Control device for hybrid vehicle

Abstract

To provide a control device for a hybrid vehicle capable of suppressing excessive limitation of an output of an engine.SOLUTION: A control device for a hybrid vehicle includes an engine that is driven by supply of alcohol-containing fuel, a generator that generates electric power by outputting reaction torque, a differential mechanism that connects the engine, the generator, and an output member connected to a driving wheel in a differentially rotatable manner, and a power storage device that is charged by supply of electric power generated by the generator, wherein the control device includes a concentration detection unit that detects an alcohol concentration which is a content of alcohol with respect to a fuel amount supplied to the engine, and a temperature detection unit that detects a temperature of the power storage device. The upper limit rotation speed of the engine is set lower as the alcohol concentration detected by the concentration detection part is higher, and the upper limit rotation speed of the engine is set lower as the temperature of the power storage device detected by the temperature detection part is lower.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a control device for a hybrid vehicle in which an engine, a generator, and drive wheels are connected via a differential mechanism, and the engine speed is controlled by the reaction torque of the generator. [Background technology]

[0002] Patent Document 1 describes a control device for a hybrid vehicle in which an engine, a first motor, and an output gear are connected to a planetary gear mechanism, and a second motor is connected to a gear train that transmits torque from the output gear to the drive wheels. This control device is configured to control the engine and the first motor when the engine suddenly decelerates from a high rotation speed state so that the first motor and a pinion gear that constitutes the planetary gear mechanism do not exceed their upper limit rotation speeds. Specifically, when a sudden deceleration is detected, the control device is configured to execute fuel cut control, lower the upper limit rotation speeds of the first motor and pinion gear, and increase the gain of feedback control of the first motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-20631 Summary of the Invention [Problem to be solved by the invention]

[0004] The control device described in Patent Document 1 performs fuel cut control and changes the upper limit of engine speed when sudden deceleration is detected, thereby quickly reducing the rotation speed of the first motor and pinion gear, which may have temporarily increased. However, because the output of the engine and first motor is changed after sudden deceleration is detected, the rotation speed of the first motor temporarily increases due to control delays and delays in reducing the engine output. In such cases, the power generated by the first motor temporarily increases sharply, which can result in excessive power acting on the power storage device and electronic components that make up the electrical circuit, potentially reducing their durability.

[0005] On the other hand, in order to suppress such a temporary sudden increase in power generation, it is conceivable to limit the engine output in advance. However, in the case of an engine that uses fuel containing alcohol such as ethanol, the maximum torque that the engine can output varies depending on the alcohol content (content ratio). In addition, the maximum torque that the engine can output varies depending on the engine speed. Therefore, if the upper limit of the engine speed is limited to limit the engine output assuming a case where the alcohol content is high, the maximum torque of the engine will also be limited even when the alcohol content is relatively low, which may result in excessive restriction of the maximum driving force of the vehicle.

[0006] The present invention has been made in light of the above technical problems, and aims to provide a control device for a hybrid vehicle that can prevent the engine output from being excessively restricted. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a control device for a hybrid vehicle including an engine that is driven by being supplied with fuel containing alcohol, a generator that generates electricity according to the reaction torque and rotation speed by outputting a reaction torque, a differential mechanism that connects the engine, the generator, and an output member connected to a drive wheel so as to be able to rotate differentially, and an electricity storage device that is supplied with the electricity generated by the generator and charged, and further includes a controller that controls the engine, a concentration detection unit that detects the alcohol concentration, which is the content of the alcohol in the amount of fuel supplied to the engine, and a temperature detection unit that detects the temperature of the electricity storage device, and the controller sets a lower upper limit rotation speed for the engine as the alcohol concentration detected by the concentration detection unit increases, and sets a lower upper limit rotation speed for the engine as the temperature of the electricity storage device detected by the temperature detection unit decreases. [Effects of the Invention]

[0008] According to this invention, the higher the alcohol concentration (i.e., the alcohol content relative to the amount of fuel supplied to the engine) is, and the lower the temperature of the power storage device is, the lower the engine upper limit rotation speed is set. Therefore, when the alcohol concentration is high, the engine rotation speed and output torque can be set low. Therefore, when the rotation speed of the generator outputting the reaction torque changes in accordance with a sudden change in the rotation speed of the output member, an excessive increase in the rotation speed of the generator can be prevented. As a result, an excessive increase in the power generated by the generator can be prevented, and a decrease in durability, such as an overcurrent flowing in the power storage device or electronic components connected to the power storage device and the generator, can be prevented. Furthermore, when the alcohol concentration is low and the maximum torque of the engine is low, the power generated by the generator can be reduced even if the generator rotation speed changes suddenly as described above. Therefore, by not setting the engine upper limit rotation speed low, excessive restriction of the engine output can be prevented.

