JP7115647B2 - electric vehicle controller - Google Patents

Description

The present disclosure relates to a control device for an electric vehicle including a generator driven by an internal combustion engine.

2. Description of the Related Art Conventionally, there has been known a control device for a series hybrid electric vehicle in which a generator driven by an internal combustion engine generates power, the generated power is supplied to a motor, and the motor drives a drive shaft (for example, Patent Document 1). reference). In the electric vehicle control device of Patent Document 1, when the number of rotations of the generator is increased due to an increase in the amount of power generation required of the generator, the inertia torque required to increase the number of rotations of the generator is reduced by internal combustion. Add to the required torque required for the engine. As described above, in the electric vehicle control device of Patent Document 1, the rotational speed of the generator is quickly increased by adding the inertia torque to the required torque required of the internal combustion engine. As a result, the acceleration performance of the electric vehicle is improved.

Also, conventionally, an electric vehicle control device having a parallel mode, a series mode, and an EV mode is known (see Patent Document 2, for example). In the electric vehicle control device of Patent Document 2, when the target rotation speed of the generator is increasing during the series mode, the inertia torque is added to the required torque required of the internal combustion engine. As described above, the electric vehicle control device of Patent Document 1 stabilizes the power generation amount by adding the inertia torque to the required torque required of the internal combustion engine. As a result, the acceleration performance of the electric vehicle is improved.

Japanese Patent Application Laid-Open No. 2003-20972 JP 2016-124318 A

However, in the electric vehicle control devices of Patent Documents 1 and 2, inert torque for increasing the rotation speed of the generator is added to the required torque required of the internal combustion engine. Therefore, the internal combustion engine needs to output torque corresponding to the inertia torque. As a result, the fuel injection amount of the internal combustion engine increases, and the fuel consumption deteriorates.

An object of the present disclosure is to provide a control device for an electric vehicle that is capable of both suppressing deterioration of fuel consumption of the electric vehicle and improving acceleration performance.

A control device for an electric vehicle according to the present disclosure is a control device for an electric vehicle including an internal combustion engine mounted on the electric vehicle, a generator, a motor, and a drive battery. The generator is driven by the internal combustion engine. The motor drives the drive shaft of the electric vehicle. A drive battery supplies power to the motor. A control device for an electric vehicle includes a driving mode control section, a battery output shortage determination section, and a power generation control section. The running mode control unit switches to a series mode in which the electric vehicle runs with the first electric power supplied from the generator to the motor and the second electric power supplied from the drive battery to the motor. The battery output shortage determination unit determines whether the second power is insufficient. The power generation control unit controls the internal combustion engine and the generator based on the first electric power. The power generation control section includes a first control mode and a second control mode. The first control mode controls the internal combustion engine to change the rotational speed of the internal combustion engine. The second control mode controls the generator to change the speed of the internal combustion engine. The power generation control unit switches from the second control mode to the first control mode when the running mode control unit switches to the series mode and the battery output shortage determination unit determines that the second power is insufficient. The power generation control unit may calculate a target rotation speed, which is a target rotation speed of the internal combustion engine, based on the first electric power, and set a lower limit value of the target rotation speed. The power generation control unit may perform correction control to increase the lower limit value when the running mode control unit switches to the series mode and the battery output shortage determination unit determines that the second power is insufficient. .

According to this control device for an electric vehicle, when the second electric power supplied from the drive battery to the motor is insufficient, the power generation control section causes the internal combustion engine to quickly change the rotation speed by itself in the first control mode. As a result, the first electric power supplied from the generator to the motor rapidly changes. Therefore, even if the second electric power is insufficient during running in the series mode, the motor is quickly supplied with the first electric power. As a result, the acceleration performance of the electric vehicle is improved. On the other hand, if the second electric power is not insufficient, the power generation control unit controls the generator and changes the rotation speed of the internal combustion engine in the second control mode. Controlling the generator may also reduce the first power. However, since the internal combustion engine does not need to increase the rotation by itself, the fuel efficiency is improved. That is, according to this control device for an electric vehicle, it is possible to suppress deterioration of the fuel consumption of the electric vehicle and improve the acceleration performance of the electric vehicle.

Further, according to this configuration, the power generation control section can increase the rotation speed of the internal combustion engine from a high rotation speed state. This makes it easier for the internal combustion engine to reach higher speeds sooner. Therefore, the generator can supply the first electric power to the motor more quickly. As a result, even when the second electric power is reduced, the acceleration performance of the electric vehicle is improved.

The power generation control unit may correct the lower limit value to a larger value as the speed of the electric vehicle increases.

According to this configuration, the higher the speed of the electric vehicle, the faster the internal combustion engine can reach a higher rotational speed. On the other hand, when the speed is low, the number of rotations of the internal combustion engine is low, so that noise and vibration caused by the rotation of the internal combustion engine can be reduced.

The power generation control unit may calculate a target rotation speed, which is a target rotation speed of the internal combustion engine, based on the first electric power. When the target rotation speed is increasing, the power generation control unit may calculate an increase rate of the target rotation speed and set a first limit value for the increase rate. When the running mode control unit switches to the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the power generation control unit sets the second limit value to be greater than the first limit value. Correction control for correction may be performed.

The second limit value may be a smaller value as the target rotation speed is higher.

According to this configuration, the power generation control section can quickly increase the rotation speed of the internal combustion engine. This makes it easier for the internal combustion engine to reach higher speeds sooner. Therefore, the generator can supply the first electric power to the motor more quickly. As a result, even when the second electric power is insufficient, the acceleration performance of the electric vehicle is improved.

The battery output shortage determination unit may include a battery temperature acquisition unit that acquires the temperature of the drive battery. The battery output shortage determination unit may determine that the second power is insufficient when the temperature acquired by the battery temperature acquisition unit is lower than or equal to the first predetermined temperature or higher than or equal to the second predetermined temperature.

The battery output of the drive battery may be limited in high temperature conditions. In addition, the drive battery may have a lower battery output in low temperature conditions. According to this configuration, the motor can receive the supply of the first electric power promptly in either state.

The second limit value may be a smaller value when the temperature of the drive battery obtained by the output shortage determination unit is equal to or higher than the first predetermined temperature than when the temperature is equal to or higher than the first predetermined temperature.

According to this configuration, when the temperature of the drive battery is in a high temperature state such as the second predetermined temperature or higher, the second limit value is suppressed to be low. As a result, when the driving battery is at a high temperature, the rotational speed of the internal combustion engine increases more slowly than when the driving battery is at a low temperature. As a result, noise and vibration caused by the rotation of the internal combustion engine can be reduced. On the other hand, when the temperature of the drive battery is lower than or equal to the first predetermined temperature, the rotational speed of the internal combustion engine increases faster than when the drive battery is at a high temperature.

The power generation control unit may calculate a rotation increase torque for increasing the rotation speed of the internal combustion engine. The power generation control unit may acquire the actual rotation speed of the internal combustion engine. In the first control mode, the power generation control section may suppress the rotational increase torque according to the actual rotational speed.

The power generation control unit may suppress the rotation increase torque when the actual rotation speed is higher than the target rotation speed.

The power generation control unit may suppress the rotational increase torque as the actual rotational speed increases.

According to this configuration, it is possible to suppress an excessive increase in rotation speed when the rotation speed of the internal combustion engine increases.

The control device for the electric vehicle may further include an accelerator opening degree determination unit that determines the accelerator opening degree. The power generation control unit may switch from the first control mode to the second control mode when the accelerator is off.

