JP2014217112A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress that a control mode of an electric motor is switched frequently when the output torque of the electric motor is limited according to the number of revolutions of the electric motor.SOLUTION: A motor ECU of a hybrid vehicle controls an inverter at either of a PWM control mode or a rectangular wave control mode according to a motion point (target motion point) of a motor MG2. A hybrid ECU of the hybrid vehicle makes the motor ECU control the inverter at either of a plurality of the control modes so that the motor MG2 outputs torque within a range of upper torque Tm2lim which is changed according to the number of revolutions Nm2 when the number of the revolutions Nm2 is included in a limit rotation range (N1 to N2) which is defined in advance so as to include the PWM control mode and the rectangular wave control mode, and limits a torque command Tm2*, that is, a change amount of the torque outputted by the motor MG2 (steps S150 to S 190).

Description

  The present invention relates to a vehicle control device including an electric motor, an inverter that drives the electric motor, and a battery that can exchange electric power with the electric motor via the inverter.

  Conventionally, as a control device for a hybrid vehicle, when an abnormality occurs in the battery, the system main relay is turned off to disconnect the battery from the power line, and the electric motor is driven using the electric power generated by the generator driven by the engine. In addition, there is known one that executes power control for bringing the voltage (system voltage VH) of the power line to which the generator and the motor are connected close to the voltage command value VHr (see, for example, Patent Document 1). This control device determines whether or not to execute the power control based on the upper and lower limit torques of the generator and the electric motor when executing the battery-less running for running the hybrid vehicle without using the electric power from the battery, When it is determined that the control cannot be executed, the execution of the batteryless traveling is stopped to suppress the system voltage VH from becoming an overvoltage. Conventionally, as a motor drive device of a hybrid vehicle or an electric vehicle, a plurality of control modes of an electric motor (inverter) such as a pulse width modulation (PWM) control mode and a rectangular wave control mode are composed of the torque and the rotational speed of the electric motor. The one that switches according to the operating point (target operating point) is known (for example, see Patent Document 2).

JP2012-153220A JP 2006-136184 A

  In the vehicle described in Patent Document 1, when the system voltage is constant, the upper limit torque is set smaller as the rotational speed is higher. For this reason, when the upper limit torque is set, if the motor's output torque increases in response to the driver's torque request and the motor speed increases, the upper limit torque is set to a smaller value as the speed increases. Accordingly, the output torque of the electric motor is suppressed. Further, when the rotation speed of the electric motor is decreased due to the suppression of the output torque, the upper limit torque is changed to the increase side in accordance with the decrease in the rotation speed, and the restriction on the output torque of the electric motor is relaxed (released). Therefore, in the vehicle described in Patent Document 1, when the upper limit torque is set, a state where the output torque of the electric motor is limited by the upper limit torque and a state where the output torque of the electric motor is not limited by the upper limit torque are repeated. The operating point of the electric motor composed of the torque and the rotational speed may frequently fluctuate (hunting). If the operating point (target operating point) of the motor frequently fluctuates across the switching point of the control mode as described in Patent Document 2, the control mode of the motor is frequently switched, and the switching of the control mode is performed. There is a risk of causing vehicle vibrations due to fluctuations in the output torque of the electric motor.

  Accordingly, the main object of the present invention is to suppress frequent switching of the control mode of the motor when the output torque of the motor is limited according to the rotation speed of the motor.

A vehicle control apparatus according to the present invention includes:
In a vehicle control device comprising: an electric motor; an inverter that drives the electric motor; and a battery that can exchange electric power with the electric motor via the inverter.
PWM control mode and rectangular wave control so that when the rotational speed of the motor is included in a predetermined limited rotational range, the motor outputs a torque within a range of an upper limit torque that is changed according to the rotational speed When the inverter is controlled by any one of a plurality of control modes including a mode, and the change point of the plurality of control modes is included in the limited rotation range, the amount of change in torque output by the motor is limited. It is characterized by doing.

