JP2013216179A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start voltage step-up at suitable timing in view of the balance between reduction of electric power consumption and travel response of a hybrid vehicle.SOLUTION: A control device 60 of a hybrid vehicle 100 comprising an internal combustion engine 4, an electricity storage device B, a voltage step-up device 20 capable of stepping up an output voltage output from the electricity storage device, an inverter 20 converting supply electric power supplied from the voltage step-up device into AC electric power, and a rotating electrical machine MG1 performing rotary driving by the AC electric power supplied from the inverter comprises: a start-up control means 61 driving the rotating electrical machine to start-up the internal combustion engine; and a voltage step-up control means 62 for controlling the voltage step-up device to start the output voltage step-up in a period from the peak of cranking electric power of the rotating electrical machine required for the start-up of the internal combustion engine to the completion of the start-up of the internal combustion engine.

Description

  The present invention relates to a technical field of a control device for a hybrid vehicle, for example, which is a control device for a hybrid vehicle, and particularly includes a booster (a boost converter) that boosts the voltage of a power storage device.

  A hybrid vehicle including both an internal combustion engine and a rotating electric machine is known as a power source for traveling. Such a hybrid vehicle includes, in addition to the internal combustion engine and the rotating electric machine, a power storage device and a booster (in other words, a boost converter) that boosts the output voltage output from the power storage device. When the output voltage is boosted by the booster, the rotating electrical machine is driven at a relatively high voltage. For this reason, high output and high efficiency (that is, loss reduction) of the rotating electrical machine are realized.

  An example of a hybrid vehicle provided with such a booster is disclosed in Patent Document 1, for example. Specifically, in Patent Document 1, when the rotating electrical machine is driven to start the internal combustion engine, the output power of the power storage device is a threshold value (specifically, it is necessary for starting the internal combustion engine by the rotating electrical machine. In the case where it is smaller than (electric power), a hybrid vehicle is disclosed in which the boosting rate by the booster is limited to a specified value or less (for example, the boosting is stopped).

  Other examples of the hybrid vehicle including the booster are disclosed in Patent Document 2 and Patent Document 3, for example. Specifically, Patent Document 2 discloses a hybrid vehicle that optimizes a boosting mode (for example, a boosted voltage after boosting) by a booster according to driving conditions. Further, in Patent Document 3, when there is a request for starting the internal combustion engine during low fuel consumption traveling, a hybrid that suppresses vibration by delaying the start of the internal combustion engine until the boosting of the output voltage of the power storage device is completed. A vehicle is disclosed.

JP 2007-290478 A JP 2007-325351 A Japanese Patent No. 4245069

  By the way, in the technique disclosed in Patent Document 1, when the output power of the power storage device at the time of starting the internal combustion engine is smaller than the threshold value, the output voltage is not boosted. However, since the output voltage of the power storage device is not boosted, the driving force of the rotating electrical machine may be insufficient after the start of the internal combustion engine is completed. Therefore, there is a possibility that the traveling response of the hybrid vehicle is deteriorated. On the other hand, whether or not to boost the output voltage is changed in real time by monitoring both the threshold (specifically, the power required to start the internal combustion engine by the rotating electrical machine) and the output voltage of the power storage device. Assuming that the technique disclosed in Patent Document 1 is improved as possible, the output voltage is boosted when the output power of the power storage device becomes larger than the threshold value. However, in some cases, the output voltage may be boosted at an unnecessarily early timing. For this reason, the power consumption of the power storage device increases due to the boosting.

  Examples of problems to be solved by the present invention include the above. An object of the present invention is to provide a control device for a hybrid vehicle that can start boosting at a suitable timing in consideration of a balance between reduction in power consumption and driving response of the hybrid vehicle.

<1>
In order to solve the above problems, a control device for a hybrid vehicle according to the present invention includes an internal combustion engine, a power storage device, a booster capable of boosting an output voltage of the power storage device, and supply power supplied from the booster. A control apparatus for a hybrid vehicle, comprising: an inverter that converts to AC power; and a rotating electric machine that is rotationally driven by the AC power supplied from the inverter, wherein the rotating electric machine is driven to start the internal combustion engine. The boosting of the output voltage is started after the cranking power of the rotating electric machine required for starting the control means and the internal combustion engine reaches a peak until the start of the internal combustion engine is completed. And a boost control means for controlling the booster.

  According to the control apparatus for a hybrid vehicle of the present invention, the start control means drives the rotating electrical machine so as to start the internal combustion engine.

  When the internal combustion engine is started under the control of the start control means, the boost control means appropriately adjusts the timing at which the booster starts boosting the output voltage of the power storage device. Specifically, the boost control means controls the booster so as to start boosting from when the cranking power reaches its peak until the start of the internal combustion engine is completed.

  Here, the “cranking power is at a peak” state means, for example, a state that requires higher cranking power than the cranking power at the time before and after or other times. Typically, the “cranking power peak” state means a state in which the cranking power is highest during the period in which the internal combustion engine is started. In addition, the “starting completion” state may be appropriately set according to the specifications of the hybrid vehicle and the specifications of the internal combustion engine. For example, the state where “starting is completed” is an example of a state where the rotational speed of the internal combustion engine becomes equal to or higher than a predetermined rotational speed after starting the start, a state where cranking power becomes zero after the start is started, or the like.

  Thus, according to the present invention, boosting is started after the cranking power reaches its peak and before the start of the internal combustion engine is completed. Therefore, according to the present invention, as compared with a hybrid vehicle in which the boosting of the output voltage is always started simultaneously with or before the start of the internal combustion engine, the power loss accompanying the boosting is reduced. For this reason, according to the present invention, the power consumption of the power storage device is reduced as compared with the hybrid vehicle in which the boosting of the output voltage is always started simultaneously with or before the start of the internal combustion engine.

  On the other hand, according to the present invention, the boosting of the output voltage is completed at a relatively early timing as compared with a hybrid vehicle in which the boosting of the output voltage is always started simultaneously with or after the completion of the start of the internal combustion engine (for example, the target voltage The output voltage is boosted). For this reason, according to the present invention, the driving force of the rotating electrical machine can be secured at an early stage as compared with the hybrid vehicle in which the boosting of the output voltage is always started simultaneously with or after the completion of the start of the internal combustion engine. In other words, according to the present invention, as compared with a hybrid vehicle in which the boosting of the output voltage is always started simultaneously with or after the completion of the start of the internal combustion engine, for example, the rotating electrical machine is immediately after the start of the internal combustion engine is completed. The driving force can be ensured. Therefore, according to the present invention, as compared with the hybrid vehicle in which the boosting of the output voltage is always started at the same time as or after the completion of the start of the internal combustion engine, the deterioration of the driving response is preferably suppressed.

  Thus, according to the hybrid vehicle control device of the present invention, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle. .

<2>
In another aspect of the hybrid vehicle control apparatus of the present invention, the boost control means is configured to perform the internal combustion at the same time as or after the initial explosion timing, which is the first ignition timing after starting the internal combustion engine. The booster is controlled to start boosting the output voltage until the start of the engine is completed.

  According to this aspect, boosting is started in synchronization with the initial explosion timing that is typically the timing after the cranking power reaches its peak (that is, at the same time as the initial explosion timing or after the initial explosion timing). . For this reason, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle.

<3>
In another aspect of the control apparatus for a hybrid vehicle of the present invention, the boost control means is configured such that when the hybrid vehicle is in the first state, the first timing when the boost of the output voltage starts is increased. The booster is controlled to be earlier than the second timing at which the boosting of the output voltage is started in the second state different from the first state.

  According to this aspect, when the hybrid vehicle is in the first state (for example, it is preferable to start boosting at a relatively early timing), boosting is started at a relatively early timing. In other words, when the hybrid vehicle is in the second state (for example, a state where boosting need not be started at a relatively early timing), the boosting is started at a relatively late timing. Therefore, the timing to start boosting is appropriately adjusted according to the operating state of the hybrid vehicle. That is, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle in accordance with the operating state of the hybrid vehicle.

<4>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, when the hybrid vehicle is in the second state, the boost control means is configured to perform the first explosion timing, which is the first ignition timing after starting the internal combustion engine, or from the first explosion timing. When the booster is controlled to start boosting the output voltage until the start of the internal combustion engine is completed, and the hybrid vehicle is in the first state, the cranking power reaches a peak. The booster is controlled so as to start boosting the output voltage after the first explosion timing.

  According to this aspect, when the hybrid vehicle is in the first state (for example, a state in which it is preferable to start boosting at a relatively early timing), the cranking power reaches a peak until the first explosion timing. In the meantime (that is, at a relatively early timing), boosting is started. On the other hand, when the hybrid vehicle is in the second state (for example, it is not necessary to start boosting at a relatively early timing), the boosting is performed in accordance with the initial explosion timing (that is, at a relatively late timing). Is started. Therefore, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle in accordance with the operating state of the hybrid vehicle.

