CN115803240A - Control devices for electric vehicles - Google Patents

Abstract

Provided is a control device for an electric vehicle capable of suppressing deterioration in fuel economy of the electric vehicle and improving acceleration performance at the same time. A control device (20) for an electric vehicle 1 is a control device for an electric vehicle (1) having an internal combustion engine (2), a generator (4), a front motor (6), a rear motor (8), and a driving battery (10) (20). The generator (4) is driven by the internal combustion engine (2). Each electric motor drives a drive shaft of the electric vehicle (1). A drive battery (10) supplies electric power to each motor. A control device (20) of an electric vehicle (1) includes a travel mode control unit (30), a battery output shortage determination unit (32), and a power generation control unit (34). A power generation control unit (34) controls the internal combustion engine (2) and the generator (4) based on the first electric power. A power generation control unit (34) includes a first control mode and a second control mode. The first control mode controls the internal combustion engine (2) to change the rotational speed of the internal combustion engine (2). The second control mode controls the generator (4) to change the rotational speed of the internal combustion engine (2). 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) switches from the second control mode to the first control mode. model.

Description

Control devices for electric vehicles

technical field

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

Background technique

Conventionally, there is known a control device for a series hybrid electric vehicle in which a generator driven by an internal combustion engine generates electricity, supplies the generated electric power to a motor, and the motor drives a drive shaft (for example, refer to Patent Document 1). In the electric vehicle control device of Patent Document 1, when the rotation speed of the generator is increased due to the increase in the amount of power generation requested from the generator, the torque for increasing the rotation speed of the generator is added to the required torque requested from the internal combustion engine. The moment of inertia required for ascent. In this way, in the electric vehicle control device of Patent Document 1, the rotational speed of the generator is rapidly increased by adding the inertia torque to the requested torque requested from the internal combustion engine. As a result, the acceleration performance of the electric vehicle improves.

In addition, conventionally, a control device for an electric vehicle having a parallel mode, a series mode, and an EV mode is known (for example, refer to Patent Document 2). In the electric vehicle control device of Patent Document 2, when the target rotational speed of the generator increases in the series mode, inertia torque is added to the requested torque requested from the internal combustion engine. In this way, in the electric vehicle control device of Patent Document 1, the amount of power generation can be stabilized by adding the inertia torque to the requested torque requested from the internal combustion engine. As a result, the acceleration performance of the electric vehicle improves.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2003-20972

Patent Document 2: Japanese Patent Laid-Open No. 2016-124318

The technical problem to be solved by the invention

However, in the electric vehicle control devices of Patent Document 1 and Patent Document 2, an inertial torque for increasing the rotational speed of the generator is added to the required torque requested from the internal combustion engine. Therefore, the internal combustion engine needs to output torque corresponding to the amount of inertia torque. As a result, the fuel injection amount of the internal combustion engine increases, and fuel economy deteriorates.

Contents of the invention

An object of the present invention is to provide a control device for an electric vehicle capable of suppressing deterioration in fuel economy of the electric vehicle and improving acceleration performance at the same time.

Technical means used to solve technical problems

A control device for an electric vehicle according to the present invention is a control device for an electric vehicle including an internal combustion engine, a generator, an electric motor, and a drive battery mounted on the electric vehicle. The generator is driven by the internal combustion engine. The electric motor drives the drive shaft of the electric vehicle. The drive battery supplies electric power to the motor. A control device for an electric vehicle includes a travel mode control unit, a battery output shortage determination unit, and a power generation control unit. The running mode control unit switches to a series mode for running the electric vehicle with first electric power supplied from the generator to the electric motor and second electric power supplied from the drive The electric motor is supplied by a battery. The insufficient battery output determination unit determines whether or not the second electric 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 unit 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 rotational 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 electric power is insufficient.

According to this electric vehicle control device, when the second electric power supplied from the driving battery to the electric motor is insufficient, the power generation control unit causes the internal combustion engine itself to rapidly change the rotational speed in the first control mode. Accordingly, the first electric power supplied from the generator to the motor changes rapidly. Therefore, even when the second electric power is insufficient during series mode running, the electric motor can quickly receive the supply of the first electric power. As a result, the acceleration performance of the electric vehicle improves. On the other hand, when the second electric power is not insufficient, the power generation control unit controls the generator in the second control mode to change the rotational speed of the internal combustion engine. When controlling the generator, the first electric power may decrease. However, since the internal combustion engine does not need to increase the rotation by itself, the fuel economy is improved. That is, according to this control device for an electric vehicle, it is possible to suppress deterioration of the fuel economy of the electric vehicle and improve acceleration performance at the same time.

The power generation control unit may calculate a target rotational speed that is a target rotational speed of the internal combustion engine based on the first electric power, and set a lower limit value of the target rotational 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 electric power is insufficient.

According to this configuration, the power generation control unit can increase the rotational speed of the internal combustion engine from a state where the rotational speed is high. As a result, the internal combustion engine tends to reach higher rotational speeds as quickly as possible. Therefore, the generator can supply the first electric power to the motor earlier. As a result, the acceleration performance of the electric vehicle can be improved even when the second electric power is reduced.

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 easier it is for the internal combustion engine to reach a higher rotational speed earlier. On the other hand, when the speed is low, the rotation speed of the internal combustion engine becomes low, so the sound 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 that is a target rotation speed of the internal combustion engine based on the first electric power. Alternatively, when the target rotational speed increases, the power generation control unit calculates an increase rate of the target rotational speed, and sets a first limit value of the increase rate. Alternatively, 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 may perform the second restriction in which the increase rate is corrected to be larger than the first restriction value. Value correction control.

Alternatively, the second limit value may be a smaller value as the target rotational speed is higher.

According to this configuration, the power generation control unit can rapidly increase the rotational speed of the internal combustion engine. As a result, the internal combustion engine tends to reach higher rotational speeds as quickly as possible. 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 can be improved.

The insufficient battery output determination unit may include a battery temperature acquisition unit that acquires the temperature of the driving battery. The battery output shortage determination unit may determine that the second electric power is insufficient when the temperature acquired by the battery temperature acquisition unit is below the first predetermined temperature or above the second predetermined temperature.

When the driving battery is at high temperature, the output of the battery may be limited. In addition, when the driving battery is in a low temperature state, the battery output may decrease. According to this configuration, in any state, the electric motor can quickly receive the supply of the first electric power.

The second limit value may be a value such that the temperature of the driving battery acquired by the insufficient battery output determination unit is lower than the first predetermined temperature or lower than the temperature of the driving battery acquired by the insufficient battery output determination unit. The second limit value in the case where the temperature is equal to or higher than the second predetermined temperature is smaller.

From this result, when the temperature of the driving battery is in a high-temperature state equal to or higher than the second predetermined temperature, the second limit value is kept low. Accordingly, when the driving battery is in a high-temperature state, the rotational speed of the internal combustion engine is gradually increased compared to when the driving battery is in a low-temperature state. As a result, sound and vibration caused by the rotation of the internal combustion engine can be reduced. On the other hand, in a low-temperature state in which the temperature of the driving battery is equal to or lower than the first predetermined temperature, the rotational speed of the internal combustion engine increases more rapidly than in a state in which the driving battery is at a high temperature.

