Drive control device for hybrid vehicle

Abstract

The drive control device for hybrid vehicle of the present invention includes a hybrid control unit 20 having: a travel mode switching control part 45 for switching between a parallel mode and a series mode on the basis of at least a vehicle speed by connection / disconnection of a clutch 16; and a regenerative control part 46 for performing regenerative braking to apply braking force to a vehicle by generating power by a front motor 4 for travel driving during deceleration travel. The travel mode switching control part 45 prohibits switching from the series mode to the parallel mode when a vehicle-speed condition for switching from the series mode to the parallel mode is satisfied, if the vehicle is in a generated power limit state in which generated power of a motor generator 9 is limited, and if a reception upper limit amount of the generated power of the motor generator 9 input to an on-vehicle drive battery is equal to or less than actual generated power of the motor generator 9.

Description

Drive control device for a hybrid vehicle

[0001] The present invention relates to a drive control device for a hybrid vehicle capable of regenerative power generation.

[0002] Conventionally, in a plug-in hybrid vehicle or a hybrid vehicle (hereinafter collectively referred to as a hybrid vehicle) equipped with an engine and an electric motor as driving power sources, vehicles capable of switching driving modes have been developed. As driving modes, an EV mode in which only an electric motor is driven, a series mode in which an electric motor and an engine are used as driving power sources, and a parallel mode are known.

[0003] For example, the vehicle described in Patent Document 1 includes a clutch (engine clutch) in the power transmission path between the engine and the driving wheels, and by disconnecting the clutch, a series mode in which the generator is driven by the engine while the vehicle is driven by the motor is possible. On the other hand, by connecting the clutch, a parallel mode in which the vehicle is driven by the engine while the driving force is assisted by the motor is possible.

[0004] Further, in Patent Document 1, the driving mode is automatically switched based on the required output required for the vehicle to travel, the traveling speed (vehicle speed) of the vehicle, etc. For example, in the medium vehicle speed range where the maximum output of the series mode is larger than that of the parallel mode, when the required output is larger than the maximum output in the parallel mode (parallel maximum output), the driving mode is switched to the series mode, and when the required output is smaller than a predetermined output that is smaller than the parallel maximum output, the driving mode is switched to the parallel mode. Also, when the driving mode is set to the series mode and is between the predetermined output and the parallel maximum output, the driving mode is maintained in the series mode.

[0005] Japanese Patent Application Laid-Open No. 2021-154812

[0006] In a vehicle that switches between a series mode and a parallel mode by connecting and disconnecting a clutch as described above, when there is a rotational speed difference (rotational speed difference) when connecting the clutch to switch from the series mode to the parallel mode, there are problems such as generation of noise and shock.

[0007] To suppress the rotational speed difference when the clutch is engaged, it is possible to do so by controlling the engine's ON / OFF state through fuel supply control and by controlling the generator connected to the engine. However, since it is difficult to control the rotational speed quickly and accurately with engine ON / OFF control, control by the generator is preferred.

[0008] However, if power generation by the generator is restricted during deceleration, for example, if regenerative power generation is being performed by the vehicle's drive motor, and further power generation by the generator to adjust the engine speed exceeds the power capacity of the vehicle's battery, then rotational speed control by the generator becomes impossible, making it difficult to adequately suppress the rotational speed difference when engaging the clutch.

[0009] This invention has been made in view of the above problems, and its objective is to provide a drive control device that suppresses the generation of noise and shock caused by clutch engagement during deceleration driving in a hybrid vehicle that can switch from series mode to parallel mode by engaging a clutch.

[0010] To achieve the above objective, the hybrid vehicle drive control device of the present invention comprises: an engine that drives the vehicle's drive wheels via a first power transmission path; an electric motor that drives the drive wheels via a second power transmission path different from the first power transmission path; a generator that generates electricity driven by the engine; a clutch provided in the first power transmission path; a storage battery that supplies power to the electric motor; and control means for driving and controlling the clutch, the engine, the electric motor, and the generator, wherein the control means disengages the clutch and drives the generator with the engine to generate electricity, while simultaneously using the power supplied from the storage battery or the generator. The vehicle has a driving mode switching control unit that switches between a series mode, in which the electric motor drives the drive wheels, and a parallel mode, in which the clutch is engaged and the engine and electric motor drive the drive wheels, based at least on the vehicle speed, wherein the driving mode switching control unit prohibits switching from the series mode to the parallel mode when the vehicle speed condition for switching from the series mode to the parallel mode is met, and the power generated by the generator is in a power generation limiting state in which the power generated by the generator is limited, and the upper limit amount of power generated by the generator that the storage battery accepts is less than or equal to the actual power generated by the generator.