<5>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, when the hybrid vehicle is in the second state, the boost control means is a time that goes back from the time required to complete the boost of the output voltage from the time when the start of the internal combustion engine is completed. When the booster is controlled to start boosting the output voltage at the final boost time, and the hybrid vehicle is in the first state, the final boost time is reached after the cranking power reaches a peak. The booster is controlled to start boosting the output voltage until.

  According to this aspect, when the hybrid vehicle is in the first state (for example, a state where it is preferable to start boosting at a relatively early timing), the cranking power reaches a peak until the final boosting time. In the meantime (that is, at a relatively early timing), boosting is started. On the other hand, when the hybrid vehicle is in the second state (for example, it is not necessary to start boosting at a relatively early timing), boosting starts at the final boosting time (that is, at a relatively late timing). Is done. Therefore, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle in accordance with the operating state of the hybrid vehicle. In particular, when the hybrid vehicle is in the second state, boosting is not started until the final boosting time, so that loss due to boosting can be reduced to the maximum.

  Note that the final boost time is the time required to complete boosting of the output voltage from the time when the start of the internal combustion engine is completed (that is, the time when the start of the internal combustion engine is estimated or predicted). This is the time when the time taken from the start of boosting to the completion thereof is traced back. Specifically, for example, when the time for completing the start of the internal combustion engine is Tc and the time required for completing the boosting of the output voltage is Ti, the final boosting time is Tc-Ti. If boosting of the output voltage of the power storage device is started by such final boosting time, the boosting is also completed when the start of the internal combustion engine is completed. Therefore, when the start of the internal combustion engine is completed, the driving force of the rotating electrical machine is preferably ensured.

<6>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, when the hybrid vehicle is in the second state, the boost control means boosts the output voltage during a period from when the cranking power reaches a peak until the start of the internal combustion engine is completed. The booster is controlled to start, and when the hybrid vehicle is in the first state, the start of the internal combustion engine until the cranking power reaches a peak or the The booster is controlled to start boosting the output voltage before starting the internal combustion engine.

  According to this aspect, when the hybrid vehicle is in the first state (for example, a state where it is preferable to start boosting at a relatively early timing), the start required power reaches a peak after starting the internal combustion engine. Before the start of the internal combustion engine or before starting the internal combustion engine (that is, at a relatively early timing), boosting is started. In other words, when the hybrid vehicle is in the first state, the control to start boosting after the cranking power reaches its peak is canceled. On the other hand, when the hybrid vehicle is in the second state (for example, the state where boosting does not have to be started at a relatively early timing), the cranking power reaches its peak and the start of the internal combustion engine is completed. Boosting is started during this period (that is, at a relatively late timing). Therefore, boosting of the output voltage of the power storage device is started at a suitable timing in consideration of the balance between the reduction in power consumption and the driving response of the hybrid vehicle in accordance with the operating state of the hybrid vehicle.

<7>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, the first state includes (i) a state in which priority is given to improving the riding comfort of the hybrid vehicle, (ii) a state in which priority is given to improving the driving response of the hybrid vehicle, and (iii) emissions to satisfy the regulations. The second state is a state other than the first state.

  According to this aspect, it is suitably determined whether or not the hybrid vehicle is in the first state (for example, a state in which boosting is preferably started at a relatively early timing). Therefore, when the hybrid vehicle is in the first state, boosting is started at a relatively early timing.

  When the hybrid vehicle is in a state where priority is given to improving the ride comfort (for example, improving the NVH (Noise Vibration Harshness) characteristics), the start of boosting is delayed for the purpose of reducing power consumption (for example, relative If the boosting is started at a later timing), the ride comfort may be sacrificed due to the delay of the boosting. Therefore, when the hybrid vehicle is in a state where priority is given to improving the ride comfort, it is preferable to start boosting at a relatively early timing.

  In addition, when the hybrid vehicle is in a state where priority is given to improving the driving response, the start of boosting is delayed for the purpose of reducing power consumption (for example, boosting is started at a relatively late timing) Due to the delay in boosting, the driving force of the rotating electrical machine may be insufficient. This is because, in many cases, it is preferable that boosting has been completed in order to extract the necessary driving force from the rotating electrical machine. Therefore, when the hybrid vehicle is in a state where priority is given to improving the driving response, it is preferable that the boosting is started at a relatively early timing.

  In addition, when the hybrid vehicle is in a state where priority is given to reducing emissions to satisfy the regulations, the start of boosting is delayed for the purpose of reducing power consumption (for example, boosting is started at a relatively late timing). ), The reduction in emissions may be sacrificed due to the delay in boosting. In other words, if the hybrid vehicle is in a state that prioritizes the reduction of emissions to meet the regulations, first of all, rather than realizing the reduction of power consumption by delaying the start of boosting, the emissions specified in the regulations It is preferable that priority is given to realizing the reduction of the above. Therefore, when the hybrid vehicle is in a state where priority is given to emission reduction for satisfying the regulations, it is preferable to start boosting at a relatively early timing.

<8>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. In the second state, the internal combustion engine is used for another purpose different from (i) a state where priority is given to reducing power consumption of the power storage device and (ii) a purpose of generating power contributing to the running of the hybrid vehicle. The first state is a state other than the second state.

  According to this aspect, it is suitably determined whether or not the hybrid vehicle is in the second state (for example, a state where boosting need not be started at a relatively early timing). Therefore, when the hybrid vehicle is in the second state, boosting is started at a relatively late timing.

  When the hybrid vehicle is in a state where priority is given to reducing the power consumption of the power storage device, the start of boosting is delayed (for example, boosting is started at a relatively late timing), thereby reducing power consumption. It is realized relatively easily. Therefore, when the hybrid vehicle is in a state where priority is given to reducing the power consumption of the power storage device, it is preferable to start boosting at a relatively late timing.

  Also, the internal combustion engine is started for another purpose different from the purpose of the hybrid vehicle generating power that contributes to the travel of the hybrid vehicle (for example, starting for the purpose of charging the power storage device or driving the auxiliary machine). ) State, even if the start of boosting is delayed, the possibility that the drivability of the rotating electrical machine is insufficient is relatively small. That is, in this case, even if the start of boosting is delayed for the purpose of reducing power consumption (for example, boosting is started at a relatively late timing), the rotating electrical machine is caused by the delay of the boosting. The possibility that the driving force is insufficient is relatively small. Therefore, in this case, boosting may be started at a relatively late timing.

<9>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, the step-up control means is (i) when the driving mode of the hybrid vehicle is a power mode that gives priority to driving response, and (ii) the driving mode of the hybrid vehicle is a comfort mode that gives priority to riding comfort. And (iii) at least one case of starting the internal combustion engine in a cold state, it is determined that the hybrid vehicle is in the first state.

  According to this aspect, the boost control means can preferably determine whether or not the hybrid vehicle is in the first state.

  For example, when the driving mode of the hybrid vehicle is the power mode, it is estimated that the hybrid vehicle is in a state where priority is given to improving the driving response. Therefore, in this case, it is preferable to determine that the hybrid vehicle is in the first state. As a result, it is preferable to start boosting at a relatively early timing in order to give priority to the driving response.

  Further, when the traveling mode of the hybrid vehicle is the comfort mode, it is estimated that the hybrid vehicle is in a state where priority is given to improving the riding comfort. Therefore, in this case, it is preferable to determine that the hybrid vehicle is in the first state, and as a result, it is preferable to start boosting at a relatively early timing in order to prioritize improvement in riding comfort.

  In addition, when the internal combustion engine in the cold state is started, it is presumed that it is preferable to prioritize the reduction of emission by warming up the catalyst that has not been warmed up. Therefore, in this case, it is preferable to determine that the hybrid vehicle is in the first state, and as a result, boosting is started at a relatively early timing in order to prioritize reduction of emissions to satisfy the regulations. It is preferable.

<10>
In the aspect of the hybrid vehicle control device that determines whether the hybrid vehicle is in the first state or the second state as described above, the step-up control means includes: (i) the shift lever is positioned in the parking range. (Ii) when the driving mode of the hybrid vehicle is an eco mode that prioritizes fuel consumption; and (iii) when the shift lever is in the driving range, the accelerator opening is equal to or less than a predetermined opening. In at least one of the cases, it is determined that the hybrid vehicle is in the second state.

  According to this aspect, the boost control means can preferably determine whether or not the hybrid vehicle is in the second state.