According to this configuration, the rotational speed of the internal combustion engine changes according to the second control mode when the accelerator is not depressed. This improves fuel efficiency.

The battery output shortage determination unit may determine that the second electric power is insufficient when the speed of the electric vehicle is equal to or higher than the first predetermined speed.

According to this configuration, the acceleration performance is improved when the speed of the electric vehicle is high.

The first predetermined temperature may be calculated based on one or both of the deterioration of the driving battery and the charging rate of the driving battery.

According to this configuration, it is possible to quickly determine the shortage of the second electric power using the first predetermined temperature based on one or both of the deterioration and the charging rate of the drive battery.

The power generation control unit may calculate a target power generation amount, which is a target power generation amount of the generator, based on the first electric power. The power generation control unit may acquire the actual power generation amount, which is the actual power generation amount of the generator. The power generation control unit may switch from the second control mode to the first control mode when the actual power generation amount is smaller than the target power generation amount.

According to this configuration, when the actual power generation amount is smaller than the target power generation amount, the power generation control unit causes the internal combustion engine to quickly increase the rotation speed by itself in the first control mode. As a result, the first electric power supplied from the generator to the motor quickly increases. Therefore, even when the second electric power is insufficient, the acceleration performance of the electric vehicle is improved.

The power generation control unit calculates a target rotation speed, which is a target rotation speed of the internal combustion engine, based on the first electric power, sets an upper limit value of the target rotation speed, and is switched to the series mode by the driving mode control unit, In addition, when the battery output shortage determination unit determines that the second electric power is insufficient, the upper limit value may be limited to a predetermined number of rotations or less.

According to this configuration, deterioration of the fuel consumption of the electric vehicle can be suppressed, and deterioration of vibration and noise caused by an increase in the rotation speed of the internal combustion engine can be suppressed while improving the acceleration performance.

The predetermined rotation speed may be a change point of the output characteristics of the internal combustion engine.

According to this configuration, for example, the power generation control unit can increase the rotation speed of the internal combustion engine until the rotation speed is output at a substantially constant slope with respect to the increase in the rotation speed of the internal combustion engine. As a result, the power generation control unit can efficiently use the output of the internal combustion engine to cause the power generator to generate power.

Further, the power generation control unit may limit the upper limit value to a predetermined number of revolutions or less when the speed of the electric vehicle is less than the second predetermined speed.

According to this configuration, the level of vibration/noise can be adjusted according to the second predetermined speed.

When the speed of the electric vehicle is equal to or higher than the second predetermined speed, the power generation control unit may increase the upper limit value as the speed increases.

According to this configuration, it is possible to increase the rotation speed of the internal combustion engine while suppressing the idling feeling.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a control device for an electric vehicle that can simultaneously suppress deterioration of fuel consumption of the electric vehicle and improve acceleration performance.

1 is a system diagram of an electric vehicle according to an embodiment of the present disclosure; FIG. 1 is a block diagram showing the configuration of an electric vehicle control device according to an embodiment of the present disclosure; FIG. FIG. 2 shows an example of a three-dimensional map according to an embodiment of the present disclosure; FIG. 4 is a diagram showing changes in target engine speed Ert with respect to accelerator opening according to the embodiment of the present disclosure; FIG. 4 is a graph showing an example of the relationship between the increase rate limit value dErtLim and the target engine speed Ert according to the embodiment of the present disclosure; 4 is a graph showing an example of the relationship between rotation increase torque UTq and engine speed deviation according to the embodiment of the present disclosure; 4 is a graph showing an example of the relationship between rotation increase torque UTq and actual engine speed Erq according to the embodiment of the present disclosure; 4 is a flow chart showing a control procedure of the control device according to the embodiment of the present disclosure; 4 is a timing chart showing changes in target engine speed Ert when the upper limit value of target engine speed Ert is changed according to the embodiment of the present disclosure; 4 is a graph showing an example of output characteristics of an internal combustion engine according to an embodiment of the present disclosure;

<First Embodiment>
A controller 20 for an electric vehicle 1 according to a first embodiment of the present disclosure will be described below with reference to the drawings. As shown in FIG. 1, an electric vehicle 1 according to this embodiment is a four-wheel drive hybrid vehicle. The electric vehicle 1 includes an internal combustion engine (ENG) 2, a generator (GEN) 4, a front motor (FrM) 6, a rear motor (RM) 8, a drive battery (BT) 10, and a control device (HVECU). 20 and an accelerator pedal 21 . In the electric vehicle 1 of this embodiment, the front motor 6 drives the front wheel drive shaft 12a of the front wheel 12 via the transaxle 16. As shown in FIG. The rear motor 8 drives the rear wheel drive shaft 14a of the rear wheel 14 via the reduction gear 8c. The front motor 6 is connected to the driving battery 10 via the front inverter 18 and is supplied with electric power (second electric power) from the driving battery 10 . The front inverter 18 has a front motor control unit (FrMCU) 6 a and a generator control unit (GCU) 4 a that controls the generator 4 . The front motor control device 6a acquires a signal from the control device 20 and controls regeneration and power running of the front motor 6 so that the front motor 6 is in a desired operating state. Similarly, the rear motor 8 is connected to the drive battery 10 via the rear inverter 8b, and is supplied with power (second power) from the drive battery 10. As shown in FIG. The rear inverter 8b has a rear motor control unit (RMCU) 8a. The rear motor control device 8a acquires a signal from the control device 20 and controls regeneration and power running of the rear motor 8 so that the rear motor 8 is in a desired operating state.

Internal combustion engine 2 drives generator 4 via transaxle 16 . The internal combustion engine 2 is driven by combustion of fuel supplied from a fuel tank (Fuel TANK) 22 . Various devices and various sensors of the internal combustion engine 2 are electrically connected to an engine control unit (ENG-ECU) 2a. The engine control device 2a acquires a signal from the control device 20 and controls the internal combustion engine 2 to achieve a desired operating state. The transaxle 16 amplifies the rotation speed of the internal combustion engine 2 and transmits it to the generator 4 . The transaxle 16 of this embodiment also has a clutch 16a that transmits and interrupts power between the internal combustion engine 2 and the front motor 6 and between the internal combustion engine 2 and the front wheel drive shaft 12a. The internal combustion engine 2 is connected to a front wheel drive shaft 12a via a clutch 16a of a transaxle 16 to drive the front wheel drive shaft 12a.

The generator 4 is driven by the internal combustion engine 2 to generate electricity. The electric power (first electric power) generated by the generator 4 can charge the drive battery 10, and also the front motor 6 and the rear motor 8 (hereinafter referred to as each motor in the specification) via the front inverter 18 and the rear inverter 8b. ) can be supplied. In this embodiment, the generator 4 is a motor generator, and can rotate the internal combustion engine 2 in addition to generating power. When driven by the internal combustion engine 2 , the generator 4 generates power by applying a load to the generator 4 . On the other hand, the power generator 4 is powered by the drive battery 10 to drive and start the internal combustion engine 2 . The generator 4 is controlled by a generator control device 4 a provided in the front inverter 18 . The generator control device 4a is electrically connected to the control device 20, acquires a signal from the control device 20, and controls power generation and power running so that the generator 4 is in a desired operating state.

The driving battery 10 is composed of a secondary battery such as a lithium ion battery, and has a battery module (not shown) composed of a plurality of battery cells. A drive battery 10 functions as a power source for each motor. Further, the driving battery 10 calculates the state of charge (hereinafter referred to as SOC) of the battery module, the deterioration state of the battery module (hereinafter referred to as SOH), and detects the voltage Bv and the battery temperature Btmp of the battery module. It has a battery monitoring unit (BMU) 10a that performs Battery monitoring unit 10 a acquires battery temperature Btmp of drive battery 10 and transmits it to control device 20 .