[0011] According to the hybrid vehicle drive control device of the present invention, when the vehicle speed conditions for switching from series mode to parallel mode are met, and the power generation is limited, making it difficult to adjust the engine speed by the generator, and the power receiving state to the storage battery is insufficient, clutch engagement is avoided, thereby suppressing clutch engagement that would generate noise and shock.

[0012] This is a schematic diagram of the drive system of a hybrid vehicle equipped with a drive control device according to an embodiment of the present invention. This is a configuration diagram of the drive control device of this embodiment. This is a timing chart showing one embodiment of the transition of various parameters and judgments due to driving mode switching control when decelerating from driving in series mode. This is a graph showing an example of setting regenerative power and generated power with respect to the upper limit of charging power. This is a graph showing an example of setting regenerative power and generated power in the state of generated power limitation when deceleration priority is given. This is a graph showing an example of setting regenerative power when the upper limit of charging power drops significantly. This is a graph showing an example of setting regenerative power when the upper limit of charging power drops slightly.

[0013] Embodiments of the present invention will be described below with reference to the drawings.

[0014] Figure 1 is a schematic diagram of the drive system of a hybrid electric vehicle (HEV) (hereinafter referred to as Vehicle 1) equipped with a drive control device according to one embodiment of the present invention. Figure 2 is a diagram of the drive control device of this embodiment.

[0015] As shown in Figure 1, the vehicle 1 of this embodiment is capable of driving by driving the front wheels 3 with the output of the engine 2, and is also equipped with an electric front motor 4 (electric motor) that drives the front wheels 3 (driving wheels).

[0016] The engine 2 is capable of driving the drive shaft 8 of the front wheel 3 via the reduction gear 7, and is also capable of driving the motor generator 9 (generator) via the reduction gear 7 to generate electricity.

[0017] The front motor 4 is powered by high-voltage electricity supplied from the drive battery 11 (storage battery) and motor generator 9 mounted on the vehicle 1 via the front inverter 10, and drives the drive shaft 8 of the front wheel 3 via the reduction gear 7. In the reduction gear 7, the power transmission path between the engine 2 and the drive shaft 8 and the power transmission path between the front motor 4 and the drive shaft 8 are partially different. The reduction gear 7 incorporates a clutch 16 that can switch the power transmission path between the output shaft of the engine 2 and the drive shaft 8, in addition to the power transmission path between the front motor 4 and the drive shaft 8.

[0018] The power transmission path between the engine 2 and the front wheel 3 corresponds to the first power transmission path of the present invention, and the power transmission path between the front motor 4 and the drive shaft 8 corresponds to the second power transmission path of the present invention. The clutch 16 connects and disconnects the first power transmission path.

[0019] The power generated by the motor generator 9 can charge the drive battery 11 via the front inverter 10 and also supply power to the front motor 4.

[0020] The drive battery 11 is composed of a secondary battery such as a lithium-ion battery and is equipped with a battery monitoring unit 11a that monitors the charge level (State of Charge, hereinafter referred to as SOC) and the like.

[0021] The front inverter 10 controls the output of the front motor 4 based on a control signal from the hybrid control unit 20, while also having the function of controlling the amount of power generated by the motor generator 9.

[0022] Furthermore, although not shown in the figures, vehicle 1 may also be equipped with a charger for charging the drive battery 11 using an external power source.

[0023] The hybrid control unit 20 is a control device for comprehensively controlling the vehicle 1, and is composed of input / output devices, memory devices (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), and the like.

[0024] As shown in Figures 1 and 2, the input side of the hybrid control unit 20 is connected to the battery monitoring unit 11a of the drive battery 11, the front inverter 10, the engine control unit 22 that drives and controls the engine 2, the accelerator opening sensor 40 that detects the amount of accelerator operation, the brake stroke sensor 41 that detects the amount of brake operation, the vehicle speed sensor 42 that detects the vehicle speed, and so on, and detection and operation information from these devices is input.

[0025] On the other hand, the output side of the hybrid control unit 20 is connected to the front inverter 10, clutch 16, and engine control unit 22.

