JP2007186048A - Hybrid car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid car for increasing the possibility of preventing the occurrence of the sliding down of a vehicle when the vehicle is climbing a hill backward. <P>SOLUTION: A decision part 342 decides whether or not a vehicle is climbing a hill backward based on a shift position signal SP and a torque command TR2 of a motor generator MG2. When it is decided that the vehicle is climbing a hill backward by a decision part 342, an upper limit temperature setting part 344 sets the upper limit temperature of the motor generator MG2 at an upper limit temperature TS2 which is higher than an upper limit temperature TS1 as a normal set value. A torque limit control part 346 executes the torque limit control of the motor generator MG2 based on a motor temperature T and the upper limit temperature set by the upper limit temperature setting part 344. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle, and more particularly to output limit control of an electric motor mounted on the hybrid vehicle.

  In recent years, hybrid vehicles have attracted attention as environmentally friendly vehicles. A hybrid vehicle is a vehicle that further includes a power storage device, an inverter, and an electric motor driven by the inverter as a power source in addition to a conventional engine.

  Japanese Patent Laid-Open No. 2003-304604 (Patent Document 1) discloses a drive device for a motor mounted as a drive source of various vehicles such as a hybrid vehicle, an electric vehicle (Electric Vehicle), and a fuel cell vehicle (Fuel Cell Vehicle). Is disclosed.

  In this motor drive device, when the motor temperature detected by the temperature sensor is equal to or higher than the limit temperature, the motor output control means limits the output of the motor. Here, the temperature change rate detection unit detects the change rate of the motor temperature, and changes the setting of the limit temperature according to the detected change rate.

  That is, when the change rate of the motor temperature is equal to or higher than the predetermined change rate, the temperature change rate detection unit determines that the temperature rise of the motor is large, sets the limit temperature to the first limit temperature, and outputs the motor output. The control means limits the output of the motor when the motor temperature becomes equal to or higher than the first limit temperature.

  On the other hand, when the change rate of the motor temperature is smaller than the predetermined change rate, the temperature change rate detection unit determines that the temperature rise of the motor is small and makes the limit temperature higher than the first limit temperature. The second limit temperature is set, and the motor output control means limits the output of the motor when the motor temperature becomes equal to or higher than the second limit temperature.

According to this motor control device, the distance that can be traveled without limiting the output of the motor is extended, the temperature of the motor can be protected, and the performance of the motor can be fully exhibited (see Patent Document 1).
JP 2003-304604 A JP 2005-83300 A Japanese Patent No. 3641245 Japanese Patent No. 3646642 JP 2000-184502 A

  In the motor driving device disclosed in Japanese Patent Application Laid-Open No. 2003-304604, when it is determined that the temperature rise of the motor is large, the output of the motor is limited based on a relatively severe limit temperature. Here, when the vehicle moves forward, hybrid travel using an engine and a motor is possible, and when the vehicle travels backward, when the above motor drive device is mounted on a hybrid vehicle that travels using only the motor, Even if the output of the motor is limited by the driving force generated by the engine, a sufficient driving force can be ensured.

  On the other hand, when the vehicle is moving backward, the output of the motor is limited, so that a driving force shortage may occur. Here, for example, when the output of the motor is limited during reverse climbing and the vehicle can slip down, such a situation should be avoided with the highest priority. There is a possibility that the temperature limit of the motor is given priority and the motor output limit is made relatively strict. As a result, in the above motor drive device, the vehicle may slide down.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a hybrid vehicle that can increase the possibility of avoiding the occurrence of vehicle slippage during reverse climbing. .

  According to the present invention, a hybrid vehicle includes a power device that generates a forward drive force of a vehicle, an electric motor that generates a forward drive force and a reverse drive force of the vehicle, a temperature detection device that detects a temperature of the electric motor, and a temperature detection. An output limiting unit that limits the output of the motor based on the temperature detected by the device and the set upper limit temperature of the motor, a determination unit that determines whether or not the vehicle is going uphill, and a vehicle that is going uphill by the judging unit And a setting unit that sets a second upper limit temperature higher than the normally set first upper limit temperature in the output limiting unit when it is determined that there is an output.

