JP7143880B2 - Power generation control device for hybrid vehicle - Google Patents

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 regeneratively operating the motor during deceleration or downhill to reduce energy loss. Here, the electric power is generated by the motor during the regenerative operation, but when the charging rate of the battery is high, the amount of power generated by the regenerative operation is reduced and the regenerative braking force is reduced.
In order to solve this problem, for example, Patent Document 1 below discloses an engine, a generator connected to the engine, an electric storage device that stores electric power, and a traction motor that generates driving force from the electric power. In a hybrid electric vehicle capable of performing an energy regeneration operation in which generated energy is converted into electric energy by power generation operation of the traction motor and stored in the capacitor, when the amount of charge in the capacitor exceeds a predetermined value during the energy regeneration operation. A hybrid electric vehicle is disclosed that includes two or more power consumption devices that consume power energy.

JP-A-2002-238105

Generally, a hybrid vehicle runs in an EV driving mode in which only the motor is driven while the battery charge rate is high, and when the battery charge rate drops, the engine drives the generator to supply power to the motor. HV running mode is entered. In other words, the engine of the hybrid vehicle is basically driven when the charging rate of the battery is low.
On the other hand, for example, when the sport mode is set to provide good operational responsiveness while driving, when the air conditioner wants to heat the vehicle, or when the user requests charging (when the charge switch is operated), etc. The engine will start regardless of the battery charge.
When the engine starts and the generator drives, the generated power is supplied to the motor, and the power supplied from the battery to the motor is reduced. Therefore, when the engine is started with a high battery charging rate, there is a problem that a state in which regenerative braking is difficult to work continues for a long time.
In the above-mentioned conventional technology, the power generated by the regenerative operation is consumed by the power consumption device (exhaust gas purification device or generator). motoring cannot be performed.
SUMMARY OF THE INVENTION 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 state of charge.

In order to achieve the above object, a power generation control apparatus for a hybrid vehicle according to the present invention drives a motor using at least one of electric power generated by an onboard generator driven by an engine and electric power stored in an onboard 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, wherein the power generation limiting unit limits the amount of power generated by the vehicle-mounted battery when the charging rate of the vehicle-mounted battery is equal to or higher than a first predetermined value. When the engine is driven, the amount of power generated by the vehicle-mounted generator is made smaller than the amount of power generated by the vehicle-mounted generator when the engine is driven in the first mode .

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

1 is an explanatory diagram showing a configuration of a hybrid vehicle 12 equipped with a power generation control device 10 according to an embodiment; FIG. 3 is a block diagram showing the functional configuration of an ECU 60; FIG. 4 is a graph showing the relationship between the power generated by the generator 31 and the required power. 4 is a graph schematically showing the degree of restriction of power generation amount; 4 is a graph showing the relationship between the charging rate of the battery 50 and the generated power. 4 is an explanatory diagram schematically showing control when the output performance of the battery 50 is degraded; FIG. 4 is a flowchart showing processing of the power generation control device 10;

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

The front wheels 21 and the rear wheels 22 are each composed of two wheels paired in the vehicle width direction. In this embodiment, the front wheels 21 are driving wheels driven by the motor 23 and the engine 25 .
The motor 23 is driven using electric power stored in the battery 50, and outputs rotational force (torque) from the output shaft 23A. It should be noted that the motor 23 can perform regenerative operation to generate regenerative power when the hybrid vehicle 12 is decelerated (eg, when the accelerator pedal is released). Electric power generated by 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 described later according to the driver's requested output and supplies the motor 23 with the adjusted power. The output demanded by the driver is calculated by the ECU 60, which will be described later, based on, for example, the operating states of an accelerator pedal, a brake pedal, a shift lever (not shown), etc., and the vehicle speed measured by a vehicle speed sensor. 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 reciprocating engine that uses gasoline as fuel. Driving of the engine 25 is controlled by an ECU 60, which will be described later.

