Control device for hybrid vehicle

Abstract

The invention relates to a control device for a hybrid vehicle, which can inhibit the output of an engine from being excessively limited. A control device for a hybrid vehicle is provided with: an engine that is driven by being supplied with an alcohol-containing fuel; a generator that generates power by outputting a reaction torque; a differential mechanism that connects the engine, the generator, and an output member connected to the drive wheels so as to be capable of differential rotation; and a power storage device that is charged by being supplied with power generated by the generator, the control device being provided with: a concentration detection unit that detects an alcohol concentration, which is the content of alcohol with respect to the amount of fuel supplied to the engine; and a temperature detection unit that detects the temperature of the electricity storage device, the control device sets the upper limit rotation speed of the engine to be lower as the alcohol concentration detected by the concentration detection unit is higher, and the control device sets the upper limit rotation speed of the engine to be lower as the temperature of the electricity storage device detected by the temperature detection unit is lower.

Description

Technical Field

[0001] The present invention relates to a control device for a hybrid vehicle, wherein an engine, a generator, and drive wheels are connected via a differential mechanism, and the control device is configured to control the engine speed by means of 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 transmission unit that transmits torque from the output gear to the drive wheels. This control device is configured to control the engine and the first motor to prevent the first motor and the pinion gear constituting the planetary gear mechanism from exceeding their upper limit rotational speed when the engine decelerates rapidly from a high-speed rotational state. Specifically, it is configured to perform fuel cut-off control upon detecting rapid deceleration and reduce the upper limit rotational speed of the first motor and the pinion gear, thereby increasing the gain of the feedback control of the first motor.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-20631 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The control device described in Patent Document 1 performs fuel cut-off control and changes the upper speed limit when a sudden deceleration is detected, thus rapidly reducing the temporarily increased speed of the first motor and pinion. However, since the output of the engine and the first motor is changed after the sudden deceleration is detected, the speed of the first motor may temporarily increase due to control delays and delays in reducing the engine output. In this case, because the generated electricity from the first motor temporarily increases sharply, there is excess power acting on the energy storage device, electronic components constituting the circuit, etc., which may reduce durability.

[0008] On the other hand, to suppress the temporary surge in generated electricity as described above, limiting engine output in advance could be considered. However, in the case of engines using fuels containing alcohols such as ethanol, the maximum torque the engine can output varies depending on the alcohol content (proportion). Furthermore, the maximum torque the engine can output varies depending on the engine speed. Therefore, if we assume a high alcohol content and limit the engine's upper speed limit to restrict engine output, even with a low alcohol content, the engine's maximum torque would be limited, potentially excessively restricting the vehicle's maximum driving force.

[0009] The present invention was made in view of the above-mentioned technical problems, and its purpose is to provide a control device for hybrid vehicles that can suppress the excessive limitation of engine output.

[0010] Methods for solving problems

[0011] To achieve the above objectives, the present invention provides a control device for a hybrid vehicle, the hybrid vehicle comprising: an engine driven by fuel containing alcohol; a generator that generates electricity corresponding to a reaction torque and a rotational speed by outputting a reaction torque; a differential mechanism that differentially rotatably connects the engine, the generator, and an output component connected to a drive wheel; and an energy storage device charged by electricity generated by the generator. The control device further comprises: a controller that controls the engine; a concentration detection unit that detects the alcohol concentration relative to the amount of fuel supplied to the engine; and a temperature detection unit that detects the temperature of the energy storage device. The higher the alcohol concentration detected by the concentration detection unit, the lower the upper limit speed of the engine is set by the controller; and the lower the temperature of the energy storage device detected by the temperature detection unit, the lower the upper limit speed of the engine is set by the controller.

[0012] Invention Effects

[0013] According to the present invention, the higher the alcohol concentration relative to the amount of fuel supplied to the engine, and the lower the temperature of the energy storage device, the lower the upper limit speed of the engine can be set. Therefore, when the alcohol concentration is high, the engine speed and output torque can be set lower. Thus, when the speed of the generator, which outputs reaction torque, changes drastically along with the speed of the output component, excessive increase in the speed of the generator can be suppressed. As a result, excessive power generation by the generator can be suppressed, and the reduction in durability, such as overcurrent flowing through the energy storage device and the electronic components connected to the energy storage device and the generator, can be suppressed. Furthermore, when the alcohol concentration is low and the maximum torque of the engine is low, even if the speed of the generator changes drastically as described above, the power generation by the generator can be suppressed. Therefore, by not setting the upper limit speed of the engine too low, excessive limitation of the engine output can be prevented.