  Preferably, the hybrid vehicle further includes an estimation unit that estimates the life of the motor based on the temperature detected by the temperature detection device, and a notification device that notifies the user of information related to the life of the motor estimated by the estimation unit.

  More preferably, the estimation unit estimates the life of the electric motor based on an integrated amount corresponding to the detected temperature exceeding the first upper limit temperature.

  Preferably, the estimation unit estimates the life of the motor based on a total time when the detected temperature exceeds the first upper limit temperature.

  Preferably, the estimation unit estimates the life of the electric motor based on the total number of times that the detected temperature exceeds the first upper limit temperature.

  In the present invention, since the vehicle is driven only by the electric motor when the vehicle is traveling backward, if the output of the electric motor is restricted by the output restricting unit when the vehicle is traveling backward, the vehicle can be lowered. Here, the setting unit sets the second upper limit temperature, which is higher than the first upper limit temperature that is normally set, in the output limiting unit during reverse climbing. And since an output restriction part restrict | limits the output of an electric motor based on the upper limit temperature set by the setting part, a setting upper limit temperature is raised during reverse climbing and the output restriction of an electric motor is eased.

  Further, in the present invention, the life of the motor can be reduced by raising the upper limit temperature of the motor, the life of the motor is estimated by the estimation unit, and information on the estimated life of the motor is notified by the notification device to the user. To be notified.

  According to the present invention, the set upper limit temperature is raised during reverse climbing, and the output limit of the electric motor is relaxed. Therefore, it is possible to avoid the occurrence of vehicle slippage during reverse climbing.

  In addition, according to the present invention, the life of the motor is estimated, and information on the estimated life of the motor is notified to the user, so that information on the vehicle maintenance time can be provided to the user.

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

  FIG. 1 is an overall block diagram for illustrating a power train of a hybrid vehicle according to an embodiment of the present invention. Referring to FIG. 1, hybrid vehicle 100 includes an engine 4, motor generators MG <b> 1 and MG <b> 2, a power distribution mechanism 3, and wheels 2. Hybrid vehicle 100 includes power storage device B, power supply line PL, ground line SL, capacitor C, inverters 10 and 20, and electronic control unit (hereinafter also referred to as "ECU") 30. The alarm device 38, the temperature sensor 40, the voltage sensor 50, and the current sensors 60 and 70 are further provided.

  Power distribution mechanism 3 is coupled to engine 4 and motor generators MG1 and MG2 to distribute power between them. For example, as the power distribution mechanism 3, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear can be used. These three rotating shafts are connected to the rotating shafts of engine 4 and motor generators MG1, MG2, respectively. For example, the engine 4 and the motor generators MG1 and MG2 can be mechanically connected to the power distribution mechanism 3 by making the rotor of the motor generator MG1 hollow and passing the crankshaft of the engine 4 through the center thereof.

  The rotating shaft of motor generator MG2 is coupled to wheel 2 by a reduction gear and an operating gear (not shown). Further, a reduction gear for the rotation shaft of motor generator MG2 may be further incorporated in power distribution mechanism 3.

  Motor generator MG1 operates as a generator driven by engine 4 and is incorporated in hybrid vehicle 100 as an electric motor that can start engine 4, and motor generator MG2 drives wheels 2. As an electric motor, the hybrid vehicle 100 is incorporated. Engine 4 is incorporated in hybrid vehicle 100 as a power source that drives motor generator MG1 and generates forward drive force of the vehicle. When the vehicle is traveling backward, driving force is obtained by rotating motor generator MG2 in the reverse direction.

