JP5907115B2 - Hybrid vehicle travel control device - Google Patents

Description

  The present invention relates to a technical field of a travel control device for a hybrid vehicle.

  In this type of technical field, intermittent operation control that repeats acceleration traveling and inertial traveling is known. For example, when the actual acceleration / deceleration cycle in the actual acceleration / deceleration driving pattern based on the current vehicle driving condition is compared with a predetermined reference acceleration / deceleration cycle, the actual acceleration / deceleration is shorter than the reference acceleration / deceleration cycle. There is one that generates a corrected acceleration / deceleration travel pattern in which the actual acceleration / deceleration period in the travel pattern is increased (see Patent Document 1).

  In addition, during acceleration traveling in intermittent operation control, at least one of immediately after the internal combustion engine is activated and immediately before the internal combustion engine is deactivated, the driving power is reduced as compared with the middle of acceleration traveling, There has also been proposed a device for increasing the speed as compared with the middle of acceleration travel (see Patent Document 2).

  In Patent Document 2, the power consumption of the vehicle, the driving energy of the internal combustion engine during acceleration travel, and the acceleration travel during one cycle from the start of inertia travel to the start of inertia travel again after acceleration travel are described. It is also disclosed that the output of the internal combustion engine is determined based on the operating time of the internal combustion engine in

JP 2009-190433 A JP 2010-006309 A

  By the way, in the inertial traveling period in which inertial traveling is performed, the internal combustion engine as a power source is stopped, but power supply to many auxiliary devices included in the hybrid vehicle needs to be continued. For this reason, in the inertia running period, the charge / discharge balance of the battery is inclined to the discharge side, and the SOC (State Of Charge) of the battery decreases with time.

  On the other hand, during the accelerated traveling period in which accelerated traveling is performed, the internal combustion engine is in an operating state. Therefore, the battery can be charged with electric power generated using a part of the power of the internal combustion engine. At this time, the power generation request output of the internal combustion engine required for charging the battery (that is, required for power generation) increases as the SOC of the battery decreases in order to maintain the SOC of the battery within a preset control range. That is, as the SOC of the battery decreases, the amount of charge to the battery increases.

  Therefore, in one cycle of the intermittent operation control consisting of one acceleration running and one inertia running, the decrease in the SOC of the battery during the inertia running period increases the SOC due to the increase in the amount of charge after a corresponding time elapse. Balance with minutes. As a result, the SOC of the battery converges to a certain convergence value during the period when the intermittent operation control is performed.

  However, the power generation request output of the internal combustion engine assumes a situation where the battery is originally continuously charged, and does not assume such a situation where the battery can be charged only intermittently. For this reason, the convergence value of the SOC is often a value lower than the SOC at the start time regardless of the value of the SOC at the start time of the intermittent operation control. Inevitably, the SOC of the battery is not always a sufficiently high value even if it is maintained within the target range when the intermittent operation control is completed.

  For this reason, in some cases, it is necessary to increase the SOC of the battery, and it may be necessary to start the internal combustion engine. Alternatively, the internal combustion engine may be forced to operate on a higher load side (side with a higher required output). Therefore, there is a possibility that the fuel consumption rate of the internal combustion engine deteriorates during a long traveling period including a period in which intermittent operation control is performed.

  Here, also in the apparatus of Patent Document 1, when the corrected acceleration / deceleration running pattern is selected, the acceleration running period becomes relatively long, and a larger amount of generated power can be obtained. The amount can be set higher and more power can be charged to the battery.

  However, the increase in the amount of charge of the battery obtained as a result of such control is proportional to the length of the acceleration travel period, and is therefore not related to the overall system requirement. Therefore, there is no guarantee that the SOC of the battery has reached a sufficiently high value after the intermittent operation control is completed. Inevitably, the above-described deterioration of the fuel consumption rate of the internal combustion engine is not necessarily avoided.

  On the other hand, Patent Literature 2 discloses a technical idea that calculates the amount of power consumption in the inertia traveling period and reflects it in the required output of the internal combustion engine during the acceleration traveling period. In this case, the decrease in SOC itself during the period in which the intermittent operation control is performed can be suppressed.

  However, if the output of the internal combustion engine changes as a result of reflecting the power consumption during the inertia running period in the required output of the internal combustion engine, the thermal efficiency of the internal combustion engine may change. This does not change when the operating point of the internal combustion engine is determined on the optimum fuel consumption operating line. When the thermal efficiency decreases, the fuel consumption rate inevitably deteriorates (that is, the fuel consumption increases).

  That is, if the SOC is to be maintained or restored by changing the output of the internal combustion engine, the fuel consumption rate of the internal combustion engine during the acceleration travel period may deteriorate. When the internal combustion engine operates at an inefficient operating point every time the acceleration travel period comes, the internal combustion engine during the period in which the intermittent operation control is performed can be suppressed even if the decrease in the SOC at the time when the intermittent operation control ends can be suppressed. There is a possibility that the fuel consumption rate will deteriorate.

  Since the intermittent operation control has at least one purpose of reducing the fuel consumption of the internal combustion engine, the fuel consumption rate in the intermittent operation period deteriorates for the purpose of maintaining the SOC at the end of the intermittent operation period. Such a situation does not match the purpose of the intermittent operation control, and is undesirable from the viewpoint of implementing the intermittent operation mode.

  As described above, conventional devices including those disclosed in the above-described prior art documents do not sufficiently assume a situation where charging of the battery is performed only intermittently, and when intermittent operation control is performed. There is still room for improvement in the fuel consumption rate of internal combustion engines.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide a travel control device for a hybrid vehicle capable of suppressing deterioration of the fuel consumption rate of an internal combustion engine in a hybrid vehicle in which intermittent operation control is performed. And

  In order to solve the above-described problems, a travel control apparatus for a hybrid vehicle according to the present invention includes a power source including an internal combustion engine, a rotating electrical machine capable of generating electric power using the power of the internal combustion engine, and a battery, As a traveling mode, inertial traveling in which power transmission from the power source to the driving wheel is stopped, and power transmission from the power source to the driving wheel is performed while charging the battery with the electric power obtained by the power generation. A hybrid vehicle travel control device that controls a hybrid vehicle configured to be capable of selecting an intermittent operation mode in which the accelerated travel is repeated, in an accelerated travel period in which the accelerated travel is performed from the SOC of the battery. A first determining means for determining a first power generation request output of the internal combustion engine required for the power generation, and an inertia traveling period in which the inertia traveling is performed. Power consumption estimation means for estimating the power consumption of the battery, and a second determination for determining a second power generation request output of the internal combustion engine required for the power generation from the length of the accelerated travel period and the estimated power consumption And a first required output of the internal combustion engine determined from the drive required output of the internal combustion engine required for driving the drive wheels and the determined first power generation required output during the acceleration travel period A second thermal output of the internal combustion engine corresponding to the second required output of the internal combustion engine determined from the first required thermal efficiency of the internal combustion engine, the required drive output and the determined second power generation required output. Comparing means for comparing with thermal efficiency, and third determining means for determining a required output of the internal combustion engine in the acceleration travel period based on the comparison result (Claim 1)

  The hybrid vehicle according to the present invention includes a power source including an internal combustion engine and a rotating electrical machine capable of generating electric power using the power of the internal combustion engine. The power source may include a rotating electric machine for driving different from the rotating electric machine capable of generating electric power. These rotating electrical machines are preferably motor generators each having both a power running function and a regenerative function. That is, it is possible to perform power regeneration with a rotating electric machine for driving during the braking period of the hybrid vehicle, etc., or to drive the rotating electric machine capable of generating power on the power running side to supply driving torque to the drive shaft. .

