JPWO2019188362A1 - Power generation control device for hybrid vehicles - Google Patents

Abstract

The hybrid vehicle 12 can drive the motor 23 by using at least one of the electric power generated by the generator 31 driven by the engine 25 and the electric power stored in the battery 50. In the first mode, the engine 25 is driven by an accelerator operation of a predetermined amount or more. In the second mode, the engine 25 is driven by an accelerator operation smaller than a predetermined amount. The power generation limiting unit 610 can limit the amount of power generated by the generator 31 in the second mode, and when the engine 25 is driven when the charge rate of the battery 50 is equal to or higher than the first predetermined value, the generator 31 is used. The amount of power generation is made smaller than the amount of power generated by the generator 31 when the engine 25 is driven when the charge rate of the battery 50 is less than the first predetermined value.

Description

The present invention relates to a power generation control device for a hybrid vehicle.

Conventionally, in a hybrid vehicle equipped with an engine and a motor, a braking force (regenerative braking force) is generated by regenerative operation of the motor during deceleration or downhill to reduce energy loss. Here, power is generated by the motor during the regenerative operation, but there is a problem that the amount of electric power received by the regenerative operation is small and the regenerative braking force is small when the battery charge rate is high.
In order to solve this, for example, Patent Document 1 below includes an engine, a generator connected to the engine, a power storage device that stores electric power, and a traveling motor that generates driving force by electric power, and when the vehicle decelerates. In a hybrid electric vehicle capable of energy regeneration operation in which the generated energy is converted into electric power energy by the power generation operation of the traveling motor and stored in the power storage device, when the charge amount of the power storage device exceeds a predetermined value during the energy regeneration operation. A hybrid electric motor equipped with two or more power consuming devices that consume power energy is disclosed.

JP-A-2002-238105

In general, a hybrid vehicle runs in EV driving mode in which only the motor is driven while the battery charge rate is high, and when the battery charge rate is low, the engine drives a generator to supply electric power to the motor. It shifts to the HV driving mode in which the vehicle travels. That is, in a hybrid vehicle, the engine is basically driven in a state where the charge rate of the battery is low.
On the other hand, for example, when the sport mode is set to have good responsiveness during driving, when you want to turn on the heating with the air conditioner, or when there is a charge request from the user (when the charge switch is operated), etc. The engine starts regardless of the battery charge rate.
When the engine is started and the generator is driven, the generated power is supplied to the motor, and the power supplied from the battery to the motor is reduced. Therefore, if the engine is started in a state where the charge rate of the battery is high, there is a problem that the state in which the regenerative braking is not effective continues for a long time.
In the above-mentioned conventional technique, the electric power generated by the regenerative operation is consumed by the electric power consumption device (exhaust gas purification device or generator), but in the state where the engine is operating as described above, the engine by the generator is used. Cannot be motorized.
The present invention has been made in view of such circumstances, and an object of the present invention is to obtain a high regenerative braking force even when the engine is started while the battery is in a high charge rate state.

In order to achieve the above object, the power generation control device for a hybrid vehicle according to the present invention drives a motor using at least one of the generated power of an in-vehicle generator driven by an engine and the electric power stored in an in-vehicle battery. Power generation control of a hybrid vehicle having a first mode in which the engine is driven by an accelerator operation of a predetermined amount or more and a second mode in which the engine is driven by an accelerator operation smaller than the predetermined amount. The device includes a power generation limiting unit capable of limiting the amount of power generated by the vehicle-mounted generator in the second mode, and the power generation limiting unit is used when the charging rate of the vehicle-mounted battery is equal to or higher than the first predetermined value. When driving the engine, the amount of power generated by the vehicle-mounted generator is the amount of power generated by the vehicle-mounted generator when the engine is driven when the charge rate of the vehicle-mounted battery is less than the first predetermined value. It is characterized by less than.

According to the present invention, when the engine is driven when the charge rate of the vehicle-mounted battery is equal to or higher than the first predetermined value in the second mode, the amount of power generated by the vehicle-mounted generator is limited. The output power (discharge amount) from the in-vehicle battery is larger than that of the vehicle-mounted battery. As a result, the amount of electric power that can be received by the in-vehicle battery during the regenerative operation of the motor increases, which is advantageous in obtaining a larger regenerative braking force.

