JP2006246562A - Hybrid vehicle and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED To quickly output driving force for traveling from an electric motor while suppressing deterioration of a battery mounted on a hybrid vehicle.
A three-element circuit operation comprising an alternator, a high-voltage battery, and a device, and a high-voltage battery based on the rotation speed Na of the alternator, the battery target current Ib * based on the state of the high-voltage battery, and the device power Pms based on the required torque of the motor. The field current If as a feed-forward term calculated using a two-element circuit operation composed of a device is corrected by a feedback term based on the difference between the battery target current Ib * and the measured battery current Ib, and the field current is corrected. The current command If * is set, and the alternator is driven using this. As a result, the power generation amount of the alternator is quickly changed in response to a sudden change in the required torque of the motor, thereby suppressing a rapid increase or decrease in the remaining capacity (SOC) of the high voltage battery. As a result, deterioration of the high voltage battery can be suppressed.
[Selection] Figure 2

Description

  The present invention relates to a hybrid vehicle and a control method thereof, and more particularly, to a hybrid vehicle that travels using power from an internal combustion engine and power from a motor that can generate power, and a control method thereof.

Conventionally, this type of hybrid vehicle includes an engine that outputs power to the rear wheels, a generator that generates power using the power of the engine, and an electric motor that outputs power to the front wheels using electric power from a battery or a generator. Have been proposed (see, for example, Patent Document 1). In this hybrid vehicle, when the electric power supplied from the battery is insufficient for the electric power supplied to the electric motor, the electric power is supplied to the electric motor by driving the generator.
JP 2003-204604 A

  However, in the above-described hybrid vehicle, the battery is over-discharged due to the delay in driving the generator, thereby promoting the deterioration of the battery, or the lack of power supply to the electric motor, resulting in the driver's intended driving force. There are cases where it cannot be output.

  One object of the hybrid vehicle and the control method thereof according to the present invention is to suppress deterioration of a battery mounted on the hybrid vehicle. Another object of the hybrid vehicle and the control method thereof according to the present invention is to quickly output a driving force based on a driving force required from an electric motor that receives a power supply from a battery and outputs a driving force for traveling. I will.

  The hybrid vehicle and the control method thereof according to the present invention employ the following means in order to achieve at least a part of the above-described object.

The hybrid vehicle of the present invention
A hybrid vehicle that travels with power from an internal combustion engine and power from an electric motor capable of generating electricity,
A generator for generating electricity using power from the internal combustion engine;
A battery capable of exchanging electric power with the electric motor and the generator;
Maximum charge / discharge power setting means for setting the maximum charge / discharge power of the battery based on the state of the battery;
Maximum generated power setting means for setting the maximum generated power of the generator based on the state of the generator;
Required driving force setting means for setting required driving force required for the electric motor;
Limit that restricts the set required driving force based on the set maximum charge / discharge power, the set maximum generated power, and the auxiliary machine power necessary for the auxiliary machine capable of supplying power from the battery Limited driving force setting means for setting a driving force,
Target charge / discharge current setting means for setting a target charge / discharge current for charging / discharging the battery based on the state of the battery;
The generator based on the set target charge / discharge current and the set limited driving force from the electric motor when the electric power required for the electric motor and the auxiliary machine and the rotation speed of the electric generator are output. Target power generation state setting means for setting the target power generation state of
Drive control means for driving and controlling the motor and the generator so that a driving force based on the set limited driving force is output from the motor and the generator is driven in the set target power generation state. When,
It is a summary to provide.

  In the hybrid vehicle of the present invention, the required driving force required for the electric motor is determined from the battery's maximum charge / discharge power set based on the battery state, the generator's maximum generated power set based on the generator state, and the battery. Set the limited driving force that is limited based on the auxiliary power required for the auxiliary equipment that can supply power, and the target charging / discharging current that sets and charges the battery that is set based on the state of the battery, and the limit that is set The target power generation state of the generator is set based on the device power necessary for the motor and the auxiliary machine and the rotation speed of the generator when the finished drive force is output from the motor. Then, the driving force based on the limited driving force set from the electric motor is output, and the electric motor and the generator are controlled to be driven in the target power generation state set by the generator. Thus, since the motor and the generator are driven in consideration of the state of the battery and the state of the generator, it is possible to suppress overdischarge and overcharge of the battery and suppress deterioration of the battery, A driving force based on the required driving force required for the electric motor can be quickly output from the electric motor.

  In such a hybrid vehicle of the present invention, the generator is a three-phase separately-excited generator, and the target power generation state setting means is a means for setting the field current of the generator as the target power generation state. You can also. In this case, the target power generation state setting means is configured to generate the power when the generator no-load power, which is the maximum power that can be output from the battery at a voltage equal to or higher than the voltage when the generator is in a no-load state, is less than the device power. A three-element circuit comprising a machine, the battery, the electric motor, and the auxiliary machine is used as a model circuit to calculate a battery current flowing through the battery by a three-element circuit calculation, and the field current is set based on the calculated battery current When the generator no-load power is equal to or higher than the device power, the battery current is calculated and calculated by a two-element circuit calculation using a two-element circuit composed of the battery, the electric motor, and the auxiliary machine as a model circuit. It may be a means for setting the field current based on the battery current. In this way, it is possible to make the calculation speed faster as compared with the case where the field current is always set by the three-element circuit calculation. Furthermore, in the hybrid vehicle of the present invention according to this aspect, the three-element circuit calculation includes a first relationship in which a sum of a circuit voltage in the three-element circuit and a power generation voltage of the generator is 0, the circuit voltage, and the A second relationship in which the sum of the battery voltage is a value of 0 and a third relationship in which the power obtained by multiplying the sum of the current of the generator and the battery current by the generated voltage matches the device power. The battery current is calculated to satisfy three relationships, and the two-element circuit calculation includes a fourth relationship in which the sum of the circuit voltage and the battery voltage is 0, and the current of the generator. It is also possible to calculate the battery current so that the power obtained by multiplying the sum of the battery current and the generated voltage by the fifth relationship matches the device power. .

