JP2017047846A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of unnecessary drive torque in a hybrid vehicle enabled to execute inverter-less travel control.SOLUTION: An ECU includes: an HV-ECU capable of detecting a shift range of a vehicle 1 and outputting a voltage instruction VAtag to an auxiliary-equipment battery; and an MG-ECU capable of detecting an auxiliary-equipment voltage VA and controlling a converter. In the case of the shift range at a non-forward range during inverter-less travel control, the HV-ECU outputs the voltage instruction VAtag different from one in the case of a forward range to a DC/DC converter (S140). In the case of the auxiliary-equipment voltage VA being a voltage corresponding to the non-forward range, the MG-ECU controls the converter so that a system voltage VH across power lines PL and NL interconnecting the converter and the inverter is equal to or higher than a counter-electromotive voltage Vc.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle that can travel using the power of at least one of an engine and a rotating electrical 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 rotor of the first motor generator, a ring gear coupled to the second motor generator via the output shaft, and a carrier coupled to the crankshaft of the engine.

  The electrical system for a high-rid vehicle includes a battery, a converter, and an inverter. The converter is configured to boost the input voltage from the battery and output it. The inverter is electrically connected between the converter and the first rotating electric machine, and is configured to be able to perform bidirectional power conversion between the battery and the first motor generator. The same applies to the second inverter.

  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 should be taken to prevent damage to the equipment. 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, back electromotive force is generated in the first motor generator by mechanically (mechanically) rotating the first motor generator by the rotational force of the engine while the inverter is in the gate shut-off state. Let At this time, the first motor generator generates a counter electromotive torque (braking torque) that acts in a direction that prevents the rotation of the first motor generator. When this counter electromotive torque acts on the sun gear from the first motor generator, a driving torque acting in the positive direction as a reaction force of the first motor generator is generated in the ring gear. By using this driving torque, retreat travel is realized.

  The inventors of the present invention have focused on the point that the following problems can occur during inverterless traveling control. That is, when the hybrid vehicle temporarily stops during inverterless travel control, 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 engine is driven, the driving torque acts in the positive direction, and the driving torque cannot be reduced to zero or acted 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 preventing the generation of the drive torque, it is conceivable that the gate is further cut off for the converter when the non-advance range is selected during the inverterless travel control. When the converter is in the gate cutoff state, the path of current (regenerative current) from the first motor generator to the battery via the converter is cut off. Thereby, since generation | occurrence | production of counter electromotive torque is prevented, generation | occurrence | production of the drive torque which acts as reaction force of counter electromotive torque can be prevented.

  Thus, in the hybrid vehicle configured to be able to execute inverter-less traveling control, the first control device configured to be able to detect the shift range, and the second control device configured to be able to control the converter and the inverter, May be employed separately. Various types of information are communicated between the first control device and the second control device in order to realize travel control according to the shift range for the entire vehicle.

  When this communication is normally performed, the second control device can receive a converter gate cutoff execution command (gate cutoff command) in a timely manner from the first control device that has detected the current shift range. Is possible. Therefore, when the shift range is switched to the non-advanced range, the second control device performs gate blocking of the converter. Thus, when the communication is normally performed, the second control device appropriately controls the gate state (whether or not the gate is cut off) of the converter according to the shift range, thereby Generation of unnecessary driving torque can be prevented.

  On the other hand, for example, when an abnormality occurs in communication, the second control device cannot receive information on the shift range (more specifically, a gate cutoff command of the converter) from the first control device. Therefore, in the second control device, it becomes impossible to appropriately control the gate state of the converter according to the shift range, and as a result, generation of drive torque is appropriately prevented when the shift range is the non-forward range. May not be possible.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a technology capable of preventing generation of unnecessary driving torque in a hybrid vehicle configured to be able to execute inverter-less traveling control. It is.