It is explanatory drawing which shows the structure of the hybrid vehicle 12 which carries the power generation control device 10 which concerns on embodiment. It is a block diagram which shows the functional structure of the ECU 60. It is a graph which shows the relationship between the generated power of a generator 31 and the required power. It is a graph which shows typically the limit degree of the amount of power generation. It is a graph which shows the relationship between the charge rate of the battery 50, and the generated power. It is explanatory drawing which shows typically the control when the output performance of a battery 50 deteriorates. It is a flowchart which shows the process of a power generation control device 10.

Hereinafter, preferred embodiments of the power generation control device for the hybrid vehicle (hereinafter, simply referred to as “power generation control device”) according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory diagram showing a configuration of a hybrid vehicle 12 equipped with the power generation control device 10 according to the embodiment.
As shown in FIG. 1, the hybrid vehicle 12 includes a traveling system 20, a power generation system 30, and an ECU 60.
The traveling system 20 is a drive mechanism for the hybrid vehicle 12, and includes front wheels 21, rear wheels 22, a motor 23, an inverter 24, an engine 25, rotation of the output shaft 23A of the motor 23, and output shaft 25A of the engine 25. It includes a transmission mechanism 26 that transmits rotation to the front wheels 21, a fuel tank 40, and a battery (vehicle-mounted battery) 50.

The front wheels 21 and the rear wheels 22 are each composed of two pairs of wheels in the vehicle width direction. In the present embodiment, the front wheels 21 are drive wheels driven by the motor 23 and the engine 25.
The motor 23 is driven by using the electric power stored in the battery 50, and outputs a rotational force (torque) from the output shaft 23A. The motor 23 can also perform regenerative operation to generate regenerative power when the hybrid vehicle 12 is decelerated (such as when the accelerator pedal is released). The electric power generated by the regenerative power generation is supplied to the battery 50 via the inverter 24 to charge the battery 50.

The inverter 24 adjusts the electric power stored in the battery 50 or the electric power generated by the generator 31, which will be described later, in accordance with the output requested by the driver and supplies the electric power to the motor 23. The driver's required output is calculated by the ECU 60, which will be described later, based on, for example, the operating state of the accelerator pedal, the brake pedal, the shift lever (not shown), the vehicle speed measured by the vehicle speed sensor, and the like. The ECU 60 controls the inverter 24 based on the calculated output requested by the driver.

The engine 25 is driven by burning the fuel supplied from the fuel tank 40 in the combustion chamber. The engine 25 is, for example, a gasoline-fueled reciprocating engine. The drive of the engine 25 is controlled by the ECU 60 described later.

The transmission mechanism 26 transmits the rotation of the output shaft 23A of the motor 23 to the front wheels 21 and the rotation of the output shaft 25A of the engine 25 to the front wheels 21. The transmission mechanism 26 includes a clutch device 27. The clutch device 27 includes a pair of clutch plates 27A and 27B and a drive unit 27C that enables the clutch plates 27A and 27B to come into contact with each other and release the contact state.

The clutch plate 27A rotates integrally with the output shaft 25A of the engine 25. The clutch plate 27B rotates integrally with the output shaft 23A of the motor 23. When the clutch plates 27A and 27B come into contact with each other by the drive unit 27C, the clutch plates 27A and 27B rotate integrally with each other. As a result, the rotation of the output shaft 25A of the engine 25 is transmitted to the front wheels 21. When the clutch plates 27A and 27B are separated from each other by the drive unit 27C, the rotation of the output shaft 25A of the engine 25 is not transmitted to the front wheels 21. The drive unit 27C is controlled by the ECU 60 described later.

The fuel tank 40 stores fuel (for example, gasoline) that is a power source for the engine 25.
The battery 50 stores electric power that is a power source of the motor 23. The battery 50 can be charged by power generation by a generator 31, which will be described later, regenerative power generation by a motor 23, and supply of an external power source from a charging connector (not shown) provided on the vehicle body of the hybrid vehicle 12.
A BMU (Battery Monitoring Unit) 50A is connected to the battery 50. The BMU 50A detects the voltage and temperature of the battery 50, the input / output current, and the like, and detects the state of the battery 50 including the charge rate (SOC: State Of Charge). The BMU 50A transmits the state of the battery 50 (charge rate, battery voltage, battery temperature, etc.) to the ECU 60.