  In the hybrid vehicle of the present invention in which the field current is set by using such a three-element circuit calculation and a two-element circuit calculation, the target power generation state setting means is configured such that the calculated battery current is the set target charge. It may be a means for setting the field current so as to substantially match the discharge current. In this case, the target power generation state setting means sequentially changes the ratio of the field current using a bisection method so that the calculated battery current is within the predetermined error range. It may be a means for setting the field current by the ratio of the field current when it matches the current. In this way, the field current can be set quickly.

  The hybrid vehicle of the present invention further includes input / output current detection means for detecting input / output current of the battery, and the drive control means is based on the detected input / output current and the set target charge / discharge current. It is also possible to correct the set target power generation state and control the generator to drive in the corrected target power generation state. In this way, the generator can be driven more appropriately.

  Further, in the hybrid vehicle of the present invention, the internal combustion engine is connected to a first axle so as to be able to output power, and the electric motor is connected so as to be able to output power to a second axle different from the first axle. It can also be made. In this case, operation control means for controlling the operation of the internal combustion engine according to the driver's accelerator operation is provided, and the required drive force setting means is means for setting the required drive force based on the driver's accelerator operation. It can also be. If it carries out like this, the driving force according to a driver | operator's accelerator operation can be rapidly and appropriately output from an internal combustion engine or an electric motor.

The hybrid vehicle control method of the present invention includes:
An internal combustion engine that can output power for traveling, an electric motor that can output power for traveling, a generator that generates electric power using the power from the internal combustion engine, and exchange of electric power with the motor and the generator A hybrid vehicle control method comprising: a battery;
A maximum charge / discharge power of the battery based on the state of the battery; a target charge / discharge current for charging / discharging the battery based on the state of the battery; and a maximum generated power of the generator based on the state of the generator. Set,
A restriction that restricts the required driving force required for the electric motor based on the set maximum charge / discharge power, the set maximum generated power, and auxiliary power required for an auxiliary machine capable of supplying power from the battery. Set the driving force
When the set target charge / discharge current and the set limited driving force are output from the motor, the generator target is based on the device power required for the motor and the auxiliary machine and the rotation speed of the generator. Set the power generation state,
The gist is to drive and control the motor and the generator so that a driving force based on the limited driving force is output from the motor and the generator is driven in the set target power generation state.

  In this hybrid vehicle control method of the present invention, the required driving force required for the electric motor is set based on the state of the battery, the maximum charge / discharge power of the battery, and the maximum generated power of the generator set based on the state of the generator And a target charging / discharging current for charging / discharging the battery set based on the state of the battery and setting a limited driving force that is limited based on the auxiliary power required for the auxiliary device that can supply power from the battery When the set limited driving force is output from the motor, the target power generation state of the generator is set based on the device power required for the motor and the auxiliary machine and the rotation speed of the generator. Then, the driving force based on the limited driving force set from the electric motor is output, and the electric motor and the generator are controlled to be driven in the target power generation state set by the generator. Thus, since the motor and the generator are driven in consideration of the state of the battery and the state of the generator, it is possible to suppress overdischarge and overcharge of the battery and suppress deterioration of the battery, A driving force based on the required driving force required for the electric motor can be quickly output from the electric motor.

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

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. The hybrid vehicle 20 of the embodiment is a vehicle that can be driven by four-wheel drive, and outputs the power from the engine 22 to the front shaft 64 via the torque converter 25, the CVT 50, and the gear mechanism 65 to drive the front wheels 63a and 63b. A front wheel drive system for driving, a rear wheel drive system for driving the rear wheels 66a and 66b by outputting the power from the motor 40 to the rear shaft 67 via the gear mechanism 68, and a motor for generating power using the power of the engine 22. 40 and an alternator 32 that supplies power to the high-voltage battery 31, and power from the high-voltage system such as the alternator 32 and high-voltage battery 31 to the auxiliary machine such as the electric oil pump 36 that generates the line hydraulic pressure of the CVT 50 and the low-voltage battery 35. A DC / DC converter 34 to be supplied and a hybrid electronic control unit 70 for controlling the entire apparatus are provided. In addition to this, the hybrid vehicle 20 also includes a mechanical oil pump 26 that generates line hydraulic pressure of the CVT 50 using power from the engine 22.

  The engine 22 is an internal combustion engine that outputs power using hydrocarbon fuel such as gasoline or light oil. An alternator 32 and a mechanical oil pump 26 are attached to a crankshaft 23 of the engine 22 by a belt 24. Operation control of the engine 22, for example, fuel injection control, ignition control, intake air amount adjustment control, and the like are performed by an engine electronic control unit (hereinafter referred to as engine ECU) 29. The engine ECU 29 communicates 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 motor 40 is configured as a well-known synchronous generator motor that can be driven as a generator and can be driven as an electric motor. The motor 40 exchanges power with the high-voltage battery 31 via the inverter 41 or receives power from the alternator 32. . The motor 40 is driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 42. Applied to the motor ECU 42 is a signal necessary for driving and controlling the motor 40, for example, a signal from a rotational position detection sensor 43 that detects the rotational position of the rotor of the motor 40, or a motor 40 detected by a current sensor (not shown). Phase current to be input. The motor ECU 42 communicates with the hybrid electronic control unit 70, and controls the drive of the motor 40 by outputting a switching control signal to the inverter 41 by a control signal from the hybrid electronic control unit 70, and if necessary. Data relating to the operating state of the motor 40 is output to the hybrid electronic control unit 70.

