JP2008068775A - Power output apparatus, method for controlling the same, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent overspeed of a first motor due to gate cut off of a boost circuit in a vehicle having the first motor, an engine and a driveshaft and second motor connected to a sun gear, a carrier and a ring gear of a planetary gear mechanism respectively and having the boost circuit for supplying boosted power from a battery to inverters for the first and second motors. <P>SOLUTION: If the first motor rotates at a speed Nm1 higher than a threshold Nref when a gate of the boost circuit (S110, S180) is cut off, the first motor outputs a predetermined torque T1 suppressing an engine speed Ne (S190). The speed increase in the engine and first motor can be suppressed compared with the case of cutting off the gate of the inverter for the first motor when the gate of the boost circuit is cut off, to avoid overspeed of the first motor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power output apparatus, a control method therefor, and a vehicle.

Conventionally, as this type of power output device, a drive motor that can drive a drive wheel and also functions as a generator, a function as a generator driven by an engine, and an electric motor for the engine A power generation motor that operates, a drive inverter that drives the drive motor, a power generation inverter that drives the power generation motor, a capacitor provided on the positive and negative buses of the drive inverter and the power generation inverter, A DC power supply that exchanges power with a drive motor and a power generation motor, and a DC / DC converter that adjusts a voltage to exchange power between the drive motor and the power generation motor and the DC power supply It has been proposed (see, for example, Patent Document 1). In this device, when an abnormality occurs in the DC / DC converter, the drive inverter and the power generation inverter are both forcibly stopped to suppress a rapid increase or decrease in the capacitor voltage.
JP 2004-112883 A

  By the way, in the above-described power output apparatus, when the engine, the drive motor and drive wheels, and the power generation motor are respectively connected to the planetary gear carrier, ring gear, and sun gear, the gate of the DC / DC converter is shut off. If both the drive inverter and the inverter for power generation are stopped, the power generation motor does not output the torque accompanying power generation, that is, the torque in the direction to hold down the engine speed, so that the collinear of the planetary gears such as when the accelerator pedal is depressed greatly In the figure, when the ring gear, carrier, and sun gear are in order of increasing rotation speed, the engine or power generation motor inertia may increase due to the inertia of the engine or power generation motor, causing the power generation motor to over-rotate. .

  A power output device, a control method thereof, and a vehicle according to the present invention include a voltage adjustment device that adjusts a voltage for exchanging electric power between the first drive circuit used for driving the first electric motor and the power storage unit. An object of the present invention is to prevent the first motor from over-rotating when the switching of the switching element of the voltage regulator is forcibly stopped.

  The power output apparatus, the control method thereof, and the vehicle control method of the present invention employ the following means in order to achieve the above-described object.

The power output apparatus of the present invention is
A power output device that outputs power to a drive shaft,
An internal combustion engine;
Connected to three shafts of the output shaft of the internal combustion engine, the drive shaft and the rotating shaft, and inputs / outputs power to / from the remaining one shaft based on power input / output to / from any two of the three shafts 3 Shaft power input / output means;
A first electric motor capable of inputting and outputting power to the rotating shaft;
A first drive circuit used for driving the first electric motor;
Power storage means capable of charging and discharging electric power;
A voltage adjusting unit that includes a switching element, and adjusts a voltage for exchanging electric power between the first drive circuit and the power storage unit by switching the switching element;
An engine that controls the first drive circuit so that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the first electric motor outputs a driving force in a direction that suppresses the rotational speed of the internal combustion engine. Control means for executing rotation speed suppression control;
It is a summary to provide.

  In the power output apparatus according to the present invention, switching of the switching element of the voltage adjusting means that includes the switching element and adjusts the voltage for exchanging power between the first drive circuit and the power storage means by switching of the switching element is forced. When the engine is turned off, engine speed suppression control is executed to control the first drive circuit so that the first electric motor outputs a driving force in a direction to hold down the rotational speed of the internal combustion engine. As a result, the rotational speed of the internal combustion engine and the rotational speed of the first electric motor are compared with those in which the first drive circuit is forcibly stopped when the switching of the switching element of the voltage adjusting means is forcibly stopped. The increase can be further suppressed, and the first motor can be further suppressed from over-rotating. Here, the “voltage adjusting unit” may be a booster circuit that can boost the voltage of the power storage unit and supply the boosted voltage to the first drive circuit. Further, “when the switching of the switching element of the voltage adjusting means is forcibly stopped” may be when the gate of the switching element of the voltage adjusting means is shut off.

