JP3527861B2 - Power generation control device for hybrid electric vehicle - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a series type hybrid electric vehicle equipped with a motor for driving a drive system of a vehicle and an engine for driving a generator, it is common to switch the power generation mode based on the remaining capacity of the battery. In other words, the generator does not generate power until the battery remaining capacity becomes less than or equal to the predetermined value, and the vehicle is driven by driving the motor with the power supplied from the battery (battery running mode), and the battery remaining capacity becomes less than or equal to the predetermined value. At this time, the engine is started and the generator is driven to start power generation, and the generated power is used to drive the motor for traveling (hybrid traveling mode).

Such a hybrid electric vehicle has the characteristics of low noise as compared with a normal engine-driven vehicle because it is driven by a motor in addition to low fuel consumption and low exhaust gas.

[0004]

Attention is paid to the fact that the hybrid electric vehicle is low in noise as described above.
Research and development is also underway on making hybrid electric vehicles for specially equipped work vehicles, which are highly demanded to reduce noise. In this specially-equipped vehicle for work, a predetermined work is performed by taking out the driving force of the motor for work by the power take-out device.

When the specially-equipped vehicle for work is made into a hybrid electric vehicle, there is a case where the specially-equipped vehicle for work is stopped at the work site for a long time to perform work. Therefore, in the work mode, that is, the power take-out device is activated. It is desired to further reduce the noise when it is in a possible state (standby state and operating state).

Therefore, it is an object of the present invention to provide a power generation control device for a hybrid electric vehicle for work which can further reduce noise in the work mode.

Incidentally, Japanese Patent Laid-Open No. 7-309144 discloses an electric vehicle equipped with a power take-out device (PTO), but there is no description concerning power generation control.

[0008]

[Means for Solving the Problems] First to solve the above problems
A power generation control device for a hybrid electric vehicle of the invention is operated by an electric generator driven by an engine to generate electric power, a battery accumulating the electric power generated by the electric generator, and the electric power from the battery or the electric generator. A motor that drives a drive system of a vehicle, and a driving force of the motor
A propeller shaft for transmitting the driving wheels, and power takeoff to take out as a working driving force of the motor is interposed between the motor and driving wheels of the vehicle, the motor
The output of the drive force of the
Actuator that switches whether to use a propeller shaft
A motor, a battery remaining capacity detecting means for detecting a remaining capacity of the battery, drive the actuator of the motor
When the vehicle is in a traveling state by setting the output destination of power to the propeller shaft, the generator when the battery remaining capacity detected by the battery remaining capacity detection means is equal to or less than a first predetermined value. power generation by the start, above
The actuator outputs the output destination of the driving force of the motor as described above.
When the power take- out device is in a workable state by using the power take-out device, the power generation by the generator is started when the battery remaining capacity is equal to or less than a second predetermined value different from the first predetermined value. And a control means.

A power generation control device for a hybrid electric vehicle according to a second aspect of the present invention is the power generation control device for a hybrid electric vehicle according to the first aspect, wherein the power take-out device has a ready state and a working state. When the power take-out device is in a standby state, the control means is configured so that the battery remaining capacity is smaller than the second predetermined value.
It is characterized in that power generation by the above-mentioned generator is prohibited until the value becomes equal to or less than a predetermined value.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a power generation control device for a hybrid electric vehicle according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a relationship between a battery remaining capacity and a power generation state in a traveling mode, and FIG. 3 is a work mode. 4 is an explanatory diagram showing the relationship between the remaining battery capacity and the power generation state, and FIGS. 4 and 5 are flowcharts of power generation control.

<Structure> As shown in FIG. 1, the present hybrid electric vehicle is of a series type having two AC induction motors 1 for driving a drive system of the vehicle and an engine 2 for power generation. Is. A speed reducer 3 is interposed between the motor 1 and the drive wheels 4, and the driving force of the motor 1 is transmitted to the drive wheels 4 via the speed reducer 3, the propeller shaft 6, and the like. The speed reducer 3 is provided with a plurality of shift stages (transmission), or simply performs constant deceleration.