  The alternator 32 is configured as a three-phase separately-excited generator, and generates direct-current power through a built-in rectifier. The alternator 32 adjusts the generated power by controlling the field current If by the hybrid electronic control unit 70.

  The high voltage battery 31 is configured as a secondary battery having a rated voltage Vh (for example, 42 [V]), stores the power supplied from the alternator 32, and exchanges power with the motor 40. The low voltage battery 35 is configured as a secondary battery having a rated voltage Vl (for example, about 12 [V]) lower than the rated voltage Vh, and stores the power supplied from the alternator 32 via the DC / DC converter 34. In addition, power is supplied to devices operating at a low voltage such as an auxiliary machine (not shown). The high voltage battery 31, the low voltage battery 35, and the DC / DC converter 34 are managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 30. The battery ECU 30 receives signals necessary for managing the high voltage battery 31 and the low voltage battery 35, for example, the battery voltage Vb from the voltage sensor 31a connected to the output terminal of the high voltage battery 31 and the battery current Ib from the current sensor 31b. The state of both batteries such as the battery temperature Tb from the temperature sensor 31c attached to the high voltage battery 31 is input, and data on the state of both batteries is output to the hybrid electronic control unit 70 by communication as necessary. Note that the battery ECU 30 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current in order to manage the high voltage battery 31 and the low voltage battery 35.

  The input shaft 51 of the CVT 50 is connected to the torque converter 25 via the clutch C1, and the groove width can be changed, and the primary pulley 53 connected to the input shaft 51 can also change the groove width. Secondary pulley 54 connected to the output shaft 52, belt 55 spanning the grooves of the primary pulley 53 and the secondary pulley 54, and the first actuator 56 and the second actuator that change the groove width of the primary pulley 53 and the secondary pulley 54. 57, and by changing the groove width of the primary pulley 53 and the secondary pulley 54 by the first actuator 56 and the second actuator 57, the power of the input shaft 51 is changed steplessly. And outputs to the output shaft 52 and. Here, the first actuator 56 is used for controlling the transmission ratio, and the second actuator 57 is configured as a hydraulic actuator used for controlling the narrow pressure of the belt 55 for adjusting the transmission torque capacity of the CVT 50. . Shift control and belt narrow pressure control of the CVT 50 are performed by a CVT electronic control unit (hereinafter referred to as CVTECU) 59. The CVTECU 59 receives the rotational speed Np of the input shaft 51 from the rotational speed sensor 61 attached to the input shaft 51 and the rotational speed Ns of the output shaft 52 from the rotational speed sensor 62 attached to the output shaft 52. The CVTECU 59 outputs drive signals to the first actuator 56 and the second actuator 57. The CVTECU 59 communicates with the hybrid electronic control unit 70, controls the transmission ratio of the CVT 50 by a control signal from the hybrid electronic control unit 70, and controls the input shaft 51 from the rotational speed sensor 61 as necessary. Data relating to the operating state of the CVT 50 such as the rotational speed Np and the rotational speed Ns of the output shaft 52 of the rotational speed sensor 62 is output to the hybrid electronic control unit 70. The CVT ECU 50 also controls the connection of the clutch C1.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an alternator current Ia from a current sensor (not shown) attached to the alternator 32, an alternator rotation speed Na from a rotation speed sensor (not shown), and an alternator from a temperature sensor 32a attached to the alternator 32. The temperature Ta, the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, the accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83 The brake stroke BS from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input through the input port. From the hybrid electronic control unit 70, a control signal for driving and controlling the alternator 32, a driving signal to the electric oil pump 36, and the like are output via an output port. The hybrid electronic control unit 70 also exchanges various control signals and data with the engine ECU 29, the battery ECU 30, the motor ECU 42, and the CVTECU 59.

  The hybrid vehicle 20 of the embodiment configured in this manner travels by driving four wheels by outputting the power from the engine 22 to the front wheels and outputting the power from the motor 40 to the rear wheels according to the driver's accelerator operation. . Further, at the time of deceleration such as when the brake pedal 85 is depressed during traveling, the clutch C1 is disconnected and the engine 22 is stopped with the engine 22 disconnected from the CVT 50, and the motor 40 is regeneratively controlled to regenerate the motor 40. Regenerative braking is used to apply braking force to the rear wheels 66 a and 66 b and to store the electric power regenerated from the motor 40 in the high-voltage battery 31.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation in driving the alternator 32 and the motor 40 will be described. FIG. 2 is a block diagram showing drive control of the alternator 32 as a control block, and FIG. 3 is executed by the hybrid electronic control unit 70 for drive control of the alternator 32 and the motor 40 including control of the alternator 32. It is a flowchart which shows an example of a drive control routine. Since the control block of FIG. 2 is performed by executing drive control by the drive control routine of FIG. 3, the operation of the hybrid vehicle 20 of the embodiment will be mainly described below using the drive control routine of FIG. This drive control 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 brake stroke BS from the brake pedal position sensor 86, and the battery temperature of the high-voltage battery 31. Necessary for control such as Tb, remaining capacity (SOC), battery current Ib, rotation speed Na of alternator 32, temperature Ta, rotation speed Nm of motor 40, and state of auxiliary machine viewed from high voltage system such as DC / DC converter 34. A process of inputting data is executed (step S100). Here, as for the battery current Ib and the battery temperature Tb of the high-voltage battery 31, those detected by the current sensor 31b and the temperature sensor 31c are input from the battery ECU 30 by communication. Further, the remaining capacity (SOC) of the high voltage battery 31 is calculated based on the battery current Ib and input from the battery ECU 30 by communication. Further, as for the rotational speed Nm of the motor 40, a value calculated based on the rotational position of the rotor detected by the rotational position detection sensor 43 is input from the motor ECU 42 by communication. As for the state of the auxiliary machine of the high-voltage system, for the DC / DC converter 34, the calculated power supplied from the high-voltage system to the low-pressure system is input as the state of the auxiliary machine. The power consumption obtained from the rated value based on the state of the on / off switch is input as the state of the auxiliary machine.