  In such a power output apparatus of the present invention, a second electric motor capable of inputting / outputting power to / from the drive shaft, and a second electric motor used for driving the second electric motor and sharing the positive and negative buses with the first drive circuit. A driving circuit; and a capacitor having a predetermined withstand voltage connected to the positive and negative buses of the first driving circuit and the second driving circuit, and the voltage adjusting means is configured to operate when the switching element is off. The electric power generated by one electric motor or the second electric motor cannot be supplied to the power storage means, and the control means is configured such that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the voltage of the capacitor It may be a means for executing overvoltage suppression control for controlling the second drive circuit so that is less than or equal to the predetermined withstand voltage. In this case, when the switching of the switching element of the voltage adjusting means is forcibly stopped, the electric power generated by the first motor is charged in the power storage means even if the engine speed suppression control is executed. Therefore, this power is charged in the capacitor and the voltage of the capacitor rises. In the power output apparatus of the present invention, by performing the overvoltage suppression control, it is possible to suppress the capacitor from becoming an overvoltage and to protect the capacitor.

  The power output apparatus according to the present invention further includes required driving force setting means for setting required driving force required for the drive shaft, and the control means forcibly turns off switching of the switching element of the voltage adjusting means. Based on the set required driving force based on the driving force output to the driving shaft and the driving force output from the second electric motor to the driving shaft when the engine speed suppression control is stopped. It may be a means for executing power output control for controlling the second drive circuit so that a driving force is output to the drive shaft.

  In the power output apparatus of the present invention, comprising a second motor and a capacitor, wherein the control means executes power output control in addition to engine speed suppression control and overvoltage suppression control, the second motor is an AC motor, and the control The means is that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the generated electric power of the first motor during the execution of the engine speed suppression control is the second electric motor during the power output control. When the power consumption is larger than the power consumption of the second motor, at least part of the surplus power that is a surplus of the power generated by the first motor with respect to the power consumption of the second motor is caused by the output of reactive power that does not contribute to generation of driving force. It may be a means for executing the overvoltage suppression control so that it is consumed. If it carries out like this, it can suppress that a capacitor | condenser becomes an overvoltage, respond | corresponding to a request | requirement driving force by consuming at least one part of surplus electric power by a 2nd motor as reactive electric power.

  In the power output apparatus according to the present invention, comprising a second motor and a capacitor, wherein the control means executes engine speed suppression control and overvoltage suppression control. The second motor is an AC motor, and the control means is the voltage adjustment means. When switching of the switching element is forcibly stopped off, at least a part of the generated electric power of the first motor at the time of execution of the engine speed suppression control is output by reactive power that does not contribute to generation of driving force. The overvoltage suppression control may be executed by the second electric motor so as to be consumed. If it carries out like this, it can suppress that a capacitor | condenser becomes an overvoltage by making a 2nd motor consume at least one part of surplus electric power as reactive power.

  The power output apparatus according to the present invention further includes a rotation speed detection unit that detects a rotation speed of the first electric motor, the first drive circuit includes a switching element, and the control unit switches the switching element of the voltage adjustment unit. When the engine is forcibly stopped off, the gate of the switching element of the first drive circuit is shut off in place of the engine speed suppression control when the detected rotation speed of the first motor is equal to or less than a predetermined rotation speed. It may be a means for executing a cutoff control for controlling the first drive circuit. If it carries out like this, when the rotation speed of a 1st electric motor is below predetermined rotation speed, it can suppress that electric power generation is performed by a 1st electric motor.

  Further, in the power output apparatus of the present invention, the engine speed suppression control is such that fuel injection of the internal combustion engine is stopped and a driving force in a direction of pressing down the speed of the internal combustion engine is output from the first electric motor. It is also possible to control the internal combustion engine and the first electric motor. In this way, it is possible to further suppress the first motor from being over-rotated as compared with the one that outputs the driving force in the direction of pressing down the rotational speed of the internal combustion engine from the first motor while operating the internal combustion engine.