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

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

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

According to this configuration, in the state where the accelerator pedal is not depressed, the rotational speed of the internal combustion engine is changed by the second control mode. As a result, fuel economy improves.

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 when the speed of the electric vehicle is high is improved.

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

According to this configuration, the shortage of the second power can be quickly determined using the first predetermined temperature based on either or both of the deterioration of the driving battery and the charging rate.

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

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

Alternatively, the power generation control unit may calculate a target rotation speed based on the first electric power, and set a lower limit value of the target rotation speed. When the battery output insufficient determination unit determines that the second electric power is insufficient, the power generation control unit limits the upper limit value to a predetermined rotational speed or less.

According to this configuration, it is possible to suppress the deterioration of the fuel economy of the electric vehicle and to improve the acceleration performance, and to suppress the deterioration of vibration and noise accompanying the increase in the rotational speed of the internal combustion engine.

The predetermined rotational speed may be a change point of the output characteristic of the internal combustion engine.

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

In addition, when the speed of the electric vehicle is lower than the second predetermined speed, the power generation control unit may limit the upper limit value to the predetermined rotational speed or less.

According to this configuration, the vibration/noise can be reduced to a degree corresponding 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 rotational speed of the internal combustion engine while suppressing the lost motion feeling.

The effect of the invention

According to the present invention, it is possible to provide a control device for an electric vehicle capable of suppressing deterioration in fuel economy of the electric vehicle and improving acceleration performance at the same time.

Description of drawings

FIG. 1 is a system diagram of an electric vehicle according to an embodiment of the present invention.

2 is a block diagram showing the configuration of a control device for an electric vehicle according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a three-dimensional map according to the embodiment of the present invention.

4 is a graph showing changes in the target engine speed Ert with respect to the accelerator opening in the embodiment of the present invention.

5 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 invention.

6 is a graph showing an example of the relationship between the rotation up torque UTq and the engine rotation speed deviation according to the embodiment of the present invention.

7 is a graph showing an example of the relationship between the rotation up torque UTq and the actual engine rotation speed Erq according to the embodiment of the present invention.

8 is a flowchart showing a control procedure of the control device according to the embodiment of the present invention.

9 is a time chart showing changes in the target engine speed Ert when the upper limit value of the target engine speed Ert is changed according to the embodiment of the present invention.

10 is a graph showing an example of output characteristics of the internal combustion engine according to the embodiment of the present invention.

Detailed ways

<First Embodiment>

Hereinafter, the control device 20 of the electric vehicle 1 according to the first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1 , an electric vehicle 1 according to the present embodiment is a four-wheel drive type hybrid vehicle. The electric vehicle 1 has 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 , a control unit (HVECU) 20 , and an accelerator pedal 21 . In the electric vehicle 1 according to the present embodiment, the front motor 6 drives the front wheel drive shaft 12 a of the front wheels 12 via the transaxle 16 . The rear motor 8 drives a rear wheel drive shaft 14a of the rear wheels 14 via a speed reducer 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 for controlling the generator 4 . The front motor control device 6a receives a signal from the control device 20, and controls the 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 driving battery 10 via the rear inverter 8b, and is supplied with electric power (second electric power) from the driving battery 10 . The rear inverter 8b has a rear motor control unit (RMCU) 8a. The rear motor control device 8a receives a signal from the control device 20, and controls the regeneration and power running of the rear motor 8 so that the rear motor 8 is in a desired operating state.

The internal combustion engine 2 drives the generator 4 via the transaxle 16 . The internal combustion engine 2 is driven by burning 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 so that it becomes a desired operating state. The transaxle 16 amplifies the rotational speed of the internal combustion engine 2 and transmits it to the generator 4 . In addition, the transaxle 16 of the present embodiment has clutches 16 a for transmitting or disconnecting power between the internal combustion engine 2 and the front electric motor 6 and between the internal combustion engine 2 and the front wheel drive shaft 12 a. The internal combustion engine 2 is connected to the front wheel drive shaft 12 a via the clutch 16 a of the transaxle 16 to drive the front wheel drive shaft 12 a.

The generator 4 generates electricity by being driven by the internal combustion engine 2 . The electric power (first electric power) generated by the generator 4 can charge the driving battery 10, and can also forward the electric motor 6 and the rear electric motor 8 via the front inverter 18 and the rear inverter 8b (in the following specification, write For each motor) supply. In the present embodiment, the generator 4 is a motor generator capable of driving the internal combustion engine 2 to rotate in addition to generating electricity. 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 generator 4 performs power running by being supplied with electric power from 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 4 a is electrically connected to the control device 20 , receives a signal from the control device 20 , controls power generation and power running, and makes the generator 4 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) configured by integrating a plurality of battery elements. The driving battery 10 functions as a power source for each motor. Further, the driving battery 10 has a battery monitoring unit (BMU) 10a that calculates the charging rate (State Of Charge, hereinafter referred to as SOC) of the battery module, and calculates the state of deterioration (State Of Health, hereinafter) of the battery module. Denoted as SOH) and the detection of the voltage Bv of the battery module and the battery temperature Btmp. The battery monitoring unit 10 a acquires the battery temperature Btmp of the driving battery 10 and sends it to the control device 20 .

The control device 20 is actually constituted by a microcomputer including a computing device, a memory, an input/output buffer, and the like. The control device 20 controls each device based on signals from various sensors and various devices, and maps and programs stored in a memory so that the electric vehicle 1 becomes a desired driving state.

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

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

Accelerator pedal 21 is a pedal for controlling acceleration and deceleration of electric vehicle 1 when the driver of electric vehicle 1 depresses it. The accelerator pedal 21 is provided with an accelerator position sensor 21 a for detecting a depressed position. The accelerator position sensor 21 a is electrically connected to the control device 20 , and sends the accelerator depression position (accelerator opening) to the control device 20 . The accelerator opening determination unit 36 includes a driver requested 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 acquired from the accelerator position sensor 21a.

The running mode control unit 30 controls the clutch 16a based on information such as the speed V, the SOC, and the accelerator opening Th, thereby switching to any one of the running modes among the parallel mode, the series mode, and the EV mode. In the parallel mode, the running mode control unit 30 connects the clutch 16 a to drive the front wheel drive shaft 12 a by both the internal combustion engine 2 and the front electric motor 6 . At this time, either or both of the electric power from the driving battery 10 (second electric power) and the electric power generated by the generator 4 (first electric power) are supplied to the front motor 6 . Rear motor 8 is similarly supplied with either or both of electric power (second electric power) from driving battery 10 and electric power (first electric power) generated by generator 4 to drive rear wheel drive shaft 14 a. In the EV mode, the travel mode control unit 30 releases the clutch 16a to supply the electric power (second electric power) of the driving battery 10 to each electric motor, so that each electric motor drives the front wheel drive shaft 12a and the rear wheel drive shaft 14a (in the EV mode). In the following instructions, it is referred to as each drive shaft).