The power generation system 30 is a mechanism for charging the battery 50, and includes an engine 25, a generator (vehicle-mounted generator) 31, and an inverter 24.

The rotation of the output shaft 25A of the engine 25 is transmitted to the rotation shaft 31A of the generator 31 via the second transmission mechanism 32. When the generator 31 becomes capable of generating electricity under the control of the ECU 60, the rotating shaft 31A rotates in response to the rotation of the output shaft 25A of the engine 25 to generate electricity. The generator 31 is connected to the inverter 24, and the AC power generated by the generator 31 is converted into DC power by the inverter 24 and charged to the battery 50.
Further, in the HV traveling mode described later, the AC power generated by the generator 31 is used as it is for driving the motor 23. In this case, the generated power of the generator 31 is supplied to the motor 23 after the frequency is appropriately converted by the inverter 24.

The generator 31 also functions as an electric motor (starter) when starting the engine 25. When starting the engine 25, the ECU 60 controls the inverter 24 to drive the generator 31. The rotation shaft 31A is rotated by driving the generator 31. Since the rotating shaft 31A is connected to the output shaft 25A of the engine 25 via the second transmission mechanism 32, when the generator 31 is driven and the rotating shaft 31A rotates, the output shaft 25A of the engine 25 can be rotated. it can.

The ECU 60 is a control unit that controls the entire hybrid vehicle 12, and functions as a power generation control device 10 for the hybrid vehicle 12.
The ECU 60 includes a CPU, a ROM for storing and storing a control program, a RAM as an operating area for the control program, an EEPROM for rewritably holding various data, an interface unit for interfacing with peripheral circuits, and the like. To.

FIG. 2 is a block diagram showing a functional configuration of the power generation control device 10 (ECU 60).
The ECU 60 functions as a drive control unit 602, an engine start request detection unit 604, a battery performance detection unit 606, a power generation control unit 608, and a power generation limiting unit 610 when the CPU executes the control program.

The drive control unit 602 includes each part of the hybrid vehicle 12, such as the motor 23, the engine 25, the generator 31, and the clutch device 27, based on parameters such as the charge rate of the battery 50 of the hybrid vehicle 12 and the required output to the hybrid vehicle 12. Controls the drive unit 27C and the like.
The drive control unit 602 maintains the traveling mode of the hybrid vehicle 12, for example, the EV traveling mode in which only the motor 23 is driven to travel, and the motor 23 and the engine 25 to drive the motor 23 and the engine 25 to maintain the charge rate of the battery 50 within a predetermined range. It is possible to switch between the HV driving mode in which the vehicle travels.
In the EV traveling mode, the engine 25 is stopped and the axle is rotated by the driving force of the motor 23 to travel. The electric power supplied to the motor 23 in the EV traveling mode is the stored electric power stored in the battery 50, and the electric power in the battery 50 is consumed except during the regenerative operation of the motor 23, and the charge rate of the battery 50 gradually decreases. To do.
In the HV driving mode (series driving mode), the engine 25 drives the generator 31 and the driving force of the motor 23 rotates the axle to drive the vehicle. In the HV traveling mode, the generated power generated by the generator 31 is supplied to the motor 23, so that the charge rate of the battery 50 is kept within a certain range.

The drive control unit 602 is a hybrid vehicle in the EV driving mode until the charging rate of the battery 50 is equal to or less than the predetermined mode switching charging rate, and in the HV driving mode when the charging rate of the battery 50 is equal to or less than the mode switching charging rate. 12 is run.
When the hybrid vehicle 12 starts traveling from the state where the battery 50 has a high charge rate (mode switching charge rate or higher), the drive control unit 602 first drives the EV travel mode hybrid vehicle 12. In the EV traveling mode, the charge rate of the battery 50 gradually decreases. Then, when the charging rate of the battery 50 becomes the mode switching charging rate, the traveling mode is switched to the HV traveling mode.
In the HV driving mode, the engine 25 is driven in addition to the motor 23, and the generator 31 is driven by the power of the engine 25 to generate electric power to supply electric power to the motor 23, so that the charge rate of the battery 50 is within a certain range. Be kept.