  When the data is input in this way, the maximum discharge power Pbmax and the maximum charge power Pbmin of the high voltage battery 31 are calculated based on the input battery temperature Tb and the remaining capacity (SOC) (step S110), and the rotation speed Na of the alternator 32 and The maximum suppliable power Pamax of the alternator 32 is calculated based on the temperature Ta (step S120), and the auxiliary power that is the sum of the current power consumption of the auxiliary that is supplied with power from the high voltage system based on the state of the auxiliary equipment Ph is calculated (step S130). Here, the maximum discharge power Pbmax and the maximum charge power Pbmin are set based on the battery temperature Tb detected by the temperature sensor 31c and the remaining capacity (SOC) of the high-voltage battery 31, and are input from the battery ECU 30 by communication. It was supposed to be. The maximum discharge power Pbmax and the maximum charge power Pbmin set the basic values of the input / output limits Win and Wout of the high voltage battery 31 based on the battery temperature Tb, and the output limit correction based on the remaining capacity (SOC) of the high voltage battery 31 It is possible to calculate by setting a coefficient and a correction coefficient for input restriction, and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 4 shows an example of the relationship between the battery temperature Tb and the input / output limits Win and Wout, and FIG. 5 shows an example of the remaining capacity (SOC) of the high-voltage battery 31, the output limiting correction coefficient, and the input limiting correction coefficient. . Regarding the maximum supplyable power Pamax, in the embodiment, the relationship between the rotational speed Na, the temperature Ta, and the maximum supplyable power Pamax of the alternator 32 is obtained by experiments and stored in the RAM 76 in advance as a map. When a number Na and a temperature Ta are given, calculation is performed by deriving the corresponding maximum suppliable power Pamax from the map. An example of the relationship between the rotational speed Na, the temperature Ta, and the maximum suppliable power Pamax of the alternator 32 is shown in FIG.

  Subsequently, the motor supplyable power Pmmax that can be supplied to the motor 40 is calculated by subtracting the auxiliary machine power Ph from the sum of the maximum supplyable power Pamax and the maximum discharge power Pbmax, and the auxiliary machine power Ph is calculated from the maximum charging power Pbmi. The motor regenerative power Pmmin that can be regenerated by the motor 40 is calculated (see the following equations (1) and (2)), and the calculated motor supplyable power Pmmax and the motor regenerative power Pmmin are calculated by the motor 40. The upper and lower limit torques Tmax and Tmin are calculated as upper and lower limit values of the torque that can be output from the motor 40 by dividing by the rotation speed Nm (step S140).

Pmmax = Pamax + Pbmax-Ph (1)
Pmmin = Pbmin-Ph (2)

  Then, the temporary motor torque Ttmp is set as a torque to be output from the motor 40 based on the accelerator opening Acc, the brake stroke BS, and the rotation speed Nm of the motor 40 (step S150), and the set temporary motor torque Ttmp is set to the upper and lower limits. The motor request torque Tm * is set by limiting with the torques Tmax and Tmin (step S160), and the motor target power Pm * to be output from the motor 40 is obtained by multiplying the set motor request torque Tm * by the rotation speed Nm of the motor 40. Set (step S170). Here, regarding the temporary motor torque Ttmp, in the embodiment, the relationship between the accelerator opening Acc, the brake stroke BS, the rotational speed Nm of the motor 40 and the temporary motor torque Ttmp is determined in advance and stored in the ROM 74 as a map. When the accelerator opening degree Acc, the brake stroke BS, and the rotation speed Nm are given, the setting is made by deriving the corresponding temporary motor torque Ttmp from the map. An example of the relationship between the accelerator opening degree Acc, the brake stroke BS, the rotational speed Nm of the motor 40, and the temporary motor torque Ttmp is shown in FIG.

  Next, the battery shared power Pbset to be charged / discharged from the high voltage battery 31 is set based on the battery temperature Tb and the remaining capacity (SOC) (step S180), and the set battery shared power Pbset and the motor target power Pm * are set. The temporary alternator power Ptmp is set as a value obtained by subtracting the auxiliary machine power Ph from the sum of the values (step S190), and the alternator target power Pa * is set as a value obtained by limiting the set temporary alternator power Ptmp with the maximum supplyable power Pamax ( Step S200). Here, regarding the battery sharing power Pbset, in the embodiment, the relationship between the battery temperature Tb, the remaining capacity (SOC), and the battery sharing power Pbset is determined in advance and stored in the ROM 74 as a map, and the battery temperature Tb and the remaining capacity are stored. When (SOC) is given, the setting is made by deriving the corresponding battery shared power Pbset from the map. An example of the relationship between the battery temperature Tb, the remaining capacity (SOC), and the battery shared power Pbset is shown in FIG.