The control device 20 is actually configured by a microcomputer including an arithmetic device, a memory, an input/output buffer, and the like. Control device 20 controls each device so that electric vehicle 1 is in a desired operating state based on signals from each sensor and various devices, as well as maps and programs stored in memory.

In this embodiment, various control devices including an engine control device 2a, a generator control device 4a, a front motor control device 6a, a rear motor control device 8a, and a battery monitoring unit 10a are provided separately from the control device 20, respectively. Various control devices are electrically connected to the control device 20 respectively. However, various control devices may be provided integrally with the control device 20 . Each control device, like the control device 20, is composed of a microcomputer including an arithmetic device, a memory, an input/output buffer, and the like.

As shown in FIG. 2 , the control device 20 has a running mode control section 30 , a battery output shortage determination section 32 , a power generation control section 34 and an accelerator opening determination section 36 . Running mode control unit 30 , battery output shortage determination unit 32 , power generation control unit 34 , and accelerator opening determination unit 36 are functional configurations realized by software stored in control device 20 . However, various controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuits). The controller 20 also acquires the rotation speeds of the front wheels 12 and the rear wheels 14 using wheel speed sensors (not shown), and the speed calculation unit 38 calculates the speed V of the electric vehicle 1 based on the rotation speeds of the wheel speed sensors.

The accelerator pedal 21 is a pedal that controls the acceleration and deceleration of the electric vehicle 1 by being depressed by the driver of the electric vehicle 1 . The accelerator pedal 21 is provided with an accelerator position sensor 21a for detecting the depressed position. The accelerator position sensor 21 a is electrically connected to the control device 20 and transmits the accelerator depression position (accelerator opening) to the control device 20 . The accelerator opening determination unit 36 includes a driver request torque calculation unit 36a. The driver requested torque calculation unit 36a calculates the driver requested torque DTq of the electric vehicle 1 based on the accelerator opening Th obtained from the accelerator position sensor 21a.

Driving mode control unit 30 selects one of parallel mode, series mode, and EV mode by controlling clutch 16a based on information such as speed V, SOC, and accelerator opening Th. Switch to run mode. In the parallel mode, the running mode control unit 30 connects the clutch 16a and drives the front wheel drive shaft 12a by both the internal combustion engine 2 and the front motor 6. FIG. At this time, the front motor 6 is supplied with one or both of the electric power (second electric power) from the drive battery 10 and the electric power (first electric power) generated by the generator 4 . Similarly, the rear motor 8 is supplied with either one or both of electric power (second electric power) from the drive battery 10 and electric power (first electric power) generated by the generator 4 to drive the rear wheel drive shaft 14a. . In the EV mode, the driving mode control unit 30 releases the clutch 16a and supplies the electric power (second electric power) of the driving battery 10 to each motor, and each motor operates the front wheel drive shaft 12a and the rear wheel drive shaft 14a (hereinafter referred to as (referred to as each drive shaft in the specification).

In the series mode, the running mode control unit 30 releases the clutch 16a, drives the generator 4 with the internal combustion engine 2, and supplies the first electric power generated by the generator 4 to each motor. In addition, when the drive power for each motor to drive each drive shaft is insufficient with the first power, the running mode control unit 30 also supplies the second power from the drive battery 10 to each motor. That is, running mode control unit 30 runs electric vehicle 1 with the first electric power and the second electric power in the series mode. In this way, in the series mode, the running mode control unit 30 adds the second electric power supplied from the drive battery 10 to each motor to the first electric power supplied from the generator 4 to each motor, thereby operating the internal combustion engine 2. The acceleration performance of the electric vehicle 1 can be improved while operating efficiently and reducing fuel consumption when the internal combustion engine 2 generates power with the generator 4 .

The running mode control unit 30 includes a drive shaft torque calculation unit 30a, a front/rear distribution calculation unit 30b, a front motor engine torque distribution calculation unit 30c, a power conversion calculation unit 30d, and a drive shaft torque limit value calculation unit 30e. include. The drive shaft torque calculator 30a acquires the driver requested torque DTq and the upper limit drive shaft torque TqLim. Drive shaft torque calculation unit 30a calculates target drive shaft torque FRTq to be generated in each drive shaft based on driver request torque DTq and upper limit drive shaft torque TqLim.

The upper limit drive shaft torque TqLim is obtained by subtracting auxiliary power consumption consumed by electronic devices mounted on the electric vehicle 1 and loss in each motor from the power generation amount GWi based on the battery upper limit power W2 and the capacity of the generator 4, which will be described later. , divided by the velocity V and then multiplied by the unit conversion factor. The upper limit drive shaft torque TqLim may be calculated in the drive shaft torque limit value calculation section 30e. However, the target drive shaft torque FRTq is not limited to these calculation methods, and a map or the like may be used, for example. After performing these calculations, the drive shaft torque calculation unit 30a transmits the target drive shaft torque FRTq to the power conversion calculation unit 30d. The power conversion calculation unit 30 d converts the target drive shaft torque FRTq into a target power generation W<b>1 and transmits the target power generation W<b>1 to the power generation control unit 34 .

The front/rear distribution calculation unit 30b obtains road surface conditions and the like, and based on the road surface conditions, etc., the target front wheel axle torque FTq to distribute the target drive axle torque FRTq to the front wheel drive shaft 12a, and the target rear wheel axle torque FTq to distribute to the rear wheel drive shaft 14a. A wheelset torque RTq is calculated and transmitted to the front motor control device 6a and the rear motor control device 8a. The front motor engine torque distribution calculation section 30c calculates a parallel engine torque PETq required for the internal combustion engine 2 during the parallel mode.

The battery output shortage determination unit 32 determines whether or not the second power supplied from the drive battery 10 to each motor is insufficient. The battery output shortage determination unit 32 includes a battery output calculation unit 32a. The battery output calculation unit 32a acquires the SOC, SOH, battery temperature Btmp, voltage Bv, etc. of the drive battery 10 from the battery monitoring unit 10a, and calculates the upper limit value of the second power that the drive battery 10 can supply to each motor. A battery upper limit power W2 is calculated. The battery output shortage determination unit 32 determines that the second power is insufficient when the battery upper limit electric power W2 of the drive battery 10 is lower than the battery upper limit electric power W2 in the normal state.

In this embodiment, the battery output shortage determination unit 32 includes a battery temperature acquisition unit 32b. Battery temperature acquisition unit 32b acquires battery temperature Btmp from battery monitoring unit 10a. The battery output shortage determination unit 32 determines that the second power is insufficient when the battery temperature Btmp is equal to or lower than the first predetermined temperature T1. The first predetermined temperature T1 is a temperature predetermined on a map based on the SOC and SOH. More specifically, as in an example of a three-dimensional map shown in FIG. 3, the battery output shortage determination unit 32 determines a value (state of power, hereinafter referred to as a value) that the driving battery 10 can output based on the SOC and the battery temperature Btmp. SOP) is defined, and a plurality of maps are stored for each SOH. As indicated by the arrow in FIG. 3, when the driving battery 10 is new (for example, SOH=100%), the SOP is 15 kw when the SOC is 20% and the battery temperature Btmp is -20.degree. be. On the other hand, when the drive battery 10 is in a deteriorated state (for example, SOH=30%), the SOP becomes 15 kw when the SOC is 20% and the battery temperature Btmp is 0°C.