[0009] Furthermore, the lower the temperature of the power storage device, the more the upper limit of the engine rotation speed is limited. In other words, when the temperature of the power storage device is high, the amount of limitation on the upper limit of the engine rotation speed is reduced. As a result, when the temperature of the power storage device is high and the amount of electric power that can be input to the power storage device is high, excessive limitation on the engine output can be prevented. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a skeleton diagram for explaining an example of a hybrid vehicle according to an embodiment of the present invention; [Figure 2] FIG. 4 is a diagram illustrating a change in maximum torque of an engine depending on the alcohol concentration. [Figure 3] FIG. 3 is a collinear diagram illustrating changes in the rotation speed of each rotating element that configures the power split mechanism. [Figure 4] FIG. 4 is a block diagram illustrating an example of control for setting an upper limit rotation speed of an engine. [Figure 5] 10 is a map for setting an upper limit of engine rotation speed based on the alcohol concentration and the temperature of the electricity storage device. [Figure 6] This is a time chart showing the change in engine speed, the change in first motor speed, the change in voltage applied to the power storage device, the change in power input to the power storage device, and the change in the execution flag for fuel cut control when the engine's upper limit speed is restricted. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described based on the embodiments shown in the drawings. Note that the embodiments described below are merely examples of specific implementations of the present invention and are not intended to limit the present invention.

[0012] Fig. 1 shows a skeleton diagram for explaining an example of a hybrid vehicle according to an embodiment of the present invention. The hybrid vehicle (hereinafter simply referred to as a vehicle) Ve shown in Fig. 1 includes an engine (ENG) 1, a first motor (MG) 2, and a second motor (not shown) as driving power sources.

[0013] Similar to engines used as a driving force source in conventional engine vehicles and hybrid vehicles, this engine 1 is configured to generate power by burning a mixture of air and fuel. The fuel can be an alcohol-containing fuel, which is a mixture of alcohol such as ethanol and gasoline.

[0014] Such alcohol-containing fuels have a higher octane number than regular gasoline, diesel, and other fuels, and therefore have a higher maximum torque that can be output. Figure 2 shows the maximum torque of engine 1 for each alcohol concentration, which is the alcohol content relative to the amount of fuel supplied to engine 1. In Figure 2, the horizontal axis represents engine speed, and the vertical axis represents engine torque.

[0015] As shown in Figure 2, similar to when conventional gasoline or diesel is used as fuel, regardless of the alcohol concentration, the maximum torque of the engine 1 increases as the engine speed increases until the engine speed reaches a predetermined speed, and once the engine speed exceeds the predetermined speed, the maximum torque of the engine 1 decreases as the engine speed increases. Furthermore, regardless of the engine speed, the maximum torque increases as the alcohol concentration increases.

[0016] As described above, the maximum torque of the engine 1 varies depending on the alcohol concentration, so a concentration sensor 3 for detecting the alcohol concentration of the fuel is provided, for example, in a fuel tank or a fuel delivery pipe (not shown). This concentration sensor 3 corresponds to the "concentration detection unit" in the embodiment of the present invention. The engine 1 is provided with a crank angle sensor 4 for detecting its rotation speed (or rotation angle).

[0017] The first motor 2 and the second motor can be configured in the same manner as motors used as driving power sources in conventional hybrid vehicles or electric vehicles. That is, in addition to functioning as motors that output driving torque when supplied with electric power, they also function as generators that convert the power of the output shaft into electric power when the output shaft is rotated. Specifically, they can be configured using a permanent magnet synchronous motor or induction motor. This first motor 2 corresponds to the "generator" in this embodiment of the present invention. Each motor 2 is provided with a resolver 5 for detecting its rotation angle.

[0018] The first motor 2 and the second motor are connected to a power storage device 7 via a power control unit (hereinafter referred to as PCU) 6 that is composed of electronic components such as an inverter (not shown). This power storage device 7 is a power supply that outputs DC voltage, similar to power supplies provided in conventional electric vehicles and hybrid vehicles, and can be composed of secondary batteries such as lithium-ion batteries or nickel-metal hydride batteries, or electric double layer capacitors. This power storage device 7 may also be composed of a battery pack in which multiple batteries are arranged in series.