  The vehicle control device performs PWM control so that, when the rotation speed of the motor is included in a predetermined limit rotation range, the motor outputs a torque within a range of an upper limit torque that is changed according to the rotation speed. The inverter is controlled by any one of a plurality of control modes including a mode and a rectangular wave control mode. And this control apparatus restrict | limits the variation | change_quantity of the torque output by an electric motor, when the switching point of a some control mode is contained in a restriction | limiting rotation area. As described above, when the upper limit torque of the motor is changed according to the number of revolutions, if the amount of change in the torque output by the motor is limited, the output torque of the motor is limited by the upper limit torque, The state in which the output torque is not limited by the upper limit torque is repeated and the motor rotation speed fluctuates, so that the operating point of the motor consisting of torque and rotation speed frequently fluctuates across the control mode switching points. Can be suppressed. Therefore, according to this control apparatus, even when the switching speed of a plurality of control modes is included in a predetermined limited rotation range, when the output torque of the motor is limited by the upper limit torque that is changed according to the rotational speed. In addition, frequent switching of the control mode of the electric motor can be satisfactorily suppressed.

  Further, when the rotational speed of the electric motor is included in the limited rotational range, the control device sets the upper limit torque to be smaller as the rotational speed is higher, and the torque output by the electric motor decreases. May not limit the amount of change in the torque. That is, even when the upper limit torque is set to be smaller as the rotation speed is higher when the rotation speed of the motor is included in the limited rotation range, the output torque is less likely to be limited by the upper limit torque when the output torque of the motor is reduced. Therefore, the possibility that the operating point of the motor frequently fluctuates across the switching points of the control mode is extremely low. Therefore, for example, if the change amount of the torque is limited only when the output torque of the electric motor increases, and the change amount of the torque is not limited when the output torque decreases, the request of the driver of the vehicle is met. Torque can be output from the electric motor.

  The vehicle may further include a boost converter capable of boosting electric power from the battery and supplying the boosted power to the inverter, and the control device is prohibited from being boosted by the boost converter, and the limited rotation The upper limit torque may be set according to the rotation speed of the electric motor so that resonance does not occur in the boost converter when the rotation speed of the electric motor is included in a region. As a result, even when a plurality of control mode switching points are included in the predetermined limited rotation range, the output torque of the electric motor is changed according to the rotation speed as the boosting by the boost converter is prohibited. When limiting by the upper limit torque, it is possible to satisfactorily suppress frequent switching of the control mode of the motor while suppressing the occurrence of resonance in the boost converter and protecting the components.

It is a schematic block diagram which shows the hybrid vehicle as a vehicle provided with the control apparatus by this invention. 5 is a flowchart illustrating an example of a drive control routine during boost inhibition that is executed when boosting by the boost converter is inhibited. It is explanatory drawing which shows an example of an upper limit torque setting map.

  Next, the form for implementing this invention is demonstrated, referring drawings.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 according to the present invention. The hybrid vehicle 20 shown in the figure is synchronized with an engine (internal combustion engine) 22 that generates power by the explosion combustion of a mixture of hydrocarbon fuel such as gasoline and light oil and air, and a single pinion planetary gear 30. Motors MG1 and MG2 configured as generator motors are included. Further, hybrid vehicle 20 includes an engine electronic control unit 24 that controls engine 22, inverters 41 and 42 for driving motors MG1 and MG2, a battery 50 electrically connected to inverters 41 and 42, an inverter Step-up converter 60 interposed between 41 and 42 and battery 50, motor electronic control unit 40 for controlling motors MG1 and MG2 via inverters 41 and 42, and battery electronic control unit 55 for managing battery 50 And a hybrid electronic control unit 70 that controls the entire vehicle while communicating with these electronic control units 24, 40, 55, and the like. Each of the electronic control units 24, 40, 55, and 70 is configured as a microcomputer centering on a CPU (not shown). Hereinafter, the “electronic control unit” is referred to as “ECU”.

  Motor MG1 mainly operates as a generator driven by engine 22 to generate electric power, and motor MG2 operates mainly as an electric motor driven by electric power from battery 50 to generate power. Motors MG1 and MG2 exchange power with battery 50 through inverters 41 and 42, respectively. Planetary gear 30 is connected to a sun gear (first element) 31 connected to a rotor (rotary shaft) of motor MG1 and to a drive shaft 35 and to a rotor (rotary shaft) of motor MG2 via transmission 36. A ring gear (second element) 32 and a planetary carrier (third element) 34 that supports the plurality of pinion gears 33 and is connected to the crankshaft (output shaft) 26 of the engine 22 via the damper 28. The drive shaft 35 connected to the ring gear 32 is connected to left and right wheels (drive wheels) DW via a gear mechanism (not shown) and a differential gear 38. The transmission 36 performs connection between the rotor of the motor MG2 and the drive shaft 35 and release of the connection, and can set the gear ratio between the rotor and the drive shaft 35 in a plurality of stages. It is controlled by the ECU 70.