[0014] Furthermore, the lower the temperature of the battery storage device, the more it limits the engine's maximum speed. In other words, when the battery storage device is hot, the limitation on the engine's maximum speed is reduced. As a result, when the battery storage device is hot and there is a high amount of electricity that can be input into it, the engine's output can be prevented from being excessively limited. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating an example of a hybrid vehicle in an embodiment of the present invention.

[0016] Figure 2 It is a line graph used to illustrate the change in the engine's maximum torque in relation to alcohol concentration.

[0017] Figure 3 It is a collinear diagram used to illustrate the changes in the rotational speed of the rotating elements that make up the power distribution mechanism.

[0018] Figure 4 This is a block diagram illustrating a control example for setting the upper limit speed of an engine.

[0019] Figure 5 It is a mapping used to set the upper limit speed of the engine based on the alcohol concentration and the temperature of the energy storage device.

[0020] Figure 6 It is a timing diagram showing the changes in engine speed, the speed of the first motor, the voltage applied to the energy storage device, the power input to the energy storage device, and the changes in the execution flag of the fuel cut-off control when the upper limit speed of the engine is limited.

[0021] Explanation of reference numerals in the attached figures

[0022] 1 engine

[0023] 2 motors

[0024] 3 Concentration Sensors

[0025] 7. Energy Storage Devices

[0026] 8 temperature sensors

[0027] 11 Power Distribution Mechanism

[0028] 12 output gears

[0029] 13 controllers

[0030] 15 wheel speed sensors

[0031] 17 Normal Speed ​​Calculation Section

[0032] 18 Upper limit speed calculation unit

[0033] 19. Upper limit speed calculation unit during malfunction

[0034] 20 Alcohol Concentration Upper Limit Speed ​​Calculation Unit

[0035] Mediation Department 21

[0036] C Planetary Carrier

[0037] P pinion

[0038] R gear ring

[0039] S Sun Gear

[0040] Ve vehicles. Detailed Implementation

[0041] The present invention will be described based on the embodiments shown in the accompanying drawings. It should be noted that the embodiments described below are merely examples of how to embody the present invention and do not limit the scope of the invention.

[0042] Figure 1 This is a schematic diagram illustrating an example of a hybrid vehicle used to illustrate an embodiment of the present invention. Figure 1 The hybrid vehicle (hereinafter referred to as the vehicle) Ve shown has an engine (ENG) 1, a first motor (MG) 2 and a second motor (not shown) as driving power sources.

[0043] This engine 1, like engines used as power sources in conventional engine vehicles or hybrid vehicles, is configured to generate power by burning a mixture of air and fuel. As the fuel, an alcohol-containing fuel, such as ethanol, can be used in combination with gasoline.

[0044] Such alcohol-containing fuels have a higher octane rating than conventional fuels like gasoline or diesel, thus enabling a higher maximum torque output. Figure 2 In this context, the maximum torque of engine 1 is expressed by alcohol concentration, which is the alcohol content relative to the amount of fuel supplied to engine 1. It should be noted that... Figure 2 The horizontal axis in the figure represents engine speed, and the vertical axis represents engine torque.

[0045] like Figure 2 As shown, similar to the previous cases using gasoline or diesel as fuel, regardless of the alcohol concentration, the maximum torque of engine 1 increases with increasing engine speed before the engine reaches the specified speed. Once the engine speed exceeds the specified speed, the maximum torque of engine 1 decreases with increasing engine speed. Furthermore, regardless of the engine speed, the higher the alcohol concentration, the greater the maximum torque.

[0046] As described above, the maximum torque of engine 1 varies depending on the alcohol concentration. Therefore, a concentration sensor 3 for detecting the alcohol concentration of the fuel is installed, for example, in a fuel tank or fuel delivery pipe (not shown). This concentration sensor 3 corresponds to the "concentration detection unit" in the embodiments of the present invention. It should be noted that engine 1 is equipped with a crank angle sensor 4 for detecting its rotational speed (or rotation angle).