In the series mode, the running mode control unit 30 disengages the clutch 16a, the internal combustion engine 2 drives the generator 4, and supplies the first electric power generated by the generator 4 to each electric motor. In addition, when the drive force of each electric motor to drive each drive shaft with the first electric power is insufficient, traveling mode control unit 30 also supplies the second electric power from driving battery 10 to each electric motor. That is, the running mode control unit 30 runs the 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 can efficiently operate the internal combustion engine 2 by adding the second electric power supplied from the driving battery 10 to the electric motors to the first electric power supplied from the generator 4 to the electric motors in the series mode. The internal combustion engine 2 consumes fuel when the generator 4 generates electricity, thereby improving the acceleration performance of the electric vehicle 1 .

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. Drive shaft torque calculation unit 30a acquires driver request torque DTq and upper limit drive shaft torque TqLim. The drive shaft torque calculation unit 30a calculates a target drive shaft torque FRTq that each drive shaft needs to generate based on the driver's requested torque DTq and the upper limit drive shaft torque TqLim.

The upper limit drive shaft torque TqLim can be obtained by subtracting auxiliary equipment consumption power consumed by electronic devices mounted on the electric vehicle 1 and losses in each motor from the power generation amount GWi based on the battery upper limit power W2 and the capacity of the generator 4 described later. , and divide the obtained value by the speed V and then multiply the unit conversion factor to calculate. The upper limit drive shaft torque TqLim can be calculated in the drive shaft torque limit value calculation unit 30e. However, the target drive shaft torque FRTq is not limited to these calculation methods, for example, a map or the like may be used. 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 and calculates the target drive shaft torque FRTq into the target generated power W1 , and sends it to the power generation control unit 34 .

The front-to-rear distribution calculation section 30b acquires the road surface condition and the like, and calculates the target front axle torque FTq distributed to the front wheel drive shaft 12a and the target rear wheel axle torque FRTq distributed to the rear wheel drive shaft 14a based on the road surface condition and the like. The torque RTq is sent to the front motor control device 6a and the rear motor control device 8a. The front-motor engine torque distribution calculation unit 30c calculates the parallel engine torque PETq required to the internal combustion engine 2 in the parallel mode.

The insufficient battery output determination unit 32 determines whether or not the second electric power supplied from the driving battery 10 to each electric motor is insufficient. The insufficient battery output 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 driving battery 10 from the battery monitoring unit 10a, and calculates the battery output as the upper limit value of the second electric power that the driving battery 10 can supply to each motor. Upper limit electric power W2. When the battery upper limit electric power W2 of the driving battery 10 is lower than the battery upper limit electric power W2 in the normal state, the battery output shortage determination unit 32 judges that the second electric power is insufficient.

In the present embodiment, the insufficient battery output determination unit 32 includes a battery temperature acquisition unit 32b. The battery temperature acquisition unit 32b acquires the battery temperature Btmp from the battery monitoring unit 10a. When the battery temperature Btmp is equal to or lower than the first predetermined temperature T1, the battery output shortage determination unit 32 determines that the second electric power is insufficient. The first predetermined temperature T1 is a temperature previously set in a map based on SOC and SOH. More specifically, as an example of the three-dimensional map shown in FIG. 3 , the insufficient battery output determination unit 32 stores a plurality of values ( State Of Power, hereinafter referred to as a map of SOP). As shown by the arrows in FIG. 3 , when the driving battery 10 is new (for example, SOH=100%), when the SOP is 15kw, the SOC is 20%, and the battery temperature Btmp is -20°C. On the other hand, when the driving battery 10 is in a degraded state (for example, SOH=30%), when the SOP is 15 kw, the SOC is 20%, and the battery temperature Btmp is 0°C.

In this way, the insufficient battery output judging unit 32 acquires the SOH and SOC, compares the acquired SOH and SOC with the three-dimensional map, and acquires an SOP (hereinafter, referred to as a reference SOP) that is judged to be a decrease in battery output from the three-dimensional map. The battery temperature Btmp. Here, the insufficient battery output determination unit 32 can also acquire the actual SOP (hereinafter referred to as actual SOP). However, the actual SOP may be corrected according to the decrease in the voltage Bv in order to prevent overdischarge of the driving battery 10 . Therefore, when the insufficient battery output determination unit 32 compares the actual SOP and the reference SOP and determines that the battery output has decreased, it may not be correctly determined. Therefore, the insufficient battery output determination unit 32 can accurately and quickly determine a decrease in the battery upper limit power W2 of the driving battery 10 by acquiring the battery temperature Btmp serving as the reference SOP. In addition, the insufficient battery output determination unit 32 may determine that the battery upper limit power W2 has decreased based on the outside air temperature or the like instead of the battery temperature Btmp. In addition, the insufficient battery output judging unit 32 may set the first predetermined temperature T1 as an extremely low temperature (for example, -20° C.) and not obtain the SOH and SOC, but may uniformly judge that it is equal to or lower than the first predetermined temperature T1. The battery upper limit power W2 is lowered. Furthermore, battery output shortage determination unit 32 may determine a decrease in battery upper limit power W2 based on either one of SOH and SOC and a two-dimensional map showing the relationship between battery temperature Btmp and SOP. In addition, the battery upper limit power W2 may also be calculated by the battery monitoring unit (BMU) 10a.

In addition, when the battery temperature Btmp is equal to or higher than the second predetermined temperature T2, the battery output shortage determination unit 32 determines that the second electric power is insufficient. 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 temperature rise of the driving battery 10 by suppressing the battery upper limit power W2. As a result, the second electric power that can be supplied from the driving battery 10 to each electric motor decreases. When the battery upper limit power W2 is suppressed while the driving battery 10 is in a high temperature state, the battery output shortage determination unit 32 determines that the second power is insufficient.

Then, the insufficient battery output determination unit 32 acquires 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 runs at high speed, the energy required for acceleration becomes large. Therefore, when the first predetermined speed Vt is higher than the first predetermined speed Vt, more first electric power and second electric power are required than when the speed is lower than the first predetermined speed Vt. Therefore, the insufficient battery output determination unit 32 can supply the first electric power to each electric motor as quickly as possible by determining that the second electric power is insufficient when the first predetermined speed Vt is higher. That is, even when the battery upper limit power W2 has not decreased and it is determined that the battery upper limit power W2 is not suppressed, the battery output shortage determination unit 32 determines that the second power is insufficient when the first predetermined speed Vt or higher is exceeded.

The power generation control unit 34 controls the internal combustion engine 2 and the generator 4 based on the target generated power W1 calculated by the drive shaft torque calculation unit 30a and the power conversion calculation unit 30d. Here, the target generated electric power W1 is a target value of the first electric power that the generator 4 needs to supply to each electric motor. In the present embodiment, the power generation control unit 34 calculates the engine requested torque ETq requested from the internal combustion engine 2 in each calculation unit described later in order to generate the target generated electric power W1 by driving the generator 4 with the internal combustion engine 2 .

