JP2017056774A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of unnecessary torque during inverter-less travel control.SOLUTION: An ECU executes control processing including the steps of: shutting off an inverter (S130), subjecting a converter to a PWM operation (S140), driving an engine (S150), and detecting a shift range (S160) in the case of abnormality occurring in the inverter (Yes for S110); controlling an engine revolution speed so that a counter-electromotive voltage Vc is higher than a system voltage VH (S180) in the case of the shift range being in a forward travel range (Yes for S170); and controlling the engine revolution speed so that a counter-electromotive voltage Vc is lower than the system voltage VH (S190) in the case of the shift range being in a non-forward travel range (No for S170).SELECTED DRAWING: Figure 7

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle that can travel using at least one power of an engine and a rotating electric machine.

  In a hybrid vehicle, a configuration including an engine, first and second motor generators, and a planetary gear mechanism is known. The planetary gear mechanism includes a sun gear coupled to the first motor generator, a ring gear coupled to the second motor generator, and a carrier coupled to the engine. The electric system of this hybrid vehicle includes a battery and an inverter. The inverter is configured to be able to convert electric power among the battery, the first motor generator, and the second motor generator.

  In the hybrid vehicle having such a configuration, when an abnormality occurs in the inverter that interferes with the rotational drive control of the first and second motor generators, appropriate measures are taken to protect the device. Is required. For example, Japanese Patent Laying-Open No. 2013-203116 (Patent Document 1) discloses a control for shutting off an inverter gate when an abnormality of the inverter is detected.

JP 2013-203116 A

  As disclosed in Patent Document 1, in the present specification, when the abnormality of the inverter occurs, the control of driving the engine and driving the vehicle while the inverter is shut off is referred to as “inverter-less traveling control”. Describe.

  During inverterless travel control, the first motor generator is caused to generate a counter electromotive voltage by mechanically rotating the first motor generator by the rotational force of the engine while the inverter is in a gate cutoff state. At this time, the first motor generator generates a braking torque (back electromotive torque) that acts in a direction that prevents the rotation of the first motor generator. When the counter electromotive torque acts on the sun gear from the first motor generator, a driving torque that acts in the positive direction as a reaction force of the counter electromotive torque is generated in the ring gear. By using this driving torque, retreat travel is realized.

  By the way, when the hybrid vehicle under inverterless travel control temporarily stops, for example, the shift range may be switched to a non-forward range such as an N (neutral) range. Even in this case, as long as the first motor generator is mechanically rotated by the engine, the drive torque acts in the positive direction, and the drive torque cannot be reduced to zero or act in the negative direction. . That is, although the non-advance range is selected, there is a possibility that torque in the direction in which the hybrid vehicle moves forward is generated.

  As a measure for suppressing the generation of drive torque, it is conceivable to stop the engine. However, in this case, since the inverter is in the gate cutoff state, the engine once stopped using the first motor generator cannot be restarted. That is, the evacuation traveling cannot be continued.

  As described above, when the shift range is operated to the non-forward range during the inverterless travel control, generation of unnecessary torque that acts in the direction of moving the hybrid vehicle forward can be suppressed without stopping the engine. Desired.

  The present invention has been made to solve the above-described problem, and an object thereof is to suppress generation of unnecessary torque during inverterless travel control in a hybrid vehicle configured to be able to execute inverterless travel control. It is.

  A hybrid vehicle according to an aspect of the present invention mechanically includes an engine, a first rotating electrical machine having a permanent magnet in a rotor, an output shaft connected to driving wheels, the engine, the first rotating electrical machine, and the output shaft. A planetary gear mechanism capable of transmitting torque between the engine, the first rotating electrical machine, and the output shaft, a second rotating electrical machine connected to the output shaft, a battery, and a voltage input from the battery are boosted. A converter configured to be able to output power, an inverter configured to be able to convert electric power between the converter and the first rotating electrical machine, and between the converter and the second rotating electrical machine, and capable of executing inverterless traveling control A control device. Inverter-less running control causes the first rotating electrical machine to generate a braking torque caused by a counter electromotive voltage by mechanically rotating the first rotating electrical machine by driving the engine and turning off the gate. In this control, the hybrid vehicle is driven with a torque acting on the output shaft as a reaction force. The control device controls the rotation speed of the engine so that the counter electromotive voltage is smaller than the voltage of the power line connecting the converter and the inverter when the shift range is the non-forward running range during the inverterless running control, When the shift range is the forward travel range, the engine speed is controlled so that the back electromotive voltage is larger than the voltage of the power line.