[0047] The first motor 2 and the second motor can be configured similarly to motors used as drive sources in conventional hybrid vehicles or electric vehicles. That is, in addition to functioning as a motor that outputs drive torque when powered, they also function as a generator that converts the power of an output shaft into electricity by rotating the output shaft. Specifically, they can be configured as permanent magnet synchronous motors or induction motors. The first motor 2 corresponds to the "generator" in the embodiments of the present invention. It should be noted that each motor 2 is equipped with a rotary transformer 5 for detecting its rotation angle.

[0048] Furthermore, the energy storage device 7 is connected to the first motor 2 and the second motor via a power control unit (hereinafter referred to as PCU) 6, which is composed of electronic components such as an inverter (not shown). Similar to the power supplies installed in conventional electric vehicles or hybrid vehicles, the energy storage device 7 is a DC voltage output power source and can be composed of secondary batteries such as lithium-ion batteries or nickel-metal hydride batteries, or double-layer capacitors. The energy storage device 7 can also be composed of a battery pack with multiple batteries connected in series.

[0049] Therefore, by controlling the PCU6, power is supplied from the energy storage device 7 to the first motor 2 and the second motor, thereby enabling the first motor 2 and the second motor to function as motors that output driving torque (torque that increases the rotational speed). Furthermore, when the first motor 2 and the second motor are driven to rotate and function as generators to produce electricity, the electricity can be charged into the energy storage device 7.

[0050] Because the internal resistance of the aforementioned energy storage device 7 varies with its temperature, a large current flows within the energy storage device 7 when its temperature is low. Therefore, the device is configured to limit the permissible discharge power output from the energy storage device 7 and the permissible charging power for charging the energy storage device 7 based on its temperature. Therefore, as... Figure 1 As shown, a temperature sensor 8 for detecting the temperature of the energy storage device 7 is provided. Additionally, an ammeter 9 for detecting the current value supplied to each motor 2 is provided between each motor 2 and the PCU6. This temperature sensor 8 corresponds to the "temperature detection unit" in the embodiment of the present invention. It should be noted that a voltmeter 10 for detecting the voltage output from the energy storage device 7 or the voltage applied to the energy storage device 7 is provided between the energy storage device 7 and the PCU6.

[0051] in addition, Figure 1 The vehicle Ve shown includes a power distribution mechanism 11 that distributes the output torque of engine 1 to first motor 2 and drive wheels (not shown). This power distribution mechanism 11 is a differential mechanism that allows differential rotation of engine 1, first motor 2, and drive wheels. Figure 1 In the example shown, a single-pinion type planetary gear is used. Specifically, it consists of a sun gear S, a ring gear R arranged concentrically with the sun gear S, and a planet carrier C that holds the pinion P, which meshes with the sun gear S and the ring gear R, so that it can rotate and revolve. A first motor 2 is connected to the sun gear S, an engine 1 is connected to the planet carrier C, and an output gear 12 for transmitting torque to the drive wheels is connected to the ring gear R. This output gear 12 corresponds to the "output component" in the embodiments of the present invention.

[0052] It should be noted that a gear transmission unit (not shown) is provided for transmitting torque from the gear ring R to the drive wheel, and the second motor is connected to this gear transmission unit to transmit torque. That is, it is configured to add the torque output from the second motor to the torque transmitted from the engine 1 to the gear transmission unit via the power distribution mechanism 11. It is configured to supply the second motor with power that is charged to the energy storage device 7, or power generated by the first motor 2.

[0053] A controller 13 is provided for controlling the aforementioned engine 1 and each motor 2 (specifically, each PCU6). Similar to the 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 the input signals and pre-stored formulas, mappings, etc.

[0054] The signals input to the controller 13 include a concentration sensor 3, a crank angle sensor 4, a rotary transformer 5, a temperature sensor 8, an ammeter 9, a voltmeter 10, an accelerator opening sensor 14 for detecting the amount of operation of the accelerator device by the driver, a wheel speed sensor 15 for detecting the rotational speed of the drive wheels, and a SOC sensor 16 for detecting the remaining charge of the battery storage device 7.