  For example, when the shift lever is located in a parking range (for example, P (Parking) range), the hybrid vehicle is not traveling, and therefore other than the purpose of generating power that contributes to the traveling of the hybrid vehicle. It is estimated that there is a high possibility that the internal combustion engine is started for the purpose. Therefore, even if the start of boosting is delayed, the possibility that the driving force of the rotating electrical machine is insufficient because the hybrid vehicle is not traveling is relatively small. Alternatively, since a certain amount of time is required for the shift lever to enter the driving range (for example, D (Driving) range) from the parking range in order to start actual driving, boosting is completed using that time. Can be made. Therefore, in this case, since the start of boosting is delayed for the purpose of reducing power consumption (for example, boosting is started at a relatively late timing), the effect is relatively small. Boosting may be started at a later timing.

  Further, for example, when the traveling mode of the hybrid vehicle is the eco mode, it is estimated that the hybrid vehicle is in a state where priority is given to reducing power consumption. Therefore, in this case, it is preferable to determine that the hybrid vehicle is in the second state. As a result, it is preferable to start boosting at a relatively late timing in order to give priority to the reduction of power consumption.

  Further, for example, when the accelerator opening is equal to or less than a predetermined opening when the shift lever is located in the traveling range, the accelerator opening is relatively small, and therefore power that contributes to the traveling of the hybrid vehicle is generated. It is estimated that there is a high possibility that the internal combustion engine is started for another purpose different from the purpose. Alternatively, since the accelerator opening is relatively small, the power required to contribute to the travel of the hybrid vehicle is relatively small. As a result, even if the start of boosting is delayed, the driving force of the rotating electrical machine The possibility of shortage is relatively small. Therefore, in this case, since the start of boosting is delayed for the purpose of reducing power consumption (for example, boosting is started at a relatively late timing), the effect is relatively small. Boosting may be started at a later timing.

<11>
As described above, the aspect of the hybrid vehicle control device in which the first timing for starting boosting when the hybrid vehicle is in the first state is earlier than the second timing for starting boosting when the hybrid vehicle is in the second state. Then, the boost control means is (i) a selection state of a shift lever operated by a driver to select a transmission of the hybrid vehicle, (ii) an accelerator opening of the hybrid vehicle, and (iii) selected by a driver. Whether or not the hybrid vehicle is in the first state or the second state, based on at least one of the travel mode selection state of the hybrid vehicle and (iv) the temperature of the internal combustion engine. judge.

  According to this aspect, the boost control means can preferably determine whether the hybrid vehicle is in the first state or the second state.

  These effects and other advantages of the present invention will be further clarified from the embodiments described below.

It is a block diagram which shows an example of a structure of the hybrid vehicle of this embodiment. It is a flowchart which shows the flow of the 1st operation example of the pressure | voltage rise operation of the pressure | voltage rise converter at the time of engine starting. It is a timing chart which shows the flow of the 1st example of a boost operation of a boost converter at the time of engine starting. It is a flowchart which shows the flow of the 2nd operation example of the pressure | voltage rise operation of the pressure | voltage rise converter at the time of engine starting. It is a timing chart which shows the flow of the 2nd example of a boost operation of the boost converter at the time of engine starting. It is a timing chart which shows the flow of the 2nd example of a boost operation of the boost converter at the time of engine starting. It is a timing chart which shows the flow of the 2nd example of a boost operation of the boost converter at the time of engine starting.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(1) Configuration of Hybrid Vehicle First, the configuration of the hybrid vehicle 100 of the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an example of the configuration of the hybrid vehicle 100 of the present embodiment.

  As shown in FIG. 1, hybrid vehicle 100 includes wheels 2, a power split mechanism 3, an engine 4, a motor generator MG1, and a motor generator MG2. Hybrid vehicle 100 includes power storage device B, boost converter 10, inverter 20, inverter 30, capacitor C1, capacitor C2, power supply line PL1, power supply line PL2, ground line SL, ECU ( Electronic Control Unit) 60.

  Power split device 3 is coupled to engine 4, motor generator MG1, and motor generator MG2. Power split device 3 distributes power among engine 4, motor generator MG1, and motor generator MG2. For example, the power split mechanism 3 is a planetary gear mechanism having three rotating shafts: a sun gear, a planetary carrier, and a ring gear. Among these gears, the rotation shaft of the sun gear on the inner periphery is connected to the motor generator MG1, and the rotation shaft of the ring gear on the outer periphery is connected to the motor generator MG2. The rotating shaft of the planetary carrier located between the sun gear and the ring gear is connected to the engine 4. The rotation of the engine 4 is transmitted to the sun gear and the ring gear by the planetary carrier and the pinion gear. As a result, the power of the engine 4 is divided into two systems. In the hybrid vehicle 100, the rotating shaft of the ring gear is connected to the axle in the hybrid vehicle 100, and the driving force is transmitted to the wheels 2 through this axle.

  Motor generator MG1 is an example of a “rotary electric machine”, and functions as a generator for charging power storage device B or supplying power to motor generator MG2, and further as an electric motor for assisting the driving force of engine 4. Is configured to do. In addition, the motor generator MG1 is configured to function as an electric motor capable of starting the engine 4 under the control of the ECU 60 (in particular, control of a start control unit 61 described later).

  Motor generator MG2 is an example of a “rotating electric machine”, and is configured to function as an electric motor that assists the power of engine 4 or as a generator that charges power storage device B.

  The power storage device B is a DC power source that can be charged and discharged, and includes, for example, a secondary battery (that is, a rechargeable battery) such as nickel metal hydride or lithium ion. Power storage device B supplies DC power to power supply line PL1. Power storage device B is charged by receiving DC power output from boost converter 10 to power supply line PL1.

  Power storage device B may be charged by receiving power from an external power source of hybrid vehicle 100. That is, the hybrid vehicle 100 may be a so-called plug-in hybrid vehicle.

  Capacitor C1 is connected between power supply line PL1 and ground line SL, and smoothes voltage fluctuations between power supply line PL1 and ground line SL.

  Boost converter 10 includes an npn transistor Q1, an npn transistor Q2, a diode D1, a diode D2, and a reactor L. Npn transistor Q1 and npn transistor Q2 are connected in series between power supply line PL2 and ground line SL. The diode D1 and the diode D2 are connected in parallel to the npn transistor Q1 and the npn transistor Q2, respectively. Reactor L is connected between power supply line PL1 and the connection point of npn transistor Q1 and npn transistor Q2.

  Boost converter 10 boosts the voltage of power supply line PL1 and outputs it to power supply line PL2 under the control of ECU 60 (in particular, control of boost control unit 63 described later). More specifically, boost converter 10 accumulates the current that flows when npn transistor Q2 is turned on as magnetic field energy in reactor L, and releases the accumulated energy to power supply line PL2 via diode D1 when npn transistor Q2 is turned off. Thus, the voltage of the power supply line PL1 is boosted (in other words, the voltage of the power supply line PL2 is set to an arbitrary voltage equal to or higher than the voltage of the power supply line PL1).

  Note that increasing the on-duty of the npn transistor Q2 increases the power storage in the reactor L, so that a higher voltage output can be obtained. On the other hand, increasing the on-duty of the npn transistor Q1 lowers the voltage of the power supply line PL2. Therefore, by controlling the duty ratio of npn transistor Q1 and npn transistor Q2, the voltage of power supply line PL2 can be set to an arbitrary voltage equal to or higher than the voltage of power supply line PL1.

  By controlling this duty ratio, boost converter 10 may output the voltage of power supply line PL1 to power supply line PL2 without boosting the voltage. That is, boost converter 10 may output the voltage of power supply line PL1 as it is to power supply line PL2.

  Capacitor C2 is connected between power supply line PL2 and ground line SL, and smoothes voltage fluctuations between power supply line PL2 and ground line SL.

  Inverter 20 and inverter 30 are provided corresponding to motor generator MG1 and motor generator MG2, respectively. Inverter 20 drives motor generator MG1 in the power running mode or the regenerative mode under the control of ECU 60. Inverter 30 drives motor generator MG2 in the power running mode or the regenerative mode under the control of ECU 60.

  The ECU 60 constitutes an example of the “control device” of the present invention, and is an electronic control unit configured to be able to control the entire operation of the hybrid vehicle 100. The ECU 60 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

  Particularly in the present embodiment, the ECU 60 preferably includes a start control unit 61 and a boost control unit 62 as logical or physical processing blocks implemented therein.

  Start control unit 61 controls motor generator MG1 to start engine 4. Specifically, the start control unit 61 calculates cranking power that is power required for the motor generator MG1 to start the engine 4, for example. Start control unit 61 outputs a control signal instructing generation of cranking torque according to the calculated cranking power to motor generator MG1. As a result, motor generator MG1 operates to generate cranking torque according to the cranking power.