  The inverters 41 and 42 include, for example, six transistors and six diodes connected to the six transistors in the reverse direction and in parallel. Boost converter 60 includes two transistors, two diodes connected in reverse and in parallel to the two transistors, and a reactor. Then, by turning on and off the two transistors of the boost converter 60, the power from the battery 50 is boosted and supplied to the inverters 41 and 42, or the power from the inverters 41 and 42 is stepped down and supplied to the battery 50 and the like. Can be. Further, a smoothing capacitor 61 for smoothing the voltage between the battery 50 and the boost converter 60 is disposed. Between the inverters 41 and 42 and the boost converter 60, the voltage between the two is set. A smoothing capacitor 62 for smoothing is disposed.

  Inverters 41 and 42 are controlled by motor ECU 40. The motor ECU 40 includes, for example, a current (not shown) for detecting a signal from a rotational position detection sensor that detects the rotational position of the rotor of the motors MG1 and MG2 and a phase current flowing in the U phase and V phase of the three-phase coils of the motors MG1 and MG2. Phase current from the sensor, voltage VL between terminals of the smoothing capacitor 61 detected by a voltage sensor (not shown) (hereinafter referred to as “voltage VL before boosting”), and terminals of the smoothing capacitor 62 detected by another voltage sensor (not shown). A signal necessary for drive control of the motors MG1 and MG2, such as an inter-voltage VH (hereinafter referred to as “voltage VH after boosting”) is input. The motor ECU 40 calculates the rotational speeds Nm1, Nm2, etc. of the motors MG1, MG2 based on the signal from the rotational position detection sensor, and outputs a switching control signal to the transistors of the inverters 41, 42. In the present embodiment, the boost converter 60 (two transistors) is controlled (switching controlled) by the hybrid ECU 70.

  The battery 50 is configured as a lithium ion secondary battery or a nickel hydride secondary battery. The battery ECU 55 that manages the battery 50 includes a charge / discharge voltage (voltage between terminals) Vb detected by a voltage sensor (not shown), a charge / discharge current Ib detected by a current sensor (not shown), and not shown. The battery temperature Tb detected by the temperature sensor is input. The battery ECU 55 calculates the charge ratio (remaining capacity) SOC of the battery 50 based on the integrated value ∫Ib of the charge / discharge current Ib. Further, the battery ECU 55 performs the charging so that the charging rate SOC of the battery 50 falls within a range between a predetermined upper limit value SH and a lower limit value SL according to a predetermined charging / discharging required power setting map (not shown). Based on the ratio SOC, charge / discharge required power Pb * (the discharge side is positive and the charge side is negative) as the target charge / discharge power of battery 50 is set. Further, the battery ECU 55 receives the input limit Win as the allowable charging power that is the power allowed for charging the battery 50 based on the charging rate SOC and the battery temperature Tb, and the allowable discharge that is the power allowed for discharging the battery 50. An output limit Wout as power is set.

  As described above, the hybrid ECU 70 inputs various signals from the ECUs 24, 40, and 55, and inputs signals from various sensors. For example, the hybrid ECU 70 detects an ignition signal from an ignition switch (start switch) (not shown), an accelerator opening (accelerator operation amount) Acc from an accelerator pedal position sensor 72 that detects the depression amount of the accelerator pedal 71, and the shift lever 73. The shift position SP from the shift position sensor 74 that detects the shift position SP corresponding to the operation position, the brake pedal position BP from the brake pedal position sensor 76 that detects the depression amount of the brake pedal 75, and the vehicle speed V from a vehicle speed sensor (not shown). Enter etc.

  The hybrid ECU 70 sets the required torque Tr * required for the drive shaft 35 based on the accelerator opening Acc from the accelerator pedal position sensor 72 and the vehicle speed V from the vehicle speed sensor when the hybrid vehicle 20 travels. Based on the required torque Tr *, the rotational speed Nr (= Nm2 / γ) of the drive shaft 35, the required charge / discharge power Pb *, etc., the required power P * required for the entire vehicle is set according to the following equation (1). In Equation (1), “Nm2” is the rotational speed of the motor MG2 detected by a rotational speed sensor (not shown), “γ” is the current speed ratio of the transmission 36, and “Loss” is Indicates loss. Further, when the engine 22 is in operation, the hybrid ECU 70 sets the target rotational speed Ne * and the target torque Te * of the engine 22 corresponding to the required power P * from a predetermined operation line, and transmits it to the engine ECU 24. To do. Then, the engine ECU 24 executes intake air amount control, fuel injection control, ignition timing control, and the like based on the target rotational speed Ne * and the target torque Te *. As a result, the engine 22 outputs power corresponding to the sum of the required travel power (Tr * × Nr) corresponding to the required torque Tr * and the required charge / discharge power Pb * required for charging / discharging the battery 50. Controlled.