  According to the travel control device for a hybrid vehicle according to the present invention, in the acceleration travel period, for example, according to the SOC of the battery detected by the SOC sensor or obtained by observing the power balance of the battery over time, A first power generation request output of the internal combustion engine required for power generation is determined. In the intermittent operation period, the first power generation required output increases stepwise until the power consumption of the battery 30 in the inertia traveling period and the power generation corresponding to the first power generation required output in the acceleration traveling period are balanced. However, the SOC of the battery decreases to a certain convergence value as described above.

  On the other hand, according to the hybrid vehicle travel control apparatus of the present invention, power generation in the acceleration travel period is required from the battery power consumption in the inertia travel period and the length of the acceleration travel period estimated by the power consumption estimation means. A second power generation demand output of the internal combustion engine is determined.

  When this second power generation request output is added to the drive request output required for driving the drive wheels during the acceleration travel period to obtain the request output of the internal combustion engine, the decrease in the SOC of the battery at the end of the intermittent operation period is as follows. Suppressed and ideally prevented.

  Particularly in the hybrid vehicle travel control apparatus according to the present invention, the comparison means compares the first thermal efficiency corresponding to the first required output and the second thermal efficiency corresponding to the second required output. The The first request output is a request output determined from the drive request output and the first power generation request output (for example, determined as an addition value or a derivative value thereof), and the second request output is , A request output determined from the drive request output and the second power generation request output (for example, determined as an addition value thereof or a derivative value thereof). The final required output of the internal combustion engine in the acceleration travel period is determined by the third determining means based on the comparison results of the thermal efficiency of the internal combustion engine when the output of the internal combustion engine is adapted to each required output.

  For example, the third determining means qualitatively indicates that the fuel consumption rate of the internal combustion engine is higher when the required output is controlled to the second required output than when the required output is controlled to the first required output. When it is determined that it does not deteriorate, or when it is determined that it does not deteriorate beyond a predetermined level, the request output is determined as the second request output or a derivative value thereof. Alternatively, the third determining means quantitatively, when the second thermal efficiency is equal to or higher than the first thermal efficiency, or when the difference between the first thermal efficiency and the second thermal efficiency is equal to or less than a predetermined value. The request output is determined to be the second request output or a derived value thereof.

  Therefore, according to the traveling control device for a hybrid vehicle according to the present invention, the SOC of the battery at the end of the intermittent operation period does not hinder the improvement effect of the fuel consumption rate of the internal combustion engine obtained by the intermittent operation mode. The SOC at the beginning of the intermittent operation period is maintained as much as possible. That is, the above-described situation in which the fuel consumption rate of the internal combustion engine deteriorates in the intermittent operation period for the purpose of maintaining the SOC of the battery does not occur. Therefore, while enjoying the benefits of the intermittent operation mode, it is possible to prevent the internal combustion engine from starting unnecessarily for the SOC recovery after the end of the intermittent operation period.

  In one aspect of the travel control apparatus for a hybrid vehicle according to the present invention, the first power generation request output is set to be larger as the battery SOC is lower, and the second power generation request output is set during the inertial travel period. This corresponds to the power consumption of the battery.

  Thus, when the first power generation request output increases as the battery SOC decreases, as described above, the battery SOC during the intermittent operation period converges to a certain convergence value. Therefore, the SOC is not permanently reduced by executing the intermittent operation mode, and for example, a situation in which the intermittent operation mode is forcibly terminated due to an excessive decrease in the SOC of the battery is avoided. The

  In another aspect of the travel control apparatus for a hybrid vehicle according to the present invention, as a result of the comparison, the third determining means determines whether the second thermal efficiency is equal to or higher than the first thermal efficiency, or the second thermal efficiency. And the first thermal efficiency are within a predetermined value, the required output is determined based on the second required output.

  According to this aspect, it is possible to suitably suppress or prevent the deterioration of the fuel consumption rate of the internal combustion engine during the intermittent operation period.

  In this aspect, the third determining means may determine the requested output as the second requested output (claim 4).

  According to this aspect, since the second required output is the required output, it is possible to prevent the battery SOC from being lowered.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid vehicle according to an embodiment of the present invention. It is a schematic block diagram of the hybrid drive device in the hybrid vehicle of FIG. It is a schematic block diagram of PCU in the hybrid vehicle of FIG. It is a block diagram of a pressure | voltage rise control part. It is a block diagram of an inverter control part. It is a flowchart of the engine output control process in the hybrid vehicle of FIG. It is a figure which illustrates the relationship between the operating point of an engine, and thermal efficiency. It is a figure explaining the time transition of SOC of a battery in connection with the effect of the engine output control process of FIG.

<Embodiment of the Invention>
Embodiments of the present invention will be described below with reference to the drawings.

<Configuration of Embodiment>
First, with reference to FIG. 1, the structure of the hybrid vehicle 1 which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle 1.

  In FIG. 1, a hybrid vehicle 1 is an example of a “hybrid vehicle” according to the present invention that includes an ECU (Electronic Control Unit) 100, a PCU (Power Control Unit) 20, a battery 30, and a hybrid drive device 10. It is.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “driving control device for a hybrid vehicle” according to the present invention. The ECU 100 can execute an “engine output control process” to be described later according to a control program stored in the ROM. The ECU 100 includes a boost control unit 110 and an inverter control unit 120 that control a later-described boost converter 21 and inverter 22 provided in the PCU 20, respectively. Details of the boost control unit 110 and the inverter control unit 120 will be described later.

  The PCU 20 converts DC power extracted from the battery 30 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Inverter 22 (not shown) configured to be able to be supplied to battery 30, the power input / output between battery 30 and each motor generator, or the power input / output between each motor generator (that is, in this case) The control unit is configured to be capable of controlling power transfer between the motor generators without using the battery 30. The PCU 20 is electrically connected to the ECU 100 and its operation is controlled by the ECU 100. The PCU 20 will be described in detail later with reference to FIG.