In this way, the battery output shortage determination unit 32 acquires the SOH and SOC, compares the acquired SOH and SOC with the three-dimensional map, and determines the battery temperature Btmp as the SOP for determining that the battery output has decreased (hereinafter referred to as the reference SOP). is obtained from the 3D map. Here, the battery output shortage determination unit 32 can also acquire an actual SOP (hereinafter referred to as actual SOP). However, the actual SOP may be corrected in accordance with the decrease in voltage Bv in order to prevent drive battery 10 from being overdischarged. Therefore, when the battery output shortage determination unit 32 determines a decrease in battery output by comparing the actual SOP and the reference SOP, there is a possibility that the determination may not be performed correctly. Therefore, the battery output shortage determination unit 32 acquires the battery temperature Btmp, which serves as the reference SOP, to accurately and quickly determine the decrease in the battery upper limit electric power W2 of the drive battery 10 . Note that the battery output shortage determination unit 32 may determine that the battery upper limit electric power W2 has decreased from the outside air temperature instead of the battery temperature Btmp. Further, the battery output shortage determination unit 32 sets the first predetermined temperature T1 to a cryogenic temperature (for example, −20° C.) and does not acquire the SOH and SOC. can be judged to be declining. Furthermore, battery output shortage determination unit 32 may determine a decrease in battery upper limit electric power W2 based on a two-dimensional map showing the relationship between either one of SOH and SOC and battery temperature Btmp and SOP. Also, the battery upper limit power W2 may be calculated by the battery monitoring unit (BMU) 10a.

Further, the battery output shortage determination unit 32 determines that the second power is insufficient when the battery temperature Btmp is equal to or higher than the second predetermined temperature T2. More specifically, when the battery temperature Btmp is equal to or higher than the second predetermined temperature T2, the battery output shortage determination unit 32 of the control device 20 suppresses the battery upper limit power W2, thereby suppressing the temperature rise of the driving battery 10. do. As a result, the second power that can be supplied from the drive battery 10 to each motor decreases. Battery output shortage determination unit 32 determines that the second power is insufficient when driving battery 10 suppresses battery upper limit power W2 in a high temperature state.

Furthermore, the battery output shortage determination unit 32 obtains the speed V, and determines that the second electric power is insufficient when the speed V is equal to or higher than the first predetermined speed Vt. That is, when the electric vehicle 1 is traveling at high speed, the energy required for acceleration increases. Therefore, when the speed is equal to or higher than the first predetermined speed Vt, larger amounts of the first electric power and the second electric power are required than when the speed is lower than the first predetermined speed Vt. Therefore, when the speed is equal to or higher than the first predetermined speed Vt, the battery output shortage determination unit 32 determines that the second power is insufficient, so that the first power can be quickly supplied to each motor. That is, the battery output shortage determination unit 32 determines that the second power is insufficient when the speed is equal to or higher than the first predetermined speed Vt even when the battery upper limit electric power W2 is not lowered and the battery upper limit electric power W2 is not suppressed. judge that it is.

The power generation control unit 34 controls the internal combustion engine 2 and the generator 4 based on the target power generation W1 calculated by the drive shaft torque calculation unit 30a and the power conversion calculation unit 30d. Here, the target generated power W1 is a target value of the first power that the generator 4 should supply to each motor. In the present embodiment, the power generation control unit 34 drives the generator 4 with the internal combustion engine 2 to generate the target power generation W1. Calculate.

The power generation control unit 34 includes a power calculation unit 34a, a target engine speed calculation unit 34b, an engine torque calculation unit 34c, and a generator torque calculation unit 34d. Based on the target power generation W1, the power calculation unit 34a calculates a target power generation amount GW to be requested of the power generator 4, taking into account the transmission loss that occurs when the first power is supplied from the power generator 4 to each motor. do. The transmission loss may be calculated based on a map recording the relationship between the power generation amount of the generator 4 and the transmission loss. The target power generation amount GW is calculated by taking into account the power to be charged in the drive battery 10, other power required for the equipment of the electric vehicle 1, and the upper limit value of the power generation amount for protecting each motor. good too.

The target engine rotation speed calculation unit 34b acquires the target power generation amount GW, and based on the target power generation amount GW, the target engine rotation speed (target rotation speed ) Compute Ert. At this time, the target engine speed calculation unit 34b refers to a map that records the fuel injection amount and ignition timing of the internal combustion engine 2, and calculates the target engine speed Ert so that the internal combustion engine 2 has the best fuel efficiency. good too. As a result, the fuel efficiency of the electric vehicle 1 is improved. Further, the target engine speed calculation unit 34b may acquire the speed V and calculate the target engine speed Ert according to the speed V. FIG. As a result, it is possible to prevent the rotation speed of the internal combustion engine 2 from becoming excessively high with respect to the speed V when the electric vehicle 1 is accelerated.

The power generation control unit 34 sets the lower limit value minErt of the target engine speed Ert. Further, when the running mode control unit 30 switches to the series mode and the battery output shortage determination unit 32 determines that the second electric power is insufficient, the power generation control unit 34 increases the lower limit value minErt. Correction control is performed to control the internal combustion engine 2 (this correction control is hereinafter referred to as lower limit value correction control in the specification and FIG. 8). As shown in FIG. 4, the lower limit value minErt is the target engine speed Ert from time T0 to time T1 when the accelerator pedal 21 is not depressed. In this embodiment, the target engine speed calculator 34b acquires the target engine speed Ert and sets the initial value of the lower limit value minErt. The initial value may be a pre-stored value. When the battery output shortage determination unit 32 determines that the second electric power is insufficient, the target engine speed calculation unit 34b corrects the lower limit value minErt of the target engine speed Ert to a value larger than the initial value. Calculation is performed (see FIG. 4 Ert during correction).

Further, the target engine speed calculation unit 34b acquires the target engine speed Ert and the speed V, and performs correction calculation to set the lower limit value minErt of the target engine speed Ert to a value larger than the initial value as the speed V increases. you can go As a result, the first electric power supplied from the generator 4 to each motor rises quickly. Therefore, the acceleration performance of the electric vehicle 1 is improved. Also, the higher the speed V of the electric vehicle 1, the faster the actual engine speed Erq, which will be described later, is likely to reach a higher speed. On the other hand, when the speed V is low, the actual engine speed Erq, which will be described later, is low, so that the noise and vibration caused by the rotation of the internal combustion engine 2 can be reduced.

When the target power generation amount GW is increasing based on the target power generation W1, the power generation control unit 34 sets the increase rate limit value dErtLim of the target engine speed Ert. When the running mode control unit 30 switches to the series mode and the battery output shortage determination unit 32 determines that the second electric power is insufficient, the power generation control unit 34 increases the increase rate limit value dErtLim. Correction control is performed to control the internal combustion engine 2 (hereinafter, in the specification and FIG. 8, this correction control is referred to as limit value correction control). The increase rate limit value dErtLim is the upper limit value of the change rate per unit time of the target engine speed Ert when the accelerator pedal 21 is depressed. That is, in FIG. 4, it corresponds to the upper limit of the slope of the target engine speed Ert from time T1 to time T2.

In this embodiment, the target engine speed calculator 34b sets the increase rate limit value dErtLim of the target engine speed Ert. The target engine speed calculation unit 34b sets an initial value (first limit value) of the increase rate limit value dErtLim from time T1 to time T2. The initial value may be a pre-stored value. The target engine speed calculation unit 34b performs correction calculation for correcting the increase rate limit value dErtLim to a second limit value larger than the initial value. As a result, the power generation control unit 34 can quickly increase the actual engine speed Erq, which will be described later. Therefore, the actual engine speed Erq, which will be described later, tends to quickly reach a higher speed. As a result, the generator 4 can supply the first electric power to each motor more quickly, and the acceleration of the electric vehicle 1 is improved.