[0055] The controller 13 calculates the required driving power (Ve) for the vehicle based on signals detected by the accelerometer opening sensor 14 and the wheel speed sensor 15. Additionally, it calculates the required charging power (SOC) for charging the battery storage device 7 based on signals detected by the SOC sensor 16. It should be noted that when the charging capacity of the battery storage device 7 exceeds the upper limit, the charging power is calculated as a negative value. Furthermore, the required power (hereinafter referred to as the required engine power) for the engine 1 is calculated by adding the driving power and the charging power.

[0056] The operating point of engine 1 with good fuel efficiency when outputting the required engine power is determined. This operating point is determined by the output torque and speed of engine 1. An optimal fuel consumption curve mapping, constructed in advance through experiments or simulations to determine the optimal fuel efficiency operating point for each engine power, is stored in controller 13. Therefore, based on the required engine power and the optimal fuel consumption curve mapping, the operating point of engine 1 is determined.

[0057] Figure 3 This is a collinear diagram illustrating the rotational speed changes of the rotating elements constituting the power distribution mechanism 11. Dashed lines represent the state where the vehicle Ve is driven at a specified speed, and solid lines represent the state of emergency braking.

[0058] It should be noted that the first motor 2 is connected to the sun gear S in the power distribution mechanism 11; therefore, the rotational speed of the sun gear S is the same as that of the first motor 2. The engine 1 is connected to the planetary carrier C; therefore, the rotational speed of the planetary carrier C is the same as that of the engine 1. Furthermore, a drive wheel is connected to the ring gear R via the output gear 12 and the gear transmission unit; therefore, the rotational speed of the drive wheel divided by the gear ratio of the gear transmission unit is the rotational speed of the ring gear R. Figure 3 For ease of explanation, the gear ratio is represented as "1". Therefore, the rotational speed of the gear ring R and the rotational speed of the drive wheel are represented as the same rotational speed.

[0059] like Figure 3 As shown, when driving at a specified vehicle speed, engine 1 is controlled to achieve the speed and torque determined based on the aforementioned engine power and optimal fuel consumption line mapping. It should be noted that the direction of engine torque is indicated by dashed arrows.

[0060] Furthermore, the reaction torque of the first motor 2 is determined such that the engine torque is output via the power distribution 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 based on the gear ratio of the power distribution mechanism 11. It should be noted that by outputting a torque from the first motor 2 that is larger 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. That is, by controlling the torque of the first motor 2, the engine speed can be continuously changed. Therefore, the power distribution mechanism 11 is configured to function as a continuously variable transmission (CVT). In other words, the reaction torque of the first motor 2 is calculated based on the torque (feedforward term) based on the torque transmitted from the engine 1 to the first motor 2 (or its estimated value) and the torque (feedback term) based on the difference between the actual speed and the target speed of the engine 1. It should be noted that the direction of the reaction torque of the first motor 2 is indicated by a dashed arrow.

[0061] As mentioned above, when traveling at a specified speed, if the speed of the drive wheels decreases sharply due to the brake pedal being pressed, etc., then... Figure 3 As shown by the solid line, while maintaining the speed of engine 1 or keeping the speed of engine 1 almost constant, the speed of the first motor 2 increases sharply. This is because the driving torque is output from engine 1 due to the control delay of engine 1's output, or due to the unavoidable delay caused by the reduction of engine 1's output.

[0062] When the rotational speed of the first motor 2 increases as described above, in order to suppress the increase in engine speed or reduce the engine speed to a level comparable to idle speed, a reaction torque is output from the first motor 2. As a result, the first motor 2 generates electricity obtained by multiplying its reaction torque by its rotational speed.

[0063] In the embodiments of the present invention, the control device is configured to suppress the power generated by the first motor 2 from exceeding the power (Win) that can be supplied to the energy storage device 7 when the rotational speed of the first motor 2 increases sharply as described above.

[0064] Figure 4 A block diagram illustrating the functional structure of its control example. Figure 4 The example shown includes a normal speed calculation unit 17, which calculates the engine speed based on the required engine power and optimal fuel consumption line, as described above. On the other hand, the upper limit speed of engine 1 is sometimes limited by considering the durability and characteristics of various components installed in vehicle Ve. Therefore, an upper limit speed calculation unit 18 is provided to calculate the upper limit speed of engine 1 based on these limiting factors. For ease of explanation, Figure 4The fault-prone upper limit speed calculation unit 19 calculates the upper limit speed determined in the event of a fault in a component installed in engine 1 or vehicle Ve.