The transmission mechanism 26 transmits rotation of the output shaft 23 A of the motor 23 to the front wheels 21 and transmits rotation of the output shaft 25 A of the engine 25 to the front wheels 21 . The transmission mechanism 26 has a clutch device 27 . The clutch device 27 includes a pair of clutch plates 27A and 27B, and a driving portion 27C that allows 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. As shown in FIG. The clutch plate 27B rotates integrally with the output shaft 23A of the motor 23. As shown in FIG. When the clutch plates 27A and 27B are brought into contact with each other by the driving portion 27C, the clutch plates 27A and 27B rotate together with each other. As a result, the rotation of the output shaft 25A of the engine 25 is transmitted to the front wheels 21. As shown in FIG. When the drive portion 27C separates the clutch plates 27A and 27B from each other, the rotation of the output shaft 25A of the engine 25 is no longer transmitted to the front wheels 21 . 27 C of drive parts are controlled by ECU60 mentioned later.

The fuel tank 40 stores fuel (for example, gasoline) that is the power source of the engine 25 .
The battery 50 stores electric power, which is the power source of the motor 23 . The battery 50 can be charged by power generation by a generator 31 (to be described later), regenerative power generation by a motor 23, and external power supply 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, temperature, and input/output current of the battery 50, and detects the state of the battery 50 including the state of charge (SOC). BMU 50A transmits the state of battery 50 (charging rate, battery voltage, battery temperature, etc.) to ECU 60 .

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

Rotation of the output shaft 25A of the engine 25 is transmitted to the rotating shaft 31A of the generator 31 via the second transmission mechanism 32 . When the generator 31 becomes capable of generating power 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 power. 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 to charge the battery 50 .
Further, in the HV running mode, which will be described later, the AC power generated by the generator 31 is directly used to drive the motor 23 . In this case, the power generated by the generator 31 is appropriately frequency-converted by the inverter 24 and then supplied to the motor 23 .

The generator 31 also functions as an electric motor (starter) for starting the engine 25 . When starting the engine 25 , the ECU 60 controls the inverter 24 to drive the generator 31 . 31 A of rotating shafts rotate when the generator 31 drives. Since the rotary 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 rotary shaft 31A rotates, the output shaft 25A of the engine 25 can be rotated. 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 that stores and stores control programs, a RAM that serves as an operating area for the control programs, an EEPROM that rewritably holds various data, an interface section that interfaces with peripheral circuits, and the like. be.

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 limiter 610 by the CPU executing the control program.

The drive control unit 602 controls each unit 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 charging rate of the battery 50 of the hybrid vehicle 12 and the required output to the hybrid vehicle 12. drive unit 27C and the like.
The drive control unit 602 selects a running mode of the hybrid vehicle 12, for example, an EV running mode in which only the motor 23 is driven and a driving mode in which the motor 23 and the engine 25 are driven to maintain the charging rate of the battery 50 within a predetermined range. It is possible to switch between the HV driving mode in which the vehicle is driven and the HV driving mode.
During the EV travel mode, the engine 25 is stopped and the driving force of the motor 23 rotates the axle to travel. The electric power supplied to the motor 23 in the EV traveling mode is accumulated electric power accumulated 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 charging rate of the battery 50 gradually decreases. do.
During the HV running mode (series running mode), the generator 31 is driven by the engine 25 and the driving force of the motor 23 rotates the axle to run. During the HV running mode, the electric power generated by the generator 31 is supplied to the motor 23, so the charging rate of the battery 50 is kept within a certain range.

The drive control unit 602 operates the hybrid vehicle in the EV running mode until the charging rate of the battery 50 becomes equal to or less than the predetermined mode switching charging rate, and in the HV running mode when the charging rate of the battery 50 becomes equal to or less than the mode switching charging rate. 12 to run.
When hybrid vehicle 12 starts running from a state where battery 50 has a high charging rate (a mode switching charging rate or higher), drive control unit 602 first causes EV running mode hybrid vehicle 12 to run. In the EV running mode, the charging rate of battery 50 gradually decreases. Then, when the charging rate of the battery 50 reaches the mode switching charging rate, the running mode is switched to the HV running mode.
In the HV traveling 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 and supply electric power to the motor 23, thereby keeping the charging rate of the battery 50 within a certain range. be kept.