  Power storage device B is connected to power supply line PL and ground line SL. Capacitor C is connected in parallel to power storage device B between power supply line PL and ground line SL. Inverters 10 and 20 are connected in parallel to power supply line PL and ground line SL. Motor generator MG1 includes a Y-connected three-phase coil as a stator coil, and is connected to inverter 10 via a three-phase cable. Motor generator MG2 includes a Y-connected three-phase coil as a stator coil, and is connected to inverter 20 via a three-phase cable. Then, the output shaft of engine 4 is mechanically coupled to the rotation shaft of motor generator MG1, and the drive shaft of wheels 2 is mechanically coupled to the rotation shaft of motor generator MG2.

  The power storage device B is a chargeable / dischargeable DC power source, and is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion. The power storage device B supplies DC power to the inverters 10 and 20. Power storage device B is charged by inverter 10 that receives the generated power from motor generator MG1 when motor generator MG1 uses the output of engine 4 to generate power. Power storage device B is charged by inverter 20 that receives the generated power from motor generator MG2 during regenerative braking by motor generator MG2. Note that a large-capacity capacitor may be used as the power storage device B.

  Capacitor C smoothes voltage fluctuations between power supply line PL and ground line SL. Inverter 10 converts a DC voltage received from power supply line PL into a three-phase AC voltage based on signal PWI1 from ECU 30, and outputs the converted three-phase AC voltage to motor generator MG1. Inverter 10 converts the three-phase AC voltage generated by motor generator MG1 using the output of engine 4 into a DC voltage based on signal PWI1 from ECU 30, and outputs the converted DC voltage to power supply line PL. .

  Inverter 20 converts a DC voltage received from power supply line PL into a three-phase AC voltage based on signal PWI2 from ECU 30, and outputs the converted three-phase AC voltage to motor generator MG2. Thereby, motor generator MG2 is driven to generate a designated torque. The inverter 20 converts the three-phase AC voltage generated by the motor generator MG2 by receiving the rotational force from the wheel 2 during regenerative braking of the vehicle into a DC voltage based on the signal PWI2 from the ECU 30, and the converted DC The voltage is output to the power supply line PL.

  Note that regenerative braking here refers to braking with regenerative power generation when the driver operating the vehicle performs a foot brake operation, or turning off the accelerator pedal while driving without operating the foot brake. This includes decelerating (or stopping acceleration) the vehicle while generating regenerative power.

  Motor generators MG1 and MG2 are three-phase AC motors, for example, three-phase AC synchronous motors. Motor generator MG <b> 1 generates a three-phase AC voltage using the output of engine 4, and outputs the generated three-phase AC voltage to inverter 10. Motor generator MG1 generates driving force by the three-phase AC voltage received from inverter 10 and starts engine 4. Motor generator MG <b> 2 generates vehicle driving torque by the three-phase AC voltage received from inverter 20. Motor generator MG2 generates a three-phase AC voltage and outputs it to inverter 20 during regenerative braking of the vehicle.

  Temperature sensor 40 detects motor temperature T of motor generator MG2, and outputs the detected motor temperature T to ECU 30. Voltage sensor 50 detects a voltage Vm between terminals of capacitor C, and outputs the detected voltage Vm to ECU 30. Current sensor 60 detects motor current MCRT1 flowing through a three-phase cable connecting inverter 10 to motor generator MG1, and outputs the detected motor current MCRT1 to ECU 30. Current sensor 70 detects motor current MCRT2 flowing in a three-phase cable connecting inverter 20 to motor generator MG2, and outputs the detected motor current MCRT2 to ECU 30.

  ECU 30 receives torque commands TR1, TR2 and shift position signal SP of motor generators MG1, MG2 from an external ECU (not shown). ECU 30 drives inverters 10 and 20 based on these input values, motor temperature T from temperature sensor 40, voltage Vm from voltage sensor 50, and motor currents MCRT1 and MCRT2 from current sensors 60 and 70. Signals PWI1 and PWI2 are generated, and the generated signals PWI1 and PWI2 are output to inverters 10 and 20, respectively.

  The torque command TR1 is based on the state of charge (SOC) of the power storage device B and the start command of the engine 4, and the torque command TR2 is based on the accelerator opening, the amount of depression of the brake pedal, the traveling state of the vehicle, and the like. And is calculated by an external ECU. The shift position signal SP is a signal indicating the selection position of the shift lever for selecting the shift range.