[0065] When the fault occurs, the upper limit speed calculation unit 19 is configured to pre-store the upper limit speed of engine 1 corresponding to the main cause of the fault, vehicle speed, etc. in the controller 13, and determine the upper limit speed of engine 1 based on the output signal from other controllers that determine the fault.

[0066] In addition, Figure 4 In the example shown, the upper limit speed calculation unit 18 includes an alcohol concentration upper limit speed calculation unit 20, which calculates the upper limit speed of the engine 1 based on the alcohol concentration and the temperature of the energy storage device 7 (battery temperature). This alcohol concentration upper limit speed calculation unit 20 is configured to calculate the upper limit speed of the engine 1 based on pre-stored... Figure 5 The mapping shown is used to calculate the upper limit speed of engine 1.

[0067] Figure 5 The mapping shown is configured such that the horizontal axis represents the alcohol concentration and the vertical axis represents the upper limit speed (upper limit Ne) of engine 1. As shown in the figure, when the temperature of the energy storage device 7 is above a specified temperature, the upper limit speed of engine 1 is set to a specified speed Ne1 regardless of the alcohol concentration. This specified speed Ne1 is, for example, set to the speed obtained by dividing the maximum generated power of the first motor 2 by the maximum torque of engine 1 (when the alcohol concentration is at its maximum value).

[0068] Furthermore, as the temperature of the energy storage device 7 decreases, the upper limit speed of the engine 1 is set to a low speed. This is because, as the temperature of the energy storage device 7 decreases, the amount of electricity that can be input to the energy storage device 7 is limited. Also, when the temperature of the energy storage device 7 is above a specified temperature, as the alcohol concentration increases, the upper limit speed of the engine 1 is set to a low speed. This is because, the higher the alcohol concentration, the greater the maximum torque of the engine 1.

[0069] Right now, Figure 5 The mapping configuration shown is such that the speed obtained by dividing the power input to the energy storage device 7, which is limited by temperature factors, by the maximum torque corresponding to the alcohol concentration, is set as the upper limit speed of the engine 1. It should be noted that in... Figure 5 In the example shown, for ease of explanation, it is indicated that when the temperature of the energy storage device 7 is the same, the upper limit speed is divided into three stages based on the alcohol concentration. However, it can also be further divided into multiple stages to determine the upper limit speed. In addition, as mentioned above, if the input power of the energy storage device 7 based on the temperature factor and the maximum torque corresponding to the alcohol concentration are determined, the upper limit speed of the engine 1 can be determined. Therefore, the upper limit speed of the engine 1 can also be determined sequentially through calculation.

[0070] Furthermore, the engine speed calculated by the normal speed calculation unit 17 and multiple upper limit speeds calculated by the upper limit speed calculation unit 18, including the fault upper limit speed calculation unit 19 and the alcohol concentration upper limit speed calculation unit 20, are input to the adjustment unit 21. The adjustment unit 21 is configured to extract the lowest speed from the multiple input speeds and output that speed as the target speed of the engine 1.

[0071] Figure 6 This diagram illustrates the changes in engine speed, first motor 2 speed (MG speed), voltage applied to the battery storage device 7, electrical power input to the battery storage device 7, and the change in the fuel cut-off control activation flag when the vehicle rapidly decelerates from a specified speed to a stop. It should be noted that solid lines represent changes when the upper limit speed of engine 1 is set based on alcohol concentration and the temperature of the battery storage device 7, while dashed lines represent changes when the upper limit speed of engine 1 is not set.

[0072] exist Figure 6 At time t0, the wheel speed, engine speed, and speed of the first motor 2 are kept constant by driving at a predetermined speed. Furthermore, at this time, by outputting driving torque from the engine 1, 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 electricity, and consequently, a predetermined voltage is applied to the energy storage device 7. Figure 6 In this context, the generated electricity is represented as a negative value. It should be noted that when the engine speed is limited due to high alcohol concentration or low temperature of the energy storage device 7, the speed is lower compared to when the engine speed is not limited. Therefore, when the engine rotation is limited, the speed of the first motor 2, the generated electricity produced by the first motor 2, and the voltage applied to the energy storage device 7 are all lower compared to when the engine speed is not limited.