The engine start request detection unit 604 detects that there is a start request for the engine 25 while traveling in the EV traveling mode in which the engine 25 is not in the driving state, and starts the engine 25.
The engine start request detection unit 604 starts the engine 25 when, for example, an accelerator operation (depression of the accelerator pedal) is performed by a predetermined amount or more, and causes the generator 31 to generate electricity. This is because when the accelerator operation exceeds a predetermined amount, the motor 23 is required to have a high output, and the electric power supplied to the motor 23 cannot be cut off only by the electric power of the battery 50 (instantaneous increase in output). This is because there is a possibility that the battery discharge will not catch up.
Here, the accelerator operation amount at which the engine 25 is started is changed by the mode setting for the vehicle (normal mode and sports mode in the present embodiment). That is, when the normal mode is set, the engine 25 starts when the accelerator operation is performed by a predetermined amount or more as described above, whereas when the sport mode is set, the engine 25 is started. The engine 25 starts when an accelerator operation smaller than a predetermined amount is performed. By setting the sport mode, it is possible to improve the acceleration response to the accelerator operation by the user.
That is, the hybrid vehicle 12 has a normal mode (first mode) in which the engine 25 is driven by an accelerator operation of a predetermined amount or more, and a second mode (sports mode) in which the engine is driven by an accelerator operation smaller than a predetermined amount. ..
The sports mode is set by, for example, the user operating an operation unit (sports mode setting switch, etc.) provided in the driver's seat.
Further, the engine start request detection unit 604 may start the engine 25, assuming that there is an engine start request when, for example, there is a heating request or a charge request (operation of the charge switch).

The battery performance detection unit 606 detects the output performance of the battery 50. The function of the battery performance detection unit 606 may be provided in the BMU 50A.
The battery performance detection unit 606 detects, for example, the degree of deterioration (SOH: State Of Health) of the battery 50 and the battery temperature. For the degree of deterioration of the battery 50, for example, the elapsed time from the start of use of the battery 50, the integrated energization amount, the change over time of the battery temperature, etc. are recorded, and a predetermined deterioration degree estimation map or a predetermined degree of deterioration based on the performance characteristics of the battery 50 can be obtained. It can be estimated based on a calculation formula or the like. Also, the battery temperature can be obtained from the BMU50A.
It is generally known that the greater the degree of deterioration of the battery 50 and the lower the battery temperature, the lower the output performance of the battery 50. The decrease in the output performance of the battery 50 means that the amount of electric power that can be output per unit time decreases regardless of the charge rate of the battery 50.

The power generation control unit 608 sets a target power generation amount in the generator 31 and controls the driving state of the engine 25 based on the target power generation amount.
In the present embodiment, basically, while the engine 25 is being driven, the generator 31 generates electric power (required electric power) required for the motor 23 to output the required output from the driver and supplies the electric power to the motor 23. In this case, the power consumption of the motor 23 is covered by the power generated by the generator 31, and the charge rate of the battery 50 does not decrease.
On the other hand, when the amount of power generation is limited by the power generation limiting unit 610 described later, a part of the required power is generated by the generator 31, and the rest is supplied to the motor 23 with the power stored in the battery 50. In this case, a part of the stored power of the battery 50 is used by the motor 23, and the charge rate of the battery 50 decreases.
That is, the power generation control unit 608 generates the required power, which is the power required to output the required output from the driver to the motor 23 when the amount of power generated by the power generation limiting unit 610 is not limited (normal time). When the power generation amount is limited by the power generation limiting unit 610, a power smaller than the required power is set as the target power generation amount in the generator 31. At this time, the shortage of the required power is supplied from the battery 50 to the motor 23.
When the required power is equal to or greater than the upper limit generated power of the generator 31, the shortage is supplemented by the power stored in the battery 50. In this case as well, the charge rate of the battery 50 decreases.