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. The power calculation unit 34 a calculates the target power generation amount GW required from the generator 4 based on the target power generation power W1 , taking into consideration the power transmission loss and the like that occur when the first power is supplied from the generator 4 to each motor. The power transmission loss can also be calculated based on a map recording the relationship between the power generation amount of the generator 4 and the power transmission loss. In addition, the target power generation amount GW may be calculated in consideration of the electric power charged to the driving battery 10 , the electric power required by other equipment of the electric vehicle 1 , and the upper limit value of the power generation amount for protecting each electric motor.

The target engine speed calculation unit 34b acquires the target power generation amount GW, and calculates a target engine speed (target speed) Ert as a target value of the speed at which the internal combustion engine 2 drives the generator 4 based on the target power generation amount GW. At this time, the target engine speed calculation unit 34b may refer to a map in which the fuel injection amount and ignition timing of the internal combustion engine 2 are recorded, and calculate the target engine speed Ert so that the internal combustion engine 2 achieves optimum fuel economy. Accordingly, the fuel economy of the electric vehicle 1 is improved. In addition, the target engine rotation speed calculation unit 34b may obtain the speed V and perform calculation so as to obtain the target engine rotation speed Ert corresponding to the speed V. Accordingly, when the electric vehicle 1 is accelerated, the rotation speed of the internal combustion engine 2 can be suppressed from increasing excessively with respect to the speed V. As shown in FIG.

The power generation control unit 34 sets a lower limit value minErt of the target engine rotation speed Ert. In addition, 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 corrects the lower limit value minErt to a large value to control the internal combustion engine. 2 (in the following description and FIG. 8 , this correction control is referred to as lower limit value correction control). As shown in FIG. 4 , the lower limit value minErt is the target engine speed Ert from time T0 when the accelerator pedal 21 is not depressed to time T1 . In the present embodiment, the target engine speed calculation unit 34b acquires the target engine speed Ert, and sets an initial value of the lower limit value minErt. The initial value may also be a pre-stored value. The target engine rotation speed calculation unit 34b performs correction calculation of correcting the lower limit value minErt of the target engine rotation speed Ert to a value larger than the initial value when the battery output shortage determination unit 32 determines that the second electric power is insufficient (see FIG. 4 , Ert) during calibration.

In addition, the target engine speed calculation unit 34b may acquire the target engine speed Ert and the speed V, and perform correction calculation of setting the lower limit minErt of the target engine speed Ert to a value larger than the initial value as the speed V increases. Thereby, the first electric power supplied from the generator 4 to each electric motor increases rapidly. Therefore, the acceleration performance of the electric vehicle 1 improves. In addition, the higher the speed V of the electric vehicle 1 is, the easier it is for the actual engine speed Erq to be described later to quickly reach a high speed. On the other hand, when the speed V is low, the actual engine rotation speed Erq, which will be described later, becomes low, so that sound and vibration caused by the rotation of the internal combustion engine 2 can be reduced.

When the target power generation amount GW increases based on the target power generation power W1, the power generation control unit 34 sets an increase rate limit value dErtLim of the target engine rotation 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 corrects the increase rate limit value dErtLim to a large value to control the internal combustion engine 2 (In the following specification and FIG. 8, this correction control is referred to as limit value correction control). The increase rate limit value dErtLim is an upper limit value of the change rate per unit time of the target engine rotation speed Ert when the accelerator pedal 21 is depressed. That is, in FIG. 4 , it corresponds to the upper limit value of the slope of the target engine rotation speed Ert from time T1 to time T2 .

In the present embodiment, the target engine speed calculation unit 34b sets the increase rate limit value dErtLim of the target engine speed Ert. The target engine rotation 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 also be a pre-stored value. The target engine rotation speed calculation unit 34b performs correction calculation of correcting the increase rate limit value dErtLim to a second limit value larger than the initial value. Accordingly, the power generation control unit 34 can quickly increase the actual engine rotation 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 electric motor more quickly, and the acceleration of the electric vehicle 1 is improved.

In addition, in the present embodiment, the target engine speed calculation unit 34b decreases the second limit value as the target engine speed Ert becomes higher. As shown in FIGS. 4 and 5, for example, during the period from 4000 rpm to 5000 rpm, by setting the second limit value of the increase rate limit value dErtLim lower than 4000 rpm, the target engine speed Ert at the time of correction (Fig. Ert) rises slowly during the calibration of 4. This makes it easy to suppress an excessive increase in the actual engine rotation speed Erq described later.

Furthermore, the target engine rotation speed calculation unit 34b may set the second limit value when the temperature of the driving battery 10 is high to a smaller value than when the temperature of the driving battery 10 is low. 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 higher than the increase rate limit value dErtLim when the battery temperature Btmp is equal to or lower than the first predetermined temperature T1. The small value of dErtLim. That is, even if the outside air temperature is normal temperature (approximately 10° C. to 25° C.), the battery temperature Btmp may be equal to or higher than the second predetermined temperature T2. Therefore, the battery temperature Btmp becomes higher than or equal to the second predetermined temperature T2 more often than the frequency of the battery temperature Btmp becomes lower than the first predetermined temperature T1. In this way, the target engine speed calculation unit 34b sets the increase rate limit value dErtLim to be smaller when the driving battery 10 generated at a higher frequency is in a high temperature state than when the driving battery 10 is in a low temperature state. value. As a result, the rotational speed of the internal combustion engine 2 gradually increases. As a result, sound 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 in a low-temperature state, the rotation speed of the internal combustion engine 2 increases more rapidly than when the driving battery 10 is in a high-temperature state.

The engine torque calculation unit 34c acquires the target power generation amount GW and the target engine speed Ert, and calculates the required engine torque ETq required for 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 power generation amount GW by the target engine rotation speed Ert, and adds the torque for changing the rotation speed of the internal combustion engine 2 if necessary. This torque is used to calculate the required engine torque ETq. The engine torque calculation unit 34c sends the engine request torque ETq to the engine control device 2a. The engine control device 2 a calculates an actual engine torque ETqr based on an actual engine rotation speed (actual rotation speed) Erq acquired from various sensors such as a crank angle sensor (not shown) of the internal combustion engine 2 . The engine control device 2a acquires the required engine torque ETq, and controls the internal combustion engine 2 so that the actual engine torque ETqr becomes the required engine torque ETq. At this time, the engine control device 2a sends the actual engine rotation speed Erq to the engine torque calculation unit 34c. The engine torque calculation unit 34c acquires the actual engine rotation speed Erq, and corrects the required engine torque ETq so that it becomes the target engine rotation speed Ert.

The generator torque calculation unit 34d acquires the required engine torque ETq, and calculates a target load torque LTq that is a target load torque of the generator 4 based on the required engine torque ETq. More specifically, the generator torque calculation unit 34d calculates the target load torque LTq by adding and subtracting the load torque LTq1 proportional to the engine required torque ETq to calculate the torque for changing the rotation speed of the internal combustion engine 2 . The generator torque calculation unit 34d may calculate the target load torque LTq based on a map recording the relationship between the engine required torque ETq and the target load torque LTq. The generator torque calculation unit 34d sends 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 power generation amount of the generator 4 and the rotation speed of the generator 4, calculates the actual load torque LTqr from the actual power generation amount GWr and the rotation speed of the generator 4, and calculates the actual load torque LTqr as the actual load torque. The generator 4 is controlled so that the torque LTqr becomes the target load torque LTq. In addition, the generator control device 4a transmits the actual power generation amount GWr to the engine torque calculation unit 34c via the generator torque calculation unit 34d.