  According to the present invention, during the inverterless travel control, when the shift range is the non-advance travel range, the engine speed is controlled so that the counter electromotive voltage becomes smaller than the voltage of the power line. Generation of braking torque of the electric machine is suppressed. For this reason, it is possible to suppress the generation of drive torque using the braking torque as a reaction force without stopping the engine. Therefore, it is possible to suppress generation of unnecessary torque during inverterless travel control.

1 is a block diagram schematically showing an overall configuration of a hybrid vehicle. It is a circuit block diagram for demonstrating the structure of the electric system of a hybrid vehicle. It is a figure which shows schematically the structure of the electric system in inverterless driving | running | working control. It is a collinear chart for demonstrating the behavior of each rotation element in inverterless traveling control. It is a figure for demonstrating the relationship between the rotational speed of MG1, a system voltage, a counter electromotive voltage, the electric current which flows through MG1, and a counter electromotive torque. It is a collinear diagram for demonstrating the behavior of each rotation element when the shift range is operated to the non-advanced travel range during inverterless travel control. It is a flowchart for demonstrating the travel control in the hybrid vehicle which concerns on this Embodiment. It is a figure which shows schematically the structure of the electric system when generation | occurrence | production of an electric current is suppressed by setting it as a back electromotive force> system voltage.

  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.

<Overall configuration of hybrid vehicle>
FIG. 1 is a block diagram schematically showing the overall configuration of the hybrid vehicle according to the present embodiment. Referring to FIG. 1, hybrid vehicle 1 (hereinafter simply referred to as vehicle 1) includes an engine 100, motor generators 10 and 20 (MG1, MG2), a planetary gear mechanism 30, drive wheels 50, and a drive. An output shaft 60 connected to the wheel 50, a battery 150, a system main relay (SMR) 160, a power control unit (PCU) 200, and an electronic control unit (ECU) ) 300.

  The vehicle 1 travels using the power of at least one of the engine 100 and the motor generator 20. The vehicle 1 travels in an electric vehicle (EV traveling) using the power of the motor generator 20 without using the power of the engine 100 and in a hybrid vehicle traveling using the power of both the engine 100 and the motor generator 20 during normal traveling described later. The traveling mode of the vehicle 1 can be switched between (HV traveling).

  The engine 100 is an internal combustion engine such as a gasoline engine or a diesel engine. Engine 100 generates motive power for vehicle 1 to travel in response to a control signal from ECU 300. The power generated by the engine 100 is output to the planetary gear mechanism 30.

  The engine 100 is provided with an engine rotation speed sensor 410. Engine rotation speed sensor 410 detects rotation speed Ne of engine 100 and outputs a signal indicating the detection result to ECU 300.

  Each of motor generators 10 and 20 is, for example, a three-phase AC permanent magnet type synchronous motor. The motor generator (first rotating electrical machine) 10 rotates the crankshaft 110 of the engine 100 using the power of the battery 150 when starting the engine 100. The motor generator 10 can also generate power using the power of the engine 100. The AC power generated by the motor generator 10 is converted into DC power by the PCU 200 and the battery 150 is charged. Further, AC power generated by the motor generator 10 may be supplied to the motor generator 20.

  The rotor of the motor generator (second rotating electrical machine) 20 is connected to the output shaft 60. Motor generator 20 rotates output shaft 60 using at least one of the electric power supplied from battery 150 and the electric power generated by motor generator 10. The motor generator 20 can also generate electric power by regenerative braking. The AC power generated by the motor generator 20 is converted into DC power by the PCU 200 and the battery 150 is charged.

  The motor generator 10 is provided with a resolver 421. Resolver 421 detects rotational speed Nm1 of motor generator 10, and outputs a signal indicating the detection result to ECU 300. Similarly, the motor generator 20 is provided with a resolver 422. Resolver 422 detects rotation speed Nm2 of motor generator 20, and outputs a signal indicating the detection result to ECU 300.

  The planetary gear mechanism 30 is configured to mechanically connect the engine 100, the motor generator 10, and the output shaft 60 so that torque can be transmitted between the engine 100, the motor generator 10, and the output shaft 60. Specifically, the planetary gear mechanism 30 includes a sun gear S, a ring gear R, a carrier CA, and a pinion gear P as rotational elements. Sun gear S is coupled to the rotor of motor generator 10. Ring gear R is coupled to output shaft 60. The pinion gear P meshes with the sun gear S and the ring gear R. Carrier CA is connected to crankshaft 110 of engine 100 and holds pinion gear P so that pinion gear P can rotate and revolve.