[0019] Therefore, by controlling the PCU 6 to supply power from the power storage device 7 to the first motor 2 and the second motor, the first motor 2 and the second motor function as motors that output drive torque (torque that increases the rotation speed). Also, when the first motor 2 and the second motor function as generators that generate power by being rotated together, that power can be charged into the power storage device 7.

[0020] The internal resistance of the power storage device 7 varies depending on its temperature, and therefore, when the temperature of the power storage device 7 is low, a large current flows through the power storage device 7. Therefore, the allowable discharge power output from the power storage device 7 and the allowable charge power for charging the power storage device 7 are configured to be limited depending on the temperature of the power storage device 7. For this reason, as shown in FIG. 1 , the power storage device 7 is provided with a temperature sensor 8 for detecting its temperature, and an ammeter 9 for detecting the value of a current flowing through each motor 2 is provided between each motor 2 and the PCU 6. The temperature sensor 8 corresponds to the "temperature detection unit" in this embodiment of the present invention. A voltmeter 10 for detecting a voltage output from the power storage device 7 or a voltage applied to the power storage device 7 is provided between the power storage device 7 and the PCU 6.

[0021] The vehicle Ve shown in FIG. 1 also includes a power split mechanism 11 that splits the output torque of the engine 1 between the first motor 2 and drive wheels (not shown). This power split mechanism 11 is a differential mechanism in which the engine 1, the first motor 2, and the drive wheels are connected to each other so as to be able to rotate differentially, and in the example shown in FIG. 1, is configured by a single-pinion planetary gear. Specifically, it is configured by a sun gear S, a ring gear R arranged concentrically with the sun gear S, and a carrier C that holds a pinion gear P meshing with the sun gear S and the ring gear R so as to be able to rotate and revolve. The first motor 2 is connected to the sun gear S, the carrier C is connected to the engine 1, and an output gear 12 is connected to the ring gear R to transmit torque to the drive wheels. This output gear 12 corresponds to the "output member" in this embodiment of the present invention.

[0022] A gear train unit (not shown) is provided for transmitting torque from the ring gear R to the drive wheels, and the second motor is connected to the gear train unit so that torque can be transmitted. That is, the system is configured so that torque output from the second motor can be added to torque transmitted from the engine 1 to the gear train unit via the power split mechanism 11. The second motor is configured to be supplied with power stored in the power storage device 7 and power generated by the first motor 2.

[0023] A controller 13 is provided to control the engine 1 and each motor 2 (specifically, each PCU 6) described above. Like controllers provided in conventional vehicles, this controller 13 is mainly composed of a microcomputer, and is configured to generate and output command signals for controlling the engine 1 and each motor 2 based on input signals and pre-stored arithmetic expressions, maps, etc.

[0024] The signals input to the controller 13 include those from the concentration sensor 3, crank angle sensor 4, resolver 5, temperature sensor 8, ammeter 9, voltmeter 10, accelerator opening sensor 14 for detecting the amount of accelerator operation by the driver, wheel speed sensor 15 for detecting the rotation speed of the drive wheels, and SOC sensor 16 for detecting the remaining charge of the storage device 7.

[0025] The controller 13 calculates the running power required for the vehicle Ve based on a signal detected by the accelerator opening sensor 14 and a signal detected by the wheel speed sensor 15. The controller 13 also calculates the charging power required to charge the power storage device 7 based on a signal detected by the SOC sensor 16. If the remaining charge of the power storage device 7 is equal to or greater than an upper limit, the charging power is calculated as a negative value. The power required for the engine 1 (hereinafter referred to as required engine power) is calculated by adding the running power and the charging power.

[0026] An operating point of the engine 1 that provides good fuel economy when the required engine power is output is determined. This operating point of the engine 1 is determined by the output torque and rotation speed of the engine 1, and an optimum fuel economy line map that has been constructed by previously determining, through experiments and simulations, operating points that provide good fuel economy for each engine power is stored in the controller 13. Therefore, the operating point of the engine 1 is determined based on the required engine power and the optimum fuel economy line map.

[0027] FIG. 3 shows a nomographic diagram illustrating changes in the rotation speed of each rotating element constituting the power split mechanism 11. The dashed line indicates the state in which the vehicle Ve is being driven at a predetermined vehicle speed, and the solid line indicates the state in which sudden braking is applied.