The power generation control unit 34 includes a first control mode and a second control mode. When the running mode control unit 30 switches to the series mode, 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, the power generation control unit 34 starts from the second control mode. Switch to the first control mode. That is, regardless of the driver's request for acceleration, when the battery upper limit power W2 decreases, the power generation control unit 34 switches from the second control mode to the first control mode. In addition, 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 for the target power generation amount GW, the power generation control unit 34 may switch from the second control mode to the first control mode. control 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 rotation increasing torque UTq required when the engine required torque ETq includes increasing the target engine rotational speed Ert. That is, the engine torque calculation unit 34c calculates the required engine torque ETq by adding the rotation up torque UTq to the engine torque ETq1 obtained based on the target power generation amount GW. The rotation up torque UTq is a torque previously set for each target engine speed Ert in consideration of the friction loss between 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.

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, the power generation control unit 34 calculates the target load torque LTq including the rotation up torque UTq in the second control mode. That is, the generator torque calculation unit 34d calculates the target load torque LTq by subtracting the rotation increase torque UTq from the load torque LTq1 commensurate with the engine required torque ETq.

In this way, in the first control mode, the internal combustion engine 2 itself increases the actual engine speed Erq, so that the intake air amount and the fuel injection amount of the internal combustion engine 2 increase compared with the second control mode. As a result, in the first control mode, the fuel economy of the internal combustion engine 2 deteriorates. 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 improves.

On the other hand, in the second control mode, the actual power generation amount GWr of the generator 4 decreases because the generator torque calculation unit 34d subtracts the rotation up torque UTq. However, since the generator 4 decreases the actual power generation amount GWr, the output of the internal combustion engine 2 is maintained, and the actual engine speed Erq of the internal combustion engine 2 increases. As a result, the fuel economy of the internal combustion engine 2 is maintained. In addition, when the target engine speed Ert is lowered, the actual engine speed Erq is lowered by increasing the target load torque LTq in the second control mode.

In addition, as shown in FIGS. 6 and 7 , in the present embodiment, the power generation control unit 34 suppresses the rotation up torque UTq in accordance with the actual engine rotation speed Erq in the first control mode. More specifically, the power generation control unit 34 may suppress the rotation up torque UTq when the actual engine rotation speed Erq is larger than the target engine rotation speed Ert. That is, as shown in FIG. 6 , the deviation (difference) between the target engine rotational speed Ert and the actual engine rotational speed Erq is calculated, and the smaller the deviation is, the smaller the rotation up torque UTq is. In the graph showing the relationship between the rotation up torque UTq and the difference shown in Fig. 6, if the deviation is less than 300rpm, reduce the value of the rotation up torque UTq, and if the deviation is less than zero, increase the rotation up The torque UTq is set to zero. Accordingly, it is possible to suppress an excessive increase in the actual engine rotation speed Erq.

Furthermore, the power generation control unit 34 may suppress the rotation increase torque UTq as the actual engine rotation speed Erq increases. That is, as shown in FIG. 7 , for example, when the actual engine rotational speed Erq is 4000 rpm or more, the power generation control unit 34 reduces the rotation up torque UTq as the actual engine rotational speed Erq becomes higher. Even in this case, it is possible to suppress an excessive increase in the actual engine rotation speed Erq.

Next, the control procedure of the power generation control unit 34 and the insufficient battery output determination unit 32 of the control device 20 according to the present embodiment will be described using the flowchart of FIG. 8 . The power generation control unit 34 starts a control operation when an ignition switch (not shown) is turned on. In addition, 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 it is determined that the power generation control unit 34 of the control device 20 has switched to the series mode (YES in S1 ), the process proceeds to S2 .

S2 to S4 are processes performed by the insufficient battery output determination unit 32 . In S2 to S4 , the insufficient battery output determination section 32 determines whether or not the second electric power is insufficient. In S2, the insufficient battery output determination unit 32 determines whether the battery temperature Btmp is equal to or lower than the first predetermined temperature T1. When the battery temperature Btmp is higher than the first predetermined temperature T1 (No in S2), the insufficient battery output 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 (YES in S2 ), the battery output shortage determination unit 32 determines that the second electric power is insufficient, and sends the determination result to the power generation control unit 34 . The power generation control unit 34 acquires the determination result of the insufficient battery output determination unit 32, and advances the processing to S10.

In S10, the power generation control unit 34 performs lower limit correction control. The power generation control unit 34 acquires the speed V (km/h), and performs lower limit value correction control in which the lower limit value minErt of the target engine rotation speed Ert is set to a larger value as the speed V is higher. At this time, for example, when the initial value of the lower limit value minErt is 0 rpm, the lower limit value minErt may be corrected to 1000 rpm. In addition, as the speed V becomes higher, the power generation control unit 34 may appropriately correct the lower limit value minErt to a value greater than 1000 rpm. In addition, in the second control mode, the power generation control unit 34 uses the initial value of the lower limit value minErt (see FIG. 4 ). When the power generation control unit 34 performs the lower limit correction control, the process proceeds to S5.

In S3, the insufficient battery output determination unit 32 determines whether or not the battery temperature Btmp is equal to or higher than the second predetermined temperature T2. When the insufficient battery output determination unit 32 determines that the battery temperature Btmp is lower than the second predetermined temperature T2 (No in S3), 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 (YES in S3 ), it determines that the second electric power is insufficient, and sends the determination result to the power generation control unit 34 . The power generation control unit 34 acquires the determination result of the insufficient battery output determination unit 32, and advances the process to S5.

In S4, the insufficient battery output determination unit 32 acquires the speed V of the electric vehicle 1, and determines whether the speed V is equal to or greater than Vt. When the battery output shortage determination unit 32 determines that the speed V is equal to or greater than Vt (YES in S4 ), it determines that the second electric power is insufficient, and sends the determination result to the power generation control unit 34 . That is, when any one of the conditions from S2 to S4 is satisfied, the battery output shortage determination unit 32 determines that the second electric power is insufficient. The power generation control unit 34 acquires the determination result of the insufficient battery output determination unit 32, and advances the process to S5. On the other hand, when the insufficient battery output determination unit 32 determines that the speed V is smaller than Vt (No in S4), it determines that the conditions from S2 to S4 are not satisfied, and determines that the second electric power is not insufficient. The insufficient battery output determination unit 32 transmits the determination result to the power generation control unit 34 . The power generation control unit 34 acquires the determination result of the insufficient battery output 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 equal to or greater than a predetermined opening Tht. When the power generation control unit 34 determines that the accelerator opening Th is equal to or greater than the predetermined opening Tht (YES in S4 ), 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 processing to S7. In addition, in S5, the power generation control unit 34 may determine whether or not the actual power generation amount GWr is less than (less than) the target power generation amount GW. The power generation control unit 34 may advance the process to S6 when determining that the actual power generation amount GWr is smaller than the target power generation amount GW.