  Further, ECU 30 estimates the life of motor generator MG2 by a method described later, and outputs information related to the life of motor generator MG2 to notification device 38.

  The notification device 38 notifies the user of information related to the life of the motor generator MG2 from the ECU 30. The notification device 38 may visually display information regarding the life of the motor generator MG2 to the user, or may be notified by voice.

  FIG. 2 is a functional block diagram of ECU 30 shown in FIG. Referring to FIG. 2, ECU 30 includes a first inverter control unit 32, a second inverter control unit 34, and a notification control unit 36.

  First inverter control unit 32 generates signal PWI1 for driving inverter 10 based on torque command TR1 of motor generator MG1, voltage Vm from voltage sensor 50, and motor current MCRT1 from current sensor 60, The generated signal PWI1 is output to inverter 10.

  Second inverter control unit 34 controls inverter 20 based on torque command TR2 of motor generator MG2, voltage Vm, motor current MCRT2 from current sensor 70, motor temperature T from temperature sensor 40, and shift position signal SP. A signal PWI2 for driving is generated, and the generated signal PWI2 is output to the inverter 20.

  Second inverter control unit 34 executes torque limit control for limiting the torque of motor generator MG2 when motor temperature T of motor generator MG2 exceeds the set upper limit temperature. Here, during reverse climbing, second inverter control unit 34 relaxes the upper limit temperature of motor generator MG2 to relieve torque limitation, and activates control signal CTL1 to output it to notification control unit 36.

  When the control signal CTL1 from the second inverter control unit 34 is activated, the notification control unit 36 estimates the life of the motor generator MG2 by a method described later based on the motor temperature T from the temperature sensor 40. Then, information related to the life of motor generator MG2 is output to notification device 38.

  FIG. 3 is a functional block diagram of the first inverter control unit 32 shown in FIG. Referring to FIG. 3, first inverter control unit 32 includes a motor control phase voltage calculation unit 322 and a PWM signal conversion unit 324.

  Motor control phase voltage calculation unit 322 calculates a voltage to be applied to each U, V, W phase coil of motor generator MG1 based on torque command TR1 of motor generator MG1, motor current MCRT1, and voltage Vm, and calculates the calculation. Each phase coil voltage is output to the PWM signal converter 324.

  The PWM signal conversion unit 324 generates a PWM (Pulse Width Modulation) signal for actually turning on / off each transistor of the inverter 10 based on each phase coil voltage received from the motor control phase voltage calculation unit 322, The generated PWM signal is output to each transistor of inverter 10 as signal PWI1.

  FIG. 4 is a functional block diagram of second inverter control unit 34 and notification control unit 36 shown in FIG. Referring to FIG. 4, second inverter control unit 34 includes determination unit 342, upper limit temperature setting unit 344, torque limit control unit 346, motor control phase voltage calculation unit 348, and PWM signal conversion unit 350. Including.

  Based on shift position signal SP and torque command TR2 of motor generator MG2, determination unit 342 determines whether or not this hybrid vehicle 100 is traveling backward. More specifically, determination unit 342 determines that hybrid vehicle 100 moves backward when shift position signal SP is in the reverse range (R range) and torque command TR2 exceeds preset threshold value TRth. It is determined that it is climbing up. If determining unit 342 determines that hybrid vehicle 100 is traveling backward, the determining unit 342 activates the control signal CTL2 and outputs the control signal CTL2 to the upper limit temperature setting unit 344.

  Upper limit temperature setting unit 344 sets the upper limit temperature of motor generator MG 2, and outputs the set upper limit temperature to torque limit control unit 346. Specifically, upper limit temperature setting unit 344 sets the upper limit temperature of motor generator MG2 to TS1 when control signal CTL2 from determination unit 342 is inactivated. On the other hand, when control signal CTL2 from determination unit 342 is activated, upper limit temperature setting unit 344 sets the upper limit temperature of motor generator MG2 to TS2 higher than TS1.