[0028] Since the first motor 2 is connected to the sun gear S in the power split mechanism 11, the rotation speed of the sun gear S is the same as the rotation speed of the first motor 2, and since the engine 1 is connected to the carrier C, the rotation speed of the carrier C is the same as the rotation speed of the engine 1. Furthermore, since the driving wheels are connected to the ring gear R via the output gear 12 and the gear train section, the rotation speed of the ring gear R is the rotation speed of the driving wheels divided by the gear ratio of the gear train section. In FIG. 3, for convenience, the gear ratio is shown as "1", and therefore the rotation speed of the ring gear R and the rotation speed of the driving wheels are shown as being the same.

[0029] As shown in Figure 3, when the vehicle is being driven at a predetermined vehicle speed, the engine 1 is controlled to achieve the rotation speed and torque determined based on the required engine power and the optimal fuel economy line map. The direction of the engine torque is indicated by the dashed arrow.

[0030] Furthermore, the reaction torque of the first motor 2 is determined so that engine torque is output via the power split mechanism 11. This reaction torque is determined to be the same magnitude as the torque transmitted from the engine 1 to the first motor 2 according to the gear ratio of the power split mechanism 11. Note that, by outputting a torque from the first motor 2 that is greater than the torque transmitted from the engine 1 to the first motor 2, the engine speed decreases. Conversely, by outputting a torque from the first motor 2 that is smaller than the torque transmitted from the engine 1 to the first motor 2, the engine speed increases and the torque transmitted to the output gear 12 decreases. In other words, the engine speed can be continuously changed by controlling the torque of the first motor 2. Therefore, the power split mechanism 11 is configured to function as a continuously variable transmission. In other words, the reaction torque of the first motor 2 is calculated based on a torque (feedforward term) based on the torque transmitted from the engine 1 to the first motor 2 (or an estimated value thereof) and a torque (feedback term) based on the difference between the actual rotation speed and the target rotation speed of the engine 1. The direction of the reaction torque of the first motor 2 is indicated by a dashed arrow.

[0031] As described above, when the rotation speed of the drive wheels suddenly drops due to, for example, the brake pedal being depressed while the vehicle is traveling at a predetermined vehicle speed, the rotation speed of the first motor 2 suddenly increases while the rotation speed of the engine 1 remains constant or remains almost unchanged, as shown by the solid line in Figure 3. This is because the drive torque is being output from the engine 1 due to a delay in the control of the engine 1 output and an unavoidable delay caused by the decrease in engine 1 output.

[0032] When the rotation speed of the first motor 2 increases in this way, a reaction torque is output from the first motor 2 to suppress the increase in engine rotation speed or to reduce the engine rotation speed to a level equivalent to idle rotation speed. As a result, the first motor 2 generates electric power calculated by multiplying the reaction torque by the rotation speed.

[0033] The control device in this embodiment of the present invention is configured to prevent the power generated by the first motor 2 from exceeding the power (Win) that can be supplied to the storage device 7 when the rotation speed of the first motor 2 increases suddenly as described above.

[0034] Fig. 4 shows a block diagram for explaining the functional configuration of this control example. The example shown in Fig. 4 includes a normal rotation speed calculation unit 17 that calculates the engine rotation speed based on the required engine power and the optimal fuel economy line, as described above. On the other hand, the upper limit rotation speed of the engine 1 may be limited in some cases, taking into account the durability and characteristics of various parts provided in the vehicle Ve. Therefore, an upper limit rotation speed calculation unit 18 is provided that calculates the upper limit rotation speed of the engine 1 based on these limiting factors. For convenience, Fig. 4 also shows a fail-time upper limit rotation speed calculation unit 19 that calculates the upper limit rotation speed to be determined in the event of a failure of the engine 1 or a part provided in the vehicle Ve.

[0035] This upper limit rotation speed calculation unit 19 in the event of a failure is configured to store in advance in the controller 13 the upper limit rotation speed of the engine 1 corresponding to the cause of the failure, the vehicle speed, etc., and to determine the upper limit rotation speed of the engine 1 based on an output signal from another controller that determines whether a failure has occurred.