  The battery 30 is a rechargeable secondary battery unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. The battery 30 has a configuration in which a plurality (for example, several hundreds) of unit battery cells such as lithium ion battery cells are connected in series. The output voltage value Vout of the battery 30 is detected by a voltage sensor (not shown) attached to the battery 30. The voltage sensor is electrically connected to the ECU 100, and the detected output voltage value Vout is appropriately referred to by the ECU 100.

  Although illustration is omitted, the hybrid vehicle 1 includes various sensors that detect various state quantities of the hybrid vehicle 1. For example, the various sensors include a vehicle speed sensor that detects the vehicle speed V of the hybrid vehicle 1, an accelerator opening sensor that detects an accelerator opening Ta that is an operation amount of an accelerator pedal, a brake pedal sensor that detects an operation amount of a brake pedal, A battery temperature sensor that detects the temperature of the battery 30, an SOC sensor that detects the SOC of the battery 30, and the like are included. Each of these sensors is electrically connected to the ECU 100, and the detected various state quantities, control quantities, or physical quantities are appropriately referred to by the ECU 100.

  The hybrid drive device 10 is a power train of the hybrid vehicle 1. Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  The hybrid drive device 10 includes an engine 200, a power split mechanism 300, an input shaft 400, a drive shaft 500, a speed reduction mechanism 600, a motor generator MG1 (hereinafter referred to as “MG1” where appropriate), a motor generator MG2 (hereinafter referred to as “MG2” as appropriate). For short).

  The engine 200 is a gasoline engine that functions as a main power source of the hybrid vehicle 1 and is an example of the “internal combustion engine” according to the present invention.

  The engine 200 includes a piston that reciprocates inside the cylinder in response to an explosive force generated when the air-fuel mixture burns in a combustion chamber formed inside the cylinder. The reciprocating motion of the piston is converted into the rotational motion of the crankshaft via the connecting rod, and is taken out from the input shaft 400 connected to the crankshaft. Note that the detailed configuration of the engine 200 is omitted here because it has a low relationship with the present invention. Although the engine 200 is a gasoline engine here, there are a wide variety of practical aspects that can be taken by the “internal combustion engine” according to the present invention. For example, the “internal combustion engine” according to the present invention is free in fuel type, cylinder arrangement, number of cylinders, fuel supply mode, valve system configuration, intake / exhaust system configuration, and the like.

  Motor generator MG1 is a motor generator that is an example of a “rotary electric machine” according to the present invention, which has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy.

  Motor generator MG2 is a motor generator having a larger physique than motor generator MG1, and, like motor generator MG1, has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. Have.

  The motor generators MG1 and MG2 are configured as synchronous motor generators and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. You may have the structure of.

  The power split mechanism 300 is a known planetary gear mechanism that includes a plurality of rotating elements that have a differential action with respect to each other.

  The power split mechanism 300 is disposed between the sun gear S1 provided at the center, the ring gear R1 provided concentrically on the outer periphery of the sun gear S1, and the sun gear S1 and the ring gear R1. A plurality of pinion gears (not shown) that revolve while rotating, and a carrier C1 that supports the rotation shaft of each pinion gear.

  The sun gear S1 is a reaction force element for bearing a reaction force torque against an engine torque Te (an example of “power” according to the present invention) that is an output torque of the engine 200, and an output to which the rotor of the motor generator MG1 is fixed. It is fixed to the rotating shaft. Therefore, the rotational speed of sun gear S1 is equivalent to MG1 rotational speed Nmg1, which is the rotational speed of motor generator MG1.

  The ring gear R1 is an output element of the power split mechanism 300, and is connected to a drive shaft 500, which is a power output shaft of the power split mechanism 300, in a manner sharing its rotational axis. The drive shaft 500 is indirectly connected to the drive wheels DW of the hybrid vehicle 1 through a differential or the like.

  The carrier C1 is connected to the input shaft 400 connected to the crankshaft of the engine 200 via the torsion damper TDP so as to share the rotation shaft, and the rotation speed is equal to the engine speed NE of the engine 200. Is equivalent.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the input shaft 400 is transferred to the sun gear S1 and the ring gear R1 by the carrier C1 with the predetermined ratio (the gear ratio between the gears). It is possible to divide the power of the engine 200 into two systems.

  At this time, in order to make the operation of the power split mechanism 300 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, the engine torque Te is applied from the engine 200 to the carrier C1. In this case, the torque Tes (another example of “power” according to the present invention) acting on the sun gear S1 is expressed by the following equation (1), and the direct torque Ter that appears on the drive shaft 500 (other than “power” according to the present invention). (Example) is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Ter = Te × 1 / (1 + ρ) (2)
Deceleration mechanism 600 is a planetary gear mechanism that includes rotation elements of sun gear S2, ring gear R2, pinion gear (not shown), and carrier C2 interposed between drive shaft 500 and motor generator MG2.

  In reduction mechanism 600, sun gear S2 is fixed to an output rotation shaft fixed to the rotor of motor generator MG2. The carrier C2 is fixed to the outer case of the hybrid drive device 10 so as not to rotate. Further, the ring gear R <b> 2 is connected to the drive shaft 500. In such a configuration, the speed reduction mechanism 600 can transmit the rotational speed Nmg2 of the motor generator MG2 to the drive shaft 500 while reducing the speed according to the speed ratio determined according to the gear ratio of each rotation element (gear).

  It should be noted that the configuration of speed reduction mechanism 600 is merely one form that can be adopted by a mechanism that decelerates the rotation of motor generator MG2, and this type of speed reduction mechanism can have various forms in practice. Further, this type of reduction mechanism is not necessarily provided in the hybrid drive device. That is, motor generator MG2 may be directly connected to drive shaft 500.

  Next, the configuration of the PCU 20 according to the present embodiment will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of the PCU 20.

  In FIG. 3, the PCU 20 includes a boost converter 21 and an inverter 22.

  In boost converter 21, one end of reactor L1 is connected to a positive line (not shown) connected to the positive electrode of battery 30, and the other end is an intermediate point between switching element Q1 and switching element Q2, that is, a switching element. It is connected to a connection point between the emitter terminal of Q1 and the collector terminal of switching element Q2.

  The switching elements Q1 and Q2 are switching means connected in series between the positive electrode line and a negative electrode line (not shown) connected to the negative electrode of the battery 30. The collector terminal of the switching element Q1 is connected to the positive electrode line, and the emitter terminal of the switching element Q2 is connected to the negative electrode line. The diodes D1 and D2 are rectifying elements that allow only current from the emitter side to the collector side in each switching element.