  Torque limit control unit 346 executes torque limit control for limiting the output torque of motor generator MG2 based on motor temperature T of motor generator MG2 and the upper limit temperature set by upper limit temperature setting unit 344. Specifically, torque limit control unit 346 receives an external ECU when motor temperature T of motor generator MG2 exceeds a threshold value defined by upper limit temperature (TS1 or TS2) set by upper limit temperature setting unit 344. The received torque command TR2 is reduced. Torque limit control unit 346 outputs torque command TRR, which is limited based on motor temperature T and the set upper limit temperature, to motor control phase voltage calculation unit 348 when motor temperature T exceeds a threshold value. To do.

  The motor control phase voltage calculation unit 348 is based on the torque command TRR from the torque limit control unit 346, the voltage Vm from the voltage sensor 50, and the motor current MCRT2 from the current sensor 70. The voltage applied to the W phase coils is calculated, and the calculated phase coil voltages are output to the PWM signal converter 350.

  PWM signal conversion unit 350 generates a PWM signal for actually turning on / off each transistor of inverter 20 based on each phase coil voltage received from motor control phase voltage calculation unit 348, and the generated PWM signal Is output to each transistor of the inverter 20 as a signal PWI2.

  The notification control unit 36 includes a calculation unit 362 and a life estimation unit 364. The calculation unit 362 is activated in response to the control signal CTL1 from the torque limit control unit 346, and integrates the amount by which the motor temperature T from the temperature sensor 40 exceeds the upper limit temperature TS1. Then, calculation unit 362 outputs the integrated value to life estimation unit 364.

  Life estimation unit 364 estimates the lifetime of motor generator MG2 based on the integrated value from calculation unit 362. More specifically, life estimation unit 364 subtracts the integrated value from calculation unit 362 from a preset value indicating the life of motor generator MG2, and sets the subtracted value as the remaining life of motor generator MG2. Then, life estimation unit 364 outputs information related to the life of motor generator MG2 including the calculated remaining life of motor generator MG2 to notification device 38.

  In the second inverter control unit 34, when the motor temperature T of the motor generator MG2 approaches the set upper limit temperature, the torque limit control unit 346 reduces the torque command of the motor generator MG2 in order to protect the motor generator MG2.

  The upper limit temperature of motor generator MG2 is set by upper limit temperature setting unit 344, and upper limit temperature setting unit 344 normally sets the upper limit temperature of motor generator MG2 to TS1. Here, when the determination unit 342 determines that the hybrid vehicle 100 is traveling backward, the upper limit temperature setting unit 344 reduces the torque limit of the motor generator MG2 by the torque limit control unit 346. The upper limit temperature is set to TS2 higher than normal.

  FIG. 5 is a diagram showing torque characteristics of motor generator MG2. Referring to FIG. 5, the horizontal axis indicates the rotation speed of motor generator MG2, and the vertical axis indicates the output torque of motor generator MG2. When the hybrid vehicle 100 is traveling forward, the engine 4 also generates torque, so the average torque of the motor generator MG2 is usually around a relatively low region R1. On the uphill slope, the average torque of motor generator MG2 increases around region R2, which is larger than region R1, but since the running torque is shared with engine 4, it does not increase to maximum torque TRmax.

  On the other hand, during reverse travel, hybrid vehicle 100 travels only with the output torque of motor generator MG2, so that the average torque of motor generator MG2 increases to around region R3 in the vicinity of maximum torque TRmax, particularly during reverse climbing. .

  Therefore, in this hybrid vehicle 100, it is assumed that the vehicle is in reverse climbing in order to prevent the vehicle generator from falling due to the torque of the motor generator MG2 being limited by torque limiting control by the torque limiting control unit 346 during reverse climbing. When the determination is made, the upper limit temperature of the motor generator MG2 is set to TS2 higher than the normal set value TS1, and the torque limit of the motor generator MG2 is relaxed.