FIG. 3 is a graph showing the relationship between the generated power of the generator 31 and the required power.
In FIG. 3, the vertical axis represents the power supplied to the motor 23 and the generated power of the generator 31, and the horizontal axis represents the required power. In FIG. 3, there are three items, that is, line L1 showing the generated power + battery output power, line L2 showing the generated power when the amount of power generation is not limited (normal time), and line L3 showing the generated power when the amount of power generation is limited. Is shown. Further, the shaded portion becomes the output power of the battery 50.
Line L1 is the sum of the generated power of the generator 31 and the output power from the battery 50, and indicates the power finally supplied to the motor 23. Line L1 is equal to the required power over the entire area.
The line L2 shows the generated power of the generator 31 when the power generation amount, which will be described later, is not limited (normal time). The line L2 is equal to the required power up to the upper limit generated power WM of the generator 31, and the power generation at the upper limit generated power WM is maintained in the region above the upper limit generated power WM. That is, in the normal state, in the region where the required power is equal to or less than the upper limit generated power WM, all the required power is generated by the generator 31 and supplied to the motor 23, and in the region where the required power exceeds the upper limit generated power WM, the upper limit is generated by the generator 31. The generated power WM is generated, and the output power of the battery 50 makes up for the shortage with the required power.
The line L3 shows the generated power of the generator 31 when the power generation amount is limited, which will be described later (when the power generation is limited). In line L3, the generated power of the generator 31 is smaller than the required power over the entire region, and the generated power of the generator 31 is smaller than that in the normal state. That is, when the power generation is limited, the amount of power generated by the generator 31 is smaller than the required power in all areas, and the output power of the battery 50 compensates for the shortage with the required power. For example, when the required power is 70 Wh, the generator 31 normally generates 70 Wh, whereas when the power generation is limited, only 40 Wh is generated, and the remaining 30 Wh is supplied from the battery 50. Therefore, when the power generation is limited, the power consumption of the battery 50 becomes larger than in the normal state, and the charging rate tends to decrease.

Returning to the description of FIG. 2, the power generation limiting unit 610 can limit the amount of power generated by the generator 31 in the sport mode (second mode). More specifically, when the power generation limiting unit 610 drives the engine 25 when the charge rate of the battery 50 is equal to or higher than the first predetermined value during the sport mode setting, the power generation amount of the generator 31 is calculated by the battery 50. The charge rate is less than the amount of power generated by the generator 31 when the engine 25 is driven when the charge rate is less than the first predetermined value.
The first predetermined value is, for example, a value having a relatively high charge rate (charge rate 80%, etc.).
Such power generation restriction is performed when the battery 50 is driven using only the generated power of the generator 31 in a high charge rate state, the high charge rate of the battery 50 continues for a long time, and it is difficult to obtain regenerative braking force. This is to continue. As described above, normally, the engine 25 of the hybrid vehicle 12 is driven in the HV driving mode when the charge rate of the battery 50 becomes low. On the other hand, when there is a start request for the engine 25 during EV driving (when the engine start request detection unit 604 detects a start request for the engine 25, such as when an accelerator operation of a predetermined amount or more is performed), the battery is used. The engine 25 is started regardless of the charging rate of 50, and the power generation of the generator 31 is started. In particular, when the sport mode is set, the engine 25 is driven more frequently than in the normal mode, and the charge rate of the battery 50 tends to increase.
By limiting the amount of power generated by the generator 31 while the sports mode is set by using the power generation limiting unit 610, the charging rate of the battery 50 can be intentionally lowered so that the regenerative braking force can be easily obtained.

While the normal mode (first mode) is set, the power generation limiting unit 610 does not have to limit the power generation. For example, when the generated power shifts along the line L2 in FIG. 3 while the normal mode is set, when the sports mode is set and the charge rate of the battery is equal to or higher than the first predetermined value of the battery 50. The generated power shifts along the line L3 in FIG.
That is, when the power generation limiting unit 610 drives the engine 25 when the charge rate of the battery 50 is equal to or higher than the first predetermined value during the sport mode setting, the power generation amount of the generator 31 is reduced to the engine 25 in the normal mode. It is limited more than the amount of power generated by the generator 31 when driving.