  In this embodiment, the switching element is composed of a switching element Q1 on the higher potential side than the connection point with the end of the reactor L1, and a switching element Q2 on the lower potential side. A boost converter is configured. However, the configuration of such a switching element is an example, and the boost converter may be a one-arm type boost converter including only the switching element Q2 in FIG.

  The switching elements Q1 and Q2 and the switching elements (Q3 to Q8 and Q13 to Q18) of the inverter 22 are configured as, for example, IGBTs (Insulated Gate Bipolar Transistors), power MOS (Metal Oxide Semiconductor) transistors, or the like.

  The capacitor C is a capacitor connected between the positive electrode line and the negative electrode line. The voltage across terminals of the capacitor C, that is, the potential difference VH between the positive line and the negative line is the output voltage of the boost converter 200.

  The inverter 22 includes an inverter circuit 22A for driving MG1 and an inverter circuit 22B for driving MG2.

  The inverter circuit 22A includes a U-phase arm (not shown) including a p-side switching element Q3 and an n-side switching element Q4, a V-phase arm (not shown) and a p-side switching including a p-side switching element Q5 and an n-side switching element Q6. The power converter includes a W-phase arm (reference numeral omitted) including an element Q7 and an n-side switching element Q8. Each arm of the inverter 22A is connected in parallel between the positive electrode line and the negative electrode line.

  The switching elements Q3 to Q8 are connected to rectifying diodes D3 to D8 that allow current to flow from the emitter side to the collector side, similarly to the switching elements Q1 and Q2. Further, an intermediate point between the p-side switching element and the n-side switching element of each phase arm in inverter circuit 22A is connected to each phase coil of motor generator MG1.

  The inverter circuit 22B has a configuration similar to that of the inverter circuit 22A. As switching elements, the p-side switching elements Q13, Q15, and Q17 are switched for the u-phase, v-phase, and w-phase, and the n-side switching is performed. Elements Q14, Q16 and Q18 are provided. The same applies to the rectifying diode.

  Boost converter 21 is controlled by boost controller 110 in ECU 100. Here, the configuration of the boost control unit 110 will be described with reference to FIG. FIG. 4 is a block diagram of the boost control unit 110. In the figure, the same reference numerals are assigned to the same parts as those in FIG.

  4, the boost control unit 110 includes an inverter input calculation unit 111, an adder / subtractor 112, a voltage control calculation unit 113, a carrier generation unit 114, and a comparator 115. Further, the boost control unit 110 is configured to be able to execute boost control according to a control program stored in advance in the ROM.

  The step-up control is control for boosting the voltage between the positive line and the negative line, that is, the output voltage VH to be higher than the output voltage of the battery 30 based on the converter control signal PWC. In step-up control, if output voltage VH is lower than target value VHtg (also referred to as VH command value), on-duty of switching element Q2 is relatively increased, and the positive line flows from battery 30 side to inverter 300 side. The current can be increased, and the output voltage VH can be increased. On the other hand, if the output voltage VH is higher than the target value VHtg, the on-duty of the switching element Q1 is relatively increased, and the current flowing through the positive line from the inverter 300 side to the battery 30 side can be increased, and the output voltage VH Can be reduced.

  Inverter input calculation unit 111 is a circuit that sets target value VHtg of output voltage VH of boost converter 200. Target value VHtg is determined such that system loss Lsys, which is a loss of the entire power system including boost converter 200, inverter 300, and motor generator MG, is minimized.

  The addition / subtraction unit 112 subtracts the detected value of the output voltage VH from the target value VHtg and outputs the subtraction result to the voltage control calculation unit 113. When the voltage control calculation unit 113 receives a subtraction result obtained by subtracting the detection value of the output voltage VH from the target value VHtg from the addition / subtraction unit 112, the voltage control calculation unit 113 calculates a control amount for making the output voltage VH coincide with the target value VHtg. At this time, for example, a known PI control calculation including a proportional term (P term) and an integral term (I term) is used. The voltage control calculation unit 113 outputs the calculated control amount to the comparator 115 as a voltage command value.

  On the other hand, the carrier generation unit 114 generates a carrier signal composed of a triangular wave and sends it to the comparator 115. In the comparator 115, the voltage command value supplied from the voltage control calculation unit 113 is compared with this carrier signal, and the above-described converter control signal PWC whose logic state changes according to the magnitude relation of the voltage value is generated. The The generated converter control signal PWC is output to switching elements Q1 and Q2 of boost converter 200. The boost control unit 110 is configured as described above.

  The configuration illustrated in FIG. 2 is a circuit configuration that realizes voltage control, but the control mode of the boost converter 200 is not limited to such voltage control.

  Next, the configuration of the inverter control unit 120 will be described with reference to FIG. FIG. 5 is a block diagram of the inverter control unit 120. In the figure, the same reference numerals are given to the same portions as those in the above-described drawings, and the description thereof will be omitted as appropriate. In FIG. 5, for simplicity of explanation, the concept of motor generator MG including motor generator MG <b> 1 and motor generator MG <b> 2 is used as the electrical load of inverter 22.

  In FIG. 5, the inverter control unit 120 includes a current command conversion unit 121, a current control unit 122, a two-phase / three-phase conversion unit 123, a three-phase / two-phase conversion unit 124, a carrier generation unit 114 (shared with the boost control unit 110). And PWM converter 125.

  Current command conversion unit 121 generates two-phase current command values (Idtg, Iqtg) based on torque command value TR of motor generator MG.

  On the other hand, the inverter 300 supplies the v-phase current Iv and the w-phase current Iw to the three-phase / 2-phase converter 124 as feedback information. In the three-phase / two-phase converter 124, the three-phase current value is converted from the v-phase current Iv and the w-phase current Iw into a two-phase current value composed of the d-axis current Id and the q-axis current Iq. The converted two-phase current value is sent to the current control unit 122.

  In the current control unit 122, based on the difference between the two-phase current command value generated in the current command conversion unit 121 and the two-phase current values Id and Iq received from the three-phase / two-phase conversion unit 124, d A two-phase voltage command value composed of the shaft voltage Vd and the q-axis voltage is generated. The generated two-phase voltage command values Vd and Vqh are sent to the two-phase / three-phase converter 123.

  In the two-phase / three-phase converter 123, the two-phase voltage command values Vd and Vq are converted into the three-phase voltage command values Vu, Vv, and Vw. The converted three-phase voltage command values Vu, Vv, and Vw are sent to the PWM conversion unit 125.