In S7, the power generation control unit 34 determines whether or not the target engine rotation speed Ert is increasing. When the power generation control unit 34 determines that the target engine rotation speed Ert is increasing (YES in S7), the process proceeds to S8. When the target engine speed Ert is increasing, the accelerator pedal 21 is depressed, the driver requested torque DTq increases, the target generated electric power W1 also increases, and the target generated 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 the predetermined opening Tht. That is, the power generation control unit 34 may simultaneously determine whether or not the target engine rotation speed Ert is increasing in S5. In addition, when the actual power generation amount GWr is smaller than the target power generation amount GW, it may be determined that the target engine rotation 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 the increase rate limit value dErtLim to a value greater than 20%. Also, in the second control mode, the initial value of the increase rate limit value dErtLim is used. When the 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 the accelerator opening Th is zero (accelerator cut). When the power generation control unit 34 determines that the accelerator is off (YES in S9), the lower limit value correction and the increase rate limit correction are simultaneously terminated, 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 proceeds to the process before S1.

When it is determined that the power generation control unit 34 is not in 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 (No in S5 ), the process proceeds to S11 , the second control mode is maintained, and the process returns to before S1 .

The power generation control unit 34 returns the process to before S5 when it determines that the target engine speed Ert has not increased (S7 No) and when it determines that the accelerator pedal has not been cut (S9 No). Thus, the first control mode is maintained until the accelerator opening Th is smaller than the predetermined opening Tht.

Next, the control device 220 of the electric vehicle 201 according to the second embodiment of the present invention will be described with reference to the drawings. In addition, since 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, description thereof will be omitted. In addition, about the control performed by the control device 220 in the second embodiment, only points different from the control in the first embodiment will be described.

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

As shown in FIG. 9 , in the time chart of the present embodiment, the battery temperature Btmp acquired by the battery temperature acquisition unit 32 a increases stepwise and the second electric power is insufficient. As shown from time 0 to time A in FIG. 9 , as the speed V of the electric vehicle 201 increases, the battery temperature Btmp also increases. During the period from time 0 to time A, the target engine speed Ert increases with the increase rate limit value dErtLim as the first limit value. When the time A is exceeded, the speed V decreases toward the time B, and the traveling mode is switched to the series mode by the traveling mode control unit 30 . On the other hand, the battery temperature Btmp does not decrease between time A and time B, either. At time B, when the battery temperature Btmp becomes equal to or higher than the second predetermined temperature T2, the battery output shortage determination unit 32 determines that the second electric 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 executes limit value correction control for correcting the increase rate limit value dErtLim (see FIG. 9 limit value correction control ON). The power generation control unit 234 may execute at least one of lower limit value correction control and switching from the second control mode to the first control mode in addition to the limit value correction control.

From time C to time D in FIG. 9 , a state in which the accelerator pedal 21 is depressed again by the user of the electric vehicle 201 is shown. During this period, the battery temperature Btmp does not decrease, but continues to maintain the series mode. In such a case, the power generation control unit 234 executes vibration/noise reduction control (hereinafter referred to as NV reduction control. NV is an abbreviation for Noise, Vibration (noise, vibration)). More specifically, power generation control unit 234 limits upper limit value maxErt to be equal to or less than predetermined rotational speed R1. As shown in the graph of the target engine speed Ert from time C to time D, the power generation control unit 234 increases the target engine speed Ert to the target engine speed by using a second limit value larger than the first limit value for the increase rate limit value dErtLim. Ert becomes the predetermined rotational speed R1. As a result, the power generation control unit 234 suppresses deterioration of fuel economy and improvement of acceleration performance of the electric vehicle 201 , and suppresses deterioration of vibration and noise accompanying an increase in the rotational speed of the internal combustion engine 2 .

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

In addition, as shown at times B to C in FIG. 9 , when the target engine speed Ert is equal to or greater than the predetermined speed R1 and the battery output shortage judgment unit 32 judges that the second electric power is insufficient, the power generation control unit 234 waits for the target engine speed. The engine speed Ert becomes the predetermined speed R1, and then the NV reduction control is executed.

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

In addition, in the section from time C to time E, since the increase rate limit value dErtLim is high, the target engine speed Ert rises rapidly, and the actual engine speed Erq also rises rapidly. On the other hand, in the case where the actual engine speed Erq of the internal combustion engine 2 is high compared to the speed V of the electric vehicle 201, the user of the electric vehicle 201 may feel uncomfortable that the vibration/noise of the electric vehicle 201 is large, or feel Whether the electric vehicle 201 is idling or not (feeling of idling). However, since the power generation control unit 234 restricts the upper limit value maxErt of the target engine speed Ert to the predetermined speed R1 when the speed is lower than the second predetermined speed V2, such a sense of incongruity hardly occurs. Then, from time D to time E, the power generation control unit 234 maintains the target engine rotation speed Ert while the speed V of the electrically powered vehicle 201 increases. Accordingly, the power generation control unit 234 can suppress a feeling of discord caused by a sudden decrease in the actual engine rotation speed Erq.

As shown from time E to time F in FIG. 9 , when the speed V of the electric vehicle 201 is from the second predetermined speed V2 to less than the third predetermined speed V3, the power generation control unit 234 relaxes the upper limit as the speed V increases. Value maxErt. The third predetermined speed V3 is a value higher than the second predetermined speed V2. In the present embodiment, the power generation control unit 234 refers to a map in which the upper limit value maxErt of the target engine rotational 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 rotation speed Ert according to the speed V, thereby relaxing the upper limit value maxErt. Accordingly, the actual power generation amount GWr also increases in accordance with the increase in the speed V. As a result, the acceleration performance of the electric vehicle 201 can be improved by suppressing the idle feeling and compensating for the insufficient output of the battery.

As shown after time F in FIG. 9 , when the third predetermined speed V3 is higher, the power generation control unit 234 cancels the restriction on the upper limit value maxErt. In the present embodiment, the speed V of the electrically powered vehicle 201 also increases after time F, so 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 rotation speed Ert. When the final target engine speed Ert is lower than 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 invention, it is possible to suppress deterioration of the fuel economy of the electric vehicle 1 , 201 and improve acceleration performance at the same time.

＜Other Embodiments＞

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, Various changes are possible in the range which does not deviate from the summary of invention. In particular, a plurality of modified examples described in this specification can be combined arbitrarily as necessary.

(a) In the first embodiment described above, 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 invention is not limited thereto. When it is determined by the battery output insufficient determination unit 32 that the second electric power is insufficient from S2 to S4, the power generation control unit 34 may obtain the determination result and immediately switch to the first control mode.

(b) In the above-mentioned first embodiment, when the driving battery 10 is below the first predetermined temperature T1 in S2 (YES in S2 ), the power generation control unit 34 performs lower limit value correction before switching to the first control mode. An example of control is described, but the present invention is not limited thereto. The lower limit correction control may be performed after switching to the first control mode.