  A hybrid vehicle according to an aspect of the present invention includes an engine, a first rotating electrical machine, an output shaft connected to drive wheels, a planetary gear mechanism, a second rotating electrical machine connected to the output shaft, and a first rotating electrical machine. A battery, a first converter, an inverter, a second battery, a second converter, and a control device configured to execute inverter-less travel control when the inverter is abnormal. . The planetary gear mechanism is configured to mechanically connect the engine, the first rotating electrical machine, and the output shaft so that torque can be transmitted between the engine, the first rotating electrical machine, and the output shaft. The first converter is configured to boost the voltage input from the first battery and output the boosted voltage. The inverter is configured to be able to convert electric power between the first converter and the first rotating electric machine, and between the first converter and the second rotating electric machine. The second converter is configured to receive a voltage command and adjust and output a voltage input from the second battery. The first rotating electrical machine generates a braking torque using a counter electromotive voltage generated by being mechanically rotated by the engine. Inverterless travel control is control in which a hybrid vehicle travels with a torque that acts on an output shaft as a reaction force of a braking torque by setting the inverter to a gate cutoff state and driving an engine. The control device is capable of detecting the shift range of the hybrid vehicle and capable of detecting the voltage of the second battery, the first control device configured to be able to output a voltage command to the second battery, and the first And a second control device configured to be able to control the converter. When the shift range is the non-forward range during the inverterless travel control, the first control device outputs a voltage command different from that when the shift range is the forward range to the second converter. In the second control device, when the voltage of the second battery is a voltage corresponding to the non-advanced range, the voltage (system voltage) of the power line connecting the first converter and the inverter becomes equal to or higher than the counter electromotive voltage. Thus, the first converter is controlled.

  According to the above configuration, for example, when communication abnormality occurs between the first control device and the second control device, information on the shift range is obtained, and the voltage of the second battery (for example, auxiliary battery) is obtained. Can be used to communicate from the first controller to the second controller. More specifically, the first control device outputs different voltage commands to the second converter when the shift range is the forward range and when the shift range is the non-forward range. When the voltage of the second battery is a voltage indicating that the shift range is the non-forward range, the second control device estimates that the non-forward range is selected, and the second converter To control the system voltage to be equal to or higher than the back electromotive voltage. Accordingly, it is possible to prevent the generation of the driving torque that acts in the direction of moving the hybrid vehicle forward, even though the non-forward range is selected.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of an unnecessary drive torque can be prevented in the hybrid vehicle comprised so that execution of inverterless driving | running | working control was possible.

1 is a block diagram schematically showing an overall configuration of a hybrid vehicle according to an embodiment. It is a circuit block diagram for demonstrating the structure of the electric system and ECU of a hybrid vehicle. It is a figure which shows roughly the structure of the electric system in inverterless driving | running | working. It is a figure which shows roughly the relationship between the rotational speed of a 1st motor generator, a system voltage, a counter electromotive voltage, and a counter electromotive torque. It is an alignment chart for explaining the behavior of each rotating element when the forward range is selected during inverterless travel control. It is a collinear diagram for demonstrating the behavior of each rotation element when the non-advance range is selected during inverterless travel control. It is a figure which shows schematically the structure of the electric system at the time of performing further the gate interruption | blocking of a converter during inverterless driving | running | working control. It is a flowchart for demonstrating the travel control in the hybrid vehicle which concerns on this Embodiment. It is a flowchart for demonstrating the control when communication abnormality arises during inverterless driving | running | working.

  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.

[Embodiment]
<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, a vehicle 1 includes an engine 100, motor generators 10, 20, a planetary gear mechanism 30, drive wheels 50, an output shaft 60 connected to the drive wheels 50, a battery 150, and a system. A main relay (SMR) 160, a power control unit (PCU) 200, and an electronic control unit (ECU) 300 are provided.

  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 a rotation speed (engine 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 electric 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 the rotational speed (MG1 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 rotational speed (MG2 rotational 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 (first 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. The voltage (hereinafter also referred to as “battery voltage”) VB of battery 150 is a high voltage of about 200V, for example.

  SMR 160 is connected in series to a power line between battery 150 and PCU 200. SMR 160 switches between a conduction state and a cutoff state between battery 150 and PCU 200 in accordance with a control signal from ECU 300.

  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 1 further includes a shift lever 500 and a position sensor 510. Shift lever 500 is provided with forward ranges such as D (drive) range and B (brake) range, and non-forward ranges such as P (parking) range, R (reverse) range, and N (neutral) range. Yes. When the user operates shift lever 500, position sensor 510 detects a position (shift range) SFT of shift lever 500 and outputs a signal indicating the detection result to ECU 300.

  The vehicle 1 further includes an auxiliary battery 610, a DC / DC converter 620, and an auxiliary load (not shown) as a configuration of an auxiliary system. The auxiliary machine load includes various electric devices (for example, an audio device, a lighting device, and a car navigation device) that assist the traveling control of the vehicle 1.