[0036] 4, the upper limit rotation speed calculation unit 18 includes an alcohol concentration upper limit rotation speed calculation unit 20 that calculates the upper limit rotation speed of the engine 1 based on the alcohol concentration and the temperature (battery temperature) of the electricity storage device 7. The alcohol concentration upper limit rotation speed calculation unit 20 is configured to calculate the upper limit rotation speed of the engine 1 based on a pre-stored map shown in FIG.

[0037] 5, the horizontal axis represents the alcohol concentration and the vertical axis represents the upper limit rotation speed (upper limit Ne) of the engine 1. As shown in the figure, when the temperature of the power storage device 7 is equal to or higher than a predetermined temperature, the upper limit rotation speed of the engine 1 is set to a predetermined rotation speed Ne1 regardless of the alcohol concentration. This predetermined rotation speed Ne1 is set to a rotation speed obtained by dividing the maximum power generated by the first motor 2 by the maximum torque of the engine 1 (when the alcohol concentration is at its maximum value), for example.

[0038] Furthermore, as the temperature of the power storage device 7 decreases, the upper limit rotation speed of the engine 1 is set to a lower rotation speed. This is because the power that can be input to the power storage device 7 is limited as the temperature of the power storage device 7 decreases. Furthermore, when the temperature of the power storage device 7 is equal to or higher than a predetermined temperature, the upper limit rotation speed of the engine 1 is set to a lower rotation speed as the alcohol concentration increases. This is because the maximum torque of the engine 1 increases as the alcohol concentration increases.

[0039] That is, the map shown in Fig. 5 is configured to set the upper limit rotation speed of the engine 1 to a rotation speed obtained by dividing the power that can be input to the power storage device 7, which is limited by temperature factors, by the maximum torque corresponding to the alcohol concentration. Note that in the example shown in Fig. 5, for convenience, the upper limit rotation speed is shown as being divided into three stages according to the alcohol concentration when the temperature of the power storage device 7 is the same, but the upper limit rotation speed may be further divided into multiple stages and set. Furthermore, since the upper limit rotation speed of the engine 1 can be set once the power that can be input to the power storage device 7 due to temperature factors and the maximum torque corresponding to the alcohol concentration are determined as described above, the upper limit rotation speed of the engine 1 may be set by sequential calculation.

[0040] Then, the engine speed calculated by the normal speed calculation unit 17 and a plurality of upper limit speeds calculated by an upper limit speed calculation unit 18 including a failure upper limit speed calculation unit 19 and an alcohol concentration upper limit speed calculation unit 20 are input to an arbitration unit 21. The arbitration unit 21 is configured to extract the lowest speed from the input plurality of speeds and output the lowest speed as the target speed of the engine 1.

[0041] 6 shows a time chart for explaining changes in engine speed, changes in the speed of the first motor 2 (MG speed), changes in the voltage applied to the power storage device 7, changes in the power input to the power storage device 7, and changes in the execution flag for fuel cut control when the vehicle is suddenly decelerated and stopped from a state in which it is traveling at a predetermined vehicle speed. Note that the changes when the upper limit of the engine 1 speed is set in accordance with the alcohol concentration and the temperature of the power storage device 7 are shown by solid lines, and the changes when the upper limit of the engine 1 speed is not set are shown by dashed lines.

[0042] At time t0 shown in FIG. 6, the vehicle is driven at a predetermined vehicle speed, so the wheel speed, engine speed, and rotational speed of the first motor 2 are kept constant. At this time, the engine 1 outputs a driving torque, and the first motor 2 outputs a reaction torque corresponding to the torque transmitted from the engine 1. Therefore, the first motor 2 generates a predetermined amount of power, and a predetermined voltage is applied to the power storage device 7 accordingly. In FIG. 6, the generated power is shown as a negative value. Note that when the engine speed is limited due to a high alcohol concentration or a low temperature of the power storage device 7, the engine speed is lower than when the engine speed is not limited. Therefore, when the engine speed is limited, the rotational speed of the first motor 2, the power generated by the first motor 2, and the voltage applied to the power storage device 7 are lower than when the engine speed is not limited.

[0043] At time t1, braking torque is applied to the drive wheels due to braking by the driver or the like, and as a result, the wheel speed begins to decrease. In such a case, as described above, due to delays in the control of the engine 1 output and unavoidable delays caused by the decrease in engine 1 output, the engine speed is maintained and the speed of the first motor 2 increases, because drive torque is being output from the engine 1. Note that the increase in the speed of the first motor 2 is determined according to the engine speed and the gear ratio of the power split device 11, so when the engine speed is not limited, the increase is greater by an amount corresponding to the difference in engine speed than when the engine speed is limited.