Further, the speed reducer 3 is provided with a power take-out device 5 for taking out the driving force of the motor 1 for work. The driving force of the motor 1 is converted into the power output device 5
Output to the propeller shaft 6 is switched by an actuator 7 such as a hydraulic drive.

That is, when the driver operates the mode changeover switch 12 in order to change from the traveling mode to the working mode, based on the changeover signal S output from the mode changeover switch 12, the EC which is the control device is operated.
In U11, a switching control signal is output to the actuator 7, and the output destination of the driving force of the motor 1 is set to the propeller shaft 6
To the power take-off device 5. When switching to the power take-out device 5, a hydraulic pump (not shown) is driven by the driving force of the motor 1 to operate an unillustrated upper body structure, and a predetermined work can be performed.

On the other hand, a generator 8 is connected to the engine 2, and the generator 8 drives the engine 2 to generate electricity.
This generated power is supplied to the motor 1 and at the same time accumulated in the battery 9. That is, the drive power of the motor 1 is supplied from the battery 9 or the generator 8 via the inverter 10.

Further, the vehicle speed V, the motor rotation speed N, the motor power consumption P, the battery remaining capacity SOC and the like are also input to the ECU 11. The vehicle speed V is detected by a vehicle speed detector 15 provided on the output side of the speed reducer 3, and the motor rotation speed N is detected by a rotation speed detector 16 provided in the motor 1. The motor power consumption P is the power supplied from the battery 9 or the generator 8 to the motor 1, and is detected by the power detector 14. The battery remaining capacity SOC is the remaining capacity of the battery 9, and is detected by the battery remaining capacity detector 13 by the current integration method, the current-voltage characteristic method, or the like.

And in this hybrid electric vehicle,
The ECU 11 performs power generation control as shown in FIGS. 2 to 5 in the traveling mode and the work mode.

That is, in the traveling mode, as shown in FIG. 2, power is not generated in the battery traveling mode until the battery remaining capacity SOC becomes 60% or less, and when the battery remaining capacity SOC becomes 60% or less. The first hybrid traveling mode is set, the engine 2 is started, and power generation by the generator 8 is started. In the first hybrid traveling mode, the power generation amount is set to 0 according to the vehicle speed V and the motor power consumption P.
Change to 10, 20, 30 kW (normal power generation). When the state of charge SOC of the battery further decreases to 30% or less, the second hybrid running mode is set. In the second hybrid traveling mode, the power generation amount is changed to 10, 20, 30 kW according to the vehicle speed V and the motor power consumption P (emergency power generation).

When the remaining battery charge SOC is recovered to 40% or more, the second hybrid running mode is switched to the first hybrid running mode, and when it is 65% or more, the first hybrid running mode is switched to the battery running mode. .

On the other hand, in the working mode, that is, when the power takeoff device 5 is in the operable state (standby state and operating state), as shown in FIG.
Until 35% or less, the power generation stop mode is set and no power generation is performed. The battery remaining capacity SOC is 35
When it becomes less than or equal to%, the first power generation mode is set and power generation is started. Note that 35% is a value that does not affect the running after the work.

This first power generation mode (SOC 30 to 35
%), As shown in the flowchart of FIG. 4, it is determined whether the motor 1 is in a driving state or a stopped state depending on whether or not the motor rotation speed N is zero (S1). Operate to generate 10kW of power (S
2). On the other hand, if the motor 1 is stopped, the engine 2
To stop the power generation (S3). That is, the power generation by the generator 8 is prohibited until the battery remaining capacity SOC becomes 30% or less.

That is, in the first power generation mode, the engine 2 is driven / stopped (power generation ON / OFF) in response to driving / stopping of the motor 1 (operation / standby of the power take-out device 5). It should be noted that the power generation is stopped after the idling state for 10 seconds.