Further, in the present embodiment, the target engine speed calculator 34b decreases the second limit value as the target engine speed Ert increases. As shown in FIGS. 4 and 5, for example, between 4000 rpm and 5000 rpm, the target engine speed Ert ( correction time Ert) rises gently. This makes it easy to suppress excessive racing of the actual engine speed Erq, which will be described later.

Furthermore, the target engine speed calculation unit 34b may set the second limit value to a smaller value when the temperature of the drive battery 10 is higher than when the temperature of the drive battery 10 is lower. More specifically, as shown in FIG. 5, the increase rate limit value dErtLim when the battery temperature Btmp is equal to or higher than the second predetermined temperature T2 is the increase rate limit value when the battery temperature Btmp is equal to or lower than the first predetermined temperature T1. It is a value smaller than dErtLim. That is, the battery temperature Btmp may be equal to or higher than the second predetermined temperature T2 even when the outside air temperature is normal temperature (approximately 10° C. to 25° C.). Therefore, the frequency that the battery temperature Btmp becomes equal to or higher than the second predetermined temperature T2 is higher than the frequency that the battery temperature Btmp becomes equal to or lower than the first predetermined temperature T1. In this way, when the drive battery 10 is in a high temperature state, which occurs more frequently, the target engine speed calculation unit 34b sets the increase rate limit value dErtLim more than when the drive battery 10 is in a low temperature state. Use a small value. As a result, the rotational speed of the internal combustion engine 2 rises slowly. As a result, noise and vibration caused by the rotation of the internal combustion engine 2 can be reduced. On the other hand, when the driving battery 10 is at a low temperature, the rotation speed of the internal combustion engine 2 increases faster than when the driving battery 10 is at a high temperature.

The engine torque calculation unit 34c acquires the target power generation amount GW and the target engine speed Ert, and calculates the engine request torque ETq requested to the internal combustion engine 2 based on the target power generation amount GW and the target engine speed Ert. More specifically, the engine torque calculation unit 34c calculates the engine torque ETq1 by dividing the target engine speed Ert from the target power generation amount GW, and adds torque for changing the speed of the internal combustion engine 2. If necessary, this torque is added to calculate the engine demand torque ETq. The engine torque calculator 34c transmits the engine demand torque ETq to the engine control device 2a. The engine control device 2a calculates the actual engine torque ETqr based on the actual engine speed (actual rotation speed) Erq obtained from various sensors such as a crank angle sensor (not shown) of the internal combustion engine 2 . The engine control device 2a acquires the engine demand torque ETq, and controls the internal combustion engine 2 so that the actual engine torque ETqr becomes the engine demand torque ETq. At this time, the engine control device 2a transmits the actual engine speed Erq to the engine torque calculator 34c. The engine torque calculator 34c acquires the actual engine speed Erq, and corrects the engine demand torque ETq so as to achieve the target engine speed Ert.

The generator torque calculation unit 34d acquires the engine demand torque ETq, and calculates a target load torque LTq, which is the target load torque of the generator 4, based on the engine demand torque ETq. More specifically, the generator torque calculation unit 34d calculates the target load torque LTq by adding or subtracting a torque for changing the rotation speed of the internal combustion engine 2 to or from the load torque LTq1 balanced with the engine demand torque ETq. The generator torque calculation unit 34d may calculate the target load torque LTq based on a map recording the relationship between the engine demand torque ETq and the target load torque LTq. The generator torque calculator 34d transmits the target load torque LTq to the generator control device 4a. The generator control device 4a detects the actual power generation amount GWr, which is the actual amount of power generated by the generator 4, and the rotation speed of the generator 4, and calculates the actual load torque LTqr from the actual power generation amount GWr and the rotation speed of the generator 4. Then, the generator 4 is controlled so that the actual load torque LTqr becomes the target load torque LTq. Further, the generator control device 4a transmits the actual power generation amount GWr to the engine torque calculation section 34c via the generator torque calculation section 34d.

The power generation control unit 34 includes a first control mode and a second control mode. The power generation control unit 34 is switched to the series mode by the running mode control unit 30, the battery output shortage determination unit 32 determines that the second electric power is insufficient, and the accelerator opening Th is equal to or greater than the predetermined opening Tht. In this case, the second control mode is switched to the first control mode. In other words, the power generation control unit 34 switches from the second control mode to the first control mode when the battery upper limit electric power W2 is decreasing even though the driver is requesting acceleration. Note that when the actual power generation amount GWr is smaller than the target power generation amount GW, that is, when the actual power generation amount GWr is insufficient with respect to the target power generation amount GW, the power generation control unit 34 switches from the second control mode to the first control mode. You can switch to mode.

In the first control mode, the power generation control unit 34 controls the internal combustion engine 2 to change the actual engine speed Erq of the internal combustion engine 2 . More specifically, in the first control mode, the power generation control unit 34 calculates the required engine torque ETq including the rotation increase torque UTq required to increase the target engine rotation speed Ert. That is, the engine torque calculation unit 34c calculates the required engine torque ETq by adding the rotation increase torque UTq to the engine torque ETq1 obtained based on the target power generation amount GW. The rotation-increasing torque UTq takes into consideration the friction loss of the internal combustion engine 2 and the generator 4, the inertial force of the crankshaft of the internal combustion engine 2 and the rotating shaft of the generator 4, and the like, and is preset for each target engine speed Ert. is.

On the other hand, in the second control mode, the power generation control unit 34 controls the generator 4 to change the actual engine speed Erq of the internal combustion engine 2 . More specifically, in the second control mode, the power generation control unit 34 calculates the target load torque LTq including the rotational increase torque UTq. That is, the generator torque calculation unit 34d calculates the target load torque LTq by subtracting the rotation increasing torque UTq from the load torque LTq1 balanced with the engine demand torque ETq.

Thus, in the first control mode, the internal combustion engine 2 increases the actual engine speed Erq by itself, so the intake air amount and the fuel injection amount of the internal combustion engine 2 increase more than in the second control mode. As a result, the fuel efficiency of the internal combustion engine 2 deteriorates in the first control mode. However, since the power generation amount of the generator 4 does not decrease, the first electric power supplied from the generator 4 to each motor does not decrease. As a result, the acceleration performance of the electric vehicle 1 is improved.

On the other hand, in the second control mode, the generator torque calculation unit 34d subtracts the rotation increasing torque UTq, so the actual power generation amount GWr of the generator 4 decreases. However, since the generator 4 reduces the actual power generation amount GWr, the actual engine speed Erq of the internal combustion engine 2 increases while the output of the internal combustion engine 2 is maintained. As a result, the fuel efficiency of the internal combustion engine 2 is maintained. Note that when the target engine speed Ert decreases, the actual engine speed Erq decreases by increasing the target load torque LTq in the second control mode.

As shown in FIGS. 6 and 7, in the present embodiment, the power generation control unit 34 suppresses the rotation increase torque UTq in accordance with the actual engine speed Erq in the first control mode. More specifically, the power generation control unit 34 may suppress the rotation increase torque UTq when the actual engine speed Erq is higher than the target engine speed Ert. That is, as shown in FIG. 6, the deviation (difference) between the target engine speed Ert and the actual engine speed Erq is calculated, and the smaller the deviation, the smaller the rotation increasing torque UTq. In the graph showing the relationship between the rotation increase torque UTq and the difference shown in FIG. 6, the rotation increase torque UTq is reduced when the deviation is less than 300 rpm, and the rotation increase torque UTq is set to zero when the deviation is zero or less. . As a result, it is possible to prevent the actual engine speed Erq from rising excessively.