An engine start request detection unit 604 detects that there is a request to start the engine 25 while the vehicle is traveling in the EV traveling mode in which the engine 25 is not in a driving state, and starts the engine 25 .
The engine start request detection unit 604 starts the engine 25 and causes the generator 31 to generate power when, for example, the accelerator operation (the accelerator pedal is depressed) by a predetermined amount or more is performed. This is because when the accelerator operation is performed by a predetermined amount or more, a high output is required of the motor 23, and the power supplied to the motor 23 cannot be covered by the power of the battery 50 alone (instantaneous output increase). This is because there is a possibility that the battery discharge cannot catch up with the
Here, the accelerator operation amount at which the engine 25 is started is changed depending on the mode setting of the vehicle (normal mode and sport mode in the present embodiment). That is, when the normal mode is set, the engine 25 is started when the accelerator is operated by a predetermined amount or more as described above. The engine 25 is started when the accelerator is operated by less than a predetermined amount. By setting the sport mode, it is possible to improve the acceleration responsiveness 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 greater than or equal to a predetermined amount, and a second mode (sport mode) in which the engine is driven by an accelerator operation smaller than a predetermined amount. .
Note that the sport mode is set by the user operating an operation unit (sport mode setting switch, etc.) provided in the driver's seat, for example.
Further, the engine start request detection unit 604 may determine that there is an engine start request and start the engine 25 when, for example, there is a request for heating or a request for charging (operation of a charge switch).

A battery performance detection unit 606 detects the output performance of the battery 50 . Note that 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 of the battery 50 (SOH: State Of Health) and battery temperature. The degree of deterioration of the battery 50 is obtained by recording, for example, the elapsed time from the start of use of the battery 50, the accumulated amount of electricity, and the change in battery temperature over time, and using a predetermined deterioration degree estimation map or map based on the performance characteristics of the battery 50. It can be estimated based on a calculation formula or the like. Also, the battery temperature can be obtained from the BMU 50A.
Generally, it is known that the higher the degree of deterioration of the battery 50 and the lower the battery temperature, the lower the output performance of the battery 50 . A decrease in the output performance of the battery 50 means a decrease in the amount of power that can be output per unit time regardless of the charging rate of the battery 50 .

A power generation control unit 608 sets a target power generation amount of the generator 31 and controls the driving state of the engine 25 based on the target power generation amount.
In this embodiment, basically, while the engine 25 is running, the generator 31 generates electric power (required electric power) necessary for the motor 23 to output the output requested by 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 charging rate of the battery 50 does not decrease.
On the other hand, when the power generation amount is limited by the power generation limiting unit 610 described later, part of the requested power is generated by the generator 31 and the remaining power stored in the battery 50 is supplied to the motor 23 . In this case, the motor 23 uses part of the power stored in the battery 50, and the charging rate of the battery 50 decreases.
That is, when the power generation limiter 610 does not limit the amount of power generation (normal time), the power generation control unit 608 sets the required power to the generator 31 to produce the required output from the driver to the motor 23 . is set as the target power generation amount at the generator 31, and when the power generation limiting unit 610 limits the power generation amount, the target power generation amount at the generator 31 is set to be less than the requested power. At this time, the shortage of the required power is supplied from the battery 50 to the motor 23 .
Further, when the required electric power is equal to or higher than the upper limit generated electric power of the generator 31, the electric power accumulated in the battery 50 is used to make up for the shortfall. Also in this case, the charging rate of the battery 50 decreases.

