratio and the absolute value of the required braking torque is larger than the absolute value of the second braking torque when the accelerator is off. When the absolute value of is equal to or less than the absolute value of the third braking torque acting on the vehicle when the first, second, and third inverters are turned on in three phases, the second and third inverters are turned on in three phases and the above. The inverter may be controlled so that the torque of the motor becomes a value of 0. Further, when the accelerator is off, the control device determines the required braking torque when the storage ratio is equal to or higher than the third ratio and the absolute value of the required braking torque is larger than the absolute value of the second braking torque. When the absolute value is larger than the absolute value of the third braking torque, the first, second, and third inverters may be turned on in three phases. By doing so, it is possible to apply the braking torque to the vehicle while further suppressing the increase in the storage ratio of the power storage device by controlling according to the power storage ratio of the power storage device and the required braking torque.

Further, in the automobile of the present invention, a second motor for traveling and a second inverter for driving the second motor and connected to the power line are provided, and the first and second motors are the first. , The first and second braking torques acting on the vehicle from the first and second motors when the second inverter is turned on for three phases are different from each other, and in the control device, the power storage ratio of the power storage device is the same when the accelerator is off. When the ratio is equal to or higher than a predetermined ratio, the first state in which the first inverter is turned on in three phases, the second state in which the second inverter is turned on in three phases, and the first state are based on a virtual shift stage based on the operation of the driver. , The third state in which the second inverter is turned on in three phases may be changed. In this way, the braking torque applied to the vehicle can be changed according to the virtual shift stage.

It is a block diagram which shows the outline of the structure of the hybrid vehicle 20 as an Example of this invention. It is a block diagram which shows the outline of the structure of the electric drive system which has motors MG1, MG2, MG3. It is a flowchart which shows an example of the accelerator-off time control routine executed by HVECU 70. It is explanatory drawing which shows an example of the relationship between the sum of torque Ton1, torque Ton1, Ton3, the sum of torque Ton1, Ton2, Ton3 and the vehicle speed V. It is explanatory drawing which shows an example of the accelerator-off time control routine of a modification. It is a block diagram which shows the outline of the structure of the hybrid vehicle 120 of a modification. It is a block diagram which shows the outline of the structure of the electric vehicle 220 of a modification.

Next, an embodiment for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an electric drive system having motors MG1, MG2, MG3. be. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1, MG2, MG3, inverters 41, 42, 43, a battery 50 as a power storage device, and a main electronic control unit. A unit (hereinafter referred to as "main ECU") 70 is provided.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel, and is connected to the carrier of the planetary gear 30 via a damper 28. The engine 22 is operated and controlled by an electronic control unit for an engine (hereinafter referred to as "engine ECU") 24.

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and in addition to the CPU, has a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Be prepared. Signals from various sensors necessary for controlling the operation of the engine 22, for example, a crank angle θcr from the crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22 and the like are input to the engine ECU 24 from the input port. Has been done. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via the output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. A rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. A drive shaft 36F connected to the front wheels 39a and 39b via a differential gear 38F is connected to the ring gear of the planetary gear 30. As described above, the crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via the damper 28.

The motor MG1 is configured as a synchronous generator motor including a rotor in which a permanent magnet is embedded and a stator in which a three-phase coil is wound. As described above, the rotor is connected to the sun gear of the planetary gear 30. ing. The motor MG2 is configured as a synchronous generator motor like the motor MG1, and the rotor is connected to the drive shaft 36F. The motor MG3 is configured as a synchronous generator motor like the motors MG1 and MG2, and the rotor is connected to the drive shaft 36R connected to the rear wheels 39c and 39d via the differential gear 38R.

The inverters 41, 42, and 43 are used to drive the motors MG1, MG2, and MG3. As shown in FIG. 2, the inverter 41 is connected to the power line 54, and the transistors T11 to T16 as six switching elements and the six diodes D11 connected in parallel to each of the six transistors T11 to T16. ~ D16 and. Two transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side with respect to the positive electrode side line and the negative electrode side line of the power line 54, respectively. Further, each of the three-phase coils (U-phase, V-phase, W-phase) of the motor MG1 is connected to each of the connection points between the pair of transistors T11 to T16. Therefore, when a voltage is applied to the inverter 41, the electronic control unit for the motor (hereinafter referred to as “ECU for the motor”) 40 adjusts the ratio of the on-time of the paired transistors T11 to T16. , A rotating magnetic field is formed in the three-phase coil of the motor MG1, and the motor MG1 is rotationally driven.