  Boost control unit 62 controls boost converter 10 to start boosting the voltage of power supply line PL1 at a timing determined according to the power peak timing, which is the timing at which the cranking power takes a peak value. As a result, boost converter 10 operates to start boosting the voltage of power supply line PL1 at a timing determined according to the power peak timing, which is the timing at which the cranking power takes a peak value.

(2) Basic operation of hybrid vehicle In the hybrid vehicle 100 of FIG. 1, the power distribution of the motor generator MG1, which mainly functions as a generator, the motor generator MG2 which mainly functions as an electric motor, and the engine 4, is divided into an ECU 60 and a power split mechanism. The traveling state is controlled by being controlled by 3. Below, operation | movement of the hybrid vehicle 100 according to several situations is demonstrated.

(2-1) When Starting For example, when starting the hybrid vehicle 100, the motor generator MG1 is driven as an electric motor using the electric energy of the power storage device B. Engine 4 is cranked by the power of motor generator MG1, and engine 4 is started.

  As will be described in detail later, in this embodiment, when engine 4 is started by cranking engine 4 by the power of motor generator MG1, boosting converter 10 boosts the voltage of power supply line PL1. The boosting start timing to be started is adjusted as appropriate.

(2-2) At the time of starting, two types of modes can be adopted depending on the power storage state of the power storage device B. For example, at the time of normal start (that is, SOC (State of Charge) is good), it is not necessary to charge power storage device B by motor generator MG1. Therefore, engine 4 is started only for warming up, and hybrid vehicle 100 is started by the power of motor generator MG2. On the other hand, when the state of charge is not good (that is, the SOC is lowered), motor generator MG1 functions as a generator by the power of engine 200. As a result, the power storage device B is charged.

(2-3) During low load traveling For example, when the vehicle is traveling at a low speed or down a gentle slope, the efficiency of the engine 4 is relatively poor. For this reason, the engine 4 is stopped by stopping the fuel injection through the injector, and the hybrid vehicle 100 travels only with the power from the motor generator MG2. At this time, if the SOC is lowered, engine 4 is started to drive motor generator MG1, and power storage device B is charged by motor generator MG1.

(2-4) During normal driving In a driving region where the fuel efficiency or combustion efficiency of the engine 4 is relatively good, the hybrid vehicle 100 travels mainly by the power of the engine 4. At this time, the power of the engine 4 is divided into two systems by the power split mechanism 3, one of which is transmitted to the wheel 2 via the axle, and the other is driven by the motor generator MG1 for power generation. Furthermore, motor generator MG2 is driven by the generated electric power, and the power of engine 4 is assisted by motor generator MG2. At this time, if the SOC is lowered, the output of the engine 4 is increased, and a part of the electric power generated by the motor generator MG1 is charged into the power storage device B.

(2-5) When deceleration is performed during braking , the motor generator MG2 is rotated by the power transmitted from the wheels 2 via the axle, and is operated as a generator. Thereby, the kinetic energy of the wheel 12 is converted into electric energy, and so-called “regeneration” is performed in which the power storage device B is charged.

(3) Boosting Operation at Engine Startup Next, with reference to FIG. 2 to FIG. 7, the boosting operation of boost converter 10 at startup of engine 4, which is an operation peculiar to hybrid vehicle 100 of the present embodiment. explain. In the following, description will be given of two operation examples related to the boosting operation of the boosting converter 10 when the engine 4 is started.

(3-1) First Operation Example First , with reference to FIG. 2 and FIG. 3, a first operation example of the boost operation of the boost converter 10 when the engine 4 is started will be described. FIG. 2 is a flowchart showing a flow of a first operation example of the boosting operation of boost converter 10 when engine 4 is started. FIG. 3 is a timing chart showing the flow of the first operation example of the boosting operation of the boosting converter 10 when the engine 4 is started.

  As shown in FIG. 2, the boost control unit 62 detects the state (for example, SOC) of the power storage device B (step S11). In addition, the boost control unit 62 detects the state of the engine 4 (for example, the engine water temperature or the like) (step S12). In addition, the boost control unit 62 detects the driving condition of the hybrid vehicle 100 (step S13).

  Thereafter, the start control unit 61 determines whether or not there is a start request for the engine 4 (step S14). The start request includes a start request for the engine 4 for generating power that contributes to the travel of the hybrid vehicle 100, a start request for the engine 4 for recovering the SOC of the power storage device B, and an auxiliary machine ( For example, a request for starting the engine 4 for the purpose of driving an alternator or the like, a request for starting the engine 4 for the purpose of warming up, and the like are given as examples.

  As a result of the determination in step S14, when it is determined that there is no request for starting the engine 4 (step S14: No), the start control unit 61 may not control the motor generator MG1 to start the engine 4. . In this case, boost control unit 63 may not control boost converter 10 to start boosting the voltage of power supply line PL1.

  On the other hand, as a result of the determination in step S14, when it is determined that there is a request for starting the engine 4 (step S14: Yes), the start flag shown in the uppermost row in FIG. 3 is a value indicating “unstarted state”. To a value indicating “starting state”. As a result, start control unit 61 controls motor generator MG1 to start engine 4. Specifically, the start control unit 61 calculates cranking power that is power required for the motor generator MG1 to start the engine 4, for example. Start control unit 61 outputs a control signal instructing generation of cranking torque according to the calculated cranking power to motor generator MG1. As a result, motor generator MG1 operates to generate cranking torque according to the cranking power. As a result, the engine 4 is started.

  At this time, the boost control unit 62 determines whether or not the current timing is a timing after the power peak timing, which is a timing at which the cranking power takes a peak value (step S15). The power peak timing means a timing at which the cranking power becomes maximum as shown in the third graph of FIG.

  In the present embodiment, the start control unit 61 calculates the necessary cranking power (or cranking torque corresponding to the cranking power) and then calculates the calculated cranking power (or the cranking power). The motor generator MG1 is controlled by feedforward control using the cranking torque) as the operation command value of the motor generator MG1. Therefore, the boost control unit 62 monitors the operation command value of the start control unit 61 or obtains necessary information (for example, past, current and future operation command values) from the start control unit 61. Thus, it may be determined whether or not the current timing is a timing after the power peak timing.

  However, the start control unit 61 directly or indirectly relates cranking power (or cranking torque corresponding to the cranking power), and sets any parameter other than the cranking power to the operation command value of the motor generator MG1. The feedback control used as may be performed. Even in this case, the boost control unit 62 monitors the operation command value of the start control unit 61 or acquires necessary information from the start control unit 61, so that the current timing is after the power peak timing. It may be determined whether it is timing.

  As a result of the determination in step S15, when it is determined that the current timing is not the timing after the power peak timing (that is, the current timing is the timing before the power peak timing) (step S15: No), the boost control The unit 62 continues to determine whether or not the current timing is a timing after the power peak timing.

  On the other hand, as a result of the determination in step S15, when it is determined that the current timing is after the power peak timing (step S15: Yes), the boost control unit 62 starts boosting the voltage of the power supply line PL1. Thus, boost converter 10 is controlled (step S16). As a result, boost converter 10 starts boosting the voltage of power supply line PL1 (step S16).

  That is, in this embodiment, as indicated by the thick solid line in the second graph in FIG. 3, boost converter 10 starts boosting the voltage of power supply line PL1 after the power peak timing. At this time, boost control unit 62 controls boost converter 10 to start boosting the voltage of power supply line PL1 after the power peak timing and until the start of engine 4 is completed. That is, boost converter 10 starts boosting the voltage of power supply line PL1 after the power peak timing and until the start of engine 4 is completed.

  It should be noted that the timing for starting boosting the voltage of the power supply line PL1 may be any timing as long as it is after the power peak timing and before the start of the engine 4 is completed. For example, start control unit 61 may control boost converter 10 to start boosting the voltage of power supply line PL1 immediately after the power peak timing. In this case, boost converter 10 starts boosting the voltage of power supply line PL1 immediately after the power peak timing. Alternatively, start control unit 61 may control boost converter 10 to start boosting the voltage of power supply line PL1 after a predetermined time has elapsed from the power peak timing. In this case, boost converter 10 starts boosting the voltage of power supply line PL1 after a predetermined time has elapsed from the power peak timing. Alternatively, start control unit 61 may control boost converter 10 so as to start boosting the voltage of power supply line PL1 immediately before the start of engine 4 is completed. In this case, boost converter 10 starts boosting the voltage of power supply line PL1 immediately before the start of engine 4 is completed.

  However, the timing to start boosting the voltage of the power supply line PL1 may be any timing that matches the initial explosion timing (that is, the first ignition timing after starting the engine 4). For example, the timing to start boosting the voltage of the power supply line PL1 may be the same timing as the initial explosion timing, or may be any timing after the initial explosion timing. Note that the initial explosion timing typically falls after the power peak timing and until the start of the engine 4 is completed.