(c) In the above-mentioned first embodiment, when the battery output shortage judging unit 32 judges that the second electric power is insufficient, the power generation control unit 34 performs the lower limit value correction control, switches to the first mode and limits An example of value correction control was described, but the present invention is not limited thereto. Even when the battery output shortage judging unit 32 judges that the second electric power is insufficient, if the user of the electric vehicle 1 selects the energy-saving mode, the power generation control unit 34 may not perform the lower limit value correction control, and may switch to Either or both of switching of the first mode and limit value correction control. Accordingly, in the case of the energy-saving mode, priority can be given to fuel economy. In addition, the power generation control unit 34 may have a selection unit allowing the user of the electric vehicle 1 to select any one of the lower limit value correction control, switching to the first mode, and limit value correction control. Thereby, the user can selectively give priority to either one of acceleration and fuel economy. In addition, the power generation control unit 34 may be linked with the navigation system of the electric vehicle 1, and when the electric vehicle 1 is traveling on a residential street, the lower limit value correction control may not be performed. Accordingly, the electric vehicle 1 can run quietly on a residential street.

(d) In the above-mentioned first and second embodiments, the case where the electric vehicle 1, 201 is a four-wheel drive type hybrid vehicle has been described as an example, but the present invention is not limited thereto. The electric vehicle 1, 201 may be a plug-in hybrid vehicle, and may have a power supply function for supplying power from the drive battery 10 to an external device (for example, a home appliance).

Symbol Description

1, 201: electric vehicle, 2: internal combustion engine, 4: generator

6: Front motor, 8: Rear motor, 10: Driving 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: insufficient battery output judging unit

32a: battery temperature acquisition unit, 34, 234: power generation control unit

36: Throttle opening judgment unit, Btmp: battery temperature

Ert: target engine speed (target speed), Erq: actual engine speed (actual speed)

GW: target power generation, GWr: actual power generation

T: Specified temperature, V: Velocity

minErt: lower limit value, dErtLim: increase rate limit value

Claims (as amended under Article 19 of the Treaty)

1. [After revision] A control device for an electric vehicle, comprising: an internal combustion engine mounted on the electric vehicle, an electric generator driven by the internal combustion engine, an electric motor for driving a drive shaft of the electric vehicle, and an electric power supply to the electric motor The driving battery is characterized in that it has:

a running mode control unit that switches to a series mode for running the electric vehicle with first electric power supplied from the generator to the electric motor and second electric power supplied to the electric motor. 2. electric power is supplied from the driving battery to the electric motor;

an insufficient battery output judging section that judges whether the second electric power is insufficient; and

a power generation control section that controls the internal combustion engine and the generator based on the first electric power,

The power generation control unit includes:

a first control mode that controls the internal combustion engine to vary the rotational speed of the internal combustion engine; and

a second control mode that controls the generator to vary the rotational speed of the internal combustion engine,

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 switches from the second control mode to the first control mode,

The power generation control section calculates a target rotation speed that is a target rotation speed of the internal combustion engine and is switched by the running mode control section based on the first electric power, and sets a lower limit value of the target rotation speed. In the case of the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the power generation control unit performs correction control to increase the lower limit value.

2. [After modification] The control device for an electric vehicle according to claim 1, characterized in that,

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

3. [After modification] The control device for an electric vehicle according to claim 1 or 2, characterized in that

The power generation control section calculates a target rotation speed that is a target rotation speed of the internal combustion engine based on the first electric power, and calculates an increase in the target rotation speed when the target rotation speed increases. rate, and set the first limit value of the increase rate, when the running mode control unit switches to the series mode and the battery output insufficient determination unit determines that the second electric power is insufficient The power generation control unit performs correction control for correcting the increase rate to a second limit value larger than the first limit value.

4. [After revision] A control device for an electric vehicle, comprising: an internal combustion engine mounted on the electric vehicle, an electric generator driven by the internal combustion engine, an electric motor for driving a drive shaft of the electric vehicle, and an electric power supply to the electric motor The driving battery is characterized in that it has:

a running mode control unit that switches to a series mode for running the electric vehicle with first electric power supplied from the generator to the electric motor and second electric power supplied to the electric motor. 2. electric power is supplied from the driving battery to the electric motor;

an insufficient battery output judging section that judges whether the second electric power is insufficient; and

a power generation control section that controls the internal combustion engine and the generator based on the first electric power,

The power generation control unit includes:

a first control mode that controls the internal combustion engine to vary the rotational speed of the internal combustion engine; and

a second control mode that controls the generator to vary the rotational speed of the internal combustion engine,

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 switches from the second control mode to the first control mode,

The power generation control section calculates a target rotation speed that is a target rotation speed of the internal combustion engine based on the first electric power, and calculates an increase in the target rotation speed when the target rotation speed increases. rate, and set the first limit value of the increase rate, when the running mode control unit switches to the series mode and the battery output insufficient determination unit determines that the second electric power is insufficient The power generation control unit performs correction control for correcting the increase rate to a second limit value larger than the first limit value.

5. [After modification] The control device for an electric vehicle according to claim 3 or 4, characterized in that,

The second limit value is a smaller value as the target rotational speed is higher.

6. The control device for an electric vehicle according to any one of claims 1 to 5, wherein:

The insufficient battery output determination unit includes a battery temperature acquisition unit that acquires a temperature of the driving 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 below a first predetermined temperature or above a second predetermined temperature.

7. The control device for an electric vehicle according to claim 4 or 5, wherein:

The insufficient battery output determination unit includes a battery temperature acquisition unit that acquires a temperature of the driving battery,

When the temperature acquired by the battery temperature acquiring unit is below a first predetermined temperature or above a second predetermined temperature, the insufficient battery output determining unit determines that the second electric power is insufficient,

The second limit value is a value that is lower than the first predetermined temperature when the temperature of the driving battery acquired by the battery output deficiency determination unit is equal to or lower than the first predetermined temperature. The second limit value is smaller when the acquired temperature of the driving battery is equal to or higher than the second predetermined temperature.

8. The control device for an electric vehicle according to any one of claims 1 to 7, wherein:

the power generation control unit calculates a rotation increasing torque for increasing the rotation speed of the internal combustion engine,

The power generation control unit acquires an actual rotation speed that is an actual rotation speed of the internal combustion engine,

In the first control mode, the power generation control section suppresses the rotation up torque according to the actual rotation speed.

9. The control device for an electric vehicle according to claim 8, wherein:

When the actual rotation speed is greater than the target rotation speed, the power generation control unit suppresses the rotation increase torque.

10. The control device for an electric vehicle according to claim 8 or 9, wherein:

The power generation control unit suppresses the rotation increasing torque as the actual rotation speed increases.

11. The control device for an electric vehicle according to any one of claims 1 to 10, wherein:

An accelerator opening degree judging unit is further provided which judges the accelerator opening degree,

When the accelerator opening is zero, the power generation control unit switches from the first control mode to the second control mode.

12. The control device for an electric vehicle according to any one of claims 1 to 11, wherein:

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.

13. The control device for an electric vehicle according to claim 6 or 7, wherein:

The first predetermined temperature is calculated based on either or both of deterioration of the driving battery and a charging rate of the driving battery.