  Although there is a possibility that a large temperature load is applied to the motor generator MG2 by raising the upper limit temperature of the motor generator MG2 from TS1 to TS2, the motor temperature T of the motor generator MG2 rarely exceeds the upper limit temperature TS1, Even if the motor temperature T exceeds the upper limit temperature TS1, it is suppressed to the upper limit temperature TS2 or less, so that the performance of the motor generator MG2 does not deteriorate immediately.

  Then, in a rare state where the motor temperature T exceeds the upper limit temperature TS1, the upper limit temperature is changed to the upper limit temperature TS2 higher than the normal upper limit temperature TS1, and an opportunity to avoid the situation where the vehicle slides down during reverse climbing is given. This is considered to have a larger merit than the case where only the temperature protection of the motor generator MG2 is achieved.

  FIG. 6 is a diagram for explaining torque limitation of motor generator MG2 by torque limitation control unit 346 shown in FIG. Referring to FIG. 6, the horizontal axis represents motor temperature T of motor generator MG2, and the vertical axis represents torque command TRR of motor generator MG2. When the torque limit control unit 346 receives the upper limit temperature TS1 (or TS2 (> TS1)) from the upper limit temperature setting unit 344, the threshold value Tth1 (<TS1) defined according to the upper limit temperature TS1 (or TS2). ) (Or Tth2 (<TS2)), when the motor temperature T is lower, the torque command TR from the external ECU is output as it is to the motor control phase voltage calculation unit 348 as the torque command TRR. On the other hand, when the motor temperature T is higher than the threshold value Tth1 (or Tth2), the torque limit control unit 346 causes the line k1 (or k2) so that the torque command TRR becomes 0 at the upper limit temperature TS1 (or TS2). To limit the torque command.

  That is, when the vehicle can slip down during reverse climbing, the upper limit temperature of motor generator MG2 is relaxed from TS1 to TS2, and as a result, the torque limit of motor generator MG2 is relaxed.

  FIG. 7 is a diagram showing how the motor temperature T of the motor generator MG2 changes during reverse climbing. Referring to FIG. 7, during reverse climbing, the upper limit temperature of motor generator MG2 is relaxed from TS1 to TS2, so that motor temperature T can exceed upper limit temperature TS1. FIG. 7 shows a case where the motor temperature T exceeds the upper limit temperature TS1 at times t1 to t2 and t3 to t4.

  Reducing the upper limit temperature of the motor generator MG2 from TS1 to TS2 does not immediately cause the performance deterioration of the motor generator MG2, but in the long term, there is a possibility that the life of the motor generator MG2 may be reduced. Here, since it is considered that the total time when the motor temperature T exceeds the upper limit temperature TS1 and the magnitude of the motor temperature T contribute to the life of the motor generator MG2, in this embodiment, the motor temperature T is the upper limit. The life of the motor generator MG2 is estimated based on the integrated value (area shown by the hatched area in FIG. 7) exceeding the temperature TS1, and the user is notified using the notification device 38.

  Although not particularly illustrated, the life of motor generator MG2 can be estimated more simply based on the total time that motor temperature T exceeds upper limit temperature TS1 or the number of times that motor temperature T exceeds upper limit temperature TS1. Good.

  FIG. 8 is a flowchart of the torque limit control by the second inverter control unit 34 shown in FIG. The process shown in this flowchart is called from the main routine and executed at regular time intervals or whenever a predetermined condition is satisfied.

  Referring to FIG. 8, second inverter control unit 34 determines whether or not the shift position is in the reverse range (R range) based on shift position signal SP (step S10). If second inverter control unit 34 determines that the shift position is in a range other than the reverse range (R range) (NO in step S10), the process proceeds to step S40, and upper limit temperature TS1 is set as the upper limit temperature of motor generator MG2. Set.