  Further, it is preferable that the voltage boost of power supply line PL1 is completed before the start of engine 4 is completed. Therefore, at the latest, the start control unit 61 boosts the voltage of the power supply line PL1 at a time obtained by subtracting the time required from the start of boosting the voltage of the power supply line PL1 to the completion thereof from the time when the start of the engine 4 is completed. It is preferable to control boost converter 10 to start the operation. In this case, boost converter 10 does not increase the voltage of power supply line PL1 at the latest by subtracting the time required from the start of boosting the voltage of power supply line PL1 to the completion of the start of engine 4 from the time when the start of engine 4 is completed. Start boosting. If the boosting of the voltage of the power supply line PL1 is started at this timing, the boosting of the voltage of the power supply line PL1 is completed before the start of the engine 4 is completed.

  Here, the “timing when the start of the engine 4 is completed” is a timing when the start flag is changed from a value indicating the “starting state” to a value indicating the “starting complete state”. The timing at which the start flag is changed to a value indicating the “start completion state” is, for example, as shown in the graph in the fourth row of FIG. A state where R_th is greater than or equal to R_th is an example. Alternatively, the timing at which the start flag is changed to a value indicating the “start completion state” is, for example, as shown in the third graph in FIG. 3, the cranking power becomes zero after starting the engine 4. State is another example. However, the condition for determining the timing at which the start flag is changed to a value indicating the “start completion state” (that is, the timing at which the start of the engine 4 is completed) depends on the specifications of the hybrid vehicle 100, the specifications of the engine 4, and the like. It may be set as appropriate.

  As described above, according to the present embodiment, the voltage of the power supply line PL1 is boosted at an arbitrary timing after the power peak timing at which the cranking power reaches a peak and until the start of the engine 4 is completed. Is started.

  Here, as indicated by the thick one-dot chain line in the second graph of FIG. 3, the voltage of the power supply line PL1 is always boosted simultaneously with the start of the engine 4 or before the start of the engine 4 is started. The hybrid vehicle of the first comparative example that is started will be described. In the hybrid vehicle of the first comparative example, the voltage increase of the power supply line PL1 is started at a relatively early timing as compared with the hybrid vehicle 100 of the present embodiment. Occur frequently. As a result, the power consumption of the power storage device in the hybrid vehicle of the first comparative example indicated by the thick one-dot chain line in the fifth graph in FIG. 3 is the present embodiment indicated by the thick line in the fifth graph in FIG. It will become larger than the power consumption of the electrical storage apparatus B in the hybrid vehicle 100 of this. That is, in the hybrid vehicle 100 of the present embodiment, compared to the hybrid vehicle of the first comparative example, the power loss due to the voltage boost of the power supply line PL1 is reduced, so the power consumption of the power storage device B is reduced. The

  On the other hand, as shown by the thick dotted line in the second graph of FIG. 3, the voltage boost of the power supply line PL1 is always started simultaneously with the completion of the start of the engine 4 or after the completion of the start of the engine 4. A hybrid vehicle of the second comparative example will be described. In the hybrid vehicle of the second comparative example, since the voltage boost of the power line PL1 is started at a relatively late timing as compared with the hybrid vehicle 100 of the present embodiment, the start of the engine 4 is completed. There is a possibility that the driving force of motor generator MG2 is insufficient. That is, in the hybrid vehicle of the second comparative example, since the voltage boost of the power supply line PL1 is not completed when the start of the engine 4 is completed, the hybrid vehicle 100 starts running when the start of the engine 4 is completed. There is a possibility that a necessary driving force of the motor generator MG2 cannot be secured. This is because, in order to ensure the driving force of motor generator MG2 necessary for traveling of hybrid vehicle 100, it is often preferable that the voltage boost of power supply line PL1 has been completed. However, in the hybrid vehicle 100 of the present embodiment, the driving force of the motor generator MG2 can be ensured at an early stage as compared with the hybrid vehicle of the second comparative example. In other words, compared to the hybrid vehicle of the second comparative example, the hybrid vehicle 100 of the present embodiment drives the motor generator MG2 without delay when the engine 4 is started or after the start of the engine 4 is completed. Power can be secured. Therefore, in hybrid vehicle 100 of the present embodiment, the deterioration of the driving response due to the insufficient driving force of motor generator MG2 is suitably suppressed as compared with the hybrid vehicle of the second comparative example. In addition, in the present embodiment, since the start of the engine 4 itself is not delayed, not only the travel response due to the insufficient driving force of the motor generator MG2, but also the deterioration of the travel response due to the delay of the start of the engine 4 is caused. Moreover, it suppresses suitably.

  As described above, according to the hybrid vehicle 100 of the present embodiment, the voltage (in other words, the voltage of the power line PL1 is changed at a suitable timing in consideration of the balance between the reduction in the power consumption of the power storage device B and the travel response of the hybrid vehicle 100. Voltage of the power storage device B) is started.

  In general, after the cranking power reaches its peak, the inertial force generated by the rotation of the cranking shaft (or the reciprocating motion of the piston), the rotation of the cranking shaft (or the reciprocating motion of the piston). The cranking power is relatively reduced due to the frictional force that is reduced by. In other words, generally, until the cranking power reaches a peak, the cranking shaft (or piston) having a large frictional force and a small inertial force is moved because the amount of momentum is relatively small or not moving. Since it is necessary, the cranking power is relatively large. For this reason, if boosting of the voltage of the power supply line PL1 is started after the cranking power reaches its peak, even if a power loss caused by boosting occurs, the power loss is started (in other words, the engine 4 The operation of the motor generator MG1 for starting 4) is hardly affected. Specifically, for example, the output power of the power storage device B hardly falls below the cranking power due to the power loss accompanying the boosting. Therefore, if boosting of the voltage of the power supply line PL1 is started after the power peak timing, the above-described effects can be enjoyed without affecting the start of the engine 4 itself.

  In addition, generally, after the initial explosion timing, the cranking power is relatively increased due to combustion in the combustion chamber of the engine 4 (in other words, spontaneous rotation of the cranking shaft accompanying the combustion). Becomes smaller. For this reason, if boosting is started at the timing of the first explosion, even if a power loss due to boosting occurs, the power loss will start the engine 4 (in other words, the motor generator MG1 for starting the engine 4). The operation) is hardly affected. Specifically, for example, the output power of the power storage device B hardly falls below the cranking power due to the power loss accompanying the boosting. Therefore, if the boosting of the voltage of the power supply line PL1 is started in accordance with the initial explosion timing, the above-described effects can be enjoyed without affecting the starting of the engine 4 itself.

  Note that the time required for the combustion to become stable in the combustion chamber of the engine 4 after the initial explosion is performed is approximately 0.3 seconds, depending on the specifications of the engine 4. This is because it takes about 3 cycles of the engine 4 to stabilize the combustion, but it is assumed that the engine 4 is rotating at 1200 rpm / rpm while the engine 4 is starting. Then, since it takes 0.1 second per cycle, the time required for the combustion to become stable is 0.1 × 3 = 0.3 seconds. On the other hand, the time required from the start of boosting the voltage of power supply line PL1 to completion is approximately 0.1 seconds, although it depends on the specifications of boost converter 10 and the like. For this reason, if the voltage boost of the power supply line PL1 is started in accordance with the initial explosion timing, the voltage boost of the power supply line PL1 is completed before the start of the engine 4 is completed.

  In the above description, the timing to start boosting the voltage of the power supply line PL1 is adjusted by directly referring to the cranking power. On the other hand, the boosting of the voltage of the power supply line PL1 is started by referring to another index having correlation with the cranking power (for example, cranking torque or the like) (that is, indirectly referring to the cranking power). The timing to perform may be adjusted.

(3-2) Second Operation Example Next, a second operation example of the boost operation of the boost converter 10 at the start of the engine 4 will be described with reference to FIGS. FIG. 4 is a flowchart showing a flow of a second operation example of the boosting operation of boost converter 10 at the start of engine 4. Each of FIGS. 5 to 7 is a timing chart showing the flow of the second operation example of the boosting operation of the boosting converter 10 when the engine 4 is started. In addition, about the operation | movement similar to the 1st operation example mentioned above, the same step number is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 4, in the second operation example, the operations from step S11 to step S14 are performed as in the first operation example. Specifically, the boost control unit 62 detects the state (for example, SOC) of the power storage device B (step S11). The boost control unit 62 detects the state of the engine 4 (for example, the engine water temperature or the like) (step S12). Boost control unit 62 detects the operating condition of hybrid vehicle 100 (step S13). The start control unit 61 determines whether there is a start request for the engine 4 (step S14). The driving conditions include, for example, the travel mode of the hybrid vehicle 100, the range of the shift lever of the hybrid vehicle 100, the presence / absence of a vibration suppression request instruction (or vibration suppression control cut instruction) to the hybrid vehicle 100, the warming of the engine 4 Examples include the machine state (for example, the temperature of the engine 4 or the catalyst), the accelerator opening, the past, present or future traveling state of the hybrid vehicle 100, and the like.