The inverters 42 and 43 are connected to the power line 54, respectively, like the inverter 41, and have six transistors T21 to T26 and T31 to T36 and six diodes D21 to D26 and D31 to D36. Then, when a voltage is applied to the inverters 42 and 43, the motor ECU 40 adjusts the ratio of the on-time of the paired transistors T21 to T26 and T31 to T36 to adjust the ratio of the on-time to the three phases of the motors MG2 and MG3. A rotating magnetic field is formed in the coil, and the motors MG2 and MG3 are rotationally driven. Hereinafter, the transistors T11 to T13, T21 to T23, and T31 to T33 of the inverters 41, 42, and 43 are referred to as "upper arm", and the transistors T14 to T16, T24 to T26, and T31 to T36 are referred to as "lower arm".

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port are included. Be prepared. Signals from various sensors necessary for driving and controlling the motors MG1, MG2, and MG3 are input to the motor ECU 40 via the input port. The signals input to the motor ECU 40 include, for example, the rotation positions θm1, θm2, θm3 from the rotation position detection sensors 44, 45, 46 that detect the rotation position of the rotor of the motors MG1, MG2, MG3, and the motor MG1, Phase currents Iu1, Iv1, Iu2, Iv2, Iu3, Iv3 from a current sensor (not shown) that detects the phase current flowing in each phase of MG2 and MG3 can be mentioned. From the motor ECU 40, switching control signals and the like to the plurality of switching elements of the inverters 41, 42, and 43 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 may use the electric angles θe1, θe2, θe3 of the motors MG1, MG2, MG3 based on the rotation positions θm1, θm2, θm3 of the rotors of the motors MG1, MG2, MG3 from the rotation position detection sensors 44, 45, 46. The angular velocities ωm1, ωm2, ωm3 and the rotation speeds Nm1, Nm2, Nm3 are calculated.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverters 41, 42, 43 via the power line 54 as described above. The battery 50 is managed by a battery electronic control unit (hereinafter, referred to as “battery ECU”) 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and in addition to the CPU, has a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Be prepared. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. The signals input to the battery ECU 52 include, for example, the voltage Vb of the battery 50 from the voltage sensor 51a attached between the terminals of the battery 50 and the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. Examples include the current Ib and the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the current Ib of the battery 50 from the current sensor 51b. The storage ratio SOC is the ratio of the amount of electric power that can be discharged to the total capacity of the battery 50.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. .. Signals from various sensors are input to the HVECU 70 via the input port. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88. The vehicle speed V can be mentioned. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via a communication port.

In the hybrid vehicle 20 of the embodiment, the parking position (P position), the reverse position (R position), the neutral position (N position), the forward position (D position), and the brake position (B position) are prepared as the shift position SP. Has been done. The B position is a position in which the driving force when the accelerator is on is the same as the D position and the braking force when the accelerator is off is larger than the D position.

In the hybrid vehicle 20 of the embodiment configured in this way, the electric vehicle (EV travel) mode in which the vehicle travels without the operation of the engine 22 (rotation is stopped) and the hybrid vehicle travels with the operation (rotation) of the engine 22. The vehicle travels in a plurality of driving modes including the (HV driving) mode.

In the EV driving mode, the vehicle basically travels as follows. The HVECU 70 first sets the required torque Td * required for traveling based on the accelerator opening degree Acc and the vehicle speed V. Subsequently, the motor MG2 and MG3 are set so that the value 0 is set in the torque command Tm1 * of the motor MG1 and the required torque Td * is output to the front wheels 39a and 39b and the rear wheels 39c and 39d based on the torque distribution ratio kt. Torque commands Tm2 * and Tm3 * are set. Here, the torque distribution ratio kt is the ratio of the torque output to the rear wheels 39c and 39d to the sum of the torque output to the front wheels 39a and 39b and the torque output to the rear wheels 39c and 39d, and is the running state (at the time of starting). It is set based on (acceleration, constant speed, deceleration, slip, etc.). Then, the torque commands Tm1 *, Tm2 *, and Tm3 * of the set motors MG1, MG2, and MG3 are transmitted to the motor ECU 40. The motor ECU 40 controls switching of a plurality of switching elements of the inverters 41, 42, and 43 so that the motors MG1, MG2, and MG3 are driven by the torque commands Tm1 *, Tm2 *, and Tm3 *.