  P * = Tr * × Nm2 / γ-Pb * + Loss (1)

  Further, the hybrid ECU 70 determines the motor MG1 according to the following equation (2) based on the target rotational speed Ne *, the rotational speed Nm2 of the motor MG2 detected by a rotational speed sensor (not shown), the gear ratio ρ of the planetary gear 30, and the current speed ratio γ. Target rotation speed Nm1 * is calculated. Further, the hybrid ECU 70 converts the torque command (target torque) Tm1 * of the motor MG1 and the torque command (target torque) Tm2 * of the motor MG2 into the input limit Win and the output limit of the battery 50 in accordance with the following equations (3) and (4). The torque commands Tm1 * and Tm2 * are set within the Wout range and transmitted to the motor ECU 40. Expression (3) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 * and rotating the engine 22 at the target rotational speed Ne *, and “Nm1” in the formula is The rotation speed of the motor MG1 detected by a rotation speed sensor (not shown), “k1” is a proportional term gain, and “k2” is an integral term gain. Then, the motor ECU 40 performs switching control of the switching elements of the inverters 41 and 42 based on the torque commands Tm1 * and Tm2 *. Thus, when engine 22 is in operation, battery 50 is charged / discharged in accordance with charge / discharge required power Pb *, and all or part of the power output from engine 22 is motors MG1, MG2 and planetary gears. By performing the torque conversion by 30, torque corresponding to the required torque Tr * is output to the drive shaft 35.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (γ ・ ρ) (2)
Tm1 * =-ρ / (1 + ρ) ・ Te * + k1 ・ (Nm1 * -Nm1) + k2 ・ ∫ (Nm1 * -Nm1) dt (3)
Tm2 * = (Tr * + Tm1 * / ρ) / γ (4)

  Further, the hybrid ECU 70 determines the battery 50 according to the target operating point of the motor MG1 composed of the torque command Tm1 * and the current rotational speed Nm1, and the target operating point of the motor MG2 composed of the torque command Tm2 * and the current rotational speed Nm2. Boost converter 60 is controlled so that the rated voltage is boosted to a predetermined voltage higher than that. That is, hybrid ECU 70 is predetermined for each of torque commands Tm1 * and Tm2 * for motors MG1 and MG2, rotational speeds Nm1 and Nm2 of motors MG1 and MG2, and stored in the ROM of hybrid ECU 70. The target boosted voltage VHtag, which is the target value of the boosted voltage VH corresponding to the traveling state of the hybrid vehicle 20, is set using the target boosted voltage setting map (not shown), and the boosted voltage VH is the target boosted voltage. Switching control of the transistors of the boost converter 60 is executed so that the voltage VHtag is obtained.

  The target post-boost voltage setting map is created so that the operation region of the motors MG1 and MG2 is divided into a non-boosting region where the pre-boosting voltage VL on the battery 50 side is not boosted by the boost converter 60 and a boosting region where the voltage is boosted. Specifically, the side where the absolute value of the motor rotation number is low is defined as the non-boosting region, and the side where the absolute value of the motor rotation number is high is defined as the boosting region. Further, in the present embodiment, a resonant circuit is configured by the reactor of boost converter 60 and smoothing capacitors 61 and 62, so that voltage or current is increased in boost converter 60 when the operating point of motors MG1 and MG2 is included in a predetermined region. Based on the fact that the resonance occurs, the target post-boost voltage setting map is created so that the boosting region includes the resonance region that is the region including the operating point of the motors MG1 and MG2 when the boost converter 60 generates the resonance. Is done. Hybrid ECU 70 then sets a value corresponding to the target operating point of motor MG1 derived from the target post-boosting voltage setting map for motor MG1, and a target of motor MG2 derived from the target post-boosting voltage setting map for motor MG2. The larger of the value corresponding to the operating point is set as the target boosted voltage VHtag.