[0073] By having the driver perform braking operations, a braking torque is applied to the drive wheels at time t1, resulting in a decrease in wheel speed. In this situation, as described above, due to a control delay in the output of engine 1, or an unavoidable delay caused by the decrease in the output of engine 1, a drive torque is output from engine 1, thus maintaining the engine speed, and the speed of the first motor 2 increases. It should be noted that since the increase in the speed of the first motor 2 is determined based on the engine speed and the gear ratio of the power distribution mechanism 11, when the engine speed is not limited, the increase is proportional to the difference in engine speed compared to when the engine speed is limited.

[0074] Furthermore, during the period when the speed of the first motor 2 increases, a reaction torque corresponding to the torque output from the engine 1 is continuously output from the first motor 2. Therefore, the generated electricity produced by the first motor 2, the voltage applied to the energy storage device 7, and the speed of the first motor 2 increase proportionally. When the engine speed is not limited, the difference between the generated electricity produced by the first motor 2, the voltage applied to the energy storage device 7, and the speed of the first motor 2 also increases accordingly. It should be noted that... Figure 6 In the example shown, at time t2 when the generated electricity from the first motor 2 reaches or exceeds a specified power level, the flag for performing the fuel cut-off control to stop supplying fuel to the engine 1 is switched to ON.

[0075] At time t3, when the engine is stopped, the speed of the first motor 2 reaches its maximum. Then, to reduce the engine speed to a level comparable to idle speed, the first motor 2 outputs torque, thereby causing both the engine speed and the speed of the first motor 2 to decrease. Along with this decrease in the speed of the first motor 2, the voltage applied to the energy storage device 7 by the electricity generated by the first motor 2 also begins to decrease. It should be noted that at time t4, because the electricity generated by the first motor 2 is less than the specified amount, the flag used for performing fuel cut-off control is switched off.

[0076] Next, at time t5, the engine speed decreases to a level comparable to the idle speed, and the speed of the first motor 2 decreases to a speed corresponding to the engine speed. As a result, the electricity generated by the first motor 2 and the voltage applied to the energy storage device 7 are maintained at a constant level.

[0077] As described above, the higher the alcohol concentration or the lower the temperature of the energy storage device 7, the lower the upper limit speed of the engine 1 is set. Therefore, even when the wheel speed decreases while the speed of the first motor 2 increases, the speed of the first motor 2 can be reduced compared to the case where the speed of the engine 1 is not limited. Furthermore, as... Figure 2 As shown, the maximum torque of engine 1 depends on the engine speed. Therefore, by setting the upper limit speed of engine 1 to a lower value, the torque output from engine 1 can be limited. In this case, the reaction torque generated by the first motor 2 can be reduced. Therefore, the power generated by the first motor 2 can be suppressed when the speed of the first motor 2 increases, and the reduction in durability such as overcurrent flowing in the PCU6 and the energy storage device 7 can be suppressed.

[0078] In other words, when the alcohol concentration is low, the upper limit speed of engine 1 is not limited, or the limitation is small. Therefore, when the alcohol concentration is low, it is possible to prevent the output torque of engine 1 from being excessively limited.

[0079] Furthermore, the lower the temperature of the energy storage device 7, the more it limits the upper limit speed of the engine 1. In other words, when the temperature of the energy storage device 7 is high, the limitation on the upper limit speed of the engine 1 is reduced. As a result, when the temperature of the energy storage device 7 is high and the amount of electricity that can be input to the energy storage device 7 is high, it is possible to prevent the output of the engine 1 from being excessively limited.

Claims

1. A control device for a hybrid vehicle, the hybrid vehicle comprising: an engine driven by being supplied with fuel containing alcohol; a generator generating electrical power corresponding to a reaction torque and a rotational speed by outputting a reaction torque; a differential mechanism differentially rotatably connecting the engine, the generator, and an output component connected to a drive wheel; and an energy storage device charged by being supplied with electrical power generated by the generator, characterized in that... The control device for the hybrid vehicle also includes: Controller, which controls the engine; A concentration detection unit detects the alcohol concentration relative to the amount of fuel supplied to the engine; and Temperature detection unit, the temperature detection unit detects the temperature of the energy storage device. The higher the alcohol concentration detected by the concentration detection unit, the lower the upper limit speed of the engine set by the controller; and the lower the temperature of the energy storage device detected by the temperature detection unit, the lower the upper limit speed of the engine set by the controller.

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