In the HV driving mode, the vehicle basically travels as follows. The HVECU 70 first sets the required torque Td * required for traveling based on the accelerator opening degree Acc and the vehicle speed V, and also sets the required torque Td * required for traveling based on the set required torque Td * and the vehicle speed V. Set the power Pd *. Subsequently, the required charge / discharge required power Pb * of the battery 50 is subtracted from the required power Pd * to calculate the required power Pe * required for the vehicle (required for the engine 22). Then, the required power Pe * is output from the engine 22, and the required torque Td * is output to the front wheels 39a and 39b and the rear wheels 39c and 39d based on the torque distribution ratio kt. Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 *, and Tm3 * of the motors MG1, MG2, and MG3 are set. Then, the target rotation speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the torque commands Tm1 *, Tm2 *, and Tm3 * of the motors MG1, MG2, and MG3 are transmitted to the motor ECU 40. The engine ECU 24 performs intake air amount control, fuel injection control, ignition control, and the like of the engine 22 so that the engine 22 is operated at the target rotation speed Ne * and the target torque Te *. The control of the inverters 41, 42, 43 by the motor ECU 40 has been described above.

Next, the operation of the hybrid vehicle 20 of the embodiment configured in this way, particularly the operation when the accelerator is off in the EV traveling mode will be described. FIG. 3 is a flowchart showing an example of an accelerator off control routine executed by the HVECU 70. This routine is repeatedly executed when the accelerator is off in the motor operation mode.

When the accelerator off control routine of FIG. 3 is executed, the HVECU 70 first inputs data such as a shift position SP, a vehicle speed V, and a storage ratio SOC of the battery 50 (step S100). Here, as the shift position SP, the one detected by the shift position sensor 82 is input. The vehicle speed V detected by the vehicle speed sensor 88 is input. The storage ratio SOC of the battery 50 is calculated based on the current Ib of the battery 50 from the current sensor 51b, and is input from the battery ECU 52 by communication.

When the data is input in this way, the required torque Td * is set based on the input shift position SP and vehicle speed V (step S110), and the motors are turned on when the inverters 41, 42, and 43 are turned on in three phases based on the vehicle speed V. The torques Ton1, Ton2, and Ton3 acting on the vehicle are estimated from MG1, MG2, and MG3 (step S120).

Since the accelerator is off, a negative value (braking torque) is set for the required torque Td *. In the embodiment, when the shift position SP is in the B position, a torque smaller (larger as an absolute value) than in the D position is set as the required torque Td *. Further, three-phase on of the inverter 41 means to turn on all of the upper arms (transistors T11 to T13) or all of the lower arms (transistors T14 to T16) of the transistors T11 to T16. The same applies to the three-phase on of the inverters 42 and 43. In the EV drive mode, the motor MG1 rotates negatively (reverse rotation to the drive shaft 36F), so when the inverter 41 is turned on in three phases, a torque that lowers the absolute value of the rotation speed Nm1 of the motor MG1 is generated, and this torque is generated. The drive shaft 36F and thus the front wheels 39a and 39b act as a braking torque (torque Ton1) via the planetary gear 30. Further, when the inverter 42 is turned on in three phases, a torque that lowers the absolute value of the rotation speed Nm2 of the motor MG2 is generated, and this torque acts as a braking torque (torque Ton2) on the drive shaft 36F and thus the front wheels 39a and 39b. Further, when the inverter 43 is turned on in three phases, a torque that lowers the absolute value of the rotation speed Nm3 of the motor MG3 is generated, and this torque acts as a braking torque (torque Ton3) on the drive shaft 36R and thus the rear wheels 39c and 39d. Therefore, the torques Ton1, Ton2, and Ton3 are all negative torques (braking torques), and in the embodiment, the torques Ton1, Ton3, and Ton2 are in the order from the larger side (smaller side as an absolute value). ..