  The battery 150 is a power storage device configured to be rechargeable. The battery 150 is typically configured to include a secondary battery such as a nickel metal hydride secondary battery or a lithium ion secondary battery, or a capacitor such as an electric double layer capacitor.

  SMR 160 is connected to a power line connecting battery 150 and PCU 200. SMR 160 is opened or closed in accordance with control signal SE from ECU 300. Thereby, the electrical connection state and interruption | blocking state of the battery 150 and PCU200 are switched.

  PCU 200 boosts the DC power stored in battery 150, converts the boosted voltage to an AC voltage, and supplies it to motor generator 10 and motor generator 20. PCU 200 converts AC power generated by motor generator 10 and motor generator 20 into DC power and supplies it to battery 150. The configuration of the PCU 200 will be described in detail with reference to FIG.

  The vehicle speed sensor 73 detects the rotational speed of the output shaft 60 as the speed (vehicle speed) VS of the vehicle 1 and outputs a signal indicating the detection result to the ECU 300.

  The vehicle 1 further includes a shift lever 500 and a position sensor 510. The shift lever 500 is a device for the user to set the shift range of the vehicle 1. When the user operates the shift lever 500, the position sensor 510 detects the position (shift position) SFT of the shift lever 500 and outputs a signal indicating the detection result to the ECU 300. ECU 300 sets a shift range corresponding to shift position SFT. The shift range includes forward travel ranges such as a D (drive) range and a B (brake) range, and non-advance travel ranges such as a P (parking) range, an R (reverse) range, and an N (neutral) range.

  Although not shown, ECU 300 includes a CPU (Central Processing Unit), a memory, an input / output buffer, and the like. ECU 300 controls each device so that vehicle 1 is in a desired running state based on signals from each sensor and device, and a map and program stored in memory. Various controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

<Electric system configuration>
FIG. 2 is a circuit block diagram for explaining the configuration of the electric system of the vehicle 1. With reference to FIGS. 1 and 2, the battery 150 is provided with a monitoring unit 440. Monitoring unit 440 detects voltage VB of battery 150, input / output current IB of battery 150, and temperature TB of battery 150, and outputs a signal indicating the detection results to ECU 300.

  PCU 200 includes a capacitor C1, a converter 210, a capacitor C2, inverters 221, 222, a voltage sensor 230, and current sensors 241, 242.

  The capacitor C1 is connected to the battery 150 in parallel. Capacitor C <b> 1 smoothes voltage VB of battery 150 and supplies it to converter 210.

  Converter 210 includes a reactor L1, switching elements Q1, Q2, and diodes D1, D2. Each of switching elements Q1, Q2 and switching elements Q3-Q14 described later are, for example, IGBTs (Insulated Gate Bipolar Transistors). Switching elements Q1 and Q2 are connected in series with each other between power line PL and power line NL connecting converter 210 and inverter 221. Diodes D1 and D2 are connected in antiparallel between the collectors and emitters of switching elements Q1 and Q2, respectively. One end of the reactor L1 is connected to the high potential side of the battery 150. The other end of reactor L1 is connected to an intermediate point between switching element Q1 and switching element Q2 (a connection point between the emitter of switching element Q1 and the collector of switching element Q2).

  Converter 210 boosts voltage VB of battery 150 in accordance with PWM (Pulse Width Modulation) control signal PWMC for switching each of switching elements Q1 and Q2, and uses the boosted voltage to power lines PL and NL. To supply. Converter 210 steps down DC voltage of power lines PL and NL supplied from one or both of inverter 221 and inverter 222 in accordance with control signal PWMC to charge battery 150. On the other hand, when converter 210 receives gate cutoff signal SDNC from ECU 300, converter 210 makes switching elements Q1, Q2 non-conductive. As a result, converter 210 enters a gate cutoff state.

  Capacitor C2 is connected to converter 210 in parallel. Capacitor C <b> 2 smoothes the DC voltage supplied from converter 210 and supplies it to inverters 221 and 222.

  Voltage sensor 230 detects a voltage across capacitor C2, that is, voltage VH between power line PL and power line NL (hereinafter also referred to as “system voltage”), and outputs a signal indicating the detection result to ECU 300.