[0026] The hybrid control unit 20 includes a request output calculation unit 44 that calculates the vehicle request output and driving torque required for driving the vehicle 1 based on the various detection amounts and various operating information such as the accelerator opening sensor 40. Based on the vehicle request output and driving torque calculated by the request output calculation unit 44, the hybrid control unit 20 transmits control signals to the engine control unit 22, the front inverter 10, and the clutch 16 of the reduction gear 7 to control the switching of the driving mode ((EV mode: electric vehicle mode), series mode, parallel mode), the output of the engine 2 and the front motor 4, and the output (generated power) of the motor generator 9.

[0027] In EV mode, the engine 2 is stopped, and the front motor 4 is driven by power supplied from the drive battery 11 to propel the vehicle 1.

[0028] In series mode, the clutch 16 of the reduction gear 7 is disengaged, and the engine 2 operates the motor generator 9. The power generated by the motor generator 9 and the power supplied from the drive battery 11 are used to drive the front motor 4 and propel the vehicle. In series mode, the rotational speed (engine speed) of the engine 2 is set appropriately, and any excess power is supplied to the drive battery 11 to charge it.

[0029] In parallel mode, the clutch 16 of the reduction gear 7 is engaged, and power is mechanically transmitted from the engine 2 through the reduction gear 7 to drive the front wheels 3. In addition, the engine 2 operates the motor generator 9 to generate electricity, and the electricity supplied from the drive battery 11 drives the front motor 4 to propel the vehicle.

[0030] The hybrid control unit 20 is equipped with a driving mode switching control unit 45 that switches the driving mode based on the vehicle speed, requested output (or requested torque), charge level of the drive battery, etc. The driving mode switching control unit 45 sets the driving mode to parallel mode in areas where the engine 2 is efficient, such as the high-speed range where the vehicle speed is 100 km / h or more. In the low-speed range where the vehicle speed is, for example, 50 km / h (parallel disengagement speed) or less, it switches between EV mode and series mode based on the requested driving torque of the vehicle 1 and the charge level (SOC) of the drive battery 11. In the mid-speed range where the vehicle speed is, for example, 50 km / h to 100 km / h, either parallel mode or series mode is selected based on the vehicle speed, requested output, etc. For example, in the mid-speed range, if the series mode can obtain a higher output than the parallel mode, the parallel mode is normally used, and the series mode is used when the requested output is above a predetermined value.

[0031] Vehicle 1 is equipped with a regenerative braking function that, when decelerating with the accelerator released, forcibly drives the front motor 4 with the rotational force of the front wheels 3 to generate electricity (regenerative power generation) and also applies braking torque (regenerative braking torque) to the front wheels 3.

[0032] The hybrid control unit 20 is equipped with a regenerative control unit 46 that controls the regenerative braking force by adjusting the regenerative power generated by the front motor 4. The regenerative braking force can be changed by the driver using the paddle shift lever 43 or the like.

[0033] The regenerative power output from the front motor 4 through regenerative power generation is used for various electrical equipment in the vehicle 1, and any surplus power is supplied to the drive battery 11 for charging.

[0034] The drive battery 11 has an upper limit (SOPin) of the charging power it can accept when charging. When the engine 2 is operating as in series mode during deceleration, the power generated by regenerative power and the power generated by the motor generator 9 driven by the engine 2 are supplied to the drive battery 11, and the total value of these is controlled so as not to exceed the upper limit (SOPin) of the charging power that the drive battery 11 can accept. In series mode, when the power supplied to the drive battery 11 is limited in this way, the regenerative power is prioritized to prevent fluctuations in regenerative braking force, and the power generated by the motor generator 9 is limited (engine power generation limit state). The upper limit of the power generated by the motor generator 9 within the upper limit (SOPin) of the charging power that the drive battery 11 can accept is the upper limit of the power generation power that can be accepted.

[0035] In this embodiment, the hybrid control unit 20 implements parallel mode transition restriction control to prohibit the transition from series mode to parallel mode when, during driving in series mode, the vehicle speed is equal to or greater than the parallel mode deactivation speed (i.e., equal to or greater than the vehicle speed at which parallel mode is possible), the engine power generation limit state is in effect, and the upper limit of power generation acceptance is less than or equal to the actual power generation amount of the motor generator 9.

[0036] Next, an example of driving mode switching control when decelerating from series mode driving will be explained using the timing chart in Figure 3. Figure 3 shows the progression of various parameters and decisions in driving mode switching control, with the example shown by a thick solid line and the reference example by a thick dashed line. Note that the example performs parallel mode transition restriction control as described above, but the reference example does not perform parallel mode transition restriction control.