  As a result of the determination in step S14, when it is determined that there is no request for starting the engine 4 (step S14: No), the start control unit 61 may not control the motor generator MG1 to start the engine 4. . In this case, boost control unit 63 may not control boost converter 10 to start boosting the voltage of power supply line PL1.

  On the other hand, as a result of the determination in step S14, when it is determined that there is a request for starting the engine 4 (step S14: Yes), the start control unit 61 controls the motor generator MG1 to start the engine 4. . As a result, the engine 4 is started.

  At this time, the boost control unit 62 sets the timing to start boosting the voltage of the power supply line PL1 based on the operating condition detected in step S13 (step S21).

  Specifically, the boost control unit 62 may determine whether or not the hybrid vehicle 100 is in a state in which priority is given to improving the driving response based on the driving condition detected in step S13. The boost control unit 62 determines whether or not the hybrid vehicle 100 is in a state of giving priority to the improvement of the driving response, so that the driving mode of the hybrid vehicle 100 (for example, the driving mode that can be specified by the driver) is the driving power. Alternatively, it may be determined whether the power mode places priority on or gives priority to the driving response. When it is determined that the traveling mode of the hybrid vehicle 100 is the power mode, it may be determined that the hybrid vehicle 100 is in a state where priority is given to improving the traveling response. On the other hand, when it is determined that the travel mode of the hybrid vehicle 100 is not the power mode, it may be determined that the hybrid vehicle 100 is not in a state where priority is given to improving the travel response.

  When it is determined that the hybrid vehicle 100 is in a state where priority is given to improving the driving response, the power supply line PL1 is compared with a case where it is determined that the hybrid vehicle 100 is not in a state where priority is given to improving the driving response. It is preferable that the timing for starting the voltage boost is advanced. In other words, the boost control unit 62 determines when the hybrid vehicle 100 starts to boost the voltage of the power supply line PL1 when it is determined that the hybrid vehicle 100 is in a state where priority is given to improving the driving response. It is preferable to set the timing to start boosting the voltage of the power supply line PL1 so as to be earlier than the timing to start boosting the voltage of the power supply line PL1 when it is determined that it is not in the state of prioritizing the power.

  This is because when the hybrid vehicle 100 is in a state where priority is given to improving the driving response, the start of boosting the voltage of the power supply line PL1 is delayed for the purpose of reducing the power consumption of the power storage device B (for example, relative If the boosting is started at a later timing), the driving power of the motor generator MG2 may be insufficient due to the delay of the boosting. In other words, the timing at which the motor generator MG2 can output the driving force necessary for the traveling of the hybrid vehicle 100 may be delayed due to the delay in boosting. This is because, as described above, in order to extract the necessary driving force from motor generator MG2, it is often preferable that the voltage boosting of power supply line PL1 has been completed. Therefore, when the hybrid vehicle 100 is in a state where priority is given to improving the driving response, it is preferable to start boosting at a relatively early timing.

  For example, when it is determined that the hybrid vehicle 100 is in a state where priority is given to improving the driving response, the boost control unit 62 is after the power peak timing as shown in the second graph of FIG. In addition, an arbitrary timing until the first explosion timing may be set to a timing at which the voltage boost of the power supply line PL1 is started. On the other hand, when it is determined that the hybrid vehicle 100 is not in a state where priority is given to improving the driving response, the boost control unit 62 is after the first explosion timing as shown in the third graph of FIG. In addition, an arbitrary timing until the start of the engine 4 is completed may be set to a timing at which the voltage of the power supply line PL1 starts to be boosted.

  Alternatively, for example, when it is determined that the hybrid vehicle 100 is in a state of giving priority to the improvement of the driving response, the boost control unit 62 performs the power control after the power peak timing as shown in the second graph of FIG. And an arbitrary timing between the start of boosting the voltage of the power supply line PL1 and the completion of the start of the engine 4 from the time when the start of the engine 4 is completed is expressed as the voltage of the power supply line PL1. You may set to the timing which starts pressure | voltage rise. On the other hand, when it is determined that the hybrid vehicle 100 is not in a state where priority is given to improving the driving response, the boost control unit 62 determines the voltage of the power supply line PL1 as shown in the third graph of FIG. A time obtained by subtracting the time required from the start of boosting to the completion of the start of the engine 4 from the time when the start of the engine 4 is completed (or any timing after that time and until the start of the engine 4 is completed) ) May be set to the timing to start boosting the voltage of the power supply line PL1.

  Alternatively, for example, when it is determined that the hybrid vehicle 100 is in a state where priority is given to improving the driving response, the boost control unit 62 starts the engine 4 as shown in the second graph of FIG. Any timing from the start to the power peak timing or any timing before starting the engine 4 may be set as a timing to start boosting the voltage of the power supply line PL1. On the other hand, when it is determined that the hybrid vehicle 100 is not in a state where priority is given to improving the driving response, the boost control unit 62 determines the engine 4 from the power peak timing as shown in the third graph of FIG. Arbitrary timing until the start-up is completed may be set as a timing to start boosting the voltage of the power supply line PL1.

  As a result, when it is determined that the hybrid vehicle 100 is in a state in which priority is given to improving the driving response, the boosting is started at a relatively early timing, and thus the deterioration of the driving response is suitably suppressed. On the other hand, when it is determined that the hybrid vehicle 100 is not in a state of giving priority to the improvement of the driving response, the power storage device B as shown by the thick solid line in each of the sixth graphs in FIGS. Power consumption is reduced.

  Alternatively, the boost control unit 62 may determine whether or not the hybrid vehicle 100 is in a state where priority is given to the improvement of NVH (Noise Vibration Harshness) characteristics based on the driving condition detected in step S13. In order to determine whether or not the hybrid vehicle 100 is in a state where priority is given to the improvement of the NVH characteristics, the boost control unit 62 determines whether or not the travel mode of the hybrid vehicle 100 is a comfort mode in which ride comfort is prioritized or prioritized. It may be determined. When it is determined that the travel mode of the hybrid vehicle 100 is the comfort mode, it may be determined that the hybrid vehicle 100 is in a state of giving priority to the improvement of the NVH characteristics. On the other hand, when it is determined that the travel mode of the hybrid vehicle 100 is not the comfort mode, it may be determined that the hybrid vehicle 100 is not in a state of giving priority to the improvement of the NVH characteristics. Alternatively, the boost control unit 62 determines whether or not a vibration suppression request instruction has been given to the hybrid vehicle 100 in order to determine whether or not the hybrid vehicle 100 is in a state of giving priority to the improvement of the NVH characteristics (in other words, Whether or not a vibration suppression control cut instruction has been issued) may be determined. When it is determined that a vibration suppression request instruction has been issued (in other words, a vibration suppression control cut instruction has not been issued), it may be determined that the hybrid vehicle 100 is in a state of giving priority to the improvement of the NVH characteristics. . On the other hand, when it is determined that the vibration suppression request instruction has not been made (in other words, the vibration suppression control cut instruction has been issued), it is determined that the hybrid vehicle 100 is not in a state of giving priority to the improvement of the NVH characteristics. May be.

  When it is determined that hybrid vehicle 100 is in a state of giving priority to the improvement of NVH characteristics, compared to the case where hybrid vehicle 100 is determined not to be in a state of giving priority to the improvement of NVH characteristics, power supply line PL1 It is preferable that the timing for starting the voltage boost is advanced. In other words, the boost control unit 62 determines when the hybrid vehicle 100 starts to boost the voltage of the power supply line PL1 when it is determined that the hybrid vehicle 100 is in a state of giving priority to the improvement of the NVH characteristic. It is preferable to set the timing to start boosting the voltage of the power supply line PL1 so as to be earlier than the timing to start boosting the voltage of the power supply line PL1 when it is determined that it is not in the state of prioritizing the power.

  This is because when the hybrid vehicle 100 is in a state where priority is given to improving the NVH characteristics, the start of boosting the voltage of the power supply line PL1 is delayed for the purpose of reducing power consumption (for example, relatively late timing). If the boosting is started at this point, the NVH characteristics may be sacrificed due to the delay of the boosting. Therefore, when the hybrid vehicle 100 is in a state where priority is given to improving the NVH characteristics, it is preferable to start boosting at a relatively early timing.