  The auxiliary battery (second battery) 610 is a power source for supplying electric power to the auxiliary load, and includes, for example, a lead storage battery. Auxiliary battery 610 voltage (hereinafter also referred to as “auxiliary voltage”) VA is a low voltage of about 12V, for example. The auxiliary battery 610 is also connected to the ECU 300, and supplies the auxiliary machine voltage VA to the ECU 300 as a driving voltage.

  DC / DC converter (second converter) 620 is electrically connected between power line connecting SMR 160 and PCU 200 and auxiliary battery 610. DC / DC converter 620 steps down battery voltage VB in accordance with voltage command VAtag from ECU 300 to charge auxiliary battery 610.

  Although not shown, ECU 300 includes a CPU (Central Processing Unit), a memory, an input / output buffer, and the like. ECU 300 controls various devices 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).

<Configuration of electrical system and ECU>
FIG. 2 is a circuit block diagram for explaining the electrical system of vehicle 1 and the configuration of ECU 300. 1 and 2, PCU 200 includes a capacitor C1, a converter 210, a capacitor C2, inverters 221, 222, a voltage sensor 230, and current sensors 241, 242. ECU 300 includes HV-ECU 310, MG-ECU 320, and engine ECU 330.

  The battery 150 is provided with a monitoring unit 440. Monitoring unit 440 detects battery voltage VB, input / output current IB of battery 150, and temperature of battery 150, and outputs a signal indicating the detection results to HV-ECU 310.

  The capacitor C1 is connected to the battery 150 in parallel. Capacitor C1 smoothes battery voltage VB and supplies it to converter 210.

  Converter (first converter) 210 boosts battery voltage VB in accordance with a control signal from MG-ECU 320, and supplies the boosted voltage to power lines PL and NL. 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 a control signal from MG-ECU 320 to charge battery 150.

  More specifically, 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, Q2 are connected in series between power line PL and power line NL. 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).

  Capacitor C2 is connected between power line PL and power line NL. Capacitor C <b> 2 smoothes the DC voltage supplied from converter 210 and supplies it to inverters 221 and 222.

  Voltage sensor 230 detects the voltage across capacitor C2, that is, voltage VH between power lines PL and NL connecting converter 210 and inverter 221 (hereinafter also referred to as “system voltage”), and outputs a signal indicating the detection result to MG. -It outputs to ECU320.

  When system voltage VH is supplied, inverter 221 converts DC voltage into AC voltage and drives motor generator 10 in accordance with a control signal from MG-ECU 320. Thereby, motor generator 10 is driven to generate torque specified by torque command value TR1.

  More specifically, 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. The configuration of inverter 222 is basically the same as the configuration of inverter 221, and therefore description thereof will not be repeated.

  Current sensor 241 detects a current (motor current) MCRT1 flowing through motor generator 10, and outputs a signal indicating the detection result to MG-ECU 320. Current sensor 242 detects a current (motor current) MCRT2 flowing through motor generator 20, and outputs a signal indicating the detection result to MG-ECU 320.

  HV-ECU 310 (first control device) generates an operation command for motor generators 10 and 20 and outputs it to MG-ECU 320. The operation commands output from the HV-ECU 310 include an operation permission command and an operation prohibition command (gate cutoff commands to the inverters 221 and 222) of the motor generators 10 and 20, the torque command value TR1 of the motor generator 10, the motor generator 20 and the like. Torque command value TR2, and command values of MG1 rotational speed Nm1 and MG2 rotational speed Nm2 are included.

  HV-ECU 310 sets a target value (hereinafter also referred to as “target system voltage”) VHtag of the output voltage of converter 210 and outputs a signal indicating the value to MG-ECU 320. Furthermore, HV-ECU 310 determines engine required power Pe * and outputs a signal indicating the value to engine ECU 330.

  MG-ECU (second control device) 320 receives an operation command for motor generators 10 and 20 and target system voltage VHtag from HV-ECU 310. In addition, MG-ECU 320 receives signals from each sensor.

  MG-ECU 320 controls converter 210 such that system voltage VH follows target system voltage VHtag based on the operation command, target system voltage VHtag and various signals. More specifically, MG-ECU 320 performs PWM (Pulse Width Modulation) method control for switching each of switching elements Q1, Q2 based on system voltage VH, target system voltage VHtag, and battery voltage VB. Signal PWMC is generated and output to converter 210. On the other hand, when MG-ECU 320 receives a gate cutoff command for converter 210 from HV-ECU 310, MG-ECU 320 generates a gate cutoff signal SDNC for shutting off each of switching elements Q1 and Q2, and outputs it to converter 210. .