FIG. 3 is a graph showing the relationship between the power generated by the generator 31 and the required power.
In FIG. 3, the vertical axis is the power supplied to the motor 23 and the power generated by the generator 31, and the horizontal axis is the required power. In FIG. 3, there are three items: a line L1 indicating generated power + battery output power, a line L2 indicating generated power when the amount of power generation is not limited (normal time), and a line L3 indicating the generated power when the amount of power generation is limited. is shown. Also, the shaded portion is the output power of the battery 50 .
A line L<b>1 is the sum of the power generated by the generator 31 and the power output 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.
A line L2 indicates the power generated by the generator 31 when the power generation amount is not limited (normal time), which will be described later. The line L2 is equal to the required electric power up to the upper limit generated power WM of the generator 31, and in the region above the upper limit generated power WM, power generation is maintained at the upper limit generated power WM. That is, normally, when the requested power is equal to or less than the upper limit generated power WM, all of the requested power is generated by the generator 31 and supplied to the motor 23, and when the requested power exceeds the upper limit generated power WM, the generator 31 generates the upper limit. In addition to generating the generated power WM, the output power of the battery 50 is used to make up for the shortage of the required power.
A line L3 indicates the power generated by the generator 31 when the power generation amount is limited (during power generation limitation), which will be described later. In the line L3, the power generated by the generator 31 is smaller than the required power over the entire area, and the power generated by the generator 31 is smaller than in normal times. That is, during power generation restriction, the amount of power generated by the generator 31 is less than the required power in all regions, and the output power of the battery 50 compensates for the shortage of the required power. For example, when the required power is 70 Wh, the generator 31 normally generates 70 Wh of power, whereas only 40 Wh of power is generated when the power generation is restricted, and the remaining 30 Wh is supplied from the battery 50 . Therefore, when power generation is limited, the power consumption of the battery 50 is greater than in normal times, and the charging rate tends to decrease.

Returning to the description of FIG. 2, the power generation limiter 610 can limit the amount of power generated by the generator 31 in the sport mode (second mode). More specifically, power generation limiting unit 610 limits the amount of power generated by generator 31 to battery 50 when engine 25 is to be driven when the charging rate of battery 50 is equal to or higher than the first predetermined value while the sport mode is set. is less than the amount of power generated by the generator 31 when the engine 25 is driven when the charging rate of is less than the first predetermined value.
The first predetermined value is, for example, a relatively high charging rate value (charging rate of 80%, etc.).
The reason why such power generation is limited is that if the vehicle is driven using only the power generated by the generator 31 in the state of high charging rate, the high charging rate of the battery 50 will continue for a long time, and it will be difficult to obtain the regenerative braking force. This is to continue. As described above, the engine 25 of the hybrid vehicle 12 is normally driven in the HV running mode when the charging rate of the battery 50 is low. On the other hand, when there is a request to start the engine 25 during EV travel (when the engine start request detection unit 604 detects a request to start the engine 25, such as when the accelerator is operated by a predetermined amount or more), the battery Regardless of the charging rate of 50, the engine 25 starts and the generator 31 starts generating power. In particular, when the sport mode is set, the engine 25 is driven more frequently than in the normal mode, and the charging rate of the battery 50 tends to increase.
By using the power generation limiting unit 610 to limit the amount of power generated by the generator 31 while the sport mode is set, the charging rate of the battery 50 can be intentionally lowered to make it easier to obtain regenerative braking force.

It should be noted that while the normal mode (first mode) is set, the power generation limiting unit 610 may not limit power generation. For example, when the normal mode is set, the generated power shifts along the line L2 in FIG. , the generated power shifts along the line L3 in FIG.
That is, power generation limiting unit 610 limits the amount of power generated by generator 31 to engine 25 in normal mode when engine 25 is to be driven when the charging rate of battery 50 is equal to or higher than the first predetermined value while sport mode is set. The amount of power generated by the generator 31 is restricted more than when the is driven.

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

Further, the power generation limiting unit 610 may asymptotically release the power generation amount limitation when the charging rate of the battery 50 becomes equal to or lower than the second predetermined value. Note that the second predetermined value (power generation limitation release charging rate) is set to a value equal to or lower than the first predetermined value (power generation limitation start charging rate).
That is, when the charging rate of the battery 50 is reduced enough to obtain a sufficient regenerative braking force, the power generation limiting unit 610 cancels the power generation limitation. If the amount of power generation is changed dramatically, the rotation speed of the engine 25 will increase sharply, giving the user a sense of discomfort. Therefore, when the power generation restriction is lifted, the power generation amount is gradually changed.