  Here, the PWM conversion unit 125 is configured to receive a carrier Car having a predetermined carrier frequency fcar from the carrier generation unit 114, and the carrier Car and the converted three-phase voltage command values Vu, Vv, and Vw. Compare the magnitude relationship with. Further, the PWM conversion unit 125 generates u-phase switching signals Gup and Gun, v-phase switching signals Gvp and Gvn, and w-phase switching signals Gwp and Gwn and changes the logic state according to the comparison result to the inverter 22. Supply.

  More specifically, among the switching signals corresponding to each phase, the signal with the identifier “p” added is the p-side switching element (Q3, Q5 and Q7 and Q13, Q15 and Q17) is a drive signal for driving, and a signal with an identifier “n” is used to drive the n-side switching elements (Q4, Q6 and Q8 and Q4, Q6 and Q18) among the switching elements of each phase. This means a drive signal for

  Here, in particular, in the comparison between the carrier Car and each phase voltage command value, when each phase voltage command value matches the carrier Car from a value smaller than the carrier Car, a switching signal for turning on the p-side switching element is generated. The Further, when each phase voltage command value matches the carrier Car from a value larger than the carrier Car, a switching signal for turning on the n-side switching element is generated. That is, the switching signal is a signal that is turned on and off, and one of the p-side and n-side switching elements is always on and the other is off.

  When inverter 22 changes or is maintained in the driving state of each switching element defined by each phase switching signal, motor generator MG is driven according to the circuit state corresponding to the changed or maintained driving state. It has a configuration. Such a control mode of the inverter 300 is a so-called PWM control mode.

  In general, the motor generator MG for driving the vehicle often uses well-known overmodulation control and rectangular wave control in addition to the PWM control described above. Also in the motor drive system 10 according to the present embodiment, the control mode of the inverter 22 is appropriately switched according to the traveling condition of the vehicle.

  Note that a battery current sensor (not shown) is attached to the PCU 20. The battery current sensor is a sensor that can detect the output current value Iout of the battery 30. The battery current sensor is electrically connected to the ECU 100, and the detected output current value Iout is appropriately referred to by the ECU 100.

<Operation of Embodiment>
Next, the operation of this embodiment will be described.

<Driving mode of hybrid vehicle 1>
The hybrid vehicle 1 has an HV travel mode and an EV travel mode as travel modes that define a power transmission mode between the hybrid drive device 10 and the drive wheels DW.

  In the HV traveling mode, by using the power split action of the power split mechanism 300, the direct drive torque Ter that is a part of the engine torque Te and the MG2 torque Tmg2 that is the output torque of the motor generator MG2 are cooperatively driven. This is a travel mode in which it is acted on (that is, on the drive wheel DW). In the HV traveling mode, electric power regeneration, that is, power generation is also performed by MG1 torque Tmg1 which is output torque of motor generator MG1 using reaction force torque Tes which is another part of engine torque Te.

  At this time, the operating point of the engine 200 (the operating condition defined by the engine speed NE and the engine torque Te) is an electric CVT (Continuously Variable Transmission) of the hybrid drive device 10 using the MG1 torque Tmg1 as a reaction torque. It can be set freely depending on the function. As a preferred embodiment, the operating point of the engine 200 is basically controlled to an optimal fuel consumption operating point that is one operating point on the optimal fuel consumption operating line where the fuel consumption rate of the engine 200 is minimized.

  On the other hand, the MG2 torque Tmg2 is basically controlled to compensate for the shortage of the direct torque Tor with respect to the drive shaft required torque required for the drive shaft 500. That is, in the HV traveling mode, cooperative control between the MG2 torque Tmg2 and the engine torque Te is performed.

  For example, in this cooperative control, the power generation amount of the motor generator MG1 and the discharge amount of the motor generator MG2 or further the discharge amount of the auxiliary device are constantly adjusted so that the SOC of the battery 30 is maintained at the target value. . For example, if the SOC of the battery 30 is higher than the target value, the ratio of the MG2 torque Tmg2 to the drive shaft required torque is increased, and the power balance is inclined to the discharge side. Conversely, if the SOC is lower than the target value, the ratio is decreased. Or the amount of power generation related to power generation performed using the power of the engine 200 is increased.

  On the other hand, the EV travel mode is a travel mode in which only the MG2 torque Tmg2 is applied to the drive shaft 500 and the hybrid vehicle 1 is traveled only by the power of the motor generator MG2. In the EV traveling mode, the engine 200 is basically in the engine stopped state (in some cases, the minimum engine operation for supplying power to the auxiliary device may be performed), so that the fuel consumption is zero, or It is so small that it can be ignored. However, since the EV traveling mode is a traveling mode inclined toward the discharge side in terms of the power balance of the battery 12, the SOC of the battery 30 basically continues to decrease. Therefore, whether or not the EV traveling mode can be executed is determined in consideration of the SOC of the battery 30.

<Overview of intermittent operation mode>
Here, the hybrid vehicle 1 is configured to be able to select an intermittent operation mode during steady running in which the vehicle speed V is generally maintained at a target vehicle speed or a constant vehicle speed. The intermittent operation mode is executed when a predetermined execution condition is satisfied whether the vehicle is traveling in the above-described EV traveling mode or traveling in the HV traveling mode.

  The intermittent operation mode is an operation mode in which acceleration traveling and inertial traveling are repeated. Although the fuel consumption is relatively large during acceleration traveling, the hybrid drive device 10 can be saved during inertial traveling where the hybrid drive device 10 can be in a no-load operation. If the consumed fuel exceeds that, the overall fuel consumption can be suppressed. For this reason, during steady running where relatively large acceleration / deceleration is not required, the vehicle is suitably executed as long as the execution condition is satisfied.

  Note that, during the inertia traveling period in the intermittent operation mode, engine 200 and motor generators MG1 and MG2 are both stopped. Therefore, the battery 30 is not charged during the inertia running period. On the other hand, the hybrid vehicle 1 is provided with various auxiliary devices that require power supply from the battery 30, and the power supply to these auxiliary devices is continued even during the inertial traveling period. For this reason, the SOC of the battery 30 basically decreases during the inertia running period.

  Therefore, in the practical operation aspect of the intermittent operation mode, it is necessary to recover the decrease in SOC during the inertia traveling period by power generation during the acceleration traveling period. That is, during the acceleration traveling period, the required output Pen required for the engine 200 is necessary for the acceleration traveling (that is, required for supplying power to the driving wheels) and the required charging output Pend for charging the battery 30. Is set based on the charging request output Penc (for example, as an added value thereof). The charge request output Penc is an example of the “power generation request output” according to the present invention. The SOC of the battery 30 is appropriately recovered by the charging action during this acceleration traveling period. In this way, in the intermittent operation mode, since the battery 30 is basically required to be charged during the acceleration travel period, it is steady regardless of whether the travel mode at the start time is the HV mode or the EV mode. In the acceleration travel period, the travel mode is the HV mode.