  If it is determined in step S10 that the shift position is in the reverse range (R range) (YES in step S10), second inverter control unit 34 sets a threshold value at which torque command TR2 of motor generator MG2 is set in advance. It is determined whether or not it is larger than TRth (step S20). If second inverter control unit 34 determines that torque command TR2 is equal to or smaller than threshold value TRth (NO in step S20), the process proceeds to step S40.

  If it is determined in step S20 that torque command TR2 is larger than threshold value TRth (YES in step S20), second inverter control unit 34 sets upper limit temperature higher than upper limit temperature TS1 as the upper limit temperature of motor generator MG2. Set TS2. That is, when the shift position is in the reverse range (R range) and the torque command TR2 is greater than the threshold value TRth, the second inverter control unit 34 determines that the vehicle is traveling in reverse, and the torque Upper limit temperature TS2 higher than normal upper limit temperature TS1 is set as the upper limit temperature of motor generator MG2 in the limit control.

  Then, when the upper limit temperature of motor generator MG2 is set in step S30 or S40, second inverter control unit 34 determines whether motor temperature T of motor generator MG2 from temperature sensor 40 exceeds threshold value Tth or not. Is determined (step S50). When second inverter control unit 34 determines that motor temperature T is equal to or lower than threshold value Tth (NO in step S50), the series of processing ends without limiting torque command TR from the external ECU. .

  If it is determined in step S50 that motor temperature T is higher than threshold value Tth (YES in step S50), second inverter control unit 34 is set in upper limit temperature TS1 set in step S40 or in step S30. Based on the upper limit temperature TS2 and the motor temperature T from the temperature sensor 40, torque limit control for limiting the torque of the motor generator MG2 is executed (step S60).

  FIG. 9 is a flowchart of control by the notification control unit 36 shown in FIG. The processing shown in this flowchart is also called and executed from the main routine at regular time intervals or whenever a predetermined condition is satisfied.

  Referring to FIG. 9, notification control unit 36 acquires motor temperature T of motor generator MG2 from temperature sensor 40 (step S110). Then, notification control unit 36 determines whether or not motor temperature T of motor generator MG2 is higher than upper limit temperature TS1 (step S120). If notification control unit 36 determines that motor temperature T is equal to or lower than upper limit temperature TS1 (NO in step S120), it terminates the series of processes without performing subsequent processes.

  When it is determined in step S120 that motor temperature T is higher than upper limit temperature TS1 (YES in step S120), notification control unit 36 integrates the amount of motor temperature T exceeding upper limit temperature TS1. That is, the notification control unit 36 integrates the difference value between the motor temperature T and the upper limit temperature TS1 (step S130).

  Next, notification control unit 36 subtracts the integrated value calculated in step S130 from a preset value indicating the life of motor generator MG2, and sets the subtracted value as the remaining life of motor generator MG2 (step S140). Then, notification control unit 36 outputs information related to the life of motor generator MG2 including the remaining life of motor generator MG2 to notification device 38 (step S150).

  As described above, in this embodiment, the upper limit temperature setting unit 344 sets the upper limit temperature TS2 higher than the normally set upper limit temperature TS1 in the torque limit control unit 346 during reverse climbing. Since torque limit control unit 346 limits the torque command of motor generator MG2 based on the upper limit temperature set by upper limit temperature setting unit 344, the upper limit temperature of motor generator MG2 is raised during reverse climbing, and the motor generator The torque limit of MG2 is relaxed. Therefore, according to this embodiment, the possibility of avoiding the occurrence of vehicle slippage during reverse climbing is increased.

  Further, when the upper limit temperature of the motor generator MG2 is raised, the life of the motor generator MG2 may be reduced. Therefore, the remaining life of the motor generator MG2 is estimated by the life estimation unit 364, and information related to the life of the motor generator MG2 is notified to the notification device 38. Is notified to the user. Therefore, according to this embodiment, it is possible to provide the user with appropriate information related to the maintenance time of the vehicle.