The power generation limiting unit 610 may change the degree of limiting the amount of power generation based on, for example, the charge rate of the battery 50. Specifically, for example, the higher the charge rate of the battery 50, the greater the degree of limitation on the amount of power generation.
FIG. 4 is a graph schematically showing the degree of limitation of the amount of power generation.
Each item in FIG. 4 is the same as in FIG. 3, but the line L3 and the line L4 are shown as lines showing the generated power when the amount of power generation is limited. Line L3 shows, for example, the generated power when the charge rate of the battery 50 is 100%, and line L4 shows, for example, the generated power when the charge rate of the battery 50 is 80%.
Comparing line L3 and line L4, the power generated at a charge rate of 100% is less than the power generated at a charge rate of 80%, and the difference from the power generated at normal times (line L2) is large. ing. As a result, the output power from the battery 50 is larger when the charge rate is 100% than when the charge rate is 80%, and the charge rate of the battery 50 can be reduced at an early stage.

Further, the power generation limiting unit 610 may asymptotically release the limitation on the amount of power generation when the charge rate of the battery 50 becomes equal to or less than the second predetermined value. The second predetermined value (power generation restriction release charge rate) is a value equal to or less than the first predetermined value (power generation limit start charge rate).
That is, the power generation limiting unit 610 releases the power generation limitation when the charge rate of the battery 50 drops to the extent that a sufficient regenerative braking force can be obtained. At that time, for example, the line L3 in FIG. 3 is perpendicular to the line L2. When the amount of power generation is changed, the number of revolutions of the engine 25 rapidly increases, giving the user a sense of discomfort. Therefore, when the power generation restriction is lifted, the amount of power generation is gradually changed.

FIG. 5 is a graph showing the relationship between the charge rate of the battery 50 and the generated power, FIG. 5A shows the charge rate of the battery 50, and FIG. 5B shows the generated power (assuming that the required power is constant).
In the example of FIG. 5, the charging rate of 70% is the second predetermined value. In the region from the charge rate of 100% (not shown) to the charge rate of 70%, the power generation limiting unit 610 sets the generated power to, for example, a value N1 along the line L3 in FIG. Further, in the region where the charging rate is 60% or less, the generated power is set to, for example, a value N2 (> N1) along the line L2 in FIG. In the region from the charging rate of 70% to the charging rate of 60% during this period, the generated power is gradually increased from the value N1 to the value N2 in inverse proportion to the charging rate.
By doing so, the limitation on the amount of power generation can be lifted without causing a sudden change in the rotation speed of the engine 25.

Further, the power generation limiting unit 610 may change the degree of limiting the amount of power generation based on the output performance of the battery 50 detected by the battery performance detecting unit 606. In this case, the power generation limiting unit 610 reduces the degree of limiting the amount of power generation when the output performance of the battery 50 is deteriorated. This is because when the output performance of the battery 50 is deteriorated, it may not be possible to supplement the insufficient power generation amount with the output power from the battery 50 due to the limitation of the power generation amount.
As described above, the index related to the output performance of the battery 50 includes, for example, the degree of deterioration of the battery 50 and the battery temperature. The greater the degree of deterioration of the battery 50 and the lower the battery temperature, the higher the output performance of the battery 50. It is known to decrease.
Therefore, the power generation limiting unit 610 reduces the degree of limitation of the amount of power generation as the degree of deterioration of the battery 50 increases, and the degree of limitation of the amount of power generation decreases as the degree of battery temperature decreases. It should be noted that reducing the degree of limitation on the amount of power generation is as described with reference to FIG.

FIG. 6 is an explanatory diagram schematically showing control when the output performance of the battery 50 deteriorates.
FIG. 6A shows a case where the output performance of the battery 50 is sufficiently high. When the output performance of the battery 50 is sufficiently high, for example, the limited power generation power WB along the line L3 in FIG. 3 is set for the required power WA, and the shortage is set as the battery output power WC (WA =). WB + WC).
FIG. 6B shows a case where the output performance of the battery 50 is deteriorated. The battery output power WD in this case is smaller than the battery output power WC shown in FIG. 6A. Therefore, the limited power generation power WB similar to that in FIG. 6A is insufficient for the required power WA. In this case, the power generation limiting unit 610 increases the generated power by the amount of the insufficient power WE, and sets the generated power of the generator 31 to WF = WB + WE.
As a result, it is possible to prevent a shortage of power supply to the motor 23 when the output performance of the battery 50 deteriorates.