  In addition, MG-ECU 320 controls inverters 221 and 222 so that motor generators 10 and 20 operate in accordance with an operation command received from HV-ECU 310. Since the control of the inverters 221 and 222 is equivalent, the control of the inverter 221 will be representatively described. When MG-ECU 320 receives an operation permission command for motor generator 10 from HV-ECU 310, MG-ECU 320 switches each of switching elements Q3-Q8 based on system voltage VH, motor current MCRT1 and torque command value TR1. The PWM control signal PWM1 is generated and output to the inverter 221. On the other hand, when MG-ECU 320 receives a gate cutoff command for inverter 221 from HV-ECU 310, MG-ECU 320 generates gate cutoff signal SDN1 for gate-shutting off each of switching elements Q3 to Q8 and outputs it to inverter 221. .

  Further, MG-ECU 320 detects an abnormality related to motor generators 10 and 20. Information regarding the abnormality detected by MG-ECU 320 is output to HV-ECU 310. The HV-ECU 310 is configured to be able to reflect such abnormality information in the operation commands of the motor generators 10 and 20.

  Engine ECU 330 receives engine rotation speed Ne from engine rotation speed sensor 410 and outputs the value to HV-ECU 330. Further, engine ECU 330 causes engine 100 to be driven at an operating point (target engine rotational speed Netag and target engine torque Ttag) determined based on engine required power Pe * determined by HV-ECU 310. The fuel injection, ignition timing, valve timing, etc. are controlled.

  In the example shown in FIG. 2, the configuration example in which the ECU 300 is divided into three units (HV-ECU 310, MG-ECU 320, and engine ECU 330) is shown. However, the HV-ECU 310 and the engine ECU 330 are combined into one unit. It is also possible to integrate. Alternatively, ECU 300 may be divided into four or more units.

<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. Hereinafter, traveling in the normal mode is referred to as “normal traveling”.

  In the evacuation mode, the inverters 221 and 222 are operated when an abnormality occurs in which the motor generators 10 and 20 cannot be normally driven by the inverters 221 and 222 due to a failure of components such as the current sensors 241 and 242. In this mode, the engine 100 is driven and the vehicle 1 is evacuated while the gate is shut off. 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 travel in the evacuation mode is referred to as “inverter-less travel”, and the control for performing inverter-less travel is referred to as “inverter-less travel control”. The inverterless travel control is performed for the purpose of protecting the equipment even when an abnormality occurs in communication between the HV-ECU 310 and the MG-ECU 320. This will be described in detail later.

  FIG. 3 is a diagram schematically showing the configuration of the electrical system during inverterless travel. Referring to FIG. 3, during inverterless travel, all switching elements Q3-Q8 included in inverter 221 are rendered non-conductive in response to gate cutoff signal SDN1 output from MG-ECU 320. 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, in response to the gate cutoff signal SDN2 output from the MG-ECU 320, all the switching elements Q9 to Q14 (see FIG. 2) included in the inverter 222 are turned off. 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, in response to control signal PWMC from MG-ECU 320, switching operations of switching elements Q1, Q2 are continued.

  Further, since engine 100 is driven during inverterless travel, engine torque Te from engine 100 is output. The motor generator 10 is mechanically rotated by the engine torque Te. Since the motor generator 10 is a 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 the back electromotive voltage Vc exceeds the system voltage VH, a regenerative current flows from the motor generator 10 toward the battery 150. At this time, a counter electromotive torque Tc is generated in the motor generator 10 that acts in a direction that prevents the rotation of the motor generator 10.

  FIG. 4 is a diagram schematically showing the relationship among the MG1 rotation speed Nm1, the system voltage VH, the counter electromotive voltage Vc, and the counter electromotive torque Tc. In FIG. 4, the horizontal axis represents the MG1 rotation speed Nm1. The upper vertical axis represents the counter electromotive voltage Vc, and the lower vertical axis represents the counter electromotive torque Tc.