  Inverter 221 includes a U-phase arm 1U, a V-phase arm 1V, and a W-phase arm 1W. Each phase arm is connected in parallel between power line PL and power line NL. U-phase arm 1U has switching elements Q3 and Q4 connected in series with each other. V-phase arm 1V has switching elements Q5 and Q6 connected in series with each other. W-phase arm 1W has switching elements Q7 and Q8 connected in series with each other. Diodes D3 to D8 are connected in antiparallel between the collectors and emitters of the switching elements Q3 to Q8, respectively. An intermediate point of each phase arm is connected to each phase coil of motor generator 10. That is, one end of the three coils of the U-phase, V-phase, and W-phase of the motor generator 10 is commonly connected to the neutral point. The other end of the U-phase coil is connected to an intermediate point between switching elements Q3 and Q4. The other end of the V-phase coil is connected to an intermediate point between switching elements Q5 and Q6. The other end of the W-phase coil is connected to an intermediate point between switching elements Q7 and Q8.

  When the system voltage VH is supplied, the inverter 221 converts the DC voltage into an AC voltage and drives the motor generator 10 according to a PWM control signal PWMI for switching each of the switching elements Q3 to Q8. To do. Thereby, motor generator 10 is driven to generate torque specified by the torque command value. On the other hand, when inverter 221 receives gate cutoff signal SDN1 from ECU 300, each of switching elements Q3 to Q8 is made non-conductive. As a result, the inverter 221 enters a gate cutoff state. Note that the configuration of inverter 222 is the same as that of inverter 221, and therefore description thereof will not be repeated.

  Current sensor 241 detects current (hereinafter also referred to as “motor current”) IM1 flowing through motor generator 10, and outputs a signal indicating the detection result to ECU 300. In the following, the direction from motor generator 10 to battery 150 is the positive direction of motor current IM1. Similarly to current sensor 241, current sensor 242 detects current IM2 flowing through motor generator 20, and outputs a signal indicating the detection result to ECU 300.

<Normal mode and evacuation mode>
ECU 300 can cause vehicle 1 to travel in one of the control modes of the normal mode and the retreat mode. The normal mode is a mode in which the vehicle 1 travels while switching between EV traveling and HV traveling as necessary. In other words, the normal mode is a mode in which the electric drive of the motor generators 10 and 20 by the inverters 221 and 222 is allowed. The traveling in the normal mode is referred to as “normal traveling”.

  The evacuation mode is an abnormality in which the motor generators 10 and 20 cannot be normally driven by the inverters 221 and 222 due to failure of components such as the resolvers 421 and 422 or the current sensors 241 and 242 (hereinafter simply referred to as “ This is a mode in which the engine 1 is driven and the vehicle 1 is evacuated while the inverters 221 and 222 are in the gate shut-off state. In other words, the evacuation mode is a mode in which the electric drive of the motor generators 10 and 20 by the inverters 221 and 222 is prohibited. The traveling in the evacuation mode is referred to as “inverterless traveling”, and the control for performing inverterless traveling is referred to as “inverterless traveling control”.

  FIG. 3 is a diagram schematically showing the configuration of the electrical system during inverterless travel control. Referring to FIG. 3, during inverterless travel control, all switching elements Q3-Q8 included in inverter 221 are rendered non-conductive in response to gate cutoff signal SDN1. Therefore, a three-phase full-wave rectifier circuit is configured by the diodes D3 to D8 included in the inverter 221. Similarly, although not shown, all switching elements Q9 to Q14 (see FIG. 2) included in inverter 222 are rendered non-conductive in response to gate cut-off signal SDN2. Therefore, a three-phase full-wave rectifier circuit is configured by diodes D9 to D14 included in inverter 222. On the other hand, in converter 210, the switching operation (PWM operation) of switching elements Q1, Q2 according to control signal PWMC is continued.

  Further, since engine 100 is driven during inverterless travel control, engine torque Te from engine 100 is output. The motor generator 10 is mechanically (mechanically) rotated by the engine torque Te. Since the motor generator 10 is a permanent magnet type synchronous motor, the rotor of the motor generator 10 is provided with a permanent magnet 12. For this reason, the counter electromotive voltage Vc is generated by rotating the permanent magnet 12 by the engine torque Te. When back electromotive voltage Vc becomes higher than system voltage VH, motor current IM1 flows through current path CP between motor generator 10 and battery 150, and power generation by motor generator 10 is performed. At this time, the motor generator 10 generates a counter electromotive torque Tc that acts in a direction that prevents the rotation of the motor generator 10.