[0044] Furthermore, even while the rotation speed of the first motor 2 is increasing, the first motor 2 continues to output a reaction torque corresponding to the torque output from the engine 1, and as a result, the power generated by the first motor 2 and the voltage applied to the power storage device 7 increase in proportion to the rotation speed of the first motor 2. When the engine rotation speed is not limited, the power generated by the first motor 2 and the voltage applied to the power storage device 7 are also higher in accordance with the difference in the rotation speed of the first motor 2. In the example shown in FIG. 6, at time t2 when the power generated by the first motor 2 becomes equal to or greater than a predetermined power, a flag is switched on to execute fuel cut control to stop the supply of fuel to the engine 1.

[0045] At time t3 when the vehicle comes to a stop, the rotation speed of the first motor 2 reaches its maximum rotation speed, and thereafter, in order to reduce the engine rotation speed to a level equivalent to idle rotation speed, the first motor 2 outputs torque, causing the engine rotation speed and the rotation speed of the first motor 2 to begin to decrease. As the rotation speed of the first motor 2 decreases, the power generated by the first motor 2 and the voltage applied to the power storage device 7 begin to decrease. At time t4, the power generated by the first motor 2 falls below a predetermined power, and the flag for executing fuel cut control is switched off.

[0046] Then, at time t5, the engine speed drops to an idle speed, and the speed of the first motor 2 drops to a speed corresponding to the engine speed, thereby maintaining constant the power generated by the first motor 2 and the voltage applied to the power storage device 7.

[0047] As described above, by setting the upper limit rotation speed of the engine 1 lower as the alcohol concentration increases or the temperature of the power storage device 7 decreases, the rotation speed of the first motor 2 can be lowered compared to when the rotation speed of the engine 1 is not limited, even when the wheel speed decreases and the rotation speed of the first motor 2 increases. Furthermore, as shown in FIG. 2 , the maximum torque of the engine 1 depends on the engine rotation speed, so setting the upper limit rotation speed of the engine 1 low can limit the torque output from the engine 1. In such a case, the reaction torque by the first motor 2 can be reduced. Therefore, the power generated by the first motor 2 when the rotation speed of the first motor 2 increases can be suppressed, and a decrease in durability, such as an overcurrent flowing through the PCU 6 or the power storage device 7, can be suppressed.

[0048] In other words, when the alcohol concentration is low, the upper limit rotation speed of engine 1 is not limited, or the amount of limitation is small, so when the alcohol concentration is low, excessive limitation of the output torque of engine 1 can be prevented.

[0049] Furthermore, the lower the temperature of the power storage device 7, the more the upper limit rotation speed of the engine 1 is limited. In other words, when the temperature of the power storage device 7 is high, the amount of limitation on the upper limit rotation speed of the engine 1 is reduced. As a result, when the temperature of the power storage device 7 is high and the electric power that can be input to the power storage device 7 is high, it is possible to prevent the output of the engine 1 from being excessively limited. [Explanation of symbols]

[0050] 1 engine 2 motors 3. Concentration sensor 7. Energy storage device 8 Temperature Sensor 11 Power split mechanism 12 Output gear 13 Controller 15 Wheel speed sensor 17 Normal rotation speed calculation section 18 Upper limit rotation speed calculation section 19. Failure upper limit rotation speed calculation section 20 Alcohol concentration upper limit rotation speed calculation unit 21 Mediation Department C Carrier P Pinion gear R ring gear S sun gear Vehicle

Claims

[Claim 1] A control device for a hybrid vehicle including an engine that is driven by being supplied with fuel containing alcohol, a generator that outputs a reaction torque to generate electric power according to the reaction torque and the rotation speed, a differential mechanism that connects the engine, the generator, and an output member connected to a drive wheel so as to be capable of differential rotation, and an electric storage device that is supplied with electric power generated by the generator and is charged, a controller for controlling the engine; a concentration detection unit that detects an alcohol concentration, which is the content of alcohol in the amount of fuel supplied to the engine; a temperature detection unit that detects a temperature of the power storage device, The controller The higher the alcohol concentration detected by the concentration detection unit, the lower the upper limit rotation speed of the engine is set; and The lower the temperature of the power storage device detected by the temperature detection unit, the lower the upper limit rotation speed of the engine is set. A control device for a hybrid vehicle.

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