  The vehicle of the present invention is a power output device of the present invention according to any one of the above-described embodiments, that is, a power output device that basically outputs power to a drive shaft, and includes an internal combustion engine and an output of the internal combustion engine. Three-axis power input / output means connected to the three axes of the shaft, the drive shaft, and the rotary shaft, and for inputting / outputting power to the remaining one axis based on power input / output to / from any two of the three axes A first electric motor capable of inputting / outputting power to / from the rotating shaft, a first drive circuit used for driving the first electric motor, power storage means capable of charging / discharging electric power, and a switching element. Voltage adjusting means for adjusting a voltage for exchanging electric power between the first drive circuit and the power storage means by switching of the first driving circuit, and when the switching of the switching element of the voltage adjusting means is forcibly stopped off, From one motor to the above And a control means for executing engine speed suppression control for controlling the first drive circuit so that a driving force in a direction for suppressing the rotation speed of the combustion engine is output, and the axle is the drive shaft. It is summarized that it is connected to.

  In the vehicle of the present invention, since the power output device of the present invention according to any one of the above-described aspects is mounted, the effect of the power output device of the present invention, for example, switching of the switching element of the voltage adjusting means is forcibly stopped off. When this is done, it is possible to further suppress the increase in the number of revolutions of the internal combustion engine and the number of revolutions of the first motor as compared with the case where the first drive circuit is forcibly stopped off, and the first motor is over-rotated. It is possible to achieve the same effect as the effect that can be further suppressed.

The method for controlling the power output apparatus of the present invention includes:
Power is input / output to the remaining one axis based on the internal combustion engine and the power input / output to / from any two of the three axes connected to the three shafts of the output shaft, the drive shaft, and the rotation shaft of the internal combustion engine. Three-axis power input / output means, a first electric motor capable of inputting / outputting power to the rotating shaft, a first drive circuit used for driving the first electric motor, and an electric storage means capable of charging / discharging electric power, A control method for a power output apparatus, comprising: a switching element, and a voltage adjusting unit that adjusts a voltage for performing power exchange between the first drive circuit and the power storage unit by switching of the switching element,
An engine that controls the first drive circuit so that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the first electric motor outputs a driving force in a direction that suppresses the rotational speed of the internal combustion engine. The gist is to execute the rotational speed suppression control.

  According to the control method of the power output apparatus of the present invention, the switching of the voltage adjusting means that has the switching element and adjusts the voltage for exchanging power between the first drive circuit and the power storage means by switching of the switching element. When the switching of the element is forcibly turned off, the engine rotational speed suppression control is executed to control the first drive circuit so that the driving force in the direction of pressing down the rotational speed of the internal combustion engine is output from the first electric motor. When the switching of the switching element of the voltage adjusting means is forcibly turned off, the first drive circuit also increases the rotation speed of the internal combustion engine and the rotation speed of the first electric motor more than those forcibly turning off the first drive circuit. It can suppress, and it can suppress that a 1st electric motor carries out overrotation more. Here, the “voltage adjusting unit” may be a booster circuit that can boost the voltage of the power storage unit and supply the boosted voltage to the first drive circuit. Further, “when the switching of the switching element of the voltage adjusting means is forcibly stopped” may be when the gate of the switching element of the voltage adjusting means is shut off.

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

  FIG. 1 is a block diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a power output apparatus according to an embodiment of the present invention, and FIG. 2 shows an outline of the configuration of an electric drive system including motors MG1 and MG2. FIG. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a motor MG2 connected to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30 via a reduction gear 35, and driving of the motors MG1 and MG2. Inverters 41 and 42 used, a booster circuit 45 capable of boosting electric power from the battery 50 and supplying the boosted power to the inverters 41 and 42, and a hybrid electronic control unit 70 for controlling the entire power output apparatus.

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

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

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

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

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 has a capacitor voltage Vc from a voltage sensor 47 mounted between terminals of the capacitor 46, an ignition signal from an ignition switch 80, and a shift position sensor 82 that detects the operation position of the shift lever 81. From the shift position SP, 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 Vehicle speed V and the like are input through the input port. The hybrid electronic control unit 70 outputs a drive signal to the booster circuit 45 through the output port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

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

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when an abnormality occurs in the booster circuit 45 and the gate is shut off will be described. Here, the abnormality of the booster circuit 45 includes, for example, that the temperature of the booster circuit 45 exceeds an allowable temperature. In the embodiment, when an abnormality occurs in the booster circuit 45, the transistors TA and TB of the booster circuit 45 are both turned off, and the gate is shut off to stop switching. Hereinafter, the operation of the booster circuit 45 when the gate is shut off will be described together with the operation when the gate is not shut off. When the booster circuit 45 is shut off, the booster circuit 45 can supply the power from the battery 50 to the inverters 41 and 42 without boosting the voltage by the diode DA, but is driven by the motors MG1 and MG2. In this state, the generated power cannot be charged in the battery 50. FIG. 3 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1, of the motors MG1, MG2. A process of inputting data necessary for control such as Nm2, gate cutoff judgment flag F is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The gate cutoff determination flag F is set to a value of 0 when the booster circuit 45 is normal by a booster circuit state determination routine (not shown), and is set when the gate cutoff is performed due to an abnormality in the booster circuit 45. It is assumed that the input is performed by reading the one set to 1 and written at a predetermined address in the RAM 76.