14. The control device for an electric vehicle according to any one of claims 1 to 13, wherein:

The power generation control section calculates a target power generation amount based on the first electric power, and acquires an actual power generation amount that is a target power generation amount of the generator, and the actual power generation amount is an actual power generation amount of the generator. power generation,

The power generation control unit switches from the second control mode to the first control mode when the actual power generation amount is smaller than the target power generation amount.

15. The control device for an electric vehicle according to any one of claims 1 to 14, wherein:

The power generation control unit calculates, based on the first electric power, a target rotational speed that is a target rotational speed of the internal combustion engine, and sets an upper limit value of the target rotational speed that is switched to by the running mode control unit. In the series mode, the power generation control unit limits the upper limit value to be equal to or less than a predetermined rotation speed when the battery output shortage determination unit determines that the second electric power is insufficient.

16. The control device for an electric vehicle according to claim 15, wherein:

The predetermined rotational speed is a change point of the output characteristic of the internal combustion engine.

17. The control device for an electric vehicle according to claim 15 or 16, wherein:

When the speed of the electric vehicle is lower than a second predetermined speed, the power generation control unit limits the upper limit value to be equal to or lower than the predetermined rotational speed.

18. The control device for an electric vehicle according to any one of claims 15 to 17, wherein:

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.

Statement or declaration (as amended under Article 19 of the Treaty)

Modify title page

(Modified under Article 19 of the Treaty)

Modify the description:

1. Claims

Claim 1 after amendment is an independent claim to which Claim 2 before amendment is added. Claim 2 after amendment is claim 3 before amendment. Claim 3 after amendment is claim 4 citing claims 2 to 3 before amendment.

The amended claim 4 refers to claim 4 citing the pre-amended independent claim 1 as an independent claim. Amended claim 5 is changed to refer to amended claim 3 and amended claim 4.

Claims (18)

1. A control device for an electric vehicle, comprising: an internal combustion engine mounted on the electric vehicle, a generator driven by the internal combustion engine, an electric motor for driving a drive shaft of the electric vehicle, and a drive battery for supplying electric power to the electric motor , characterized by having: a running mode control unit that switches to a series mode for running the electric vehicle with first electric power supplied from the generator to the electric motor and second electric power supplied to the electric motor. 2. electric power is supplied from the driving battery to the electric motor; an insufficient battery output judging section that judges whether the second electric power is insufficient; and a power generation control section that controls the internal combustion engine and the generator based on the first electric power, The power generation control unit includes: a first control mode that controls the internal combustion engine to vary the rotational speed of the internal combustion engine; and a second control mode that controls the generator to vary the rotational speed of the internal combustion engine, 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 switches from the second control mode to The first control mode. 2. The control device for an electric vehicle according to claim 1, wherein: The power generation control section calculates a target rotation speed that is a target rotation speed of the internal combustion engine and is switched by the running mode control section based on the first electric power, and sets a lower limit value of the target rotation speed. In the case of the series mode and the battery output shortage determination unit determines that the second electric power is insufficient, the power generation control unit performs correction control to increase the lower limit value. 3. The control device for an electric vehicle according to claim 2, wherein: The power generation control unit corrects the lower limit value to a larger value as the speed of the electric vehicle increases. 4. The control device for an electric vehicle according to any one of claims 1 to 3, wherein: The power generation control section calculates a target rotation speed that is a target rotation speed of the internal combustion engine based on the first electric power, and calculates an increase in the target rotation speed when the target rotation speed increases. rate, and set the first limit value of the increase rate, when the running mode control unit switches to the series mode and the battery output insufficient determination unit determines that the second electric power is insufficient The power generation control unit performs correction control for correcting the increase rate to a second limit value larger than the first limit value. 5. The control device for an electric vehicle according to claim 4, wherein: The second limit value is a smaller value as the target rotational speed is higher. 6. The control device for an electric vehicle according to any one of claims 1 to 5, wherein: The insufficient battery output determination unit includes a battery temperature acquisition unit that acquires a temperature of the driving 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 below a first predetermined temperature or above a second predetermined temperature. 7. The control device for an electric vehicle according to claim 4 or 5, wherein: The insufficient battery output determination unit includes a battery temperature acquisition unit that acquires a temperature of the driving battery, When the temperature acquired by the battery temperature acquiring unit is below a first predetermined temperature or above a second predetermined temperature, the insufficient battery output determining unit determines that the second electric power is insufficient, The second limit value is a value that is lower than the first predetermined temperature when the temperature of the driving battery acquired by the battery output deficiency determination unit is equal to or lower than the first predetermined temperature. The second limit value is smaller when the acquired temperature of the driving battery is equal to or higher than the second predetermined temperature. 8. The control device for an electric vehicle according to any one of claims 1 to 7, wherein: the power generation control unit calculates a rotation increasing torque for increasing the rotation speed of the internal combustion engine, The power generation control unit acquires an actual rotation speed that is an actual rotation speed of the internal combustion engine, In the first control mode, the power generation control section suppresses the rotation up torque according to the actual rotation speed. 9. The control device for an electric vehicle according to claim 8, wherein: When the actual rotation speed is greater than the target rotation speed, the power generation control unit suppresses the rotation increase torque. 10. The control device for an electric vehicle according to claim 8 or 9, wherein: The power generation control unit suppresses the rotation increasing torque as the actual rotation speed increases. 11. The control device for an electric vehicle according to any one of claims 1 to 10, wherein: An accelerator opening degree judging unit is further provided which judges the accelerator opening degree, When the accelerator opening is zero, the power generation control unit switches from the first control mode to the second control mode. 12. The control device for an electric vehicle according to any one of claims 1 to 11, wherein: 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. 13. The control device for an electric vehicle according to claim 6 or 7, wherein: The first predetermined temperature is calculated based on either or both of deterioration of the driving battery and a charging rate of the driving battery. 14. The control device for an electric vehicle according to any one of claims 1 to 13, wherein: The power generation control section calculates a target power generation amount based on the first electric power, and acquires an actual power generation amount that is a target power generation amount of the generator, and the actual power generation amount is an actual power generation amount of the generator. power generation, The power generation control unit switches from the second control mode to the first control mode when the actual power generation amount is smaller than the target power generation amount. 15. The control device for an electric vehicle according to any one of claims 1 to 14, wherein: The power generation control unit calculates, based on the first electric power, a target rotational speed that is a target rotational speed of the internal combustion engine, and sets an upper limit value of the target rotational speed that is switched to by the running mode control unit. In the series mode, the power generation control unit limits the upper limit value to be equal to or less than a predetermined rotation speed when the battery output shortage determination unit determines that the second electric power is insufficient. 16. The control device for an electric vehicle according to claim 15, wherein: The predetermined rotational speed is a change point of the output characteristic of the internal combustion engine. 17. The control device for an electric vehicle according to claim 15 or 16, wherein: When the speed of the electric vehicle is lower than a second predetermined speed, the power generation control unit limits the upper limit value to be equal to or lower than the predetermined rotational speed. 18. The control device for an electric vehicle according to any one of claims 15 to 17, wherein: 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.

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