FIG. 7 is a flowchart showing the processing of the power generation control device 10.
While the hybrid vehicle 12 is running, the drive control unit 602 determines whether or not the charge rate of the battery 50 is equal to or higher than the mode switching charge rate (step S700), and if it is equal to or higher than the mode switching charge rate (step S700: Yes). The hybrid vehicle 12 is run in the EV running mode in which the engine 25 is stopped (step S702), and if it is less than the mode switching charge rate (step S700: No), the hybrid vehicle 12 is driven to run while generating power. The hybrid vehicle 12 is driven in the HV traveling mode (step S704).

When traveling in the normal mode while traveling in the EV mode (step S705: No), when an accelerator operation of a predetermined amount or more is performed, that is, the accelerator operation amount becomes the first predetermined amount α or more. If so, the engine 25 starts (step S706). In this case, the power generation control unit 608 sets the power generation amount of the generator 31 as usual (along the line L2 in FIG. 3) (step S712).

On the other hand, when the sport mode is set during the running in the EV mode (step S705: Yes), the accelerator operation is smaller than the predetermined amount, that is, the accelerator operation amount is smaller than the first predetermined amount α. The engine 25 is started when the predetermined amount β or more of 2 is reached (step S708).

While the sport mode is set, the power generation control unit 608 determines whether or not the charge rate of the battery 50 is equal to or higher than the first predetermined value (step S710). When the charge rate of the battery 50 is less than the first predetermined value (step S710: No), the battery 50 is in a state where it can accept the electric power generated when the motor 23 regenerates, so that it is normal (FIG. 3). The power generation amount of the generator 31 is set (along the line L2) (step S712).
On the other hand, when the charge rate of the battery 50 is equal to or higher than the first predetermined value (step S710: Yes), the battery 50 cannot accept the electric power generated when the motor 23 regenerates, and a sufficient regenerative braking force can be obtained. It is determined that this is not the case, and the power generation limiting unit 610 limits the amount of power generated by the generator 31 (step S714). In this case, the power generation limiting unit 610 sets the power generation amount of the generator 31 along the line L3 of FIG. 3, and appropriately changes the power generation amount limiting degree based on the output performance and the charging rate of the battery 50.
Until the charge rate of the battery 50 becomes equal to or less than the second predetermined value (step S716: No loop), the process returns to step S714 and the limit of the amount of power generation is continued. When the charge rate of the battery 50 becomes equal to or less than the second predetermined value (step S716: Yes), the limitation on the amount of power generation is gradually released. That is, the power generation amount of the generator 31 is gradually increased to match the power generation amount at the normal time.

As described above, when the power generation control device 10 according to the embodiment drives the engine 25 when the charge rate of the battery 50 is equal to or higher than the first predetermined value while the sports mode is set, the amount of power generated by the generator 31 is generated. Therefore, the output power (discharge amount) from the battery 50 is larger than that when the power generation amount is not limited. As a result, the amount of electric power that can be received by the battery 50 during the regenerative operation of the motor 23 increases, which is advantageous in obtaining a larger regenerative braking force.
Further, if the power generation control device 10 changes the degree of limitation of the power generation amount based on the charge rate of the battery 50, it is advantageous in appropriately setting the power generation amount of the generator 31. For example, the higher the charge rate of the battery 50, the greater the degree of limitation on the amount of power generation, which is advantageous in reducing the charge rate of the battery 50 in a shorter time. As a result, it becomes more advantageous in obtaining the regenerative braking force.
Further, in the power generation control device 10, when the charge rate of the battery 50 becomes equal to or less than the second predetermined value, if the limitation on the amount of power generation is asymptotically released, the amount of power generation can be increased without giving a sense of discomfort to the user. It is advantageous to return to normal.
Further, in the power generation control device 10, if the degree of limitation of the amount of power generation is reduced when the output performance of the battery 50 is deteriorated, the power supply to the motor 23 becomes insufficient due to the shortage of the output power from the battery 50. Can be prevented.
Further, in the power generation control device 10, if the degree of deterioration of the battery 50 is increased, the degree of limitation of the amount of power generation is reduced, or if the degree of limitation of the amount of power generation is reduced as the battery temperature of the battery 50 is low, the degree of deterioration of the in-vehicle battery is reduced. It is possible to prevent the power supply to the motor from being insufficient when the output performance is lowered due to the decrease in battery temperature.