  Further, the motor ECU 40 performs a sine wave PWM control mode using a sine wave PWM voltage, an overmodulation PWM control mode using an overmodulation PWM voltage, and a rectangular wave control using a rectangular wave voltage in accordance with the target operating points of the motors MG1 and MG2. The inverters 41 and 42 are switching-controlled by any one of three control modes called modes. In the sine wave PWM control mode, the transistors of the inverters 41 and 42 are turned on / off in accordance with the voltage difference between the sine wave voltage command value and a carrier wave such as a triangular wave, thereby providing an output having a sine wave fundamental wave component. In this mode, voltage (PWM voltage) is obtained. When the sine wave PWM control mode is used, the modulation factor Kmd, which is the ratio of the output voltage (amplitude of the fundamental wave component) to the boosted voltage VH, can be set within a range of approximately 0 to 0.61. The overmodulation PWM control mode performs control similar to the above-described sine wave PWM control mode after distorting the carrier wave so as to reduce the amplitude, and the modulation factor Kmd is approximately 0.61 to 0. It can be set within the range of .78. Furthermore, the rectangular wave control mode can theoretically generate a fundamental wave component having the maximum amplitude (modulation factor Kmd≈0.78), and the phase of a rectangular voltage with a constant amplitude can be set as a torque command. It is possible to control the motor torque by changing it according to.

  In the present embodiment, the motor ECU 40 is predetermined for each of the torque commands Tm1 *, Tm2 * for the motors MG1, MG2, the rotational speeds Nm1, Nm2 of the motors MG1, MG2, and the motors MG1, MG2. A control mode used to control the inverter 41 corresponding to the motor MG1 and the inverter 42 corresponding to the motor MG2 is determined using a control mode setting map (not shown) stored in the ROM. The control mode setting map includes a sine wave PWM control area in which the sine wave PWM control mode is used, and an overmodulation PWM in order from both the non-boosting area and the boosting area in order from the lowest motor rotation speed. It is created so as to be divided into an overmodulation PWM control region in which the control mode is used and a rectangular wave control region in which the rectangular wave control mode is used. In the present embodiment, the control mode setting map indicates that the control mode in the resonance region, which is the region including the operating point of the motor MG1 or MG2 when resonance occurs in the boost converter 60, is the sine wave PWM control mode. The control mode in the region including the other target operating point of the motors MG1 and MG2 when one target operating point of the motors MG1 and MG2 is included in the resonance region is created as the sine wave PWM control mode. . As described above, by using the sine wave PWM control mode which is superior in control accuracy compared to the overmodulation PWM control mode and the rectangular wave control mode when the target operating point of the motor MG1 or MG2 is included in the resonance region, the boost converter 60 In addition, it is possible to properly control the inverters 41 and 42 while protecting the components so that an excessive voltage does not act on the smoothing capacitors 61 and 62 or an excessive current does not flow.

  Next, the operation of hybrid vehicle 20 when boosting by boost converter 60 is prohibited due to failure of boost converter 60 or the like will be described. FIG. 2 is a flowchart illustrating an example of a boost prohibition drive control routine that is repeatedly executed by the hybrid ECU 70 at predetermined intervals when boosting by the boost converter 60 is prohibited.

  In the execution of the drive control routine when the pressure increase is prohibited in FIG. 2, first, the hybrid ECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 72, the vehicle speed V from a vehicle speed sensor (not shown), and the rotational speeds Nm1, Nm2 of the motors MG1, MG2. Data required for control, such as the charge / discharge required power Pb * of the battery 50 and the values of the input / output limits Win and Wout, are input (step S100). The rotational speeds Nm1, Nm2 of the motors MG1, MG2 are input from the motor ECU 40 through communication, and the charge / discharge required power Pb * and the input / output limits Win, Wout of the battery 50 are input from the battery ECU 55 through communication.

  After the data input process of step S100, the hybrid ECU 70 sets the required torque Tr * required for the drive shaft 35 based on the accelerator opening degree Acc input in step S100 and the vehicle speed V from the vehicle speed sensor. The required power P * required for the entire vehicle is set according to the equation (1) (step S110), and the target rotational speed Ne * and target torque Te * of the engine 22 are set based on the set required power P * (step S110). S120). Further, the hybrid ECU 70 uses the rotational speeds Nm1, Nm2 of the motors MG1, MG2 input in step S100, the target rotational speed Ne * of the engine 22, etc., and the torque of the motor MG1 according to the above formulas (2) and (3). The command Tm1 * is set within the range of the input limit Win and the output limit Wout of the battery 50, and the torque command Tm2 * of the motor MG2 is set according to the above equation (4) using the required torque Tr * and the torque command Tm1 *. It is set within the range of the input limit Win and the output limit Wout of the battery 50 (step S130).

