JP2000295707A - Power generation control device of hybrid electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation control device of a hybrid electric automobile for the work capable of more reducing noise in the case of a working mode. SOLUTION: When a vehicle is in the state of running, power generation with a generator 8 is started when the residual capacity of a battery detected by a battery residual capacity detector 13 is at most 60%. When a power taking- out device 5 taking out the driving power of a motor as the power for work is in the state that working is possible, power generation with the generator 8 is started when the residual capacity of the battery is at most 35%. When the power taking-out device 5 is in the state of standby, the generator 8 is so controlled that power generation is forbidden until the residual capacity of the battery becomes 30% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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 hybrid electric vehicle including a motor for driving a drive system of a vehicle and an engine for driving a generator, a power generation mode is generally switched based on a remaining battery capacity. In other words, the generator does not generate power until the remaining battery capacity becomes equal to or less than the predetermined value, and the vehicle runs by driving the motor with the electric power supplied from the battery (battery running mode). At this time, the engine is started and the generator is driven to start power generation, and the generated power drives the motor to run (hybrid running mode).

[0003] Such a hybrid electric vehicle is characterized by low noise and low noise compared to a normal engine driven vehicle because it is driven by a motor in addition to low fuel consumption and low exhaust gas.

[0004]

Attention has been paid to the fact that the hybrid electric vehicle has low noise as described above.
Research and development is also underway on the development of hybrid electric vehicles for specially equipped work vehicles, for which there is a high demand for low noise. In this work specially-equipped vehicle, predetermined work is performed by taking out the driving force of the motor as work for use by the power take-out device.

[0005] When the specially equipped work vehicle is converted to a hybrid electric vehicle, the specially equipped work vehicle may be stopped at the work site for a long time to perform work. It is desired to further reduce noise when in the enabled state (standby state and operating state).

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power generation control device for a working hybrid electric vehicle that can further reduce noise in the working mode.

Japanese Patent Application Laid-Open No. 7-309144 discloses an electric vehicle provided with a power take-out device (PTO), but does not describe power generation control.

[0008]

Means for Solving the Problems A first method for solving the above problems is described below.
A power generation control device for a hybrid electric vehicle according to the present invention is configured to operate with a generator driven by an engine to generate power, a battery storing power generated by the generator, and power from the battery or the generator. A motor for driving a drive system of a vehicle, a power take-out device interposed between the motor and the drive wheels of the vehicle to take out the driving force of the motor for work, and a remaining battery for detecting a remaining capacity of the battery Capacity detection means, and when the vehicle is in a running state, when the remaining battery capacity detected by the remaining battery capacity detection means is equal to or less than a first predetermined value, power generation by the generator is started, and Is in the operable state when the remaining battery charge is equal to or less than a second predetermined value different from the first predetermined value. And having a control means for starting the power generation by the serial generator.

A power generation control device for a hybrid electric vehicle according to a second invention is the power generation control device for a hybrid electric vehicle according to the first invention, wherein the operable state of the power take-out device has a standby state and an operating state; When the power take-out device is in a standby state, the control means may control a third state in which the remaining battery charge is smaller than the second predetermined value.
The power generation by the generator is prohibited until the predetermined value becomes equal to or less than a predetermined value.

[0010]

Embodiments of the present invention will be described below 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 state of charge of a battery and a power generation state in a driving mode, and FIG. FIG. 4 is an explanatory diagram showing the relationship between the state of charge of the battery and the state of power generation, 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 including two AC induction motors 1 for driving a drive system of the vehicle and an engine 2 for power generation. It 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 speeds (transmission), or simply performs a constant speed reduction.

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 transferred to the power take-out device 5.
Output to the propeller shaft 6 or 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 to switch from the running mode to the work mode, the control device EC is controlled based on the changeover signal S output from the mode changeover switch 12.
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-out device 5. When switching to the power take-out device 5, the hydraulic pump (not shown) is driven by the driving force of the motor 1 to operate the upper frame (not shown), thereby performing a predetermined operation.

On the other hand, a generator 8 is connected to the engine 2, and the generator 8 generates power by driving the engine 2.
This generated power is supplied to the motor 1 and stored in the battery 9 at the same time. That is, the driving power of the motor 1 is supplied from the battery 9 or the generator 8 via the inverter 10.

The ECU 11 is also supplied with a vehicle speed V, a motor speed N, a motor power consumption P, a state of charge SOC, and the like. 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 on the motor 1. The motor power consumption P is power supplied from the battery 9 or the generator 8 to the motor 1 and is detected by the power detector 14. The state of charge SOC is the state of charge of the battery 9 and is detected by the state-of-charge detector 13 using a current integration method, a current-voltage characteristic method, or the like.

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

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

When the state of charge SOC recovers and becomes 40% or more, the second hybrid drive mode is switched to the first hybrid drive mode, and when it becomes 65% or more, the first hybrid drive mode is switched to the battery drive mode. .

On the other hand, in the work mode, that is, when the power take-out device 5 is in an 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. Then, the remaining battery capacity SOC becomes 35
%, The first power generation mode is set, and power generation is started. It should be noted that 35% is a value that does not affect running after the work is completed.

This first power generation mode (SOCs 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 based on whether or not the motor speed N is zero (S1). To generate 10 kW of power (S
2). On the other hand, if the motor 1 is stopped, the engine 2
Is also stopped to stop 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) according to the drive / stop of the motor 1 (operation / standby of the power take-out device 5). In order to stop the power generation, the operation is stopped after an 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 based on whether or not the motor rotation 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 rotated at a high speed to generate 10 kW (S13). If the motor rotation speed N is low, the engine 2 is also rotated at a low speed and the power generation amount is 5k.
W (S14). On the other hand, if the result of determination in step S11 is that motor 1 is in a stopped state, engine 2 is also stopped (S15). That is, the remaining battery charge SOC is 30
%, The power generation by the generator 8 is prohibited.