  Further, when the vibration suppression control is not performed in the hybrid vehicle 100, the cranking torque and the motor are compared even when the vehicle speed of the hybrid vehicle 100 is the same as that when the vibration suppression control is performed. The peak of the multiplier with the rotation speed of the generator MG1 tends to be small. Therefore, when vibration suppression control is not performed in hybrid vehicle 100, even if boosting of power supply line PL1 is not started (or is not completed), motor generator MG1 operating at the voltage before boosting causes engine 4 to There is a relatively high possibility that the cranking torque necessary for starting will be satisfied. In other words, when the vibration suppression control is not performed in the hybrid vehicle 100, even if the boosting of the power supply line PL1 is not started (or is not completed), there is a relative possibility that the start of the engine 4 is affected. Lower. Therefore, when the vibration suppression control is not performed in the hybrid vehicle 100, boosting may not be started at a relatively early timing (in other words, boosting may be started at a relatively late timing).

  When it is determined that the hybrid vehicle 100 is in a state where priority is given to improving the NVH characteristics, the timing at which the voltage of the power supply line PL1 starts to be boosted is such that the hybrid vehicle 100 prioritizes improvement of the driving response. It may be set in the same manner as when it is determined that there is. Similarly, when it is determined that the hybrid vehicle 100 is not in a state where priority is given to improving the NVH characteristics, the timing at which the voltage of the power supply line PL1 starts to be boosted is a state where the hybrid vehicle 100 prioritizes improvement of the driving response described above. It may be set in the same manner as the case where it is determined that there is not.

  Alternatively, the boost control unit 62 determines whether or not the hybrid vehicle 100 is in a state of giving priority to emission reduction (for example, emission reduction for satisfying regulations) based on the driving condition detected in step S13. May be. The boost control unit 62 determines whether or not the engine 4 (or a catalyst included in the engine 4) is in a cold state in order to determine whether or not the hybrid vehicle 100 is in a state where priority is given to reduction of emissions. May be. When it is determined that the engine 4 is in the cold state, it is estimated that the catalyst is not warmed up, and thus there is a possibility that the emission may deteriorate. Accordingly, when it is determined that the engine 4 is in the cold state, even if it is determined that the hybrid vehicle 100 is in a state of giving priority to the emission reduction in order to reduce the emission by warming up the catalyst. Good. On the other hand, when it is determined that the engine 4 is not in the cold state (that is, in the warm-up state), it is assumed that the catalyst is also warmed up, so that the emission may be deteriorated. Few. Therefore, when it is determined that the engine 4 is not in the cold state, it may be determined that the hybrid vehicle 100 is not in a state in which priority is given to reducing emissions. The boost control unit 62 may determine whether or not the engine 4 is in a cold state based on, for example, the temperature of the engine 4 (particularly, the coolant temperature), the temperature of the catalyst, or the like.

  When it is determined that the hybrid vehicle 100 is in a state of giving priority to emission reduction, the voltage of the power line PL1 is compared with the case where it is determined that the hybrid vehicle 100 is not in a state of giving priority to emission reduction. It is preferable that the timing for starting the boosting is advanced. In other words, when the hybrid vehicle 100 determines that the hybrid vehicle 100 is in a state of giving priority to emission reduction, the timing at which the hybrid vehicle 100 starts boosting the voltage of the power supply line PL1 gives priority to emission reduction. It is preferable to set the timing to start boosting the voltage of the power supply line PL1 so as to be earlier than the timing to start boosting the voltage of the power supply line PL1 when it is determined that it is not in the state to be activated.

  This is because when the hybrid vehicle 100 is in a state of giving priority to emission reduction, the start of boosting the voltage of the power supply line PL1 is delayed for the purpose of reducing power consumption (for example, at a relatively late timing). When the boosting is started), there is a risk that the emission reduction is sacrificed due to the delay of the boosting. In other words, when the hybrid vehicle 100 is in a state of giving priority to the reduction of emissions, it is first defined in the law rather than realizing a reduction in power consumption by delaying the start of boosting the voltage of the power supply line PL1. It is preferable to prioritize achieving reduced emissions. Therefore, when the hybrid vehicle 100 is in a state of giving priority to emission reduction, it is preferable to start boosting at a relatively early timing.

  Note that when it is determined that the hybrid vehicle 100 is in a state of giving priority to emission reduction, the above-described hybrid vehicle 100 is in a state of giving priority to improving the driving response. May be set in the same manner as that determined. Similarly, when it is determined that the hybrid vehicle 100 is not in a state in which priority is given to reducing emissions, the timing at which the voltage of the power supply line PL1 starts to be boosted is in a state in which the hybrid vehicle 100 gives priority to improving the driving response. It may be set in the same manner as the case where it is determined that there is no.

  Alternatively, the boost control unit 62 determines whether or not the hybrid vehicle 100 is in a state of giving priority to reduction of power consumption (that is, power consumption of the power storage device B) based on the driving condition detected in step S13. Also good. The boost control unit 62 determines whether or not the traveling mode of the hybrid vehicle 100 is an eco mode that prioritizes low fuel consumption traveling in order to determine whether or not the hybrid vehicle 100 is in a state of prioritizing reduction of power consumption. May be determined. When it is determined that the travel mode of the hybrid vehicle 100 is the eco mode, it may be determined that the hybrid vehicle 100 is in a state where priority is given to reducing power consumption. On the other hand, when it is determined that the travel mode of the hybrid vehicle 100 is not the eco mode, it may be determined that the hybrid vehicle 100 is not in a state where priority is given to reducing power consumption.

  When it is determined that the hybrid vehicle 100 is in a state of giving priority to reduction of power consumption, the power supply line PL1 is compared with a case where it is determined that the hybrid vehicle 100 is not in a state of giving priority to reduction of power consumption. It is preferable that the timing for starting the voltage boost is delayed. In other words, when the hybrid vehicle 100 determines that the hybrid vehicle 100 is in a state of giving priority to the reduction of power consumption, the timing at which the hybrid vehicle 100 starts boosting the voltage of the power supply line PL1 reduces the power consumption of the hybrid vehicle 100. It is preferable to set the timing to start boosting the voltage of the power supply line PL1 so as to be later than the timing to start boosting the voltage of the power supply line PL1 when it is determined that the state is not in the priority state.

  Note that when it is determined that the hybrid vehicle 100 is in a state of giving priority to the reduction of power consumption, the timing at which the voltage of the power supply line PL1 starts to be boosted is such that the above-described hybrid vehicle 100 gives priority to the improvement of the driving response. It may be set in the same manner as the case where it is determined that there is no. Similarly, when it is determined that the hybrid vehicle 100 is not in a state where priority is given to reducing power consumption, the timing at which the voltage of the power supply line PL1 starts to be boosted is a state where the hybrid vehicle 100 prioritizes improvement of the driving response described above. It may be set in the same manner as in the case where it is determined that there is.

  Alternatively, the boost control unit 62 determines whether the engine 4 start request in step S14 is different from the generation of power that contributes to the travel of the hybrid vehicle 100 based on the driving condition detected in step S13. 4 may be determined (hereinafter, referred to as “running non-travel start request” as appropriate). Note that the non-travel start request includes, for example, a start request for the engine 4 for the purpose of recovering the SOC of the power storage device B, a start request for the engine 4 for the purpose of driving an auxiliary machine (for example, an alternator, etc.) An example is a request for starting the engine 4 for the purpose of warming up.

  The boost control unit 62 determines whether or not the start request in step S14 is a non-traveling purpose start request, so as to select a transmission (more specifically, a transmission gear) of the hybrid vehicle 100. The range of the shift lever operated by may be determined. When it is determined that the shift lever is in the P range, it may be determined that the start request in step S14 is a start request other than the travel purpose. On the other hand, if it is determined that the shift lever is not in the P range, it may be determined that the start request in step S14 is not a travel non-start request.

  Alternatively, the boost control unit 62 determines whether or not the accelerator opening is equal to or smaller than the predetermined opening in addition to the shift lever range, in order to determine whether or not the start request in step S14 is a start request other than the travel purpose. It may be determined whether or not. When it is determined that the shift lever is in the D range and the accelerator opening is equal to or less than the predetermined opening, it may be determined that the start request in step S14 is a start request other than the traveling purpose. On the other hand, when it is determined that the shift lever is not in the D range or the accelerator opening is not equal to or less than the predetermined opening, it may be determined that the start request in step S14 is not a non-traveling purpose start request.