  As one of the configurations that can be adopted by the hybrid vehicle according to the present invention, power is supplied to the drive wheels only by the driving motor generator, and the engine and the power generating motor generator drive the driving motor generator. In some cases, the power generation system covers electric power (for example, a so-called series hybrid system). In such a case, the travel mode that the hybrid vehicle can take is only the EV travel mode. However, in this case as well, in the accelerated traveling period in the intermittent operation mode, it is still necessary to increase the power generation load of the engine 200 to increase the charge scale of the battery.

  When the intermittent operation mode is executed, the vehicle speed V of the hybrid vehicle 1 is maintained in a predetermined range including, for example, the target vehicle speed (preferably the vehicle speed at the start time) with the vehicle speed V at the start time as the target vehicle speed. The For example, when the vehicle speed V decreases to the lower limit value VLL due to inertial traveling, the acceleration traveling starts, and when the vehicle speed V increases to the upper limit value VUL due to accelerated traveling, the inertial traveling starts.

  The intermittent operation mode is, for example, in response to an execution request as a kind of control signal that occurs when the driver of the hybrid vehicle 1 operates an operation button in the vehicle interior or when the steady running state continues for a predetermined time or longer. Executed. However, the execution condition of the intermittent operation mode is not limited to this.

  During inertial running in the intermittent operation mode, whether during EV traveling or HV traveling, power supply to the drive shaft 500 is not required, so the output torque Tmg2 of the motor generator MG2 becomes zero.

  There are roughly two types of control modes in which the output torque Tmg2 of MG2 is zero. One is control of the inverter 22B that makes the target torque of the motor generator MG2 zero (so-called zero torque control), and the other is to stop the operation of the inverter 22B itself, and the inverter 22B supplies power including the battery 30 and the boost converter 21. This is control (so-called shutdown control) for electrically disconnecting from the system. Any of these may be selected, but shutdown control is desirable from the viewpoint of suppressing power consumption during coasting. On the other hand, it is not uncommon to require acceleration / deceleration traveling that deviates from normal traveling during inertial traveling. If shutdown control is performed in such a case, it is necessary to start up the inverter 22 in order to supply any appropriate positive or negative torque from the motor generator MG2 to the drive shaft 500. Therefore, the power supply from motor generator MG2 is delayed by the startup time of inverter 22 and the operation stabilization time. Such a response delay is disadvantageous in terms of power performance and drivability. In view of these points, in the inertia running period, either one may be appropriately selected from the viewpoint of power consumption and drivability.

  Although not provided in the hybrid drive device 10 according to the present embodiment, a power transmission path between the input shaft 400 and the drive shaft 500 or a power transmission path between the speed reduction mechanism 600 and the drive shaft 500. In addition, a clutch for interrupting power transmission may be provided. When such a clutch is provided and the clutch is controlled to be released during the inertia traveling period in the intermittent operation mode, the friction loss acting on the drive wheel DW during the inertia traveling period can be reduced. Can be extended as much as possible.

<Details of engine output control processing>
During the period in which the intermittent operation mode is executed, the ECU 100 executes an engine output control process. The engine output control process is a process for controlling the output of the engine 200 during the acceleration travel period. Details of the engine output control process will be described below.

  First, the flow of the engine output control process will be described with reference to FIG. FIG. 6 is a flowchart of the engine output control process.

  In FIG. 6, the ECU 100 determines whether or not inertial running has been started (step S110). It should be noted that whether or not inertial running has started means, in other words, whether or not acceleration running has ended. When inertial running is not started (step S110: NO), that is, when acceleration running is continued, the process enters a standby state at step S110.

  When inertial running is started (step S110: YES), that is, when acceleration running is finished, ECU 100 calculates battery output Pout (for example, the unit is kW) (step S120). The battery output Pout is calculated from the output voltage value Vout and the output current value Iout related to the battery 30 according to the following equation (3).

Pout = Vout · Iout (3)
When the battery output Pout is calculated, the calculated battery output Pout is integrated and converted into a power consumption amount Wout (for example, the unit is kJ) (step S130).

  The ECU 100 records the battery output Pout calculated in step S120 in a RAM, a flash memory, or the like at every calculation timing. At this time, the obtained battery output Pout is integrated and updated with the past battery output Pout already recorded. The operation according to step S130 corresponds to this update process. The power consumption amount Wout as the integrated value is cleared every time the process returns to step S110.

  The ECU 100 determines whether or not the inertia running has ended (step S140). Note that whether or not the inertial running has ended means, in other words, whether or not the acceleration running has started. If inertial running has not ended (step S140: NO), the process returns to step S120. That is, the calculation of the battery output Pout and the calculation of the power consumption amount Wout are continued.

  When the inertia traveling is finished (step S140: YES), the acceleration traveling time Tacc is calculated (step S150). The acceleration travel time Tacc is the length of the acceleration travel period. The acceleration travel time Tacc is, for example, a set acceleration A in the intermittent operation mode (a fixed value or a variable value updated as appropriate, but a value applied to the current acceleration travel is used). And the upper limit vehicle speed VUL and acceleration / deceleration VLL in the intermittent operation mode are calculated by the following equation (4). The set acceleration / deceleration including the set acceleration A and the upper and lower limit speeds are stored as setting information for the intermittent operation mode.

Tacc = (VUL−VLL) / A (4)
Here, the acceleration travel time Tacc is calculated arithmetically from the difference between the upper and lower limit speeds of the intermittent operation mode and the set acceleration A. However, the upper and lower limit speeds and the set acceleration A do not change from the previous acceleration travel time. Based on the premise, the acceleration travel time may be counted in the immediately preceding acceleration travel period and used for step S150.

  When the acceleration travel time Tacc is calculated, the second charge request output reference value Penc2bs is calculated (step S160). Second charging request output reference value Penc2bs is calculated according to the following equation (5).

Penc2bs = Wout / Tacc (5)
As is clear from the above equation (5), the second required charging output reference value Penc2bs is a unit time for charging the battery 30 during the accelerated traveling period with the power corresponding to the power consumed by the battery 30 during the inertia traveling period. Required charge amount (for example, unit is kW).

  When the second charge request output reference value Penc2bs is calculated, the second charge request output Penc2 is calculated according to the following equation (6) (step S160). The second charge request output Penc2 corresponds to the power generation load of the engine 200 necessary for charging the battery 30 with the electric power consumed during the inertia travel period, and the “second power generation request according to the present invention”. It is an example of “output”.

  Penc2 = Penc2bs / ηchg (6).