  FIG. 4 is a collinear diagram for explaining the behavior of each rotating element during inverterless travel control. Referring to FIG. 4, the planetary gear mechanism 30 is configured as described with reference to FIG. 1, so that the rotational speed of the sun gear S (= rotational speed Nm1) and the rotational speed of the carrier CA (= rotational speed Ne). The rotational speed of the ring gear R (= rotational speed Nm2) has a relationship of being connected by a straight line on the alignment chart.

  As described above, when the motor generator 10 is mechanically rotated by the engine torque Te during the inverterless travel control, the motor generator 10 applies the counter electromotive torque Tc in a direction (negative direction) that prevents the motor generator 10 from rotating. Occur. When the counter electromotive torque Tc acts on the sun gear S from the motor generator 10, the ring gear R generates a driving torque Tep that acts in the positive direction as a reaction force of the counter electromotive torque Tc. By this drive torque Tep, the inverter 1 traveling of the vehicle 1 is realized.

  The relationship described below exists among the rotational speed Nm1, the system voltage VH, the counter electromotive voltage Vc, the motor current IM1, and the counter electromotive torque Tc.

  FIG. 5 is a diagram for explaining the relationship among the rotational speed Nm1, the system voltage VH, the counter electromotive voltage Vc, the motor current IM1, and the counter electromotive torque Tc. In FIG. 5, the horizontal axis represents the rotational speed Nm1. The vertical axis represents the counter electromotive voltage Vc, the motor current IM1, and the counter electromotive torque Tc in order from the top.

  As shown in FIG. 5, the counter electromotive voltage Vc has a characteristic that the value increases as the rotational speed Nm1 increases. In a region where the rotational speed Nm1 is lower than Nth (non-forward travel range region), the back electromotive voltage Vc is less than the system voltage VH. That is, when the voltage difference between the back electromotive voltage Vc and the system voltage VH is expressed as ΔV (= Vc−VH), the voltage difference ΔV is negative. In this case, motor current IM1 does not flow from motor generator 10 to battery 150 through current path CP, and power generation by motor generator 10 is not performed. Therefore, the counter electromotive torque Tc is not generated.

  On the other hand, in the region where the rotational speed Nm1 is higher than Nth (inverter-less travelable region), the back electromotive voltage Vc is higher than the system voltage VH, so the voltage difference ΔV is positive. For this reason, the motor current IM1 flows through the current path CP. The motor current IM1 increases as the voltage difference ΔV increases. The motor generator 10 generates a counter electromotive torque Tc and generates a driving torque Tep as a reaction force of the counter electromotive torque Tc.

<Vehicle forward restraint during inverterless travel control>
During the inverterless travel control, when the vehicle 1 is operated, for example, when the shift range of the vehicle 1 is operated to a non-forward travel range (P range, R range or N range), drive torque may be generated.

  FIG. 6 is a collinear diagram for explaining the behavior of each rotating element when the shift range is operated to the non-forward travel range during the inverterless travel control. As shown in FIG. 6, the drive torque Tep that acts in the direction in which the vehicle 1 moves forward (forward direction) is generated in the ring gear R, even though the non-forward running range is selected by the shift operation. there is a possibility. In FIG. 6, the situation in which the vehicle 1 is stopped is shown as an example, but the same applies to the case where the shift range is operated to the N range while the vehicle 1 is traveling.

  It is conceivable to stop the engine 100 as a countermeasure for suppressing the generation of the drive torque Tep. However, since inverter 221 is in a gate cutoff state, engine 100 once stopped cannot be restarted using motor generator 10. That is, the evacuation traveling cannot be continued.

  Therefore, according to the present embodiment, during the inverterless travel control, when the shift range is a non-forward travel range, the engine rotation speed is controlled so that the back electromotive voltage becomes smaller than the voltage of the power line, When the shift range is the forward travel range, the engine speed is controlled so that the back electromotive voltage is greater than the voltage of the power line. Thereby, since the back electromotive voltage becomes lower than the boosted voltage, the generation of the motor current IM1 is suppressed, so that the generation of the drive torque Tep can be suppressed.