  When the data is thus input, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V. And the required power Pe * required for the engine 22 is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 4 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotational speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by a conversion factor, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35.

  Subsequently, the value of the gate cutoff determination flag F is checked (step S120). When the gate cutoff determination flag F is 0, that is, when the booster circuit 45 is normal, the target rotation of the engine 22 is based on the required power Pe *. A number Ne * and a target torque Te * are set (step S130). This setting is performed based on the operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 5 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Next, using the set target rotational speed Ne *, the rotational speed Nr (Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed Nm1 of the motor MG1 is given by the following equation (1). * And a torque command Tm1 * of the motor MG1 based on the calculated target rotation speed Nm1 * and the current rotation speed Nm1 (2) based on the calculated rotation speed Nm1 * (step S140). Using *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Grt of the reduction gear 35, a torque command Tm2 * of the motor MG2 is calculated by the equation (3) (step S150). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 6 is a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30. In FIG. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. The two thick arrows on the R axis indicate that the torque Tm1 output from the motor MG1 acts on the ring gear shaft 32a and the torque Tm2 output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Torque. Expressions (1) and (3) can be easily derived by using this alignment chart. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S160), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control. Further, the motor ECU 40 that receives the torque commands Tm1 * and Tm2 * causes the motor MG1 to be driven by the torque command Tm1 * and the motor MG2 to be driven by the torque command Tm2 * by the motor control routine illustrated in FIG. Switching control of the switching elements of the inverters 41 and 42 is performed. The motor control routine of FIG. 7 will be described later.

  When the gate shutoff determination flag F is 1 in step S120, that is, when the booster circuit 45 is abnormal and the gate is shut off, a fuel cut command is transmitted to the engine ECU 24 (step S170). The engine ECU 24 that has received the fuel cut command controls a fuel injection valve (not shown) so as to stop fuel injection of the engine 22.

  Subsequently, the rotational speed Nm1 of the motor MG1 is compared with a threshold value Nref (step S180). When the rotational speed Nm1 of the motor MG1 is larger than the threshold value Nref, it is determined that the motor MG1 may be over-rotated, and the engine 22 A predetermined torque T1 in a direction to hold down the rotational speed Ne is set in the torque command Tm1 * of the motor MG1 (step S190), the required torque Tr *, the torque command Tm1 * of the motor MG1, the gear ratio ρ of the power distribution and integration mechanism 30, and the deceleration Using the gear ratio Gr of the gear 35, the torque command Tm2 * of the motor MG2 is set by the above equation (3) (step S200). Here, the threshold value Nref is a threshold value used for determining whether or not the motor MG1 may be over-rotated, and is set to a rotational speed slightly smaller than the maximum rotational speed allowed for the motor MG1. be able to. The predetermined torque T1 is a torque for suppressing an increase in the rotational speed Ne of the engine 22 and the rotational speed Nm1 of the motor MG1, and is determined by characteristics of the engine 22 and the motor MG1. Now, consider the case where the gate of the booster circuit 45 is cut off. At this time, if both the motors MG1 and MG2 also perform gate shut-off, power generation and consumption by the motors MG1 and MG2 is eliminated, so that the increase and decrease of the capacitor voltage Vc can be suppressed, but the motor MG1 to the engine 22 The torque in the direction of pressing down the rotational speed Ne of the engine is not output, so the ring gear 32 (ring gear shaft 32a) and the carrier are arranged in ascending order of the rotational speed in the nomographic chart of the power distribution and integration mechanism 30 such as when the accelerator pedal 83 is largely depressed. 34 (engine 22) and sun gear 31 (motor MG1), the rotational speed Ne of the engine 22 and the rotational speed Nm1 of the motor MG1 are increased by the inertia of the rotating system including the engine 22 and the motor MG1, and the motor MG1 is excessively rotated. There is a risk of becoming. On the other hand, in the embodiment, by outputting the torque in the direction to hold down the rotation speed Ne of the engine 22 from the motor MG1, the increase in the rotation speed Ne of the engine 22 and the rotation speed Nm1 of the motor MG1 can be further suppressed. It is possible to further suppress the over rotation of MG1. Moreover, at this time, as described above, since the fuel of the engine 22 is cut, it is possible to further suppress the motor MG1 from over-rotating as compared with the engine 22 operating.