FIG. 5 is a graph showing the relationship between the charging rate of the battery 50 and the generated power. FIG. 5A shows the charging 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 a region from a charging rate of 100% (not shown) to a charging rate of 70%, the power generation limiting unit 610 sets the generated power to, for example, the value N1 along the line L3 in FIG. Also, in the region where the charging rate is 60% or less, the generated power is set to a value N2 (>N1) along the line L2 in FIG. 3, for example. 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 restriction on the power generation amount can be lifted without causing a sudden change in the rotational speed of the engine 25 .

Further, the power generation limiting unit 610 may change the degree of power generation amount limitation based on the output performance of the battery 50 detected by the battery performance detection unit 606 . In this case, power generation limiting unit 610 reduces the degree of power generation amount limitation when the output performance of battery 50 is declining. This is because when the output performance of the battery 50 is degraded, there is a possibility that the output power from the battery 50 cannot make up for the insufficient amount of power generation due to the restriction on the amount of power generation.
As described above, indicators related to the output performance of the battery 50 include, for example, the degree of deterioration of the battery 50 and the battery temperature. known to decline.
Therefore, power generation limiting unit 610 reduces the degree of limitation of the amount of power generation as the degree of deterioration of battery 50 increases, and reduces the degree of limitation of the amount of power generation as battery temperature decreases. It should be noted that reducing the degree of restriction on the amount of power generation is as described with reference to FIG. 4 .

FIG. 6 is an explanatory diagram schematically showing control when the output performance of the battery 50 is lowered.
FIG. 6A shows a case where the output performance of battery 50 is sufficiently high. When the output performance of the battery 50 is sufficiently high, for the required power WA, for example, the limit generated power WB along the line L3 in FIG. 3 is set, and the shortfall is set as the battery output power WC (WA= WB+WC).
FIG. 6B shows the case where the output performance of the battery 50 is degraded. The battery output power WD in this case is less than the battery output power WC shown in FIG. 6A. Therefore, the limit generated 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 insufficient power supply to the motor 23 when the output performance of the battery 50 is degraded.

FIG. 7 is a flow chart showing processing of the power generation control device 10 .
While the hybrid vehicle 12 is running, the drive control unit 602 determines whether the charging rate of the battery 50 is equal to or higher than the mode switching charging rate (step S700). The hybrid vehicle 12 is driven in the EV driving mode in which the engine 25 is stopped (step S702), and if the charging rate is less than the mode switching charging rate (step S700: No), the engine 25 is driven to generate power while driving. The hybrid vehicle 12 is driven in the HV driving mode (step S704).

When the vehicle is running in the normal mode while driving in the EV mode (step S705: No), if the accelerator is operated by a predetermined amount or more, that is, the accelerator operation amount becomes a first predetermined amount α or more. If so, the engine 25 is started (step S706). In this case, the power generation control unit 608 normally sets the power generation amount of the generator 31 (along the line L2 in FIG. 3) (step S712).

On the other hand, when the sports mode is set while driving in the EV mode (step S705: Yes), the accelerator operation amount is smaller than the predetermined amount, that is, the accelerator operation amount is smaller than the first predetermined amount α. 2, the engine 25 is started (step S708).

While the sport mode is set, power generation control unit 608 determines whether the charging rate of battery 50 is equal to or higher than a first predetermined value (step S710). If the charging 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 power generated when the motor 23 regenerates, so the normal operation ( The power generation amount of the generator 31 is set (along the line L2) (step S712).
On the other hand, if the charging rate of the battery 50 is equal to or higher than the first predetermined value (step S710: Yes), the battery 50 cannot receive the electric power generated when the motor 23 regenerates, and sufficient regenerative braking force cannot be obtained. Therefore, the power generation limiting unit 610 limits the power generation amount of 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 in FIG.
Until the charging rate of the battery 50 becomes equal to or lower than the second predetermined value (step S716: No loop), the process returns to step S714 to continue limiting the power generation amount. When the charging rate of the battery 50 becomes equal to or lower than the second predetermined value (step S716: Yes), the restriction on the power generation amount is gradually lifted. That is, the power generation amount of the generator 31 is gradually increased to match the normal power generation amount.