  Here, ηchg is the charging efficiency of the battery 30 and is, for example, a value of about 0.8 (that is, 80%). The charging efficiency ηchg is stored in advance as a fixed value in the ROM. The charging efficiency ηchg is taken into account as in the above equation (6) because the electric power that is finally charged to the battery 30 when the second charging request output reference value Penc2bs is added to the required output of the engine 200 is as follows: This is to match the power consumption during the inertia running period. In other words, this is a measure in anticipation that a part of the generated power of MG1 using a part of the power of engine 200 (torque Tes) is converted into heat and consumed.

  When the second charging request output Penc2 is calculated, the ECU 100 calculates the first thermal efficiency η1 (step S180). The first efficiency η1 is the thermal efficiency of the engine 200 when the first required output Pen1 is adopted as the required output Pen of the engine 200. The first required output Pen1 is calculated according to the following equation (7).

Pen1 = Pend + Penc1 (7)
Here, as described above, Pend is a drive request output for supplying power to the drive shaft during the acceleration travel period. The value of the drive request output Pend is determined by a known method based on the required drive force acquired from the control map based on the vehicle speed V and the set acceleration for the acceleration travel period.

  Penc1 is a first charge request output. The first charge request output Penc1 is acquired from the control map according to the SOC of the battery 30 at that time. The first charge request output Penc1 is an example of the “first power generation request output” according to the present invention. The first charge request output Penc1 is set to increase step by step as the SOC of the battery 30 is lower.

  The first thermal efficiency η1 is acquired from the thermal efficiency map. The thermal efficiency map is a control map that describes the thermal efficiency η of the engine 200 in a form associated with the engine speed NE and the engine torque Te. The thermal efficiency map is stored in, for example, the ROM, and when the first required output Pen1 is determined, the ECU 100 determines an operating point (corresponding to the first required output Pen1 on the optimum fuel consumption line from the separately stored operating point map. That is, the optimum fuel efficiency operating point) is determined, and the thermal efficiency η corresponding to the operating point is acquired from the thermal efficiency map as the first thermal efficiency η1. In addition, the operation | movement which selects an applicable value from such a map is also one aspect | mode of calculation.

  When the first thermal efficiency η1 is calculated, the ECU 100 calculates the second thermal efficiency η2 (step S190). The second efficiency η1 is the thermal efficiency of the engine 200 when the second required output Pen2 is adopted as the required output Pen of the engine 200. The second required output Pen2 is calculated according to the following equation (8).

Pen2 = Pend + Penc2 (8)
Here, Penc2 is the second charge request output calculated in step S170. The second thermal efficiency η2 is acquired from the thermal efficiency map in the same manner as the first thermal efficiency η1. When the second required output Pen2 is determined, the ECU 100 determines an operating point corresponding to the second required output Pen2 (that is, the optimal fuel efficiency operating point) on the optimal fuel efficiency line from the separately stored operating point map. The thermal efficiency η corresponding to the operating point is acquired from the thermal efficiency map as the second thermal efficiency η2.

  When the first thermal efficiency η1 and the second thermal efficiency η2 are calculated, the ECU 100 compares these and determines whether or not the second thermal efficiency η2 is equal to or higher than the first thermal efficiency η1 (step S200).

  When the second thermal efficiency η2 is equal to or higher than the first thermal efficiency η1 (step S200: YES), the ECU 100 sets the required output Pen of the engine 200 during the acceleration travel period to the second required output Pen2 (step S210), and processing To step S110. On the other hand, when the second thermal efficiency η2 is less than the first thermal efficiency η1 (step S200: NO), the ECU 100 sets the required output Pen of the engine 200 during the acceleration travel period to the first required output Pen1 (step S220), and processing To step S110. The engine output control process is performed in this way.

  Here, the engine output control will be described visually with reference to FIG. FIG. 7 is a diagram showing the relationship between the operating point of the engine 200 and the thermal efficiency. In FIG. 7, the same reference numerals are given to portions overlapping with the above-described drawings, and the description thereof is omitted as appropriate.

  In FIG. 7, the vertical axis represents the engine torque Te, and the horizontal axis represents the engine speed NE. One coordinate point on this coordinate plane corresponds to the operating point of the engine 200.

  The optimum fuel consumption operation line indicated by the solid line in the figure is a line obtained by connecting the operation points (optimum fuel consumption operation points) at which the fuel consumption rate is minimized for each engine output Pe. Usually, the operating point of the engine 200 is controlled to the optimum fuel consumption operating point on this optimum fuel consumption line.

  Here, when the equal output lines corresponding to the first required output Pen1 and the second required output Pen2 calculated in the engine output control are represented on the coordinate plane of FIG. 7, the illustrated equal output lines Lpen1 (see the broken line) and This is the iso-output line Lpen2 (see broken line). The operating point of the engine 200 when the required output Pen is set to the first required output Pen1 is an operating point m1 (see a white circle) corresponding to the intersection of the optimal fuel consumption operating line and the equal output line Lpen1. Similarly, the operating point of the engine 200 when the required output Pen is set to the second required output Pen2 is an operating point m2 (see a white circle) corresponding to the intersection of the optimal fuel consumption operating line and the equal output line Lpen2. Become.

  Here, in FIG. 7, the thermal efficiency of the engine 200 is like an elliptical hatching region. For example, the isothermal efficiency region Aef1 in which the thermal efficiency η is ηt1 is the darkest hatching region, the isothermal efficiency region Aef2 in which the thermal efficiency η is ηt2 (ηt2 <ηt1) is an intermediate hatching region, and the thermal efficiency η is ηt3 (ηt3 The isothermal efficiency region Aef3 that satisfies <ηt2) is the thinnest hatched region. Needless to say, the actual thermal efficiency is classified more finely, and the equal thermal efficiency region is also developed over the entire area on the coordinate plane other than shown. Shown is a conceptual diagram for simplifying the explanation.

  FIG. 7 shows a situation where the first thermal efficiency η1 corresponding to the first required output Pen1 and the second thermal efficiency η2 corresponding to the second required output Pen2 are equal. That is, the operating points corresponding to both required outputs belong to the same isothermal efficiency region.

  In such a case, according to the engine output control process described above, the second request output Pen2 is adopted as the request output Pen of the engine 200. Further, although different from the illustrated relationship, the thermal efficiency related to the isothermal efficiency region to which the operating point m1 corresponding to the first required output Pen1 belongs is equal to the isothermal efficiency region to which the operating point m2 corresponding to the second required output Pen2 belongs. When higher than the thermal efficiency, the first required output Pen1 is adopted as the required output Pen of the engine 200.

  Next, the effect of engine output control will be described with reference to FIG. FIG. 8 is a diagram illustrating the time transition of the SOC of the battery 30 during the intermittent operation period. In the figure, the same reference numerals are given to the same portions as those in the above-described drawings, and the description thereof will be omitted as appropriate.