  Subsequently, the power command Pm1 (Tm1 * · Nm1) of the motor MG1 obtained by multiplying the torque command Tm1 * of the motor MG1 by the current rotational speed Nm1 of the motor MG1 and the torque command Tm2 * of the motor MG2 The motor power Pm is calculated as the sum of the power consumption Pm2 (Tm2 * · Nm2) of the motor MG2 obtained by multiplying the rotation speed Nm2 (step S210), and the calculated value of the motor power Pm is examined (step S220). When the motor power Pm is greater than or equal to 0, the surplus power Psur is set to 0 (step S230), and when the motor power Pm is negative, the surplus power Psur is set to the absolute value of the motor power Pm (step S240). , Torque commands Tm1 *, Tm2 * of motors MG1, MG2 and surplus power Psur are transmitted to motor ECU 40. And transmitted (step S250), and terminates the drive control routine. Here, the process of checking the value of the motor power Pm in step S220 determines whether the motor power Pm when driving the motors MG1, MG2 with the torque commands Tm1 *, Tm2 * is on the power consumption side or the generated power side. It is a process to check. Now, since it is considered that the gate of the booster circuit 45 is shut off, the booster circuit 45 can supply the power from the battery 50 to the inverters 41 and 42 without boosting, as described above. However, the battery 50 cannot be charged with the electric power generated by the motors MG1 and MG2. Therefore, when the motor power Pm is greater than or equal to 0, that is, on the power consumption side, the power from the battery 50 can be supplied to the inverters 41 and 42 via the booster circuit 45, but the motor power Pm is a negative value. In other words, when the power generation side is reached, surplus power Psur is stored in the capacitor 46, and the capacitor voltage Vc increases. In the processing of steps S220 to S240, the surplus power Psur is set. The surplus power Psur set in this way is used in the motor control routine of FIG.

  When the rotation speed Nm1 of the motor MG1 is equal to or less than the threshold value Nref in step S180, it is determined that the motor MG1 is not likely to over-rotate, and a gate cutoff command is transmitted to the motor ECU 40 to the inverter 41 of the motor MG1 (step S260). Then, the processes after step S200 described above are executed. Receiving the instruction, motor ECU 40 performs gate blocking of the switching element of inverter 41 of motor MG1. Thereby, it can suppress that electric power generation is performed by motor MG1. Further, in this case, since the power consumption Pm1 of the motor MG1 is 0, considering that the motor MG2 functions as an electric motor, such as when the driver depresses the accelerator pedal 83 and travels forward or backward, The motor power Pm becomes a positive value (power consumption side) (step S220), and the value 0 is set for the surplus power Psur (step S230).

  Next, the process of the motor ECU 40 that has received the torque commands Tm1 *, Tm2 * and the surplus power Psur will be described. FIG. 7 is a flowchart illustrating an example of a motor control routine executed by the motor ECU 40. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the motor control routine is executed, the motor ECU 40 first determines the phase currents Iu1, Iv1, Iu2, Iv2 of the motors MG1, MG2 from current sensors (not shown) and the motors MG1, MG2 from the rotational position detection sensors 43, 44. Data necessary for control, such as the rotor rotational positions θm1, θm2, torque commands Tm1 *, Tm2 *, surplus power Psur, and the value of the gate shutoff determination flag F, are input (step S300). Here, the torque commands Tm1 *, Tm2 *, and surplus power Psur can be input by communication from the hybrid electronic control unit 70 as set by the drive control routine of FIG. A hybrid electronic device having a value of 0 when the booster circuit 45 is normal and a value of 1 when the gate circuit is shut off due to an abnormality in the booster circuit 45 is determined by a booster circuit state determination routine (not shown). It can be input from the control unit 70 by communication.