Subsequently, the storage ratio SOC of the battery 50 is compared with the threshold value Sref1 and the threshold value Sref2 larger than the threshold value Sref1 and the threshold value Sref3 larger than the threshold value Sref2, and the required torque Td * is the sum of the torque Ton1 and the torque Ton1 and Ton3, and the torque Ton1 and 1. Compare with the sum of Ton2 and Ton3 (steps S130 to S180). Here, for example, 60%, 65%, 70% or the like is used as the threshold value Sref1, and as the threshold value Sref2, for example, a value larger than the threshold value Sref1 such as 8%, 10% or 12% is used, and the threshold value is used. As Sref3, for example, a value larger than the threshold value Sref2, such as 8%, 10%, or 12%, is used. Further, FIG. 4 shows an example of the relationship between the sum of torque Ton1, torque Ton1 and Ton3, the sum of torque Ton1, Ton2 and Ton3 and the vehicle speed V.

First, the storage ratio SOC of the battery 50 is compared with the threshold value Sref1 (step S130), and when the storage ratio SOC of the battery 50 is less than the threshold value Sref1, the required torque Td * is set in the torque command Tm2 * of the motor MG2 and the motor. The torque commands Tm1 * and Tm3 * of MG1 and MG3 are set to values 0 and transmitted to the motor ECU 40 (step S190) to end this routine. In this case, the motor MG2 is regeneratively driven by the torque command Tm2 * (= Td *), and the motors MG1 and MG3 are driven so that the torque becomes 0 (d-axis current is supplied). By such control, the required torque Td * can be applied to the vehicle.

In step S130, when the storage ratio SOC of the battery 50 is equal to or higher than the threshold Sref1, the storage ratio SOC of the battery 50 is compared with the threshold Sref2 (step S140), and when the storage ratio SOC of the battery 50 is less than the threshold Sref2, the inverter 41 A phase on command is transmitted to the motor ECU 40 (step S200), a value obtained by subtracting torque Ton1 from the required torque Td * is set in the torque command Tm2 * of the motor MG2, and a value 0 is set in the torque command Tm3 * of the motor MG3. These are transmitted to the motor ECU 40 (step S210), and this routine is terminated. In this case, the inverter 41 is turned on in three phases. When the inverter 41 is turned on in three phases, current circulates between the motor MG1 and the inverter 41, so that power is not supplied from the inverter 41 to the battery 50. The motor MG2 is regeneratively driven by the torque command Tm2 * (= Td * -Ton1) when the required torque Td * is smaller than the torque Ton1 (large as an absolute value), and is torque when the required torque Td * is larger than the torque Ton1. It is driven by force with the command Tm2 * (= Td * -Ton1), and is driven so that the torque becomes 0 when the required torque Td * and the torque Ton1 are equal. The motor MG3 is driven so that the torque becomes 0. By such control, the demand is made while suppressing the increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The torque Td * can be applied to the vehicle.

In step S140, when the storage ratio SOC of the battery 50 is the threshold value Sref2 or more, the required torque Td * is compared with the torque Ton1 (step S150), and when the required torque Td * is the torque Ton1 or more (absolute value is less than or equal to), the above is described. The processing of steps S200 and S210 of the above is executed, and this routine is terminated. In this case, the inverter 41 is turned on in three phases, the motor MG2 is driven by power running by the torque command Tm2 * (= Td * -Ton1) or driven so that the torque becomes a value 0, and the motor MG3 has a torque value 0. Driven to be. By such control, the demand is made while suppressing the increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The torque Td * can be applied to the vehicle.

When the required torque Td * is smaller than the threshold Ton1 (large as an absolute value) in step S150, the storage ratio SOC of the battery 50 is compared with the threshold Sref3 (step S160), and the storage ratio SOC of the battery 50 is less than the threshold Sref3. Occasionally, a three-phase on command of the inverters 41 and 43 is transmitted to the motor ECU 40 (step S220), and a value obtained by subtracting the sum of the torque Ton1 and Ton3 from the required torque Td * is set in the torque command Tm2 * of the motor MG2. Is transmitted to the motor ECU 40 (step S230), and this routine is terminated. In this case, the inverters 41 and 43 are turned on in three phases. When the required torque Td * is smaller than the sum of the torques Ton1 and Ton3 (large as an absolute value), the motor MG2 is regeneratively driven by the torque command Tm2 * (= Td * -Ton1-Ton3), and the required torque Td * is the torque. When it is larger than the sum of Ton1 and Ton3, it is driven by torque command Tm2 * (= Td * -Ton1-Ton3), and when the required torque Td * and the sum of torque Ton1 and Ton3 are equal, the torque becomes 0. Driven. By such control, the demand is made while suppressing the increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The torque Td * can be applied to the vehicle.