  FIG. 7 is a flowchart for illustrating travel control in vehicle 1 according to the present embodiment. The flowchart shown in FIG. 7 is called from the main routine and executed when a predetermined condition is satisfied or every predetermined period. Each step (hereinafter abbreviated as S) in this flowchart is basically realized by software processing by ECU 300, but may be realized by hardware processing using an electronic circuit fabricated in ECU 300.

  Referring to FIGS. 1, 2, and 7, in S <b> 110, ECU 300 determines whether or not the above-described inverter abnormality has occurred. If an inverter abnormality has not occurred (NO in S110), ECU 300 advances the process to S120, sets the control mode to the normal mode, and performs normal traveling of vehicle 1. Thereafter, ECU 300 returns the process to the main routine.

  If an inverter abnormality has occurred (YES in S110), ECU 300 sets the control mode to the evacuation mode and performs inverterless travel of vehicle 1 in S130 to S190. Hereinafter, inverterless travel control of the vehicle 1 will be described in detail.

  In S130, ECU 300 outputs inverters 221 and 222 to a gate cutoff state by outputting gate cutoff signals SDN1 and SDN2. Thereby, inverters 221 and 222 can be protected.

  Further, ECU 300 outputs a control signal PWMC to cause converter 210 to perform a PWM operation (S140). Further, ECU 300 drives engine 100 (or maintains the driving state) (S150). More specifically, current path CP is maintained in an electrically connected state (conducting state) by PWM operation of converter 210, so that motor current IM 1 from motor generator 10 can flow to battery 150.

  In S160, ECU 300 detects a shift range corresponding to shift position SFT based on a signal from position sensor 510. Further, ECU 300 determines whether or not the detected shift range is a forward travel range (S170).

  When the shift range is the forward travel range, that is, when the shift range is the D range or the B range (YES in S170), ECU 300 advances the process to 180 so that counter electromotive voltage Vc is greater than system voltage VH. The engine speed Ne is controlled. Specifically, the ECU 300 controls the engine 100 to adjust the rotational speed Ne, so that the rotational speed Nm1 is in a region where the back electromotive voltage Vc is higher than the system voltage VH (inverterless travelable region shown in FIG. 5). To maintain. ECU 300 controls engine 100 such that, for example, rotation speed Nm1 of motor generator 10 becomes a first target rotation speed set in a region where counter electromotive voltage Vc is higher than system voltage VH. The first target rotation speed may be a predetermined value or may be set based on the state of the vehicle 1. When the resolver 421 is in a normal state, the ECU 300 acquires the rotational speed Nm1 of the motor generator 10 using the resolver 421. When the resolver 421 is in an abnormal state, the ECU 300 generates a motor generator based on the engine rotational speed Ne, the rotational speed Nm2 of the motor generator 20 that can be acquired using the resolver 422, and the gear ratio in the planetary gear mechanism 30. A rotational speed Nm1 of 10 may be estimated. In addition, when the resolvers 421 and 422 are in an abnormal state, the ECU 300 determines the motor generator 10 based on the engine speed Ne, the vehicle speed VS that can be acquired using the vehicle speed sensor 73, and the gear ratio in the planetary gear mechanism 30. The rotational speed may be estimated.

  On the other hand, when the shift range is the non-forward running range, that is, when the shift range is the P range, N range or R range (NO in S170), ECU 300 advances the process to S190 and counter electromotive voltage Vc is greater than system voltage VH. The engine speed Ne is controlled so as to decrease. Specifically, the ECU 300 controls the engine 100 to adjust the rotational speed Ne, thereby rotating the rotational speed Nm1 in a region where the back electromotive voltage Vc is lower than the system voltage VH (non-advance traveling range region shown in FIG. 5). To maintain. ECU 300 controls engine 100 such that, for example, rotation speed Nm1 of motor generator 10 becomes a second target rotation speed set in a region where counter electromotive voltage Vc is lower than system voltage VH. The second target rotation speed may be a predetermined value or may be set based on the state of the vehicle 1.

  When the process of S180 or the process of S190 ends, ECU 300 returns the process to the main routine.

  An operation of ECU 300 mounted on vehicle 1 according to the present embodiment based on the above-described structure and flowchart will be described.

  For example, it is assumed that an inverter abnormality has occurred during EV traveling (YES in S110) and inverterless traveling is started.

  In this case, the inverters 221 and 222 are turned off (S130), and the converter is PWM-operated (S140). Then, the engine 100 is started to be in a driving state (S150), and a shift range is detected (S160).