  When the data is input in this way, the electrical angles θe1 and θe2 are calculated by multiplying the input rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 by the number of pole pairs P1 and P2 of the motors MG1 and MG2 (step S310). The sum of the phase currents flowing through the U-phase, V-phase, and W-phase of the three-phase coils of MG1 and MG2 is set to 0, and the phase currents Iu1, Iv1, Iu2, and Iv2 are expressed by the following formulas (4) and (5) as d-axis, q Coordinate conversion (three-phase to two-phase conversion) into shaft currents Id1, Iq1, Id2, and Iq2 (step S320), and torque commands Tm1 * and Tm2 * of motors MG1 and MG2 to d-axis and q-axis current commands Id1 * , Iq1 *, Id2 *, Iq2 * are set (step S330).

  Subsequently, the value of the gate interruption determination flag F is checked (step S340), and when the gate interruption determination flag F is a value 1, that is, when the boosting circuit 45 is abnormal and the gate interruption is performed, the surplus power Psur is The value is checked (step S350). When the gate cutoff determination flag F is 0, that is, when the booster circuit 45 is normal, or when the surplus power Psur is 0 even when the gate cutoff determination flag F is 1, the gate cutoff of the booster circuit 45 is When surplus power Psur is not generated, the following equation (6) is obtained using phase currents Id1, Iq1, Id2, Iq2 of motors MG1, MG2 and current commands Id1 *, Iq1 *, Id2 *, Iq2 *. The voltage commands Vd1 *, Vq1 *, Vd2 *, Vq2 * for the d-axis and q-axis of the motors MG1, MG2 are calculated by (9) (step S370). Here, in Expressions (6) to (9), “k3”, “k5”, “k7”, “k9” are proportional coefficients, and “k4”, “k6”, “k8”, “k10” are It is an integral coefficient.

  Then, the voltage commands Vd1 *, Vq1 *, Vd2 *, and Vq2 * of the d-axis and q-axis are applied to the three-phase coils U-phase, V-phase, and W-phase of the motors MG1 and MG2 by the following equations (10) to (13) The coordinate commands (two-phase to three-phase conversion) are converted into voltage commands Vu1 *, Vv1 *, Vw1 *, Vu2 *, Vv2 *, and Vw2 * to be performed (step S380), and the voltage commands Vu1 *, Vv1 *, Vw1 *, Vu2 *, Vv2 *, and Vw2 * are converted into PWM signals for switching the inverters 41 and 42 (step S390), and the converted PWM signals are output to the inverters 41 and 42, so that the motors MG1 and MG2 are output. Drive control is performed (step S400), and the motor control routine is terminated.

  In steps S340 and S350, when the gate shutoff determination flag F is 1 and the surplus power Pm is a positive value, that is, when the booster circuit 45 is gate shut off and surplus power Psur is generated, reactive power that does not contribute to torque is reduced to the motor. The current command Id2 * calculated in step S320 is corrected by the following equation (14) so that surplus power Pm is consumed by the motor MG2 by being applied to MG2 (step S360), and the processing after step S370 described above is executed. To do. Here, in Equation (14), “K” is a conversion coefficient to current. As described above, when surplus power Pm is generated when the gate of booster circuit 45 is shut off, surplus power Pm is consumed by motor MG2 by supplying reactive power that does not contribute to torque to motor MG2. Thus, an excessive increase in the capacitor voltage Vc can be suppressed. As a result, the capacitor 46 can be prevented from being overvoltage, and the capacitor 46 can be protected.

  According to the hybrid vehicle 20 of the above-described embodiment, when an abnormality occurs in the booster circuit 45 and the gate is shut off, the motor MG1 outputs a torque in the direction of pressing down the rotational speed Ne of the engine 22, so When the gate of the circuit 45 is shut off, the motor MG1 can further suppress the increase in the rotational speed Ne of the engine 22 and the rotational speed Nm1 of the motor MG1 as compared with the motor MG1 that shuts off the gate. Over-rotation can be further suppressed. Moreover, according to the hybrid vehicle 20 of the embodiment, when the gate of the booster circuit 45 is cut off, the fuel of the engine 22 is cut, so that the motor MG1 is over-rotated as compared with the one that operates the engine 22. This can be further suppressed.

  Further, according to the hybrid vehicle 20 of the embodiment, when the gate of the booster circuit 45 is shut off and the generated power Pm1 of the motor MG1 is larger than the consumed power Pm2 of the motor MG2, the generated power Pm1 is consumed to the consumed power Pm2. The surplus power Psur obtained by reducing the power consumption is consumed by the motor MG2 by the reactive power that does not contribute to the generation of torque, so that an increase in the capacitor voltage Vc can be suppressed. As a result, the capacitor 45 can be prevented from being overvoltage, and the capacitor 46 can be protected.