  When the alternator target power Pa * is thus set, the battery target charge / discharge power Pb * to be charged / discharged from the high voltage battery 31 as a value obtained by adding the auxiliary machine power Ph to the value obtained by subtracting the alternator target power Pa * from the motor target power Pm *. Is set (step S210), and the target battery charge / discharge power Pb * is output in the current state of the high voltage battery 31 based on the set battery target charge / discharge power Pb *, battery temperature Tb, and remaining capacity (SOC). The battery target voltage Vb * and the battery target current Ib * necessary for this are set (step S220). FIG. 9 shows an example of the relationship among the remaining capacity (SOC) of the high voltage battery 31, the battery target charge / discharge power Pb *, the battery target voltage Vb *, and the battery target current Ib * when the battery temperature Tb is a certain temperature. In the example of FIG. 9, the battery target voltage Vb * and the battery target current Ib * satisfying the relationship Pb * = Vb * · Ib * may be obtained from the voltage-current characteristics of the high-voltage battery 31 determined by the remaining capacity (SOC). I understand that.

  Next, the field current If of the alternator 32 is set by executing the field current setting process illustrated in FIG. 10 (step S230), and the battery target current Ib * of the high-voltage battery 31 is set to the set field current If. Field current command If * is set as a value obtained by adding a feedback term that acts in the direction in which the difference between the detected battery current Ib and the detected battery current Ib is canceled (step S240). The set motor request torque Tm * is set in the motor ECU 42. At the same time, the field current command If * is transmitted to a field controller (not shown) incorporated in the alternator 32 to drive the alternator 32 (step S250), and the drive control routine is terminated. The motor ECU 42 that has received the motor request torque Tm * performs switching control of the switching element of the inverter 41 so that the motor request torque Tm * is output from the motor 40.

  In the field current setting process, first, a value 0.5 is set as an initial value for the field current ratio Rif and a value 1 is set for the counter N (step S300). Then, using this field current Rif, the battery operation current Ibs, which is the current of the high voltage battery 31 in the model circuit composed of the alternator 32, the high voltage battery 31, and the device, is calculated by the calculation current calculation process illustrated in FIG. S310). FIG. 12 shows an example of the model circuit.

  In the calculation current calculation process, first, the field current If is set based on the field current ratio Rif (step S400), and the alternator when the alternator 32 is operated at the rotation speed Na with the set field current If and temperature Ta. 32 no-load voltage Va0 is set (step S410). The no-load voltage Va0 can be obtained from the characteristic curve based on the temperature Ta, the rotation speed Na, and the alternator current Ia of the alternator 32. An example of the characteristic curve of the alternator 32 at a certain temperature when the field current If is 100% is shown in FIG. In the example of FIG. 13, the no-load voltage Va0 can be obtained as a voltage when the alternator current Ia is 0 with respect to the curve of the rotational speed Na of the alternator 32.

  Next, the electric power output from the high voltage battery 31 when the no-load voltage Va0 of the alternator 32 is set to the battery voltage Vb from the current state such as the remaining capacity (SOC) of the high voltage battery 31 and the battery temperature Tb is set as power generation unnecessary power Pmin. Calculate (step S420). That is, the voltage-current characteristic of the high-voltage battery 31 is obtained from the battery temperature Tb and the remaining capacity (SOC) (see FIG. 9), the current is obtained with the voltage in the obtained voltage-current characteristic as the no-load voltage Va0, and the obtained current and no-load The power generation unnecessary power Pmin is calculated by multiplying the voltage Va0.

  Then, the device power Pms is calculated as the sum of the motor target power Pm * and the auxiliary power Ph (step S430), and the calculated device power Pms is compared with the power generation unnecessary power Pmin (step S440). When the device power Pms is greater than the power generation unnecessary power Pmin, it is determined that the alternator 32 needs to be driven, and the three-element circuit including the alternator 32, the high-voltage battery 31, and the device in the model circuit illustrated in FIG. The circuit voltage V0, the alternator current Ia, and the battery current Ib are solved by performing the three-element circuit operation illustrated in FIG. 14 (step S450), and when the device power Pms is equal to or less than the power generation unnecessary power Pmin, the alternator 32 is not required to be driven. Then, the two-element circuit operation illustrated in FIG. 15 is performed on the two-element circuit including the high-voltage battery 31 and the device in the model circuit illustrated in FIG. 12 as two elements, and the circuit voltage V0 and the battery current Ib are solved. (Step S460), and the calculation current calculation process is terminated. Here, the circuit voltage V0, the alternator current Ia, and the battery current Ib are obtained as solutions in the three-element circuit calculation, and the circuit voltage V0 and the battery current Ib are obtained as solutions in the two-element circuit calculation. In step S310 of the ten field current setting processes, only the battery current Ib needs to be obtained. Therefore, only the battery current Ib is used among the solutions obtained by the calculation current calculation process. The three-element circuit calculation and the two-element circuit calculation will be briefly described below.