[0037] In Figure 3 and in sections <1> to <3> and <7> described below, the examples and reference examples are common, <4> to <6> are reference examples, and <4'> to <6'> are examples.

[0038] <1> With the accelerator operated at a nearly constant position, a series priority determination is made, and the vehicle is running in series mode. The series priority determination is made when the driving mode is determined to be series mode based on various conditions such as vehicle speed, requested output, and the SOC of the drive battery 11. The final determination to enter series mode is the series determination, and at this point, the final series determination is also ON.

[0039] <2> By turning the accelerator OFF, the series priority determination fails, and the system transitions to parallel start mode, provided that the vehicle speed is equal to or greater than the parallel disengagement speed mentioned above. This causes the target engine speed to switch to the speed when the clutch is directly engaged (gradually decreasing).

[0040] <3> As the brake pedal is operated, the torque required by the driver decreases. In order to ensure the regenerative braking torque (pedal regenerative torque) at this time, the lower limit of the generator torque, which is the lower limit of the torque consumed for power generation by the motor generator 9 (generator torque), is limited.

[0041] <4> In the reference example, because the lower limit torque of the generator is restricted, the generator torque generated by the motor generator 9 cannot suppress the engine speed to the target speed, so fuel cut is performed to reduce the engine speed.

[0042] <4'> In the embodiment, when the lower limit torque of the generator > the generator torque F / F (the target torque of the motor generator 9), a charge / discharge power shortage (series priority determination prioritizing series mode) is determined and the system transitions to series mode (i.e., series mode is maintained). The lower limit torque of the generator corresponds to the upper limit of power acceptance in the present invention, which is the portion of the power that can be charged (accepted) into the drive battery 11 that is generated by the motor generator 9. The generator torque F / F is the target torque, but it corresponds to the actual power generated in the present invention.

[0043] Furthermore, because the generator's lower torque limit is restricted and the engine speed cannot be reduced by the generator torque alone, fuel cut-off is implemented to lower the engine speed.

[0044] <5> In the reference example, when the engine speed approaches the target engine speed, it returns from fuel cut. To further suppress the decrease in engine speed, correction is made to the power running side by rotational speed feedback by the motor generator 9. Next, in order to prevent the engine speed from surging as the fuel cut returns, an attempt is made to correct to the regeneration side by controlling the motor generator 9, but since it is limited by the generator lower limit torque, the engine speed surges.

[0045] The target engine speed (the speed at clutch direct connection) ≒ the engine speed continues for a predetermined time, it is determined that the rotational synchronization is completed and the transition is made to the clutch engagement mode. However, since the clutch 16 engages in a state where a rotational speed difference has occurred, gear rattle and shock are generated.

[0046] <5'> In the embodiment, when the engine speed approaches the target engine speed, it returns from fuel cut. To further suppress the decrease in engine speed, correction is made to the power running side by rotational speed feedback by the motor generator 9. Next, in order to prevent the engine speed from surging as the fuel cut returns, an attempt is made to correct to the regeneration side by controlling the motor generator 9, but since it is limited by the generator lower limit torque, the engine speed surges by about several tens of revolutions.

[0047] <6> In the reference example, fuel cut is performed for deceleration (accel OFF deceleration) due to accel off in the parallel mode.

[0048] <6'> In the embodiment, when the pedal regeneration torque decreases, the generator lower limit torque is relaxed. And when the generator lower limit torque is relaxed more than the hysteresis threshold value, the charge / discharge power shortage is released and the series priority becomes invalid.

[0049] Here, the parallel determination is established based on the vehicle speed condition (the vehicle speed is equal to or higher than the parallel release vehicle speed), and the transition is made to the parallel mode. Also, fuel cut is performed for deceleration due to accel off in the parallel mode.

[0050] <7> When the vehicle speed is lower than the parallel release vehicle speed, the transition is made to the series mode.

[0051] As described above, in the vehicle 1 of this embodiment, the driving mode is switched according to the vehicle's driving speed, requested output, etc. However, when the vehicle speed is below the parallel disengagement speed, the parallel mode is restricted and a driving mode other than the parallel mode (series mode or EV mode) is selected, and the parallel mode is possible when the vehicle speed exceeds the parallel disengagement speed (parallel vehicle speed condition).

[0052] When the parallel vehicle speed condition is met, for example, if the vehicle is detected as being in parallel mode due to the accelerator being released while driving in series mode, the clutch 16 will engage and the vehicle will attempt to transition to parallel mode.