  In the hybrid vehicle 20 of the embodiment, when the rotation speed Nm1 of the motor MG1 is larger than the threshold value Nref when the gate of the booster circuit 45 is shut off, a predetermined torque T1 in a direction to hold down the rotation speed Ne of the engine 22 is applied from the motor MG1. The predetermined torque T1 is not limited to a fixed value, but may be set based on the rotational speed Nm1 of the motor MG1 or the capacitor voltage Vc. Here, when the predetermined torque T1 is set based on the capacitor voltage Vc, if the predetermined torque T1 is set so that the capacitor voltage Vc does not exceed a predetermined withstand voltage Vcmax, the surplus power Psur is reduced to the motor by the reactive power. It is good also as what is not consumed by MG2.

  In the hybrid vehicle 20 of the embodiment, the output of the predetermined torque T1 from the motor MG1 or the gate of the inverter 41 is cut off according to the rotational speed Nm1 of the motor MG1, but the engine MG1 is replaced with the engine speed Nm1. It is good also as what performs according to the rotation speed Ne of 22.

  In the hybrid vehicle 20 of the embodiment, when the gate of the booster circuit 45 is being cut off, when the rotational speed Nm1 of the motor MG1 is greater than the threshold value Nref, a predetermined torque T1 in a direction to hold down the rotational speed Ne of the engine 22 is applied from the motor MG1. When the output number Nm1 of the motor MG1 is less than or equal to the threshold value Nref, the inverter 41 of the motor MG1 is gate-cut. However, the predetermined number of directions in which the rotation speed Ne of the engine 22 is suppressed regardless of the number of revolutions Nm1 of the motor MG1. The torque T1 may be output from the motor MG1.

  In the hybrid vehicle 20 of the embodiment, all of the surplus power Psur is consumed by the motor MG2 by reactive power, but a part of the surplus power Psur may be consumed by the motor MG2 by reactive power. In this case, the degree to which the motor MG2 is consumed by the reactive power may be set based on the capacitor voltage Vc or the like. For example, the capacitor voltage Vc is set to the target voltage Vc * set as a voltage lower than the withstand voltage Vcmax of the capacitor 46. Can be set to approach.

  In the hybrid vehicle 20 of the embodiment, the surplus power Psur when the generated power Pm1 of the motor MG1 is larger than the power consumption Pm2 of the motor MG2 is consumed by the motor MG2 by reactive power. When * is not set, at least a part of the generated power Pm1 of the motor MG1 may be consumed by the motor MG2 by reactive power.

  In the hybrid vehicle 20 of the embodiment, the torque command Tm2 * of the motor MG2 is set so that the required torque Tr * is output to the ring gear shaft 32a as the drive shaft even when the gate of the booster circuit 45 is shut off. However, at this time, the torque command Tm2 * of the motor MG2 may be set so that the torque obtained by limiting the required torque Tr * with the torque limit Tlim is output to the ring gear shaft 32a. Here, the torque limit Tlim may be set such that, for example, the higher the vehicle speed V is, the smaller the vehicle travels at a vehicle speed of 20 km / h, 30 km / h, or 40 km / h.

  In the hybrid vehicle 20 of the embodiment, when the gate of the booster circuit 45 is shut off, the fuel of the engine 22 is cut. Instead, the engine 22 is idled or a slight torque is output. It is good also as what drives in the driving | running | working state to do.

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

  In addition, it is not limited to those applied to such hybrid vehicles, but is incorporated into non-moving equipment such as forms of power output devices mounted on moving bodies such as vehicles other than automobiles, ships, and aircraft, and construction equipment. A power output device may be used. Furthermore, it is good also as a form of the control method of such a power output device.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention can be used in the power output apparatus and the vehicle manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. It is a block diagram which shows the outline of a structure of the electric drive system containing motor MG1, MG2. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30. It is explanatory drawing which shows an example of the motor control routine performed by motor ECU40. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier 35, reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line , 60 gear mechanism, 62 differential gear, 63a, 63b drive wheel, 64a, 64b wheel, 70 electronic control unit for hybrid, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever , 82 shift position sensor, 83 accelerator pedal, 84 an accelerator pedal position sensor, 85 brake pedal, 86 a brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor.