When the storage ratio SOC of the battery 50 is equal to or greater than the threshold value Sref3 in step S160, the required torque Td * is compared with the sum of the torques Ton1 and Ton3 (step S170), and the required torque Td * is equal to or greater than the sum of the torques Ton1 and Ton3 (absolute value). In the following cases), the processing of steps S220 and S230 described above is executed, and this routine is terminated. In this case, the inverters 41 and 43 are turned on in three phases, and the motor MG2 is driven by power running or the torque becomes 0 by the torque command Tm2 * (= Td * -Ton1-Ton3). By such control, the demand is made while suppressing the increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The torque Td * can be applied to the vehicle.

When the required torque Td * is smaller than the sum of the torques Ton1 and Ton3 (large as an absolute value) in step S170, the required torque Td * is compared with the sum of the torques Ton1, Ton2 and Ton3 (step S180), and the required torque Td is compared. When * is equal to or greater than the sum of torques Ton1, Ton2, and Ton3 (absolute value is less than or equal to), a three-phase on command of the inverters 41 and 43 is transmitted to the motor ECU 40 (step S240), and a value is sent to the torque command Tm2 * of the motor MG2. Set 0 (step S250) to end this routine. In this case, the inverters 41 and 43 are turned on in three phases, and the motor MG2 is driven so that the torque becomes zero. By such control, torque is suppressed while suppressing an increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The sum torque of To1 and Ton3 can be applied to the vehicle.

When the required torque Td * is smaller than the sum of the torques Ton1, Ton2, and Ton3 in step S180 (the absolute value is large), the three-phase on command of the inverters 41, 42, and 43 is transmitted to the motor ECU 40 (step S260). , End this routine. In this case, the inverters 41, 42, and 43 are turned on in three phases. By such control, torque is suppressed while suppressing an increase in the storage ratio SOC of the battery 50 as compared with the case where the motor MG2 is regeneratively driven with the required torque Td * without turning on the three phases of the inverters 41, 42, and 43. The torque of the sum of To1, Ton2, and Ton3 can be applied to the vehicle.

In the hybrid vehicle 20 of the embodiment described above, at least three phases of the inverter 41 are turned on when the storage ratio SOC of the battery 50 is equal to or higher than the threshold value Sref1 when the accelerator is off in the EV traveling mode. As a result, the braking torque can be applied to the vehicle while suppressing an increase in the storage ratio SOC of the battery 50 as compared with the inverters 41, 42, and 43 in which none of the inverters 41, 42, and 43 are turned on in three phases. Moreover, unlike the one in which the engine 22 during fuel cut is motorized by the motor MG1 to apply braking torque to the drive shaft 36F, the vehicle does not rotate the engine 22 (without generating the rotation noise of the engine 22). The braking torque can be applied to the engine. That is, the EV traveling mode can be continued.

In the hybrid vehicle 20 of the embodiment, a uniform value is used as the threshold values Sref1, Sref2, and Sref3 for the storage ratio SOC of the battery 50 regardless of the shift position SP. However, when the shift position SP is the B position, a smaller value may be used as the thresholds Sref1, Sref2, and Sref3 as compared with the case of the D position. When the accelerator is off and the shift position SP is in the B position, the required torque Td * is smaller (as an absolute value) than in the D position, so the generated power when the motor MG2 is regenerated becomes large, and the battery The storage ratio SOC of 50 tends to increase. In this modification, when the shift position SP is in the B position, the thresholds Sref1, Sref2, and Sref3 are made smaller than in the D position, so that the inverter 41 and the like are set from a state where the storage ratio SOC of the battery 50 is low. The phase can be turned on. As a result, the power generated by the regenerative drive of the motor MG2 can be reduced, and an increase in the storage ratio SOC of the battery 50 can be suppressed.