  If the shift range is, for example, the D range (YES in S170), engine speed Ne is controlled so that counter electromotive voltage Vc is greater than system voltage VH (S180). Thereby, since the motor current IM1 continuously flows through the current path CP, the counter electromotive torque Tc can be generated. Thereby, the vehicle 1 can obtain a driving force in the forward direction by the driving torque Tep using the counter electromotive torque Tc as a reaction force, and can perform retreat.

  On the other hand, when the vehicle 1 is temporarily stopped and the shift range is, for example, the N range (NO in S170), the engine speed is set so that the back electromotive voltage Vc is smaller than the system voltage VH. Ne is controlled (S190). As a result, as shown in FIG. 8, no current flows in the direction from motor generator 10 to battery 150, so that the occurrence of counter electromotive torque Tc can be suppressed. As a result, it is possible to suppress the generation of the driving force torque Tep using the counter electromotive torque Tc as a reaction force without stopping the engine 100.

  As described above, according to the vehicle 1 according to the present embodiment, when the shift range is operated to the non-forward travel range during the inverterless travel control, the back electromotive voltage Vc becomes smaller than the system voltage VH. Thus, the engine speed Ne is controlled. Therefore, generation of motor current IM1 in current path CP between motor generator 10 and battery 150 is suppressed. Thereby, since the generation of the counter electromotive torque Tc by the motor generator 10 is suppressed, the generation of the driving torque Tep using the counter electromotive torque Tc as a reaction force can be suppressed without stopping the engine 100. Therefore, it is possible to suppress generation of unnecessary torque during inverterless travel control.

Hereinafter, modifications will be described.
In the embodiment described above, when the shift range is the non-advanced travel range during the inverterless travel control, the engine is set so that the rotational speed Nm1 of the motor generator 10 becomes the second target rotational speed in the non-advanced travel range region. Although described as controlling 100, for example, the second target rotational speed may be a rotational speed close to the inverterless travelable region, for example. In this way, when the shift range is switched from the non-advanced travel range to the forward travel range, the driving force can be generated with good responsiveness.

  Alternatively, the second target rotation speed may be set so that the rotation speed Nm1 of the motor generator 10 is in the non-advance traveling range region and the operation state of the engine 100 is an engine rotation speed with good fuel efficiency. In this way, the fuel efficiency of engine 100 can be improved when vehicle 1 is stopped.

  In the above-described embodiment, the vehicle 1 including the planetary gear mechanism 30 has been described as an example. For example, the transmission is connected to at least one of the sun gear S, the ring gear R, and the carrier CA of the planetary gear mechanism 30. There may be.

In addition, you may implement combining the above-mentioned modification, all or one part.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 hybrid vehicle, 1U, 1V, 1W arm, 10, 20 motor generator, 12 permanent magnet, 30 planetary gear mechanism, 50 drive wheels, 60 output shaft, 73 vehicle speed sensor, 100 engine, 110 crankshaft, 150 battery, 160 SMR , 200 PCU, 210 converter, 221, 222 inverter, 230 voltage sensor, 241, 242 current sensor, 300 ECU, 410 engine speed sensor, 421, 422 resolver, 440 monitoring unit, 500 shift lever, 510 position sensor.

Claims (1)

A hybrid vehicle,
Engine,
A first rotating electric machine having a permanent magnet in the rotor;
An output shaft connected to the drive wheels;
A planetary gear mechanism that mechanically connects the engine, the first rotating electrical machine, and the output shaft, and is capable of transmitting torque between the engine, the first rotating electrical machine, and the output shaft;
A second rotating electrical machine connected to the output shaft;
Battery,
A converter configured to boost and output a voltage input from the battery;
An inverter configured to convert electric power between the converter and the first rotating electric machine, and between the converter and the second rotating electric machine;
And a control device configured to be able to execute inverter-less travel control,
In the inverterless running control, the braking torque caused by the counter electromotive voltage is generated in the first rotating electrical machine by causing the inverter to be in a gate cutoff state and mechanically rotating the first rotating electrical machine by driving the engine. And controlling the hybrid vehicle to travel with a torque acting on the output shaft as a reaction force of the braking torque,
When the shift range is a non-forward travel range during the inverter-less travel control, the control device is configured so that the counter electromotive voltage is smaller than a voltage of a power line connecting the converter and the inverter. A hybrid vehicle that controls the rotational speed of the engine so that the counter electromotive voltage is larger than the voltage of the power line when the rotational speed is controlled and the shift range is a forward travel range.

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