  In the three-element circuit operation, as shown in FIG. 14, first, the previous solution is set as the initial value of the current solution (step S500), and the sum of the circuit voltage V0 and the voltage Va of the alternator 32 according to Kirchhoff's law. From the first relationship (fa) in which the value is 0, the second relationship (fb) in which the sum of the circuit voltage V0 and the battery voltage Vb is 0, the device power Pms, the alternator 32 and the high-voltage battery 31 For a simultaneous equation consisting of a third relationship (fpm) that coincides with the supplied power (Va · (Ib + Ia)), a solution vector Fx = T (fa represents a transposed matrix) Tx Is calculated (step S510), and it is determined whether the square norm of the solution vector Fx is less than the allowable error (step S520). Here, the first relationship fa can be obtained from, for example, FIG. 13 as the relationship among the alternator current Ia, the field current If, and the rotation speed Na of the alternator 32. Further, the second relationship fb can be obtained from FIG. 9, for example, as the relationship between the battery current Ib and the remaining capacity (SOC). When the square norm of the solution vector Fx is not less than the allowable error, the alternator current Ia, the field current If, and the rotation speed Na are related to the first relation fa, the second relation fb, and the third relation fpm. The Jacob matrix J obtained as a determinant by partial differentiation is calculated (step S430), and the circuit voltage as a next initial value is obtained by multiplying the solution vector Fx by the inverse matrix of the obtained jacob matrix J from the left side. V0, alternator current Ia, and battery current Ib are updated (step S540), and the process returns to step S510. Therefore, steps S510 to S540 are repeatedly executed until the square norm of the solution vector Fx is less than the allowable error. When the square norm of the solution vector Fx is less than the allowable error by such an iterative process, the obtained solution vector Fx is transferred to the circuit solution buffer as X = [V0 Ia Ib] T (T represents a transposed matrix). (Step S550) The three-element circuit calculation is terminated. As shown in FIG. 15, the two-element circuit calculation can be performed in the same way as not considering the first relation fa in the three-element circuit calculation as understood from FIG. 14. Therefore, it is assumed that this process has been described with the description of the three-element circuit operation.

  Returning to the field current setting process of FIG. In step S310, the battery current Ib calculated in this way is set as the battery calculated current Ibs. When the battery calculation current Ibs is thus calculated, it is determined whether or not the absolute value of the difference between the battery calculation current Ibs and the battery target current Ib * is larger than the threshold value Iref (step S320). Here, the threshold value Iref is used to determine whether or not the calculated battery current Ib (battery calculated current Ibs) has converged to the battery target current Ib *. It can be set according to the accuracy to be performed. When the absolute value of the difference between the battery calculated current Ibs and the battery target current Ib * is greater than the threshold value Iref, it is determined that the battery calculated current Ibs has not converged to the battery target current Ib *, and the battery calculated current Ibs is If it is greater than Ib *, it is determined whether or not the field current ratio Rif is 0 (step S340). If the field current ratio Rif is not 0, the value 0.5 is divided by the square of the value of the counter N. This is subtracted from the currently set field current ratio Rif to set a new field current ratio Rif (step S350), the counter N is incremented by 1 (step S380), and the process returns to step S310. On the other hand, when the battery operation current Ibs is larger than the battery target current Ib *, it is determined whether or not the field current ratio Rif is a value 1 (step S360), and when the field current ratio Rif is not a value 1, the value 0.5 is determined. Is divided by the square of the value of the counter N and added to the currently set field current ratio Rif to set a new field current ratio Rif (step S370), and the counter N is incremented by 1 (Step S380), the process returns to Step S310. That is, the field current ratio Rif is set using the bisection method so that the battery operation current Ibs converges to the battery target current Ib *. When the absolute value of the difference between the battery calculated current Ibs and the battery target current Ib * becomes equal to or smaller than the threshold value Iref during the repeated execution of the processes of steps S310 to S380, the battery calculated current Ibs becomes the battery target current Ib *. The field current If is determined using the field current ratio Rif set at that time (step S390), and the field current setting process is terminated. Here, the field current If can be obtained as the product of the alternator current Ia and the field current ratio Rif. When the field current ratio Rif is 0 in step S340 or when the field current ratio Rif is 1 in step S360, the field current ratio Rif cannot be obtained for the outside of the field current ratio Rif. It is determined that it is not necessary to repeat the processes of S310 to S380, the field current If is set using the field current ratio Rif set at that time (step S390), and the field current setting process is terminated. .

  The relationship between the drive control routine of FIG. 3 described above and the control block of FIG. 2 will be supplemented. The field current calculator in the control block of FIG. 2 is the process of step S230 of the drive control routine, and inputs the difference between the output from the field current calculator and the battery target current Ib * and the battery current Ib. The processing up to the adder that sets the field current command If * by adding the output of the device is the processing of step S240. As can be seen from the control block of FIG. 2, the field current command If * is determined based on the rotation speed Na of the alternator 32 and the battery target current Ib * set based on the state of the high voltage battery 31 and the torque required for the motor 40. Feedback for correcting the field current If based on the deviation between the battery target current Ib * and the measured battery current Ib in feedforward control for determining the field current If of the alternator 32 from the device power Pms calculated based on It is set by adding control. Therefore, for example, when the accelerator pedal 83 is suddenly depressed, the alternator 32 is quickly driven with a more appropriate field current command If * by a term by the feedforward control (field current If from the field current calculator). Therefore, it is possible to suppress a rapid decrease in the remaining capacity (SOC) of the high voltage battery 31 and to suppress excessive power from being taken out from the high voltage battery 31. As a result, deterioration and damage of the high voltage battery 31 can be suppressed. In addition, since the field current command If * is set by correcting the field current If by the term by feedback control (output from the PI device), the drive of the alternator 32 deviates from the calculated value due to secular change or disturbance. Even if it becomes, the alternator 32 can be driven more appropriately. As a result, the remaining capacity (SOC) of the high voltage battery 31 can be brought close to the target value. Of course, the torque required from the motor 40 can be output.

  According to the hybrid vehicle 20 of the embodiment described above, the calculation is based on the battery target current Ib * set based on the rotation speed Na of the alternator 32 and the state of the high voltage battery 31 and the torque required for the motor 40. Since the alternator 32 is driven using feedforward control for obtaining the field current If of the alternator 32 from the device power Pms, the drive of the alternator 32 can be made to follow the sudden change in power required for the motor 40 quickly. As a result, it is possible to suppress a sudden change or excessive increase / decrease in the remaining capacity (SOC) of the high voltage battery 31 and to prevent excessive power from being taken out from the high voltage battery 31. Can be suppressed. Moreover, the battery operation current Ibs is calculated based on the device power Pms as the sum of the motor target power Pm * and the auxiliary device power Ph and the power generation unnecessary power Pmin that does not require the alternator 32 to be driven. By using the bisection method to converge the battery calculation current Ibs to the battery target current Ib *, the battery calculation current Ibs can be calculated quickly and the field current If can be calculated quickly. Can be done.