In the hybrid vehicle 20 of the embodiment, a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and a brake position (B position) are prepared as shift position SPs. It was supposed to be. However, in addition to these positions or in place of the brake position (B position), a sequential shift position (S position) having an upshift instruction position and a downshift instruction position may be prepared. Here, the S position is a position in which the driving force when the accelerator is on and the braking force when the accelerator is off (braking force larger than the D position) are changed according to the shift stage M of the virtual stepped transmission. As a result, in the S position, it is possible to give the driver a feeling of shifting due to the virtual stepped transmission. As the virtual stepped transmission, for example, a 4-speed transmission, a 5-speed transmission, a 6-speed transmission, a 7-speed transmission, an 8-speed transmission, and the like can be considered.

When the accelerator is off at the shift position SP and the accelerator is off, when the storage ratio SOC of the battery 50 is less than the threshold Sref, the braking torque of the vehicle is changed according to the shift stage M by the regenerative drive of the motor MG2, and the storage ratio of the battery 50 is stored. When the ratio SOC is equal to or higher than the threshold value Sref, the braking torque of the vehicle may be changed according to the shift stage M by turning on at least one of the inverters 41, 42, and 43 in three phases. In the latter case, the HVECU 70 may execute the accelerator off control routine of FIG. In this modification, a 7-speed transmission is considered as a virtual transmission. Further, the torque (braking torque) acting on the vehicle when at least one of the inverters 41, 42, and 43 is turned on in three phases is the torque from the larger side (smaller side as an absolute value) in this modification. The order is as follows: Ton1, Torque Ton3, Torque Ton2, Torque Ton1, Ton3 sum, Torque Ton1, Ton2 sum, Torque Ton2, Ton3 sum, Torque Ton1, Ton2, Ton3 sum.

When the accelerator off control routine of FIG. 5 is executed, the HVECU 70 first inputs the shift stage M (step S300), and determines whether or not the input shift stage M is the 7th speed stage (step). S310), when it is determined that the shift stage M is the 7th speed stage, a three-phase on command of the inverter 41 is transmitted to the motor ECU 40 (step S320), and this routine is terminated. In this case, the inverter 41 is turned on in three phases, and the torque Ton1 acts on the vehicle from the motor MG1.

When it is determined in step S310 that the shift stage M is not the 7th speed stage, it is determined whether or not the shift stage M is the 6th speed stage (step S330), and when it is determined that the shift stage M is the 6th speed stage, it is determined. A three-phase on command of the inverter 43 is transmitted to the motor ECU 40 (step S340), and this routine is terminated. In this case, the inverter 43 is turned on in three phases, and the torque Ton3 acts on the vehicle from the motor MG3.

When it is determined in step S330 that the shift stage M is not the 6th speed stage, it is determined whether or not the shift stage M is the 5th speed stage (step S350), and when it is determined that the shift stage M is the 5th speed stage, it is determined. The three-phase on command of the inverter 42 is transmitted to the motor ECU 40 (step S360), and this routine is terminated. In this case, the inverter 42 is turned on in three phases, and the torque Ton2 acts on the vehicle from the motor MG2.

When it is determined in step S350 that the shift stage M is not the 5th speed stage, it is determined whether or not the shift stage M is the 4th speed stage (step S370), and when it is determined that the shift stage M is the 4th speed stage, it is determined. The three-phase on command of the inverters 41 and 43 is transmitted to the motor ECU 40 (step S380), and this routine is terminated. In this case, the inverters 41 and 43 are turned on in three phases, and the torque of the sum of the torques Ton1 and Ton3 acts on the vehicle from the motors MG1 and MG3.

When it is determined in step S370 that the shift stage M is not the 4th speed stage, it is determined whether or not the shift stage M is the 3rd speed stage (step S390), and when it is determined that the shift stage M is the 3rd speed stage, it is determined. The three-phase on command of the inverters 41 and 42 is transmitted to the motor ECU 40 (step S400), and this routine is terminated. In this case, the inverters 41 and 42 are turned on in three phases, and the torque of the sum of the torques Ton1 and Ton2 acts on the vehicle from the motors MG1 and MG2.