10 Power generation control device 12 Hybrid vehicle 23 Motor 25 Engine 31 Generator 50 Battery 60 ECU
602 Drive control unit 604 Engine start request detection unit 606 Battery performance detection unit 608 Power generation control unit 610 Power generation limit unit

Claims (9)

It is possible to drive the motor by using at least one of the electric power generated by the in-vehicle generator driven by the engine and the electric power stored in the in-vehicle battery.
The first mode in which the engine is driven by an accelerator operation of a predetermined amount or more, and
A second mode in which the engine is driven by an accelerator operation smaller than the predetermined amount, and
It is a power generation control device of a hybrid vehicle having
A power generation limiting unit capable of limiting the amount of power generated by the in-vehicle generator in the second mode is provided.
When the engine is driven when the charge rate of the vehicle-mounted battery is equal to or higher than the first predetermined value, the power generation limiting unit determines the amount of power generated by the vehicle-mounted generator and the charge rate of the vehicle-mounted battery is the first. The amount of power generated by the in-vehicle generator when the engine is driven when the value is less than the predetermined value of
A power generation control device for hybrid vehicles. When the power generation limiting unit drives the engine when the charge rate of the vehicle-mounted battery is equal to or higher than the first predetermined value, the power generation limiting unit drives the engine with the amount of power generated by the vehicle-mounted generator in the first mode. The amount of power generated by the in-vehicle generator is less than the amount of power generated by the in-vehicle generator.
The power generation control device for a hybrid vehicle according to claim 1. Further provided with a power generation control unit for controlling the amount of power generated by the in-vehicle generator.
When the power generation amount is not limited by the power generation limiting unit, the power generation control unit sets the required power generation, which is the power required to output the required output from the driver to the motor, to the target power generation amount of the on-board generator. When the power generation amount is limited by the power generation limiting unit, a power smaller than the required power is set as the target power generation amount of the in-vehicle generator.
The shortage of the required power is supplied from the vehicle-mounted battery to the motor.
The power generation control device for a hybrid vehicle according to claim 1 or 2. The power generation limiting unit changes the degree of limiting the amount of power generation based on the charging rate of the in-vehicle battery.
The power generation control device for a hybrid vehicle according to any one of claims 1 to 3, wherein the power generation control device according to any one of claims 1 to 3. The power generation limiting unit increases the degree of limitation of the amount of power generation as the charging rate of the in-vehicle battery increases.
The power generation control device for a hybrid vehicle according to claim 4. When the charge rate of the vehicle-mounted battery becomes equal to or less than a second predetermined value smaller than the first predetermined value, the power generation limiting unit asymptotically releases the limitation on the amount of power generation.
The power generation control device for a hybrid vehicle according to any one of claims 1 to 5, characterized in that. Further equipped with a battery performance detection unit that detects the output performance of the in-vehicle battery,
When the output performance of the in-vehicle battery is deteriorated, the power generation limiting unit reduces the degree of limiting the amount of power generation.
The power generation control device for a hybrid vehicle according to any one of claims 1 to 6, characterized in that. The battery performance detection unit detects the degree of deterioration of the in-vehicle battery and determines the degree of deterioration.
The power generation limiting unit reduces the degree of limitation of the amount of power generation as the degree of deterioration of the in-vehicle battery increases.
The power generation control device for a hybrid vehicle according to claim 7. The battery performance detection unit detects the battery temperature of the vehicle-mounted battery and determines the battery temperature.
The power generation limiting unit reduces the degree of limitation of the amount of power generation as the battery temperature of the vehicle-mounted battery becomes lower.
The power generation control device for a hybrid vehicle according to claim 7.

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