  Further, according to the hybrid vehicle 20 of the embodiment, the alternator 32 is driven using feedback control that corrects the field current If based on the deviation between the battery target current Ib * and the actually measured battery current Ib. Even if the drive of the alternator 32 deviates from the calculated value due to disturbance or the like, the alternator 32 can be driven more appropriately. As a result, the remaining capacity (SOC) of the high voltage battery 31 can be brought close to the target value. Of course, according to the hybrid vehicle 20 of the embodiment, it is possible to output torque corresponding to the operation of the driver from the motor 40.

  In the hybrid vehicle 20 of the embodiment, the battery operation current Ibs is converted into a three-element circuit based on the device power Pms as the sum of the motor target power Pm * and the auxiliary power Ph and the power generation unnecessary power Pmin that does not require the alternator 32 to be driven. When the calculation and the two-element circuit calculation are separately performed, the three-element circuit calculation of FIG. 14 and the two-element circuit calculation of FIG. 15 are performed. However, the present invention is not limited to this, and a three-element circuit operation or a two-element circuit operation by another method may be used.

  In the hybrid vehicle 20 of the embodiment, a three-element circuit including an alternator 32, a high-voltage battery 31, a motor 40, and an auxiliary device is used as a model circuit. However, when there is no auxiliary device that supplies power from the high-voltage battery 31 The three-element circuit including the alternator 32, the high-voltage battery 31, and the motor 40 may be calculated as a model circuit without considering the auxiliary machine.

  In the hybrid vehicle 20 of the embodiment, the field current ratio Rif is set using the bisection method to converge the battery calculation current Ibs to the battery target current Ib *. However, a method other than the bisection method is used. The battery calculation current Ibs may be converged to the battery target current Ib *.

  In the hybrid vehicle 20 of the embodiment, from the rotation speed Na of the alternator 32, the battery target current Ib * set based on the state of the high voltage battery 31, and the device power Pms calculated based on the torque required for the motor 40. In addition to the feedforward control for obtaining the field current If of the alternator 32, the feedback control for correcting the field current If based on the deviation between the battery target current Ib * and the measured battery current Ib is added to the field current command If *. However, it is possible to perform only feedforward control and not consider feedback control.

  In the hybrid vehicle 20 of the embodiment, the battery sharing power Pbset to be charged / discharged from the high voltage battery 31 is set based on the battery temperature Tb and the remaining capacity (SOC), but the remaining capacity (SOC) is independent of the battery temperature Tb. The battery sharing power Pbset to be charged / discharged from the high voltage battery 31 may be set based on the above, or the battery sharing power Pbset may be set by other methods.

  In the hybrid vehicle 20 of the embodiment, the front wheel drive system is configured by the engine 22, the torque converter 25, and the CVT 50. However, the front wheel drive system may be configured by the engine 22, the torque converter 25, and the stepped transmission. The front wheel drive system may be configured by the engine 22, the planetary gear, and the two motors, or any other configuration may be used as long as it travels by the power of the engine 22 and the motor 40. Further, in the hybrid vehicle 20 of the embodiment, the front wheel drive system is configured by the engine 22, the torque converter 25, and the CVT 50, and the rear wheel drive system is configured by the motor 40. Conversely, the front wheel drive system is configured by the motor 40. In addition, the rear wheel drive system may be configured by the engine 22, the torque converter 25, and the CVT 50.

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

  The present invention is applicable to the automobile manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a block diagram which shows the drive control of the alternator 32 as a control block. 4 is a flowchart showing an example of a drive control routine executed by a hybrid electronic control unit 70. It is explanatory drawing which shows an example of the relationship between battery temperature Tb and input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the remaining capacity (SOC) of the high voltage battery 31, an output limiting correction coefficient, and an input limiting correction coefficient. It is explanatory drawing which shows an example of the relationship between the rotation speed Na of the alternator 32, temperature Ta, and the maximum suppliable electric power Pamax. It is explanatory drawing which shows an example of the relationship between accelerator opening Acc, brake stroke BS, the rotation speed Nm of the motor 40, and the temporary motor torque Ttmp. It is explanatory drawing which shows an example of the relationship between battery temperature Tb, remaining capacity (SOC), and battery share electric power Pbset. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the high voltage battery 31, battery target charging / discharging electric power Pb *, battery target voltage Vb *, and battery target current Ib *. It is a flowchart which shows an example of a field current setting process. It is a flowchart which shows an example of a calculation electric current calculation process. It is a block diagram which shows an example of the model circuit of 3 elements which consists of the alternator 32, the high voltage battery 31, and an apparatus. It is explanatory drawing which shows an example of the characteristic curve of the alternator 32 in a certain temperature when the field current If is 100%. It is a flowchart which shows an example of 3 element circuit calculation. It is a flowchart which shows an example of 2 element circuit calculation.