  When it is determined that the start request in step S14 is a non-travel start request, the voltage of the power supply line PL1 is compared to the case where the start request in step S14 is determined not to be a non-travel start request. It is preferable that the timing of starting the boosting is delayed. In other words, the boost control unit 62 determines that the timing for starting boosting the voltage of the power supply line PL1 when the start request in step S14 is determined to be a non-running start request is the start request in step S14. It is preferable to set the timing to start boosting the voltage of the power supply line PL1 so as to be later than the timing to start boosting the voltage of the power supply line PL1 when it is determined that it is not an unintended start request.

  This is because when the shift lever is in the P range, since the hybrid vehicle 100 is not traveling, it is necessary for the motor generator MG2 to generate driving force to contribute to the traveling of the hybrid vehicle 100 at an early stage. Relatively low. Accordingly, the necessity of starting boosting at a relatively early timing until the shift lever is in the P range is relatively reduced. In addition, when the shift lever is in the P range, the shift lever needs to be changed to the D range in order for the hybrid vehicle 100 to start traveling. In this case, the time when the shift lever is changed from the P range to the D range can be used as the time during which the voltage of the power supply line PL1 is boosted. Accordingly, the necessity of starting boosting at a relatively early timing until the shift lever is in the P range is relatively reduced. For this reason, when the shift lever is in the P range (that is, when the start request in step S14 is a start request outside the travel purpose), boosting does not have to be started at a relatively early timing (in other words, Boosting may be started at a relatively late timing).

  Alternatively, when the shift lever is in the D range and the accelerator opening is equal to or smaller than the predetermined opening (that is, the request for the driving force to contribute to traveling of the hybrid vehicle 100 is relatively small), the hybrid vehicle 100 The vehicle speed is estimated to be relatively low. When the vehicle speed of hybrid vehicle 100 is relatively low, the speed of motor generator MG1 is lower than that of hybrid vehicle 100 when the vehicle speed is relatively high (for example, the accelerator opening is larger than a predetermined value). Even if the ranking torque is the same, the rotational speed during startup changes within a relatively narrow range. Therefore, when the shift lever is in the D range and the accelerator opening is equal to or less than the predetermined opening, even if the boosting of the power line PL1 is not started (or is not completed), the motor that operates at the voltage before the boosting. There is a relatively high possibility that the cranking torque necessary for starting the engine 4 will be satisfied by the generator MG1. In other words, when the shift lever is in the D range and the accelerator opening is equal to or less than the predetermined opening, even if the boosting of the power line PL1 is not started (or is not completed), the start of the engine 4 is affected. The possibility is relatively low. Therefore, when the shift lever is in the D range and the accelerator opening is equal to or less than the predetermined opening, boosting may not be started at a relatively early timing (in other words, boosting is started at a relatively late timing). May be).

  Note that when the start request in step S14 is determined to be a non-travel start request, the timing at which the voltage of the power supply line PL1 starts to be boosted is such that the hybrid vehicle 100 prioritizes the improvement of the travel response. It may be set in the same manner as the case where it is determined that there is no. Similarly, when it is determined that the start request in step S14 is not a non-travel start request, the timing at which the voltage of power supply line PL1 starts to be boosted is such that hybrid vehicle 100 prioritizes improving the travel response. It may be set in the same manner as when it is determined that there is.

  Thereafter, the boost control unit 62 determines whether or not the current timing is the timing set in step S21 (that is, the timing to start boosting the voltage of the power supply line PL1) (step S22).

  As a result of the determination in step S22, when it is determined that the current timing is not the timing set in step S21 (step S22: No), the boost control unit 62 is the timing set in step S21. Continue to determine whether or not.

  On the other hand, as a result of the determination in step S22, when it is determined that the current timing is the timing set in step S21 (step S22: Yes), the boost control unit 62 increases the voltage of the power supply line PL1. Boost converter 10 is controlled to start (step S16). As a result, boost converter 10 starts boosting the voltage of power supply line PL1 (step S16).

  As described above, in the second operation example, similarly to the first operation example, the power source is operated at a suitable timing in consideration of the balance between the reduction in power consumption of the power storage device B and the driving response of the hybrid vehicle 100. Boosting of the voltage of the line PL1 (in other words, the voltage of the power storage device B) is started. In particular, in the second operation example, boosting of the voltage of the power supply line PL1 is started at a more suitable timing in consideration of the driving conditions of the hybrid vehicle 100. Therefore, the balance between the reduction in power consumption of power storage device B and the driving response of hybrid vehicle 100 can be more suitably achieved according to the driving conditions of hybrid vehicle 100.

  It should be noted that the present invention can be modified as appropriate without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a control device for a hybrid vehicle with such a change is also applicable to the technology of the present invention. Included in thought.

2 Wheel 3 Power split mechanism 4 Engine 10 Boost converter 20 Inverter 30 Inverter 60 ECU
61 Start Control Unit 62 Boosting Control Unit B Power Storage Device PL1, PL2 Power Line SL SL Ground Line MG1, MG2 Motor Generator

Claims (10)

An internal combustion engine, a power storage device, a booster capable of boosting the output voltage of the power storage device, an inverter that converts supply power supplied from the booster to AC power, and the AC power supplied from the inverter A control device for a hybrid vehicle comprising a rotating electric machine that is driven to rotate,
Start control means for driving the rotating electrical machine to start the internal combustion engine;
The boosting is performed so that the boosting of the output voltage is started after the cranking power of the rotating electrical machine required for starting the internal combustion engine reaches a peak until the start of the internal combustion engine is completed. And a boost control means for controlling the device.   The boost control means boosts the output voltage at the initial explosion timing, which is the first ignition timing after the start of the internal combustion engine, or between the initial explosion timing and the completion of the startup of the internal combustion engine. The hybrid vehicle control device according to claim 1, wherein the booster is controlled so as to start the operation.   The step-up control means outputs the output when the first timing to start boosting the output voltage when the hybrid vehicle is in the first state is when the hybrid vehicle is in a second state different from the first state. The hybrid vehicle control device according to claim 1, wherein the booster is controlled to be earlier than a second timing at which voltage boosting is started. The boost control means includes:
When the hybrid vehicle is in the second state, the start of the internal combustion engine is completed simultaneously with the initial explosion timing, which is the first ignition timing after the start of the internal combustion engine, or until the start of the internal combustion engine is completed. Controlling the booster to start boosting the output voltage during
When the hybrid vehicle is in the first state, the booster is controlled so as to start boosting the output voltage between the peak of cranking power and the timing of the first explosion. The control apparatus for a hybrid vehicle according to claim 3. The boost control means includes:
When the hybrid vehicle is in the second state, the output voltage is reduced at a final boost time that is a time that goes back from the time when the start of the internal combustion engine is completed until the boost of the output voltage is completed. Controlling the booster to start boosting;
When the hybrid vehicle is in the first state, the booster is controlled to start boosting the output voltage between the cranking power peaking and the final boosting time. The control apparatus for a hybrid vehicle according to claim 3. The boost control means includes:
When the hybrid vehicle is in the second state, the booster is configured to start boosting the output voltage from when the cranking power reaches a peak until the start of the internal combustion engine is completed. Control
When the hybrid vehicle is in the first state, the output voltage is from the start of the internal combustion engine until the cranking power reaches a peak or before the start of the internal combustion engine. The hybrid vehicle control device according to claim 3, wherein the booster is controlled so as to start boosting of the vehicle. The first state includes (i) a state in which priority is given to improving the riding comfort of the hybrid vehicle, (ii) a state in which priority is given to improving the driving response of the hybrid vehicle, and (iii) a reduction in emissions to satisfy laws and regulations. Is at least one of the prioritized states,
The control apparatus for a hybrid vehicle according to any one of claims 3 to 6, wherein the second state is a state other than the first state. In the second state, the internal combustion engine is started for another purpose different from (i) a state where priority is given to reducing power consumption of the power storage device and (ii) a purpose of generating power that contributes to travel of the hybrid vehicle. At least one of the states to start
The control apparatus for a hybrid vehicle according to any one of claims 3 to 7, wherein the first state is a state other than the second state.   The boost control means is (i) when the driving mode of the hybrid vehicle is a power mode that gives priority to driving response, and (ii) when the driving mode of the hybrid vehicle is a comfort mode that gives priority to riding comfort, And (iii) in at least one case of starting the internal combustion engine in a cold state, it is determined that the hybrid vehicle is in the first state. The control apparatus of a hybrid vehicle as described in the item.   The boost control means includes (i) when the shift lever is in a parking range, (ii) when the driving mode of the hybrid vehicle is an eco mode that prioritizes fuel consumption, and (iii) when the shift lever is in a driving range. 10. The hybrid vehicle according to claim 3, wherein the hybrid vehicle is determined to be in the second state in at least one of the cases where the accelerator opening is equal to or less than a predetermined opening in a state located at The control apparatus of the hybrid vehicle as described in any one.

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