Alternatively, in the first power generation mode, power generation control as shown in the flowchart of FIG. 5 may be performed.
That is, it is determined whether the motor 1 is in a driving state or a stopped state depending on whether or not the motor rotational speed N is zero (S11). It is determined whether the rotation is low or low (S12). If the motor rotation speed N is high, the engine 2 is also set to high rotation and the amount of power generation is 10 kW (S13). If the motor rotation speed N is low, the engine 2 is also set to low rotation and the power generation amount is 5 k.
Set to W (S14). On the other hand, if the result of determination in step S11 is that the motor 1 is in a stopped state, the engine 2 is also stopped (S15). That is, the battery remaining capacity SOC is 30
The power generation by the generator 8 is prohibited until it becomes less than or equal to%.

In other words, in this case, the engine 2 is driven / stopped (power generation ON / OFF) in accordance with the driving / stopping of the motor 1 (operation / standby of the power take-out device 5).
The amount of power generation is changed by changing the rotation speed of the engine 2 according to the motor rotation speed N.

When the SOC of the battery is further reduced to 30% or less, the second power generation mode is set,
Continuous power generation of 10kW is performed. Since the power generation amount in the first power generation mode is set in consideration of the expected work pattern, it is normally considered that the battery remaining capacity SOC does not decrease to 30%, but the work pattern is unexpected. Is performed, that is, when the driving / stopping of the motor 1 (driving / stopping of the engine 2) is repeated more frequently than expected, it takes some time until the engine 2 is actually started to generate electricity. Since there is a delay, the remaining battery charge SOC may decrease. Therefore, in consideration of such a case, the battery remaining capacity SOC is 30
When it becomes less than or equal to%, 10 kW of continuous power generation is performed. However, the power generation amount of 10 kW is the minimum value necessary to reduce noise as much as possible.

As shown in FIG. 3, when the state of charge SOC of the battery recovers and becomes 35% or more, the second power generation mode is switched to the first power generation mode, and when it becomes 40% or more, the first power generation mode is set.
Switch from the power generation mode to the power generation stop mode.

<Operation / Effect> As described above, according to the power generation control device of the present embodiment, when the vehicle is in the traveling state (in the traveling mode), the battery detected by the battery remaining capacity detector 13 is detected. When the remaining capacity SOC is 60% or less, which is the first predetermined value, power generation by the generator 8 is started, and when the power takeoff device 5 is in a workable state (in the working mode), the battery remaining capacity SOC is Is less than 35% which is a second predetermined value different from the first predetermined value, the power generation by the generator 8 is started.

For this reason, when the vehicle is in the running state, importance is attached to the running and power generation is started at the time when the battery state of charge SOC becomes 60% or less, whereas the power take-out device 5 is in the workable state. Sometimes driving is not important,
Since it is possible to change the set value of the battery remaining capacity at which power generation is started (here, 35%) and perform power generation control in the direction in which power generation is not performed as much as possible, work with extremely low noise is possible.

Further, when the power take-off device 5 is in the standby state, the power generation by the generator 8 is prohibited until the remaining battery charge SOC becomes 30% or less which is the third predetermined value smaller than the second predetermined value. Therefore, it is possible to work with lower noise.

Further, as shown in FIG. 5, when the rotation speed of the engine 2 is changed in accordance with the motor rotation speed N in the first power generation mode to change the amount of power generation, the engine rotation speed is further lowered, resulting in further lowering. It is possible to reduce noise.

Furthermore, since the engine 2 is operated and stopped in accordance with the standby state and the operating state of the power takeoff device 5 (the stopped state and the driven state of the motor 1), the engine operating noise for the worker at the time of working Feels good.

That is, as shown in FIG. 6, power generation is prohibited until the battery remaining capacity SOC becomes 30% or less.
It is conceivable that continuous power generation of 10 kW will be performed at the time when it becomes less than or equal to%, but in this case, the battery remaining capacity SOC
Is 30% or less, the engine 2 always operates to generate power regardless of the state of the power takeoff device 5, so the engine speed increases / idle depending on the operation / standby of the power takeoff device. The feeling of engine operating noise is poorer than that of a specially equipped working vehicle driven by an engine. On the other hand, in the above case, the work is normally performed in the first power generation mode (SOC 30 to 35%), and in this first power generation mode, the engine 2 is driven / operated according to the operation / standby of the power takeoff device 5. Since it stops, the engine operation sound feels good.