Explanation of symbols

20 Hybrid Vehicle, 22 Engine, 23 Crankshaft, 24 Belt, 25 Torque Converter, 26 Mechanical Oil Pump, 30 Battery ECU, 31 High Voltage Battery, 31a Voltage Sensor, 31b Current Sensor, 31c Temperature Sensor, 32 Alternator, 34 DC / DC converter, 35 Low voltage battery, 36 Electric oil pump, 40 Motor, 41 Inverter, 42 Motor ECU, 43 Rotation position detection sensor, 50 CVT, 51 Input shaft, 52 Output shaft, 53 Primary pulley, 54 Secondary pulley, 55 Belt, 56 1st actuator, 57 2nd actuator, 59 CVTECU, 61 Rotational speed sensor, 62 Rotational speed sensor, 63a, 63b Front wheel, 64 Front shaft, 65 Gear mechanism, 66a, 6b Rear wheel, 67 Rear axle, 70 Hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accel pedal, 84 Accel pedal position sensor, 85 Brake pedal , 86 Brake pedal position sensor, 88 Vehicle speed sensor, C1 clutch.

Claims (10)

A hybrid vehicle that travels with power from an internal combustion engine and power from an electric motor capable of generating electricity,
A generator for generating electricity using power from the internal combustion engine;
A battery capable of exchanging electric power with the electric motor and the generator;
Maximum charge / discharge power setting means for setting the maximum charge / discharge power of the battery based on the state of the battery;
Maximum generated power setting means for setting the maximum generated power of the generator based on the state of the generator;
Required driving force setting means for setting required driving force required for the electric motor;
Limit that restricts the set required driving force based on the set maximum charge / discharge power, the set maximum generated power, and the auxiliary machine power necessary for the auxiliary machine capable of supplying power from the battery Limited driving force setting means for setting a driving force,
Target charge / discharge current setting means for setting a target charge / discharge current for charging / discharging the battery based on the state of the battery;
The generator based on the set target charge / discharge current and the set limited driving force from the electric motor when the electric power required for the electric motor and the auxiliary machine and the rotation speed of the electric generator are output. Target power generation state setting means for setting the target power generation state of
Drive control means for driving and controlling the motor and the generator so that a driving force based on the set limited driving force is output from the motor and the generator is driven in the set target power generation state. When,
A hybrid car with The hybrid vehicle according to claim 1,
The generator is a three-phase separately excited generator,
The target power generation state setting means is means for setting a field current of the generator as the target power generation state.   The target power generation state setting means is configured such that when the generator no-load power, which is the maximum power that can be output from the battery at a voltage equal to or higher than the voltage when the generator is in a no-load state, is less than the device power, the generator and the generator A battery current flowing through the battery is calculated by a three-element circuit calculation using a three-element circuit composed of a battery, the electric motor, and the auxiliary machine as a model circuit, and the field current is set based on the calculated battery current, When the generator no-load power is equal to or higher than the device power, the battery current is calculated by a two-element circuit calculation using a two-element circuit composed of the battery, the electric motor and the auxiliary machine as a model circuit, and the calculated battery current The hybrid vehicle according to claim 2, which is means for setting the field current based on the base. A hybrid vehicle according to claim 3,
In the three-element circuit operation, the first relationship in which the sum of the circuit voltage in the three-element circuit and the power generation voltage of the generator is 0, and the sum of the circuit voltage and the battery voltage is 0. The battery current is calculated so as to satisfy the following three relations: a relation of 2 and a third relation in which the power obtained by multiplying the sum of the generator current and the battery current by the generated voltage matches the device power Is an operation to
In the two-element circuit calculation, the fourth relationship in which the sum of the circuit voltage and the battery voltage is 0, and the power obtained by multiplying the sum of the generator current and the battery current by the generated voltage are It is an operation for calculating the battery current so as to satisfy the two relationships of the fifth relationship that matches the device power.
Hybrid car.   5. The hybrid vehicle according to claim 3, wherein the target power generation state setting means is means for setting the field current so that the calculated battery current substantially coincides with the set target charge / discharge current. 6.   The target power generation state setting means sequentially changes the ratio of the field current using a bisection method so that the calculated battery current matches the set target charge / discharge current within a predetermined error range. 6. The hybrid vehicle according to claim 5, wherein the hybrid vehicle is means for setting the field current according to a ratio of the field current during the operation. A hybrid vehicle according to any one of claims 1 to 6,
Input / output current detection means for detecting the input / output current of the battery,
The drive control unit corrects the set target power generation state based on the detected input / output current and the set target charge / discharge current, and the generator is driven in the corrected target power generation state. A hybrid vehicle that is a means to control. A hybrid vehicle according to any one of claims 1 to 7,
The internal combustion engine is connected to the first axle so that power can be output.
The electric motor is connected to a second axle different from the first axle so that power can be output. A hybrid vehicle according to claim 8, wherein
Comprising an operation control means for controlling the operation of the internal combustion engine in accordance with a driver's accelerator operation;
The requested driving force setting means is means for setting the requested driving force based on a driver's accelerator operation. An internal combustion engine that can output power for traveling, an electric motor that can output power for traveling, a generator that generates electric power using the power from the internal combustion engine, and exchange of electric power with the motor and the generator A hybrid vehicle control method comprising: a battery;
A maximum charge / discharge power of the battery based on the state of the battery; a target charge / discharge current for charging / discharging the battery based on the state of the battery; and a maximum generated power of the generator based on the state of the generator. Set,
A restriction that restricts the required driving force required for the electric motor based on the set maximum charge / discharge power, the set maximum generated power, and auxiliary power required for an auxiliary machine capable of supplying power from the battery. Set the driving force
When the set target charge / discharge current and the set limited driving force are output from the motor, the generator target is based on the device power required for the motor and the auxiliary machine and the rotation speed of the generator. Set the power generation state,
A method for controlling a hybrid vehicle, wherein a driving force based on the limited driving force is output from the electric motor and the electric motor and the electric generator are driven and controlled so that the electric generator is driven in the set target power generation state.

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