  Next, hybrid ECU 70 calculates upper limit torque Tm2lim of motor MG2 using rotation speed Nm2 of motor MG2 input in step S100 and an upper limit torque setting map stored in the ROM of hybrid ECU 70 in advance. Set (step S140). FIG. 3 shows an example of the upper limit torque setting map with a solid line. As shown in the figure, the upper limit torque setting map used when the boost operation is prohibited is created so as to change the upper limit torque Tm2lim according to the rotation speed Nm2 of the motor MG2. That is, the upper limit torque setting map is when the rotational speed Nm2 of the motor MG2 is lower than a predetermined rotational speed N1 (for example, 800 rpm) and higher than a predetermined rotational speed N2 (> N1, for example, 1000 rpm). In addition, the maximum output torque of the motor MG2 corresponding to the rotational speed Nm2 when the voltage based on the rated voltage of the battery 50 (= the boosted voltage VH at the time of non-boosting) is applied to the motor MG2 as the upper limit torque Tm2lim To the maximum output torque). In the present embodiment, the upper limit torque setting map indicates that the upper limit torque Tm2lim is smaller than the maximum output torque when the rotation speed Nm2 of the motor MG2 is included in the limited rotation range from the rotation speed N1 to N2. The higher the number Nm2, the smaller the setting.

  As shown in FIG. 3, the rotational speeds N1 and N2 that define the limited rotation range, and the upper limit torque Tm2lim in the limited rotation range are the operating points included in the above-described resonance range (see the dotted line in FIG. 3). It is determined not to be driven. Further, the limited rotation speed range (revolution speeds N1 and N2) is somewhat higher than the rotation speed range that defines the resonance range so that the output torque of the motor MG2 does not fluctuate excessively by abruptly changing the upper limit torque Tm2lim. To have a margin of. In the present embodiment, the first switching line (see the one-dot chain line in FIG. 3) that defines the boundary between the sine wave PWM control region and the overmodulation PWM control region of the motor MG2 during non-boosting, and the motor during non-boosting The second switching line (see the two-dot chain line in FIG. 3) that defines the boundary between the overmodulation PWM control region and the rectangular wave control region of MG2 is included in the limited rotation region. That is, the torque line defined by the upper limit torque Tm2lim within the limited rotation range intersects with both the first and second switching lines.

  After setting the upper limit torque Tm2lim in this manner, the hybrid ECU 70 determines whether or not the rotation speed Nm2 of the motor MG2 input in step S100 is included in the above-described limited rotation range (N1 to N2) (step). S150). When it is determined that the rotational speed Nm2 of the motor MG2 is included in the limited rotational speed range, the hybrid ECU 70 determines that the rotational speed Nm2 (previous Nm2) of the motor MG2 input in step S100 during the previous execution of this routine is in step S100. It is determined whether or not it is greater than the input current rotational speed Nm2 (current Nm2) of the motor MG2, that is, whether or not the motor MG2 is decelerating (step S160).

  When it is determined in step S160 that the motor MG2 is decelerating, the hybrid ECU 70 determines that the torque command Tm2 * (current Tm2 *) set in step S130 is the torque command for the motor MG2 that was set when this routine was last executed. It is determined whether or not it is greater than the sum of Tm2 * (previous Tm2 *) and a predetermined relatively small rate value ΔT (for example, a value of about 1N) (step S170). If it is determined that the current Tm2 * is greater than the sum of the previous Tm2 * and the rate value ΔT, the hybrid ECU 70 determines that the previous Tm2 * and the rate value ΔT are limited so that the amount of change in the torque command Tm2 * is limited. Is set to the torque command Tm2 * (step S180), the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the motors MG1 and MG2 Torque commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S190), and the process of shifting to step S100 is executed again.