  As shown in FIG. 4, the counter electromotive voltage Vc has a characteristic that it becomes higher as the MG1 rotation speed Nm1 is higher. In the region where the Mg1 rotation speed Nm1 is lower than the predetermined value Nvh, the counter electromotive voltage Vc is less than the system voltage VH, so that no current flows from the motor generator 10 to the battery 150. Therefore, the counter electromotive torque Tc is not generated.

  On the other hand, in the region where Mg1 rotation speed Nm1 exceeds predetermined value Nvh, counter electromotive voltage Vc is higher than system voltage VH, and thus a current flows from motor generator 10 to battery 150. This current corresponds to a difference ΔV between the back electromotive voltage Vc and the system voltage VH (hereinafter also abbreviated as “voltage difference”). At this time, a counter electromotive torque Tc corresponding to the voltage difference ΔV is generated in the motor generator 10. A region where the back electromotive voltage Vc is higher than the system voltage VH is a region where the back electromotive torque Tc is generated, that is, a region where inverterless travel can be performed.

  FIG. 5 is an alignment chart for explaining the behavior of each rotating element when the forward range (D range or B range) is selected during inverterless travel control. Referring to FIG. 5, the planetary gear mechanism 30 is configured as described with reference to FIG. 1, whereby the rotational speed of the sun gear S (= MG1 rotational speed Nm1) and the rotational speed of the carrier CA (= engine rotational speed). Ne) and the rotational speed of the ring gear R (= MG2 rotational speed Nm2) have a relationship of being connected by a straight line on the alignment chart.

  During inverterless travel, engine torque Te is output from engine 100. When the motor generator 10 is mechanically rotated by the engine torque Te, the motor generator 10 generates a counter electromotive voltage Vc. At this time, the motor generator 10 generates the counter electromotive torque Tc in a direction to stop the rotation of the motor generator 10 according to the voltage difference ΔV (see FIG. 4). 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.

<Preventing vehicle advance during inverterless travel control>
Here, when the vehicle 1 is temporarily stopped during the inverterless travel control, for example, the shift range SFT of the vehicle 1 is switched to the non-forward range (P range, R range, or N range). We focused on the following points that could arise.

  FIG. 6 is a collinear diagram for explaining the behavior of each rotating element when the non-advance range is selected during the inverterless travel control. Referring to FIG. 6, even though the non-advance range is selected by the shift operation, the ring gear R may generate drive torque Tep that acts in the direction in which the vehicle 1 moves forward (forward direction). There is sex.

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

  Further, as another measure for preventing the generation of the drive torque Tep, when the non-advance range is selected during the inverterless travel control, the converter 210 is set so that the system voltage VH becomes equal to or higher than the back electromotive voltage Vc. It is possible to control. More specifically, it is conceivable that the gate of the converter 210 is also cut off.

  FIG. 7 is a diagram schematically showing the configuration of the electrical system when the gate of converter 210 is further shut off during inverterless travel control. Referring to FIG. 7, when counter electromotive voltage Vc is higher than system voltage VH (Vc> VH), counter electromotive torque Tc is generated, and capacitor C2 is charged by the regenerative current thereby. However, since converter 210 is in a gate-blocked state, no charge transfer from capacitor C2 to capacitor C1 occurs, so system voltage VH increases as capacitor C2 charges. Finally, when the system voltage VH becomes equal to or higher than the counter electromotive voltage Vc, the counter electromotive torque Tc is not generated. Therefore, it is possible to prevent the generation of the drive torque Tep using the counter electromotive torque Tc as a reaction force.

  Here, as described with reference to FIG. 2, communication of the operation command and gate cutoff command of converter 210 is performed from HV-ECU 310 to MG-ECU 320 in accordance with shift range SFT. When this communication is normally performed, MG-ECU 320 can receive a gate cutoff command for converter 210 from HV-ECU 310 that has detected shift range SFT in a timely manner. Therefore, when the shift range SFT is switched to the non-forward range during the inverterless travel control, the MG-ECU 320 controls the converter 210 to the gate cutoff state so that the system voltage VH becomes equal to or higher than the counter electromotive voltage Vc. can do.

  On the other hand, when an abnormality occurs in communication, MG-ECU 320 cannot receive a gate cutoff command for converter 210 from HV-ECU 310. Therefore, MG-ECU 320 cannot appropriately control the gate state of converter 210 according to shift range SFT, and as a result, when shift range SFT is a non-forward range, generation of drive torque Tep is appropriately performed. There is a possibility that it cannot be prevented.