Furthermore, the power generation control unit 34 may suppress the rotation increase torque UTq as the actual engine speed Erq increases. That is, as shown in FIG. 7, for example, when the actual engine speed Erq is 4000 rpm or more, the power generation control unit 34 decreases the rotation increase torque UTq as the actual engine speed Erq increases. Even in this case, it is possible to prevent the actual engine speed Erq from rising excessively.

Next, the control procedure of the power generation control section 34 and the battery output shortage determination section 32 of the control device 20 of the present embodiment will be described with reference to the flowchart of FIG. The power generation control unit 34 starts a control operation when an ignition switch (not shown) is turned on. Also, the power generation control unit 34 starts the control operation in the state of the second control mode.

In S1, the power generation control unit 34 determines whether or not the running mode has been switched to the series mode by the running mode control unit 30 . When the power generation control unit 34 of the control device 20 determines that the mode has been switched to the series mode (S1 Yes), the process proceeds to S2.

S2 to S4 are processes performed by the battery output shortage determination unit 32 . In S2 to S4, the battery output shortage determination unit 32 determines whether or not the second power is insufficient. In S2, the battery output shortage determination unit 32 determines whether or not the battery temperature Btmp is equal to or lower than the first predetermined temperature T1. If the battery temperature Btmp is higher than the first predetermined temperature T1 (S2 No), the battery output shortage determination unit 32 advances the process to S3. On the other hand, when the battery temperature Btmp is equal to or lower than the first predetermined temperature T1 (S2 Yes), the battery output shortage determination unit 32 determines that the second power is insufficient, and transmits the determination result to the power generation control unit 34 . The power generation control unit 34 acquires the determination result of the battery output shortage determination unit 32, and advances the process to S10.

In S10, the power generation control unit 34 performs lower limit value correction control. The power generation control unit 34 acquires the speed V (km/h) and performs lower limit correction control to increase the lower limit minErt of the target engine speed Ert as the speed V increases. At this time, for example, if the initial value of the lower limit minErt is 0 rpm, the lower limit minErt may be corrected to 1000 rpm. Further, the power generation control unit 34 may appropriately correct the lower limit minErt to a value larger than 1000 rpm as the speed V increases. Note that in the second control mode, the power generation control unit 34 uses the initial value of the lower limit value minErt (see FIG. 4). After performing the lower limit value correction control, the power generation control unit 34 advances the process to S5.

In S3, the battery output shortage determination unit 32 determines whether the battery temperature Btmp is equal to or higher than the second predetermined temperature T2. When the battery output shortage determination unit 32 determines that the battery temperature Btmp is less than the second predetermined temperature T2 (S3 No), the process proceeds to S4. On the other hand, when the battery output shortage determination unit 32 determines that the battery temperature Btmp is equal to or higher than the second predetermined temperature T2 (S3 Yes), it determines that the second electric power is insufficient, and outputs the determination result to the power generation control unit 34. Send to The power generation control unit 34 acquires the determination result of the battery output shortage determination unit 32, and advances the process to S5.

In S4, the battery output shortage determination unit 32 acquires the speed V of the electric vehicle 1 and determines whether the speed V is equal to or higher than Vt. When the battery output shortage determination unit 32 determines that the speed V is equal to or higher than Vt (S4 Yes), the battery output shortage determination unit 32 determines that the second power is insufficient, and transmits the determination result to the power generation control unit 34 . That is, the battery output shortage determination unit 32 determines that the second power is insufficient when any one of the conditions from S2 to S4 is satisfied. The power generation control unit 34 acquires the determination result of the battery output shortage determination unit 32, and advances the process to S5. On the other hand, when the battery output shortage determination unit 32 determines that the speed V is less than Vt (S4 No), it determines that none of the conditions of S2 to S4 is satisfied, and the second power is not insufficient. I judge. The battery output shortage determination unit 32 transmits this determination result to the power generation control unit 34 . The power generation control unit 34 acquires the determination result of the battery output shortage determination unit 32, and advances the process to S5.

In S5, the power generation control unit 34 determines whether or not the accelerator opening Th is greater than or equal to a predetermined opening Tht. When the power generation control unit 34 determines that the accelerator opening Th is greater than or equal to the predetermined opening Tht (S4 Yes), the process proceeds to S6. In S6, the power generation control unit 34 switches from the second control mode to the first control mode. After switching to the first control mode, the power generation control unit 34 advances the process to S7. In S5, the power generation control unit 34 may determine whether or not the actual power generation amount GWr is less than (smaller than) the target power generation amount GW. When the power generation control unit 34 determines that the actual power generation amount GWr is less than the target power generation amount GW, the process may proceed to S6.

In S7, the power generation control unit 34 determines whether or not the target engine speed Ert is increasing. When the power generation control unit 34 determines that the target engine speed Ert is increasing (S7
Yes), the process proceeds to S8. A case where the target engine speed Ert is increasing means a case where the accelerator pedal 21 is depressed, the driver demanded torque DTq increases, the target power generation W1 also increases, and the target power generation amount GW increases. That is, the electric vehicle 1 is in an accelerating state. The power generation control unit 34 may determine that the target engine speed Ert is increasing when the accelerator opening Th is equal to or greater than a predetermined opening Tht. That is, the power generation control unit 34 may simultaneously determine in S5 whether or not the target engine speed Ert is increasing. Further, when the actual power generation amount GWr is smaller than the target power generation amount GW, it may be determined that the target engine speed Ert is increasing.

In S8, the power generation control unit 34 performs limit value correction control. Here, for example, if the initial value of the increase rate limit value dErtLim is 20%, the power generation control unit 34 may perform correction to set it to a value greater than 20%. Note that the initial value of the increase rate limit value dErtLim is used in the second control mode. If limit value correction control is performed in S7, the process proceeds to S9.

In S9, the power generation control unit 34 acquires the accelerator opening Th from the accelerator opening determination unit 36, and determines whether or not the accelerator opening Th is zero (accelerator off). When the power generation control unit 34 determines that the accelerator is off (S9 Yes), both the lower limit value correction and the increase rate limit correction are completed, and the process proceeds to S11. In S11, the power generation control unit 34 switches from the first control mode to the second control mode, and advances the process before S1.

When the power generation control unit 34 determines that it is not the series mode (S1 No), the process returns to before S1. When it is determined that the accelerator opening Th is smaller than the predetermined opening Tht (S5 No), the process proceeds to S11, the second control mode is maintained, and the process returns to before S1.

When the power generation control unit 34 determines that the target engine speed Ert has not increased (S7
No), and if it is determined that the accelerator is not turned off (S9 No), the process returns to before S5. As a result, the first control mode is maintained until the accelerator opening Th becomes smaller than the predetermined opening Tht.

Next, a control device 220 for an electric vehicle 201 according to a second embodiment of the present disclosure will be described with reference to the drawings. Note that the system configurations of the electric vehicle 1 and the control device 220 in the second embodiment are the same as those in the first embodiment, so description thereof will be omitted. Also, regarding the control performed by the control device 220 in the second embodiment, only points that differ from the control in the first embodiment will be described.

A control device 220 in the second embodiment differs from the control device 20 in the first embodiment in that a power generation control unit 234 sets an upper limit maxErt in addition to a lower limit minErt of the target engine speed Ert.