  As described above, in hybrid vehicle 20, when boosting by boost converter 60 is prohibited, rotation speed Nm2 of motor MG2 is within a limited rotation range (N1 to N2) in which upper limit torque Tm2lim is changed according to rotation speed Nm2. When the motor MG2 is decelerated and the current Tm2 * is larger than the sum of the previous Tm2 * and the rate value ΔT, the torque command Tm2 *, that is, the amount of change in the output torque of the motor MG2 is limited. (Steps S150 to S180). Accordingly, it is possible to suppress fluctuations in the rotational speed Nm2 by repeating the state where the output torque of the motor MG2 is limited by the upper limit torque Tm2lim and the state where the output torque of the motor MG2 is not limited by the upper limit torque Tm2lim. it can. That is, in hybrid vehicle 20, when a relatively large torque request is made from the driver while boosting by boost converter 60 is prohibited, the output torque of motor MG2 increases in response to the driver's torque request. As a result, the rotational speed Nm2 is increased, and the upper limit torque Tm2lim is set to be small as the rotational speed Nm2 is increased, so that the output torque of the motor MG2 is suppressed, and the output torque is suppressed, so that the rotational speed Nm2 is decreased. It can be suppressed that the upper limit torque Tm2lim is changed to the increase side and the limitation on the output torque of the motor MG2 is released (relaxed).

  As a result, as shown by a thick solid arrow in FIG. 3, the operating point (target operating point) of the motor MG2 determined from the torque command Tm2 * and the rotational speed Nm2 is the control mode switching point (inverter 42) of the motor MG2 (inverter 42). It is possible to suppress frequent fluctuations across the first switching line and the second switching line. Therefore, in hybrid vehicle 20, even if a predetermined limited rotation range includes a plurality of control mode switching points, the upper limit torque that changes the output torque of motor MG2 in accordance with the rotational speed Nm2 in the limited rotation range. When limiting by Tm2lim, it is possible to satisfactorily suppress frequent switching of the control mode of the motor MG2, and to satisfactorily suppress occurrence of vehicle vibration due to fluctuations in the output torque of the motor MG2 due to switching of the control mode. It becomes possible. Further, in hybrid vehicle 20, even if a plurality of control mode switching points are included in a predetermined limited rotation range, the output torque of motor MG <b> 2 is set to the number of rotations as boosting by boost converter 60 is prohibited. When limiting by the upper limit torque Tm2lim that is changed according to Nm2, the occurrence of resonance in the boost converter 60 is suppressed, and an excessive voltage acts on the boost converter 60 and the smoothing capacitors 61 and 62, or an excessive current is generated. It is possible to protect the parts so that they do not flow.

  On the other hand, if it is determined in step S150 that the rotational speed Nm2 of the motor MG2 is not included in the range of the limited rotational range (N1 to N2), if it is determined in step S160 that the motor MG2 is not decelerated, and When it is determined in step S170 that the current Tm2 * is equal to or less than the sum of the previous Tm2 * and the rate value ΔT, the hybrid ECU 70 limits the output torque of the motor MG2 by the upper limit torque Tm2lim and the upper limit torque Tm2lim. It is assumed that the state of not being repeated is low, and a value obtained by limiting the torque command (current torque command) Tm2 * set in step S130 with the upper limit torque Tm2lim is reset to the torque command Tm2 * (step S200). Then, hybrid ECU 70 transmits target rotational speed Ne * and target torque Te * of engine 22 to engine ECU 24, and also transmits torque commands Tm1 * and Tm2 * of motors MG1 and MG2 to motor ECU 40 (step S190). The process of moving to step S100 is executed again.

  As described above, the motor ECU 40 as the control device of the hybrid vehicle 20 operates in accordance with the PWM control mode (sine wave PWM control mode and overmodulation PWM control mode) and the rectangular wave according to the operating point (target operating point) of the motor MG2. The hybrid ECU 70 as a control device for the hybrid vehicle 20 controls the inverter 42 in any one of the control modes, and the limited rotation range (N1 to N2) determined in advance so as to include a switching point between the PWM control mode and the rectangular wave control mode. ) Includes the number of revolutions Nm2 of the motor MG2, and the motor MG2 outputs any torque within the range of the upper limit torque Tm2lim that is changed according to the number of revolutions Nm2. The inverter 42 is controlled by the torque command Tm of the motor MG2. * That limits the amount of change of torque output by the motor MG2 (step S150~S190). As described above, when the upper limit torque Tm2lim of the motor MG2 is changed according to the rotation speed Nm2, if the amount of change in the torque output by the motor MG2 is limited, the output torque of the motor MG2 is limited by the upper limit torque Tm2lim. When the rotational speed Nm2 fluctuates due to repeated state and unrestricted state, the operating point of the motor MG2 composed of the torque command Tm2 * and the rotational speed Nm2 frequently fluctuates across the control mode switching points. Can be suppressed. Therefore, in hybrid vehicle 20, even if a plurality of control mode switching points are included in a predetermined limited rotation range, output torque of motor MG 2 is limited by upper limit torque Tm 2 lim that is changed according to rotation speed Nm 2. At this time, it is possible to satisfactorily suppress frequent switching of the control mode of the motor MG2 (inverter 42).