  In FIG. 8, in order from the top, the vehicle speed V, the first charge request output Penc1, the SOC of the battery 30 charged according to the first charge request output, the second charge request output Penc2, and the battery 30 charged according to the second charge request output. The time transition of each SOC is illustrated.

  During the intermittent operation period, the vehicle speed V changes in a sawtooth shape between the control center vehicle speed Vcent, which is a substantial target vehicle speed, and the lower limit vehicle speed VLL and the upper limit vehicle speed VUL. The periods corresponding to the illustrated times t1 to t2, t3 to t4, and t5 to t6 are acceleration traveling periods, and the periods corresponding to the illustrated times t0 to t1, t2 to t3, t4 to t5, and t6 to t7 are inertial traveling. It is a period. FIG. 8 illustrates a situation in which traveling in the intermittent operation mode is started at time t0.

  Here, when the charge request output Penc is set to the first charge request output Penc1, that is, when the request output Pen of the engine 200 is set to the first request output Pen1, the SOC of the battery 30 is intermittently operated. From SOC0 at time t = 0, which is the start time of the period, a gradually decreasing trend gradually follows. This is because the power generation amount during the acceleration travel period is not balanced with the power consumption during the inertia travel period. Further, in the process in which the SOC follows a decreasing trend, the first charge request output Penc1 gradually increases as the SOC decreases. At the stage where the power generation amount obtained according to the increased first charge request output Penc1 is balanced with the power consumption amount during the inertia running period, the SOC of the battery 30 averages to the convergence value SOCcent. In FIG. 8, the power generation amount obtained in the acceleration travel period from time t5 to t6 is balanced with the amount of power consumed in the inertia travel period from time t4 to t5. As described above, when the required output Pen of the engine 200 is controlled to the first required output Pen1 defined by the first charging request output Penc1, the SOC during the intermittent operation period decreases from the SOC at the time of starting the intermittent operation. Accordingly, in some cases, after the end of the intermittent operation mode, a situation where the engine 200 starts for power generation or a situation where the power generation load of the engine 200 increases occurs, and a long-term fuel consumption rate including the intermittent operation period occurs. Can get worse. In the figure, the first charge request output Penc1 at time t0, which is the start of intermittent operation, is zero, but if there is a charge request at the time when traveling in the intermittent operation mode is started, the value is It may be an initial value at time t0.

  On the other hand, when the charge request output Penc is set to the second charge request output Penc2, that is, when the request output Pen of the engine 200 is set to the second request output Pen2, the SOC of the battery 30 is On average, it is maintained at SOC0 at time t0, which is the start time of the intermittent operation period. This is because the power generation amount during the acceleration travel period is balanced with the power consumption during the inertia travel period.

  In this way, when the charge request output Penc is set to the second charge request output Penc2, ideally, the SOC does not change before and after the execution of the intermittent operation mode. Therefore, unnecessary deterioration of the fuel consumption rate after the end of the intermittent operation period does not occur. The second request output Pen2 corresponding to the second charge request output Penc2 is selected when the thermal efficiency does not decrease as compared with the first request output Pen1 corresponding to the first charge request output Penc1. For this reason, since the second required output Pen2 is selected, the engine 200 does not always operate at an operating point where the fuel consumption rate is not good during the acceleration travel period. That is, according to the engine output control process, it is possible to suitably suppress the deterioration of the fuel consumption rate of the engine 200 over a long period including the intermittent operation period.

  In the present embodiment, the selection of the second required output Pen2 is permitted when the second thermal efficiency η2 is equal to or higher than the first thermal efficiency η1, but this is an example. In practice, when the second required output Pen2 is selected, the thermal efficiency during the acceleration travel period is often slightly lower than when the first required output Pen1 is selected. On the other hand, if the decrease in the thermal efficiency is within the allowable range, the deterioration of the fuel consumption rate from the long-term viewpoint due to the decrease in the SOC described above to the convergence value SOCcent has a greater influence on the deterioration of the fuel consumption rate. Can give. From such a viewpoint, a permissible deviation may be set in advance between the second thermal efficiency η2 and the first thermal efficiency η1 experimentally, empirically, or theoretically. For example, when the deterioration in thermal efficiency when the second required output Pen2 is selected falls within about 1%, the second required output Pen2 may be set as the required output Pen.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

  The present invention is applicable to travel control of a hybrid vehicle that can be intermittently operated in the intermittent operation mode.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 20 ... PCU, 30 ... Battery, MG1, MG2 ... Motor generator, 100 ... ECU, 200 ... Engine, 300 ... Power split mechanism, 400 ... Input shaft, 500 ... Drive shaft, 600 ... Deceleration mechanism.

Claims (4)

A power source including an internal combustion engine;
A rotating electrical machine capable of generating electric power by the power of the internal combustion engine;
A battery and
As a running mode at the time of steady running, inertial running in which power transmission from the power source to the driving wheel is stopped, and power from the power source to the driving wheel while charging the battery with electric power obtained by the power generation A hybrid vehicle travel control device that controls a hybrid vehicle configured to be able to select an intermittent operation mode in which transmission and acceleration acceleration are repeated,
First determining means for determining, from the SOC of the battery, a first power generation request output of the internal combustion engine required for the power generation in an accelerated traveling period in which the accelerated traveling is performed;
Power consumption estimating means for estimating the power consumption of the battery during the inertia running period in which the inertia running is performed;
Second determining means for determining a second power generation request output of the internal combustion engine required for the power generation from the length of the acceleration travel period and the estimated power consumption;
The internal combustion engine corresponding to the first demand output of the internal combustion engine determined from the drive demand output of the internal combustion engine required for driving the drive wheels and the determined first power generation demand output during the acceleration travel period A first thermal efficiency of the engine, and a second thermal efficiency of the internal combustion engine corresponding to the second required output of the internal combustion engine determined from the required drive output and the determined second power generation required output A comparison means for performing the comparison;
And a third determining means for determining a required output of the internal combustion engine during the acceleration travel period based on the comparison result. The first power generation request output is set larger as the SOC of the battery is lower,
The travel control device for a hybrid vehicle according to claim 1, wherein the second power generation request output corresponds to power consumption of the battery during the inertia traveling period. As a result of the comparison, when the second thermal efficiency is equal to or higher than the first thermal efficiency, or the deviation between the second thermal efficiency and the first thermal efficiency is within a predetermined value, The travel control device for a hybrid vehicle according to claim 1, wherein the request output is determined based on the second request output. The travel control apparatus for a hybrid vehicle according to claim 3, wherein the third determining means determines the required output to be the second required output.

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