As shown in FIG. 9, the timing chart of the present embodiment shows an example in which the battery temperature Btmp acquired by the battery temperature acquisition unit 32a rises step by step and the second power is insufficient. As shown from time 0 to time A in FIG. 9, as speed V of electric vehicle 201 increases, battery temperature Btmp increases. The target engine speed Ert increases from time 0 to time A with the increase rate limit value dErtLim at the first limit value. After time A, the speed V decreases toward time B, and the running mode control unit 30 switches the running mode to the series mode. On the other hand, the battery temperature Btmp does not decrease from time A to time B either. At time B, when the battery temperature Btmp reaches or exceeds the second predetermined temperature T2, the battery output shortage determination unit 32 determines that the second power is insufficient.

When the running mode control unit 30 switches to the series mode and the battery output shortage determination unit 32 determines that the second electric power is insufficient, the power generation control unit 234 corrects the increase rate limit value dErtLim. Executes value correction control (see ON of limit value correction control in FIG. 9). In addition to limit value correction control, power generation control unit 234 may also perform at least one of lower limit value correction control and switching from the second control mode to the first control mode.

From time C to time D in FIG. 9, the user of the electric vehicle 201 depresses the accelerator pedal 21 again. During that time, the battery temperature Btmp does not drop, and the series mode continues. In such a case, the power generation control unit 234 executes vibration/noise reduction control (hereinafter referred to as NV reduction control, where NV is an abbreviation for Noise and Vibration). More specifically, the power generation control unit 234 limits the upper limit value maxErt to a predetermined rotational speed R1 or less. As shown in the graph of the target engine speed Ert from time C to time D, the power generation control unit 234 keeps the increase rate limit value dErtLim higher than the first limit value until the target engine speed Ert reaches the predetermined speed R1. The target engine speed Ert is increased using a large second limit value. As a result, the power generation control unit 234 suppresses the deterioration of the fuel consumption of the electric vehicle 201 and improves the acceleration performance, while suppressing the deterioration of the vibration and noise accompanying the increase in the rotational speed of the internal combustion engine 2 .

Here, the predetermined rotation speed R1 may be a change point of the output characteristics of the internal combustion engine 2 . FIG. 10 is a graph showing output characteristics of the internal combustion engine 2. As shown in FIG. As shown in FIG. 10, the maximum engine output of the internal combustion engine 2 has a substantially constant slope up to a predetermined rotation speed R1, and after exceeding the predetermined rotation speed R1, the slope of the maximum engine output decreases. The power generation control unit 234 increases the target engine speed Ert up to the predetermined engine speed R1 using the second limit value as the increase rate limit value dErtLim. As a result, the power generation control unit 234 efficiently uses the output of the internal combustion engine 2 and quickly supplies the first power to the motor.

As shown from time B to time C in FIG. 9 , the power generation control unit 234 determines that the battery output shortage determination unit 32 determines that the second electric power is insufficient when the target engine rotation speed Ert is equal to or higher than the predetermined rotation speed R1. When it is determined that the target engine speed Ert reaches the predetermined speed R1, the NV reduction control is executed.

As shown from time D to time E in FIG. 9, the power generation control unit 234 limits the target engine speed Ert to a predetermined speed R1 or less when the speed V of the electric vehicle 201 is less than the second predetermined speed V2. In this embodiment, from time D to time E, the speed V of the electric vehicle 201 continues to increase. During this period, the power generation control unit 234 limits the upper limit value maxErt of the target engine speed Ert by maintaining the target engine speed Ert at the predetermined speed R1.

Further, in the section from time C to time E, since the increase rate limit value dErtLim is high, the target engine speed Ert rises quickly, and the actual engine speed Erq also rises quickly. On the other hand, when the actual engine speed Erq of the internal combustion engine 2 is higher than the speed V of the electric vehicle 201, the user of the electric vehicle 201 feels uncomfortable with the large vibration and noise of the electric vehicle 201, or the electric vehicle 201 A sense of incongruity (feeling of idle running) as if the driver were running idle may occur. However, when the engine speed is less than the second predetermined speed V2, the power generation control unit 234 limits the upper limit value maxErt of the target engine speed Ert to the predetermined speed R1. Furthermore, from time D to time E, power generation control unit 234 maintains target engine speed Ert while speed V of electric vehicle 201 is increasing. As a result, the power generation control unit 234 can suppress the discomfort caused by the rapid decrease in the actual engine speed Erq.

As shown from time E to time F in FIG. 9 , when the speed V of the electric vehicle 201 is equal to or greater than the second predetermined speed V2 and less than the third predetermined speed V3, the power generation control unit 234 controls the upper limit value as the speed V increases. Relax maxErt. The third predetermined speed V3 is higher than the second predetermined speed V2. In this embodiment, the power generation control unit 234 refers to a map in which the upper limit value maxErt of the target engine speed Ert increases stepwise as the speed V increases. The power generation control unit 234 increases the upper limit value maxErt of the target engine speed Ert according to the speed V, thereby relaxing the upper limit value maxErt. As a result, as the speed V increases, the actual power generation amount GWr also increases. As a result, the lack of battery output can be compensated for while suppressing the idling feeling, and the acceleration performance of the electric vehicle 201 can be improved.

As shown after time F in FIG. 9, the power generation control unit 234 cancels the restriction on the upper limit value maxErt when the speed is equal to or higher than the third predetermined speed V3. In the present embodiment, since the speed V of the electric vehicle 201 increases even after time F, the power generation control unit 234 maintains the target engine speed Ert at the maximum speed Rmax, which is the maximum value of the target engine speed Ert. Thereafter, when the accelerator pedal 21 is released and the electric vehicle 201 decelerates, the power generation control unit 234 decreases the target engine speed Ert. When the target engine speed Ert finally falls below the predetermined speed R1, the power generation control unit 234 ends the NV reduction control.

As described above, according to the control device 20, 220 of the electric vehicle 1, 201 of the present disclosure, it is possible to suppress the deterioration of the fuel consumption of the electric vehicle 1, 201 and improve the acceleration performance.

<Other embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the scope of the invention. In particular, multiple modifications described herein can be arbitrarily combined as required.

(a) In the above-described first embodiment, the power generation control unit 34 switches to the first control mode when determining that the accelerator opening Th is equal to or greater than the predetermined opening Tht, but the present disclosure is not limited to this. When the battery output shortage determining unit 32 determines that the second power is insufficient in S2 to S4, the power generation control unit 34 may acquire the determination result and immediately switch to the first control mode.

(b) In the first embodiment described above, when the drive battery 10 is at or below the first predetermined temperature T1 in S2 (Yes in S2), the power generation control unit 34 performs the lower limit value correction control before switching to the first control mode. Although an example has been described, the present disclosure is not limited to this. Lower limit value correction control may be performed after switching to the first control mode.

(c) In the above-described first embodiment, when the battery output shortage determining unit 32 determines that the second power is insufficient, the power generation control unit 34 performs lower limit value correction control and switches to the first mode. , and limit value correction control, the present disclosure is not limited to this. If the user of the electric vehicle 1 selects the eco mode even if the battery output shortage determination unit 32 determines that the second power is insufficient, the power generation control unit 34 performs lower limit value correction control, Either or all of the switching to the 1 mode and the limit value correction control may not be performed. As a result, in the case of eco mode, priority can be given to fuel efficiency. Further, the power generation control unit 34 may have a selection unit that allows the user of the electric vehicle 1 to select any one of lower limit value correction control, switching to the first mode, and limit value correction control. This allows the user to selectively give priority to either acceleration or fuel economy. Further, the power generation control unit 34 is interlocked with the navigation system of the electric vehicle 1, and when the electric vehicle 1 is traveling in a residential area, the lower limit value correction control need not be performed. As a result, the electric vehicle 1 can quietly run in a residential area.