  In the above embodiment, the rate value ΔT is used to limit the amount of change in the torque command Tm2 * (steps S170 and S180), but the amount of change in the torque command Tm2 * is, for example, a slow change process such as an annealing process. May be limited. In the above embodiment, it is determined in step S160 whether or not the current Tm2 * is greater than the sum of the previous Tm2 * and the rate value ΔT. In step S160, the current Tm2 * is greater than the previous Tm2 *. It may be determined whether or not the value is also larger. That is, when the rotational speed Nm2 is higher and the upper limit torque Tm2lim is set smaller as the rotational speed Nm2 is higher when the rotational speed Nm2 of the motor MG2 is included in the limited rotational range as in the above embodiment, the output torque of the motor MG2 decreases. Therefore, the output torque is less likely to be limited by the upper limit torque Tm2lim, and the possibility that the operating point (target operating point) of the motor MG2 frequently fluctuates across the control mode switching points is extremely low. Therefore, for example, the change amount of the output torque (torque command Tm2 *) is limited only when the output torque of the motor MG2 increases, and when the output torque (torque command Tm2 *) decreases, the change amount of the output torque is set. If it does not limit, it becomes possible to output the torque according to the request | requirement of the driver | operator of the hybrid vehicle 20 from motor MG2. In the step-up prohibition drive control routine of FIG. 3, the process of step S160 may be omitted. 3 may be applied to the motor MG1, not only when boosting by the boost converter 60 is prohibited, but for example, overheating of the motor MG2, the inverter 42, etc. For the purpose of suppression (part protection), it may be applied when the upper limit torque of the motor MG2 or the like is changed according to the rotational speed Nm2 or the like in a predetermined limited rotation range.

  The hybrid vehicle 20 includes two motors MG1 and MG2 and a planetary gear 30, but the vehicle to which the present invention is applied has a generator driven by an engine, traveling power, and regenerative braking force. It may be a series-type hybrid vehicle including an output motor, and is a parallel type (including a generator motor that can output at least regenerative braking force, or a generator motor that can output driving power in addition to the regenerative braking force ( 1-motor type) hybrid vehicle or an electric vehicle including only an electric motor as a power generation source for traveling may be used. Furthermore, in the hybrid vehicle 20, a simple reduction gear mechanism may be employed instead of the transmission 36.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention. Absent.

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

  20 hybrid vehicle, 22 engine, 24 engine electronic control unit, 28 damper, 30 planetary gear, 32 ring gear, 33 pinion gear, 35 drive shaft, 36 transmission, 38 differential gear, 40 motor electronic control unit, 41, 42 inverter, 50 battery , 55 Battery electronic control unit, 60 Boost converter, 61, 62 Smoothing capacitor, 70 Hybrid electronic control unit, 71 Accelerator pedal, 72 Accelerator pedal position sensor, 73 Shift lever, 74 Shift position sensor, 75 Brake pedal, 76 Brake pedal position Sensor, MG1, MG2 motor.

Claims (2)

In a vehicle control device comprising: an electric motor; an inverter that drives the electric motor; and a battery that can exchange electric power with the electric motor via the inverter.
PWM control mode and rectangular wave control so that when the rotational speed of the motor is included in a predetermined limited rotational range, the motor outputs a torque within a range of an upper limit torque that is changed according to the rotational speed When the inverter is controlled by any one of a plurality of control modes including a mode, and the change point of the plurality of control modes is included in the limited rotation range, the amount of change in torque output by the motor is limited. A control apparatus for a vehicle. The vehicle control device according to claim 1,
When the rotational speed of the electric motor is included in the limited rotational range, the upper limit torque is set to be smaller as the rotational speed is higher, and when the torque output by the electric motor is reduced, the amount of change in the torque The vehicle control device is characterized by not limiting the vehicle.

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