Claims (9)

A power output device that outputs power to a drive shaft,
An internal combustion engine;
Connected to three shafts of the output shaft of the internal combustion engine, the drive shaft and the rotating shaft, and inputs / outputs power to / from the remaining one shaft based on power input / output to / from any two of the three shafts 3 Shaft power input / output means;
A first electric motor capable of inputting and outputting power to the rotating shaft;
A first drive circuit used for driving the first electric motor;
Power storage means capable of charging and discharging electric power;
A voltage adjusting unit that includes a switching element, and adjusts a voltage for exchanging electric power between the first drive circuit and the power storage unit by switching the switching element;
An engine that controls the first drive circuit so that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the first electric motor outputs a driving force in a direction that suppresses the rotational speed of the internal combustion engine. Control means for executing rotation speed suppression control;
A power output device comprising: The power output device according to claim 1,
A second electric motor capable of inputting and outputting power to the drive shaft;
A second drive circuit used for driving the second electric motor, wherein the first drive circuit shares a positive bus and a negative bus;
A capacitor having a predetermined withstand voltage connected to the positive and negative buses of the first drive circuit and the second drive circuit;
With
The voltage adjusting unit is a unit that cannot supply the electric power generated by the first electric motor or the second electric motor to the electric storage unit when the switching element is in an off state,
The control means performs overvoltage suppression control for controlling the second drive circuit so that the voltage of the capacitor is equal to or lower than the predetermined withstand voltage when switching of the switching element of the voltage adjusting means is forcibly stopped. Power output device that is means. The power output device according to claim 1 or 2,
A required driving force setting means for setting a required driving force required for the drive shaft;
When the switching of the switching element of the voltage adjusting unit is forcibly turned off, the control unit includes a driving force that is output to the drive shaft in accordance with the execution of the engine speed suppression control and a second electric motor. The power output is a means for executing power output control for controlling the second drive circuit so that a drive force based on the set required drive force is output to the drive shaft by a drive force output to the drive shaft. apparatus. The power output device according to claim 3 according to claim 2,
The second electric motor is an AC electric motor;
When the switching of the switching element of the voltage adjusting unit is forcibly turned off, the control unit is configured such that the generated electric power of the first motor at the time of executing the engine speed suppression control is the power at the time of the power output control. When the power consumption of the second motor is greater than the power consumption of the second motor, at least part of the surplus power that is the surplus of the power generated by the first motor with respect to the power consumption of the second motor A power output device, which is means for executing the overvoltage suppression control so that the second motor is consumed. The power output device according to claim 2,
The second electric motor is an AC electric motor;
When the switching of the switching element of the voltage adjusting unit is forcibly turned off, the control unit is configured such that at least a part of the generated electric power of the first motor at the time of executing the engine speed suppression control is a driving force. A power output device, which is means for executing the overvoltage suppression control so that the second electric motor is consumed by an output of reactive power that does not contribute to generation. The power output device according to any one of claims 1 to 5,
A rotation speed detecting means for detecting the rotation speed of the first electric motor;
The first drive circuit includes a switching element,
The control means replaces the engine speed suppression control when the switching of the switching element of the voltage adjusting means is forcibly turned off and the detected speed of the first electric motor is equal to or lower than a predetermined speed. A power output device that is a means for executing a shut-off control for controlling the first drive circuit so that the gate of the switching element of the first drive circuit is shut off.   In the engine speed suppression control, the internal combustion engine and the first electric motor are controlled so that the fuel injection of the internal combustion engine is stopped and a driving force in the direction of pressing down the rotational speed of the internal combustion engine is output from the first electric motor. The power output device according to any one of claims 1 to 6, wherein the power output device is a control for controlling the power.   A vehicle on which the power output device according to claim 1 is mounted and an axle is connected to the drive shaft. Power is input / output to the remaining one axis based on the internal combustion engine and the power input / output to / from any two of the three axes connected to the three shafts of the output shaft, the drive shaft, and the rotation shaft of the internal combustion engine. Three-axis power input / output means, a first electric motor capable of inputting / outputting power to the rotating shaft, a first drive circuit used for driving the first electric motor, and an electric storage means capable of charging / discharging electric power, A method for controlling a power output apparatus, comprising: a switching element, and a voltage adjusting unit that adjusts a voltage for performing power exchange between the first drive circuit and the power storage unit by switching the switching element,
An engine that controls the first drive circuit so that when the switching of the switching element of the voltage adjusting means is forcibly turned off, the first electric motor outputs a driving force in a direction that suppresses the rotational speed of the internal combustion engine. A method for controlling a power output apparatus that executes rotational speed suppression control.