(d) In the first embodiment and the second embodiment, the case where the electric vehicle 1, 201 is a four-wheel drive hybrid vehicle has been described as an example, but the present disclosure is not limited to this. The electric vehicle 1, 201 can be a plug-in hybrid car, and may have a power feeding function to feed power from the drive battery 10 to external devices (for example, home appliances).

1, 201: electric vehicle, 2: internal combustion engine, 4: generator 6: front motor, 8: rear motor, 10: drive battery 12a: front wheel drive shaft, 14a: rear wheel drive shaft, 20, 220: control device 21 : Accelerator pedal 21a: Accelerator position sensor 30: Driving mode control unit 32: Battery output shortage determination unit 32a: Battery temperature acquisition unit 34, 234: Power generation control unit 36: Accelerator opening determination unit Btmp: Battery temperature Ert : target engine speed (target speed), Erq: actual engine speed (actual speed)
GW: target power generation amount, GWr: actual power generation amount, T: predetermined temperature, V: speed minErt: lower limit value, dErtLim: increase rate limit value

Claims (18)

An electric vehicle having an internal combustion engine mounted on the electric vehicle, a generator driven by the internal combustion engine, a motor driving a drive shaft of the electric vehicle, and a drive battery supplying electric power to the motor a controller,
a driving mode control unit for switching to a series mode for driving the electric vehicle by first electric power supplied from the generator to the motor and second electric power supplied from the drive battery to the motor;
a battery output shortage determination unit that determines whether the second power is insufficient;
a power generation control unit that controls the internal combustion engine and the generator based on the first electric power;
with
The power generation control unit
a first control mode for controlling the internal combustion engine to change the rotational speed of the internal combustion engine;
a second control mode for controlling the generator to change the rotation speed of the internal combustion engine;
including
When the running mode control unit switches to the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the second control mode is switched to the first control mode. ,
Based on the first electric power, a target rotation speed, which is a target rotation speed of the internal combustion engine, is calculated, a lower limit value of the target rotation speed is set, and the running mode control unit switches to the series mode, and performing correction control to increase the lower limit value when the battery output shortage determination unit determines that the second power is insufficient;
Electric vehicle control device. The power generation control unit corrects the lower limit value to a larger value as the speed of the electric vehicle increases.
The control device for an electric vehicle according to claim 1. The power generation control unit calculates a target rotation speed, which is a target rotation speed of the internal combustion engine, based on the first electric power, and calculates an increase rate of the target rotation speed when the target rotation speed is increasing. Also, the first limit value of the increase rate is set, the running mode control unit switches to the series mode, and the battery output shortage determination unit determines that the second electric power is insufficient. when the increase rate is corrected to a second limit value larger than the first limit value, performing correction control;
The control device for an electric vehicle according to claim 1 or 2. An electric vehicle having an internal combustion engine mounted on the electric vehicle, a generator driven by the internal combustion engine, a motor driving a drive shaft of the electric vehicle, and a drive battery supplying electric power to the motor a controller,
a driving mode control unit for switching to a series mode for driving the electric vehicle by first electric power supplied from the generator to the motor and second electric power supplied from the drive battery to the motor;
a battery output shortage determination unit that determines whether the second power is insufficient;
a power generation control unit that controls the internal combustion engine and the generator based on the first electric power;
with
The power generation control unit
a first control mode for controlling the internal combustion engine to change the rotational speed of the internal combustion engine;
a second control mode for controlling the generator to change the rotation speed of the internal combustion engine;
including
When the running mode control unit switches to the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the second control mode is switched to the first control mode. ,
A target rotation speed, which is a target rotation speed of the internal combustion engine, is calculated based on the first electric power, and if the target rotation speed is increasing, an increase rate of the target rotation speed is calculated, and When the driving mode control unit switches to the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the increase rate Perform correction control to correct to a second limit value larger than the first limit value,
Electric vehicle control device. The second limit value is a smaller value as the target rotation speed is higher.
The control device for an electric vehicle according to claim 3 or 4. The battery output shortage determination unit includes a battery temperature acquisition unit that acquires the temperature of the drive battery,
The battery output shortage determination unit determines that the second power is insufficient when the temperature acquired by the battery temperature acquisition unit is lower than or equal to a first predetermined temperature or higher than or equal to a second predetermined temperature.
The control device for an electric vehicle according to any one of claims 1 to 5. The battery output shortage determination unit includes a battery temperature acquisition unit that acquires the temperature of the drive battery,
The battery output shortage determination unit determines that the second electric power is insufficient when the temperature acquired by the battery temperature acquisition unit is equal to or lower than a first predetermined temperature or equal to or higher than a second predetermined temperature,
The second limit value is a smaller value when the temperature of the drive battery obtained by the battery output shortage determination unit is equal to or higher than the second predetermined temperature than when the temperature is equal to or lower than the first predetermined temperature.
The control device for an electric vehicle according to claim 4 or 5. The power generation control unit calculates a rotation increase torque for increasing the rotation speed of the internal combustion engine,
Acquiring an actual rotation speed, which is the actual rotation speed of the internal combustion engine;
In the first control mode, suppressing the rotational increase torque according to the actual rotational speed;
The electric vehicle control device according to any one of claims 1 to 7. The power generation control unit suppresses the rotation increase torque when the actual rotation speed is higher than the target rotation speed.
The control device for an electric vehicle according to claim 8. The power generation control unit suppresses the rotation increase torque as the actual rotation speed increases.
The control device for an electric vehicle according to claim 8 or 9. further comprising an accelerator opening determination unit that determines the accelerator opening,
The power generation control unit switches from the first control mode to the second control mode when the accelerator opening is zero.
The electric vehicle control device according to any one of claims 1 to 10. The battery output shortage determination unit determines that the second electric power is insufficient when the speed of the electric vehicle is equal to or higher than a first predetermined speed.
The electric vehicle control device according to any one of claims 1 to 11. the first predetermined temperature is calculated based on one or both of the deterioration of the driving battery and the charging rate of the driving battery;
The control device for an electric vehicle according to claim 6 or 7. The power generation control unit calculates a target power generation amount, which is a target power generation amount of the generator, based on the first electric power, acquires an actual power generation amount, which is an actual power generation amount of the generator,
switching from the second control mode to the first control mode when the actual power generation amount is smaller than the target power generation amount;
The electric vehicle control device according to any one of claims 1 to 13. The power generation control unit calculates a target rotation speed, which is a target rotation speed of the internal combustion engine, based on the first electric power, sets an upper limit value of the target rotation speed, and controls the driving mode control unit to When the series mode is switched to and the battery output shortage determination unit determines that the second power is insufficient, the upper limit value is limited to a predetermined number of rotations or less.
The electric vehicle control device according to any one of claims 1 to 14. The predetermined rotation speed is a change point of the output characteristics of the internal combustion engine,
The control device for an electric vehicle according to claim 15. When the speed of the electric vehicle is less than a second predetermined speed, the power generation control unit limits the upper limit value to the predetermined number of revolutions or less.
The electric vehicle control device according to claim 15 or 16. When the speed of the electric vehicle is equal to or higher than a second predetermined speed, the power generation control unit increases the upper limit value as the speed increases.
The electric vehicle control device according to any one of claims 15 to 17.

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