As described above, when the power generation control device 10 according to the embodiment drives the engine 25 when the charging rate of the battery 50 is equal to or higher than the first predetermined value while the sport mode is set, the power generation amount of the generator 31 is is limited, the output power (amount of discharge) from the battery 50 is increased compared to when the power generation amount is not limited. As a result, the amount of electric power that can be accepted by the battery 50 increases during the regenerative operation of the motor 23, which is advantageous in obtaining a greater regenerative braking force.
Further, if the power generation control device 10 changes the degree of limitation of the power generation amount based on the charging rate of the battery 50, it is advantageous in setting the power generation amount of the generator 31 appropriately. For example, the higher the charging rate of the battery 50, the greater the degree of restriction on the power generation amount, which is advantageous in reducing the charging rate of the battery 50 in a shorter time. As a result, it is more advantageous in obtaining regenerative braking force.
Further, in the power generation control device 10, when the charging rate of the battery 50 becomes equal to or lower than the second predetermined value, if the restriction on the power generation amount is asymptotically lifted, the power generation amount can be increased without causing discomfort to the user. Useful for getting back to normal.
Further, in the power generation control device 10, when the output performance of the battery 50 is degraded, if the degree of limitation of the power generation amount is reduced, the power supply to the motor 23 will be 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 limitation of the amount of power generation is reduced as the degree of deterioration of the battery 50 increases, or if the degree of limitation of the amount of power generation is reduced as the battery temperature of the battery 50 decreases, deterioration of the vehicle-mounted battery can be prevented. It is possible to prevent shortage of electric power supplied to the motor when output performance is lowered due to battery temperature drop.

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 limiting unit

Claims (8)

The vehicle can run by driving a motor using at least one of power generated by an on-vehicle generator driven by an engine and power stored in an on-vehicle battery,
a first mode in which the engine is driven by an accelerator operation of a predetermined amount or more;
a second mode in which the engine is driven by an accelerator operation smaller than the predetermined amount;
A power generation control device for 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,
When driving the engine when the charging rate of the vehicle battery is equal to or higher than a first predetermined value, the power generation limiting unit limits the amount of power generated by the vehicle generator to drive the engine in the first mode. less than the amount of power generated by the in-vehicle generator when the
A power generation control device for a hybrid vehicle, characterized by: Further comprising a power generation control unit that controls 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 adjusts the required power, which is the power required to output the requested output from the driver to the motor, to the target power generation amount of the in-vehicle power generator. and when limiting the amount of power generation by the power generation limiting unit, setting a power smaller than the requested power as a target power generation amount of the in-vehicle generator,
The shortage of the required power is supplied from the on-vehicle battery to the motor.
A power generation control device for a hybrid vehicle according to claim 1 , characterized in that: The power generation limiting unit changes the degree of limitation of the amount of power generation based on the charging rate of the vehicle battery.
3. A power generation control device for a hybrid vehicle according to claim 1 or 2, characterized in that: The power generation limiting unit increases the degree of limitation of the power generation amount as the charging rate of the vehicle battery increases.
4. A power generation control device for a hybrid vehicle according to claim 3 , wherein: The power generation limiter asymptotically cancels the limit on the amount of power generation when the charging rate of the on-vehicle battery becomes equal to or less than a second predetermined value that is smaller than the first predetermined value.
A power generation control device for a hybrid vehicle according to any one of claims 1 to 4 , characterized in that: further comprising a battery performance detection unit that detects the output performance of the in-vehicle battery,
The power generation limiting unit reduces the degree of limitation of the power generation amount when the output performance of the vehicle battery is degraded.
A power generation control device for a hybrid vehicle according to any one of claims 1 to 5 , characterized in that: The battery performance detection unit detects the degree of deterioration of the vehicle battery,
The power generation limiting unit reduces the degree of limitation of the amount of power generation as the degree of deterioration of the on-vehicle battery increases.
7. A power generation control device for a hybrid vehicle according to claim 6 , wherein: The battery performance detection unit detects a battery temperature of the vehicle battery,
The power generation limiting unit reduces the degree of limitation of the power generation amount as the battery temperature of the vehicle battery is lower.
7. A power generation control device for a hybrid vehicle according to claim 6 , wherein:

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