  Therefore, according to the present embodiment, information regarding shift range SFT is transmitted from HV-ECU 310 to MG-ECU 320 using auxiliary machine voltage VA instead of communication between HV-ECU 310 and MG-ECU 320. Adopt the configuration to do.

  More specifically, the HV-ECU 320 outputs different voltage commands VAtag to the DC / DC converter 620 when the shift range SFT is the forward range and when the shift range SFT is the non-forward range. As an example, the HV-ECU 320 sets 15V as the voltage command VTag when the shift range SFT is the forward range, and 11V when the shift range SFT is the non-forward range.

  When the auxiliary machine voltage VA is a voltage corresponding to the forward range (for example, 15V ± 2V), the MG-ECU 320 estimates that the forward range is selected, while the auxiliary machine voltage VA is not in the non-forward range. When the voltage corresponds to (for example, 11V ± 2V), it is estimated that the non-forward range is selected. When MG-ECU 320 estimates that shift range SFT is the non-forward range, MG-ECU 320 causes system voltage VH between power lines PL and NL connecting converter 210 and inverter 221 to be equal to or higher than back electromotive voltage Vc. To control the converter 210. Accordingly, it is possible to prevent the generation of the driving torque Tep that acts in the direction in which the vehicle 1 is moved forward even though the non-forward range is selected.

  FIG. 8 is a flowchart for illustrating travel control in vehicle 1 according to the present embodiment. The flowchart of FIG. 8 and FIG. 9 to be described later 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 produced in ECU 300. .

  1, 2, and 9, in S <b> 10, ECU 300 (HV-ECU 310 or MG-ECU 320) determines whether or not an abnormality has occurred in communication between HV-ECU 310 and MG-ECU 320. To do. When communication abnormality has not occurred (NO in S10), ECU 310 causes vehicle 1 to normally travel ((S30). On the other hand, when communication abnormality has occurred (YES in S10), vehicle 1 causes vehicle 1 to travel without inverter ( S20).

  FIG. 9 is a flowchart for explaining control when communication abnormality occurs during inverterless travel. In FIG. 9, a series of processes executed by the HV-ECU 310 is shown on the left side in the figure, and a series of processes executed by the MG-ECU 320 is shown on the right side in the figure.

  Referring to FIGS. 1, 2, and 9, in S <b> 110, HV-ECU 310 determines whether vehicle 1 is traveling without an inverter. If vehicle 1 is not traveling without an inverter (NO in S110), HV-ECU 310 returns the process to the main routine.

  In contrast, when vehicle 1 is traveling without an inverter (YES in S110), HV-ECU 310 detects shift range SFT based on the detection signal from position sensor 510 (S120). Further, HV-ECU 310 determines whether or not detected shift range SFT is a non-forward range (S130).

  When shift range SFT is a non-forward range, that is, shift range SFT is a P range, an R range, or an N range (YES in S130), HV-ECU 310 sets voltage command VAtag for auxiliary battery 610 to threshold value Vth ( For example, it is set to V1 (for example, 11V) which is a value less than 13V) (S140).

  On the other hand, when shift range SFT is the forward range, that is, when shift range SFT is the D range or the B range (NO in S130), HV-ECU 310 sets voltage command VAtag to a value equal to or greater than threshold value Vth V2. (For example, 15V) is set (S150). Thereafter, the HV-ECU 310 returns the process to the main routine.

  On the other hand, in S210, MG-ECU 320 determines whether vehicle 1 is traveling in an inverter-less manner. If vehicle 1 is not traveling without an inverter (NO in S210), MG-ECU 320 returns the process to the main routine.

  On the other hand, when vehicle 1 is traveling without an inverter (YES in S210), MG-ECU 320 detects auxiliary machine voltage VA (S220). Then, MG-ECU 320 determines whether or not detected auxiliary machine voltage VA is less than threshold value Vth (S230).

  If auxiliary machinery voltage VA is less than threshold value Vth (YES in S230), MG-ECU 320 estimates that the non-advance range is selected, and also performs gate shutoff for converter 210 (S240). Thereby, generation | occurrence | production of the drive torque Tep which acts on the direction which advances the vehicle 1 can be prevented.