[0053] Furthermore, the vehicle 1 of this embodiment is capable of regenerative braking and charges the drive battery 11 with power obtained by regenerative power generation during deceleration driving, but there is an upper limit (SOPin) to the amount of charging power that the drive battery 11 can accept.

[0054] Therefore, as shown in Figure 3, when regenerative power generation is performed during engine operation, such as during deceleration, the drive battery 11 is supplied with regenerative power and power generated by the motor generator 9. However, the sum of the regenerative power and power generated is controlled so as not to exceed the upper limit of the charging power (SOPin).

[0055] In this configuration, when controlling the sum of regenerative power and generated power so as not to exceed the upper limit of charging power (SOPin), in this embodiment, securing the degree of deceleration through regeneration is prioritized over power generation by the drive battery 11, and the generated power is controlled (limited) over the regenerative power.

[0056] However, when engine torque > generator torque, the rotational speed of the clutch 16 on the engine 2 side increases, so it may be possible to decide whether to prioritize regenerative power over generated power from the power that the drive battery 11 can accept, depending on the engine speed. In this case, the threshold for this engine speed is determined by the relationship between engine torque and generator torque. Furthermore, rotational speed control is basically performed by feedback control of the generator torque.

[0057] In this way, when a parallel mode is detected from series mode and the system attempts to switch to parallel mode, the motor generator 9 is used to control the engine speed in order to suppress the rotational speed difference when the clutch 16 is engaged.

[0058] However, when the power generated by the motor generator 9 is limited (power generation limited state), the motor generator 9 cannot adequately adjust (reduce) the engine speed, which may cause noise or shock when the clutch is engaged.

[0059] In this embodiment, when the vehicle speed exceeds the parallel disengagement speed and the parallel vehicle speed condition is met, if a parallel determination is made due to the accelerator being turned off or the like while driving in series mode, the generated power is limited and the upper limit of the generated power acceptance (i.e., the lower limit torque of the motor generator 9) is less than or equal to the actual generated power (i.e., the generator torque F / F), then switching from series mode to parallel mode is prohibited.

[0060] This maintains series mode, avoiding engagement of the clutch 16 with a rotational speed difference, thereby suppressing the generation of noise and shock.

[0061] Furthermore, in the above configuration, the power generation limit is applied when deceleration of vehicle 1 by regenerative braking is prioritized. As shown in Figure 4, regenerative braking force is prioritized and secured, suppressing driver discomfort (deterioration of drivability). In addition, by prohibiting the transition to parallel mode, clutch 16 engagement is avoided, and the generation of noise and shock associated with clutch engagement can be suppressed.

[0062] In practice, the generator power limit state is set when the generator power limit state is greater than the generator power limit state, by comparing the generator lower limit torque and the generator torque F / F. However, as shown in Figure 5, the generator power limit state is set when the regenerative power is greater than or equal to a threshold (generative power determination threshold), so that regenerative power can be secured and the power recovery rate from driving energy can be maximized. Furthermore, by prohibiting the transition to parallel mode, the engagement of the clutch 16 can be avoided, and the generation of noise and shock associated with clutch engagement can be suppressed.

[0063] Furthermore, as shown in Figures 6 and 7, the power generation limiting state may be implemented when the upper limit of the charge power that the drive battery 11 can accept, SOPin, decreases, such as when the drive battery 11 is fully charged or at extremely low temperatures. As shown in Figure 6, when the upper limit of the charge power SOPin decreases significantly and falls below the power generation determination threshold, only regenerative power generation is performed. Therefore, the regenerative braking force can be secured as large as possible.

[0064] As shown in Figure 7, the power generation limiting state may be entered when the upper limit of the charging power, SOPin, decreases slightly and exceeds the power generation determination threshold. In this case, as the upper limit of the charging power, SOPin, decreases, power generation is reduced while ensuring regenerative power, but the transition to parallel mode is prohibited, thereby avoiding engagement of the clutch 16 and suppressing the generation of noise and shock associated with the engagement of the clutch 16.

[0065] Furthermore, when the brake operation is released and the pedal regenerative torque decreases, the driving mode switching control unit 45 reduces the generator lower limit torque (increases it to negative) in accordance with the decrease in regenerative power. Instead of the charge / discharge power shortage being released and series priority being invalidated when the generator lower limit torque falls below zero (increases to negative), the charge / discharge power shortage is released and series priority is invalidated when the generator lower limit torque is reduced below the hiss threshold (generator torque F / B shortage determination hiss) (becomes negative by the amount of the generator torque F / B shortage determination hiss), and the system transitions to parallel mode.