  In the above embodiment, it is determined whether or not the vehicle is traveling backward on the basis of the shift position signal SP and the torque command TR2. However, instead of the shift position signal SP, the motor generator MG The rotation direction may be used, and instead of the torque command TR2, the actual torque detected by using the torque sensor or the motor current MCRT2 flowing in the motor generator MG2 may be used. In addition, an attitude sensor that detects the inclination of the vehicle may be provided separately to determine whether the vehicle is going backward.

  In the above embodiment, the torque command of motor generator MG2 is limited. However, the motor current of motor generator MG2 may be limited directly.

  Further, the information regarding the life of the motor generator MG2 that is notified to the user by the notification device 38 may include information that prompts the user to maintain the vehicle when the life of the motor generator MG2 approaches.

  In the above embodiment, the power storage device B is a secondary battery or a capacitor. However, the power storage device B may be replaced with a fuel cell. Further, a boost converter that boosts the DC voltage from power storage device B may be provided between power storage device B and inverters 10 and 20.

  In the above, engine 4 corresponds to “power device” in the present invention, and motor generator MG2 corresponds to “electric motor” in the present invention. The temperature sensor 40 corresponds to the “temperature detection device” in the present invention, and the torque limit control unit 346 corresponds to the “output limitation unit” in the present invention. Furthermore, upper limit temperature setting unit 344 corresponds to the “setting unit” in the present invention, and notification control unit 36 corresponds to the “estimating unit” in the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

1 is an overall block diagram for illustrating a power train of a hybrid vehicle according to an embodiment of the present invention. FIG. It is a functional block diagram of ECU shown in FIG. It is a functional block diagram of the 1st inverter control part shown in FIG. It is a functional block diagram of the 2nd inverter control part and alerting | reporting control part which are shown in FIG. It is a figure showing torque characteristics of motor generator MG2. FIG. 5 is a diagram for explaining torque limitation of motor generator MG2 by a torque limitation control unit shown in FIG. It is the figure which showed the mode of the change of the motor temperature of the motor generator MG2 at the time of reverse climbing. 3 is a flowchart of torque limit control by a second inverter control unit shown in FIG. 2. It is a flowchart of control by the alerting | reporting control part shown in FIG.

Explanation of symbols

  2 wheels, 3 power distribution mechanisms, 4 engines, 10 and 20 inverters, 30 ECUs, 32 first inverter control units, 34 second inverter control units, 36 notification control units, 38 notification devices, 40 temperature sensors, 50 voltages Sensor, 60, 70 Current sensor, 100 Hybrid vehicle, 322, 348 Motor control phase voltage calculation unit, 324, 350 PWM signal conversion unit, 342 determination unit, 344 upper limit temperature setting unit, 346 Torque limit control unit, 362 calculation unit 364 Life estimation unit, B power storage device, C capacitor, PL power supply line, SL ground line, MG1, MG2 motor generator.

Claims (5)

A power unit for generating a forward driving force of the vehicle;
An electric motor for generating forward drive force and reverse drive force of the vehicle;
A temperature detecting device for detecting the temperature of the electric motor;
An output limiting unit that limits the output of the electric motor based on the temperature detected by the temperature detection device and the set upper limit temperature of the electric motor;
A determination unit for determining whether or not the vehicle is going uphill;
A setting unit configured to set, in the output limiting unit, a second upper limit temperature that is higher than the first upper limit temperature that is normally set when the determination unit determines that the vehicle is going uphill. Hybrid car. An estimation unit that estimates the life of the electric motor based on a temperature detected by the temperature detection device;
The hybrid vehicle according to claim 1, further comprising: a notification device that notifies a user of information related to the life of the motor estimated by the estimation unit.   The hybrid vehicle according to claim 2, wherein the estimation unit estimates a lifetime of the electric motor based on an integrated amount corresponding to the detected temperature exceeding the first upper limit temperature.   The hybrid vehicle according to claim 2, wherein the estimation unit estimates a life of the electric motor based on a total time when the detected temperature exceeds the first upper limit temperature.   The hybrid vehicle according to claim 2, wherein the estimation unit estimates a life of the electric motor based on a total number of times that the detected temperature exceeds the first upper limit temperature.

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