When it is determined in step S390 that the shift stage M is not the third speed stage, it is determined whether or not the shift stage M is the second speed stage (step S410), and when it is determined that the shift stage M is the second speed stage, it is determined. The three-phase on command of the inverters 42 and 43 is transmitted to the motor ECU 40 (step S420), and this routine is terminated. In this case, the inverters 42 and 43 are turned on in three phases, and the torque of the sum of the torques Ton2 and Ton3 acts on the vehicle from the motors MG2 and MG3.

When it is determined in step S410 that the shift stage M is not the second speed stage, it is determined that the shift stage M is the first speed stage, and the three-phase on command of the inverters 41, 42, 43 is transmitted to the motor ECU 40 (step S430). ), End this routine. In this case, the inverters 41, 42, and 43 are turned on in three phases, and the torque of the sum of the torques Ton1, Ton2, and Ton3 acts on the vehicle from the motors MG1, MG2, and MG3.

By such control, the braking torque applied to the vehicle can be changed according to the shift stage M, specifically, the brake torque can be increased as the shift stage M becomes a low speed stage.

In the hybrid vehicle 20 of the embodiment, the battery 50 is used as the power storage device, but a capacitor may be used instead of the battery 50.

Although the hybrid vehicle 20 of the embodiment includes the engine ECU 24, the motor ECU 40, the battery ECU 52, and the main ECU 70, at least two of them may be configured as a single electronic control unit.

In the embodiment, as shown in FIG. 1, the engine 22 and the motor MG1 are connected to the drive shaft 36F connected to the front wheels 39a and 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36F to connect the rear wheels. The hybrid vehicle 20 has a configuration in which the motor MG3 is connected to the drive shaft 36R connected to the 39c and 39d, and the battery 50 is connected to the motors MG1, MG2, MG3 via the power line 54. However, as shown in FIG. 6, the motor MG2 is connected to the drive shaft 36F connected to the front wheels 39a and 39b via the transmission 130, and the engine 22 is connected to the motor MG2 via the clutch 129 to connect the rear wheels 39c. A hybrid vehicle 120 may be configured in which the motor MG3 is connected to the drive shaft 36R connected to the motor MG2, and the battery 50 is connected to the motors MG2 and MG3 via the power line 54. Further, as shown in FIG. 7, the motor MG2 is connected to the drive shaft 36F connected to the front wheels 39a and 39b, and the motor MG3 is connected to the drive shaft 36R connected to the rear wheels 39c and 39d. The electric vehicle 320 may be configured in which the battery 50 is connected to the power line 54 via the power line 54. In addition, the hybrid vehicle 20 and 120 of FIGS. 1 and 6 and the electric vehicle 320 of FIG. 7 may be configured by removing the motor MG3 and the inverter 43.

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 will be described. In the embodiment, the motor MG2 corresponds to the "motor", the inverter 42 corresponds to the "inverter", the battery 50 corresponds to the "storage device", and the HVECU 70 and the motor ECU 40 correspond to the "control device".

As for the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of means for solving the problems of the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these examples, and the present invention is not limited to these embodiments, and various embodiments are used without departing from the gist of the present invention. Of course it can be done.

The present invention can be used in the automobile manufacturing industry and the like.

20,120 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crank shaft, 28 damper, 30 planetary gear, 36F, 36R drive shaft, 38F, 38R differential gear, 39a, 39b Front wheel, 39c, 39d rear wheel, 40 motor electronic control unit (motor ECU), 41, 42, 43 inverter, 44, 45, 46 rotation position detection sensor, 50 battery, 52 battery electronic control unit (battery ECU), 54 power line, 57 condenser, 70 main electronic control unit (main ECU), 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, 129 clutch, 130 transmission, 220 electric vehicle, MG1, MG2, MG3 motor.

Claims (1)

With a driving motor
The inverter that drives the motor and
A power storage device connected to the inverter via a power line,
A control device that controls the inverter so that the motor is regeneratively driven when the accelerator is off.
It is a car equipped with
When the storage ratio of the power storage device is equal to or higher than a predetermined ratio when the accelerator is off, the control device turns on the inverter in three phases.
automobile.

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