  On the other hand, when auxiliary machine voltage VA is equal to or higher than threshold value Vth (NO in S230), MG-ECU 320 estimates that the forward range is selected, and does not perform gate shut-off of converter 210, and converter 210 Continue switching operation. That is, MG-ECU 320 performs boost control of converter 210 within a range where system voltage VH does not exceed counter electromotive voltage Vc so that counter electromotive torque Tc is generated (S250). Since the back electromotive voltage Vc depends on the MG1 rotation speed Nm1, it can be estimated from the MG1 rotation speed Nm1 by using a predetermined map or function. Thereafter, MG-ECU 320 returns the process to the main routine.

  As described above, according to the present embodiment, MG-ECU 320 estimates shift range SFT based on auxiliary device voltage VA, and determines whether or not to perform gate blocking of converter 210 in accordance with estimated shift range SFT. Can be determined appropriately. As a result, it is possible to control whether or not to generate the drive torque Tep that acts in the direction of moving the vehicle 1 forward according to the current shift range SFT.

  In the present embodiment, the example in which the voltage command value VAtag of the auxiliary machine voltage is set lower when the non-forward range is selected than when the forward range is selected has been described. This magnitude relationship may be reversed. That is, the auxiliary machine voltage VAtag may be set higher when the non-forward range is selected than when the forward range is selected.

[Modification]
In the above embodiment, an example in which the non-advance range is estimated to be selected when the auxiliary machine voltage VA is less than the threshold value Vth and the gate of the converter 210 is shut off by the MG-ECU 320 is described. The method for preventing the occurrence of the counter electromotive torque Vc is not limited to this. In other words, MG-ECU 320 performs boost control of converter 210 (switching of switching elements Q1 and Q2 included in converter 210) so that system voltage VH is higher than back electromotive voltage Vc, instead of the process of S240 of FIG. Control). In S250, as described above, control of converter 210 is performed such that system voltage VH is equal to or lower than counter electromotive voltage Vc.

  Further, in the embodiment and the modification thereof, as an example, a configuration in which information regarding the shift range SFT is transmitted using the auxiliary machine voltage VA when an abnormality occurs in communication between the HV-ECU 310 and the MG-ECU 320. explained. However, transmission of information regarding the shift range SFT using the auxiliary machine voltage VA may be performed when the communication is normal.

  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 vehicle, 1U, 1V, 1W, 2U, 2V, 2W arm, 10, 20 motor generator, 12 permanent magnet, 30 planetary gear mechanism, S sun gear, R ring gear, CA carrier, P pinion gear, 50 drive wheels, 60 output shaft , 100 engine, 110 crankshaft, 150 battery, 210 converter, 221, 222 inverter, 230, 440 voltage sensor, 241, 242 current sensor, 410 engine speed sensor, 421, 422 resolver, 500 shift lever, 510 position sensor, 610 Auxiliary battery, 620 DC / DC converter, C1, C2 capacitor, Q1-Q14 switching element, D1-D14 diode, L1 reactor, PL, NL Power line.

Claims (1)

A hybrid vehicle,
Engine,
A first rotating electrical machine;
An output shaft connected to the drive wheels;
A planetary gear mechanism configured to mechanically connect the engine, the first rotating electrical machine, and the output shaft, and to transmit torque between the engine, the first rotating electrical machine, and the output shaft; ,
A second rotating electrical machine connected to the output shaft;
A first battery;
A first converter configured to boost and output a voltage input from the first battery;
An inverter configured to convert electric power between the first converter and the first rotating electrical machine, and between the first converter and the second rotating electrical machine;
A second battery;
A second converter configured to receive a voltage command and adjust and output a voltage input from the second battery;
When the inverter is abnormal, comprising a control device configured to be able to execute inverter-less travel control,
The first rotating electrical machine generates a braking torque using a counter electromotive voltage generated by being mechanically rotated by the engine,
The inverterless travel control is a control for causing the hybrid vehicle to travel with a torque acting on the output shaft as a reaction force of the braking torque by driving the engine with the inverter turned off.
The control device includes:
A first control device configured to be able to detect a shift range of the hybrid vehicle and to output the voltage command to the second converter;
A second controller configured to be able to detect the voltage of the second battery and to control the first converter;
When the shift range is a non-forward range during the inverterless travel control, the first control device outputs a voltage command different from that when the shift range is a forward range to the second converter. ,
When the voltage of the second battery is a voltage corresponding to the non-advanced range, the second control device has a voltage of a power line connecting the first converter and the inverter equal to or higher than the counter electromotive voltage. A hybrid vehicle that controls the first converter so that