[0033]

As described above in detail with the embodiments of the invention, according to the power generation control device for a hybrid electric vehicle of the first invention, the actuator drives the motor.
When the vehicle is in a traveling state by setting the propeller shaft as the output destination of the power, when the battery remaining capacity detected by the battery remaining capacity detection means is less than or equal to the first predetermined value, the generator starts power generation and the actuator operates. Mo
The output destination of the driving force of the motor is the power take-off device.
When the power take-off device is more ready to work,
When the battery remaining capacity is equal to or less than a second predetermined value different from the first predetermined value, power generation by the generator is started.

For this reason, when the vehicle is in the running state, power generation is started when the remaining battery capacity becomes equal to or less than the first predetermined value while the running is emphasized, whereas the power take-out device is in the workable state. In some cases, running is not emphasized, the set value of the battery remaining capacity at which power generation is started can be changed, and power generation control can be performed in a direction in which power generation is not performed as much as possible. Therefore, work with extremely low noise is possible.

Further, according to the power generation control device for the hybrid electric vehicle of the second invention, the workable state of the power take-out device has a standby state and an operating state, and when the power take-out device is in the stand-by state, the battery remains. Since the power generation by the generator is prohibited until the capacity becomes equal to or less than the third predetermined value which is smaller than the second predetermined value, it is possible to work with lower noise.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a power generation control device for a hybrid electric vehicle according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a battery remaining capacity and a power generation state in a traveling mode.

FIG. 3 is an explanatory diagram showing a relationship between a battery remaining capacity and a power generation state in a work mode.

FIG. 4 is a flowchart of power generation control.

FIG. 5 is a flowchart of another power generation control.

FIG. 6 is an explanatory diagram showing a relationship between another battery remaining capacity and a power generation state in a work mode.

[Explanation of symbols]

1 motor 2 engine 3 reducer 4 drive wheels 5 Power take-off device 6 Propeller shaft 7 Actuator 8 generator 9 battery 10 inverter 11 ECU 12 Mode selector switch 13 Battery remaining capacity detector

Front page continuation (51) Int.Cl. ⁷ Identification code FI F02D 29/00 F02D 29/00 B 29/06 29/06 D H02J 7/14 H02J 7/14 C H02P 9/04 H02P 9/04 L ( 72) Inventor Sadao Imai 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) Reference JP-A-7-284201 (JP, A) JP-A-5-328521 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60L 11/00-11/18 B60K 6/04 F02D 29/00-29/06 H02J 7/14 H02P 9/04

Claims (2)

(57) [Claims] 1. A generator that is driven by an engine to generate electric power, a battery that stores the electric power generated by the generator, and a drive system of a vehicle that is operated by the battery or the electric power from the generator. And a professional that transmits the driving force of the motor to the drive wheels of the vehicle.
A power take-out device, which is interposed between the peller shaft, the motor and the drive wheels of the vehicle to take out the drive force of the motor for work, and an output destination of the drive force of the motor to the power take-out device.
To switch between the above and the above propeller shaft.
The actuator, the battery remaining capacity detecting means for detecting the remaining capacity of the battery, and the actuator raise the output destination of the driving force of the motor.
When the vehicle is in a traveling state by using the propeller shaft, the generator starts power generation when the battery remaining capacity detected by the battery remaining capacity detection means is equal to or less than a first predetermined value , and the actuator is actuated.
Is the output destination of the driving force of the motor is the power take-off device
When the power take-out device is in a workable state, the control means for starting power generation by the generator when the remaining battery capacity is equal to or less than a second predetermined value different from the first predetermined value. A power generation control device for a hybrid electric vehicle, comprising: 2. The power generation control device for a hybrid electric vehicle according to claim 1, wherein a workable state of the power take-out device has a standby state and an operating state, and the control means causes the power take-out device to wait. In a state, a power generation control device for a hybrid electric vehicle, wherein power generation by the generator is prohibited until the battery remaining capacity becomes equal to or less than a third predetermined value that is smaller than the second predetermined value.