[0066] In other words, if the upper limit of power generation acceptance is greater than the actual power generation plus the equivalent value of the generator torque F / B deficiency determination hiss (second predetermined value), the prohibition on switching from series mode to parallel mode is lifted.

[0067] This makes it possible to suppress the frequency of switching between series mode and parallel mode when the lower limit torque of the generator changes near zero due to changes in pedal regenerative torque, that is, when the upper limit of power acceptance and the actual power generated fluctuate up or down.

[0068] Furthermore, the generator torque F / B deficiency determination hiss equivalent value is the torque required to control the engine speed to the target speed by generating electricity from the motor generator 9 in series mode. Therefore, it is possible to suppress the transition to parallel mode with an excessive delay after the generator lower limit torque falls below zero, thereby suppressing a decrease in energy efficiency.

[0069] This concludes the description of the embodiments, but the embodiments of the present invention are not limited to those described above. For example, in the above embodiments, the torque related to the power generated by each device (generator lower limit torque or generator torque F / F) is used as a parameter for determining when to prohibit switching from series mode to parallel mode in the parallel mode transition restriction control, but the power generated may be used directly for determination.

[0070] Furthermore, although the vehicle 1 in the above embodiment is a front-wheel drive vehicle, the present invention can also be applied to a four-wheel drive vehicle equipped with rear motors that drive the left and right rear wheels 5, for example. It can also be applied to vehicles with different details in the structure of the drive system.

[0071] Furthermore, although the vehicle 1 in this embodiment is a hybrid vehicle, the present invention can also be applied to plug-in hybrid vehicles (PHEVs) that are capable of external charging or external power supply.

[0072] This invention can be widely applied to vehicles that switch between series mode and parallel mode by engaging and disengaging a clutch based on vehicle speed or the like.

[0073] 1 Vehicle (hybrid vehicle) 2 Engine 3 Front wheels (driving wheels) 4 Front motor (electric motor) 9 Motor generator (generator) 11 Drive battery (storage battery) 16 Clutch 20 Hybrid control unit (control means) 45 Driving mode switching control unit 46 Regenerative control unit

Claims

1. The vehicle comprises: an engine that drives the vehicle's drive wheels via a first power transmission path; an electric motor that drives the vehicle's drive wheels via a second power transmission path different from the first power transmission path; a generator that generates electricity driven by the engine; a clutch provided in the first power transmission path; a storage battery that supplies power to the electric motor; and control means for controlling the clutch, the engine, the electric motor, and the generator, wherein the control means includes a driving mode switching control unit that switches between, at least based on the vehicle speed, a series mode in which the clutch is disengaged and the engine drives the generator to generate electricity while the electric motor is driven by power supplied from the storage battery or the generator to drive the vehicle's drive wheels; and a parallel mode in which the clutch is engaged and the engine and the electric motor drive the vehicle's drive wheels. The driving mode switching control unit is characterized in that, when the vehicle speed conditions for switching from the series mode to the parallel mode are met, the power generated by the generator is in a power generation limiting state in which the power generated by the generator is limited, and the upper limit of the amount of power generated by the generator that the storage battery can accept is less than or equal to the actual power generated by the generator, the driving control device for a hybrid vehicle prohibits switching from the series mode to the parallel mode.

2. The drive control device for a hybrid vehicle according to claim 1, wherein the control means includes a regenerative control unit that generates electricity with the electric motor when the vehicle is decelerating and performs regenerative braking to apply braking force to the vehicle, and the power generation limit state is a deceleration priority state in which the deceleration of the vehicle by regenerative braking is given priority.

3. The drive control device for a hybrid vehicle according to claim 1, wherein the control means includes a regenerative control unit that generates electricity with the electric motor when the vehicle is decelerating and performs regenerative braking to apply braking force to the vehicle, and the power generation limiting state is when the power generated by the regenerative braking is greater than or equal to a predetermined value.

4. The drive control device for a hybrid vehicle according to claim 1, characterized in that the power generation limiting state is a state in which the upper limit amount of power generation received has fallen to a first predetermined value or less.

5. The driving mode switching control unit releases the prohibition on switching from the series mode to the parallel mode when the upper limit of the generated power acceptance is greater than the actual generated power plus a second predetermined value, as described in any one of claims 1 to 4.

6. The drive control device for a hybrid vehicle according to claim 5, characterized in that the second predetermined value is power that generates the torque necessary to control the rotational speed of the engine to a target rotational speed by generating power from the generator in the series mode.

Images