That is, in this case, the engine 2 is driven / stopped (power generation ON / OFF) according to the drive / stop of the motor 1 (operation / standby of the power take-out device 5), and
The power generation amount is also changed by changing the rotation speed of the engine 2 according to the motor rotation speed N.

When the state of charge of the battery SOC is further reduced to 30% or less, the second power generation mode is set.
A continuous power generation of 10 kW is performed. Since the power generation amount in the first power generation mode is set in consideration of the expected work pattern, it is generally considered that the state of charge of the battery SOC does not decrease to 30%. Is performed, that is, when driving / stopping of the motor 1 (driving / stopping of the engine 2) is repeated more frequently than expected, it takes a certain time until the engine 2 is started and power is actually generated. Due to the delay, the remaining battery capacity SOC may be reduced. Therefore, in consideration of such a case, the state of charge of the battery SOC becomes 30%.
%, The power is continuously generated at 10 kW. However, the power generation amount of 10 kW is a minimum value required to reduce the noise as much as possible.

As shown in FIG. 3, the state of charge is switched from the second power generation mode to the first power generation mode when the state of charge of the battery SOC recovers and becomes 35% or more.
The mode is switched 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 (during the traveling mode), the battery detected by the battery remaining capacity detector 13 is used. When the state of charge SOC is equal to or less than the first predetermined value of 60%, power generation by the generator 8 is started, and when the power take-out device 5 is in a workable state (in a work mode), the state of charge of the battery SOC Is less than or equal to a second predetermined value different from the first predetermined value of 35%, power generation by the generator 8 is started.

For this reason, when the vehicle is in a running state, power generation is started when the state of charge of the battery SOC is reduced to 60% or less with emphasis on running, whereas the power take-out device 5 is in a workable state. Sometimes driving is not important,
The set value of the battery remaining capacity at which power generation is started is changed (here, 35%), and power generation control can be performed in a direction in which power generation is not performed as much as possible, so that work with very low noise can be performed.

When the power take-off device 5 is in the standby state, the power generation by the generator 8 is prohibited until the state of charge of the battery SOC becomes equal to or less than 30%, which is the third predetermined value smaller than the second predetermined value. Therefore, work with lower noise can be performed.

As shown in FIG. 5, when the power generation amount is changed by changing the rotation speed of the engine 2 in accordance with the motor rotation speed N in the first power generation mode, the engine rotation speed is further reduced. Noise can be reduced.

Further, since the operation and stop of the engine 2 are performed in accordance with the standby state and the operation state (the stop state and the drive state of the motor 1) of the power take-out device 5, the engine operation sound for the worker at the time of work is performed. Feeling is good.

That is, as shown in FIG. 6, power generation is prohibited until the state of charge of the battery SOC becomes 30% or less.
%, It is conceivable to perform continuous power generation of 10 kW, but in this case, the remaining battery capacity SOC
Is 30% or less, the engine 2 always operates to generate power regardless of the state of the power take-out device 5, so that the engine speed increases / idle according to the operation / standby of the power take-out device. The feeling of engine operation noise is worse than that of a specially equipped working vehicle driven by an engine. On the other hand, in the above case, work is normally performed in the first power generation mode (SOC 30 to 35%). In the first power generation mode, the engine 2 is driven / operated according to the operation / standby of the power take-out device 5. Because it stops, the feeling of the engine operation sound is good.

[0033]

As described above in detail with the embodiments of the present invention, according to the power generation control device for a hybrid electric vehicle of the first invention, when the vehicle is in a running state, the battery remaining capacity detecting means is used. When the detected remaining capacity of the battery is equal to or less than the first predetermined value, the power generation by the generator is started, and when the power take-out device is in the operable state, the second remaining capacity is different from the first predetermined value. When the value is equal to or less than the predetermined value, power generation by the generator is started.

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

According to the power generation control device for a hybrid electric vehicle of the second invention, the operable state of the power take-out device includes a standby state and an operating state. Since the power generation by the generator is prohibited until the capacity becomes equal to or less than the third predetermined value smaller than the second predetermined value, work with lower noise can be performed.

[Brief description of 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 state of charge of a battery and a state of power generation in a traveling mode.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Engine 3 Reduction gear 4 Driving wheel 5 Power take-out device 6 Propeller shaft 7 Actuator 8 Generator 9 Battery 10 Inverter 11 ECU 12 Mode changeover switch 13 Battery remaining capacity detector

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/14 H02P 9/04 L H02P 9/04 B60K 9/00 E (72) Inventor Nobuaki Takeda Tokyo 5-33-8 Shiba, Minato-ku, Mitsubishi Motors Corporation (72) Inventor Sadao Imai 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3G093 AA04 AA15 BA32 DB00 DB01 DB23 EB09 FA11 FB05 5G060 AA05 BA02 DB07 5H115 PA05 PG04 PI16 PI22 PI29 PU01 PU24 PU26 RB08 RB11 RE01 RE02 SE02 SE05 TB01 TI02 TO14 TR19 TU20 5H590 AA06 CA07 CA23 CB01 CE05 HA01 HA06 HA27

Claims (2)

[Claims] An electric generator driven by an engine to generate electric power, a battery for storing electric power generated by the electric generator, and a drive system for driving a vehicle driven by electric power from the battery or the electric generator. A power take-out device interposed between the motor and the driving wheels of the vehicle to take out the driving force of the motor for work; a battery remaining capacity detecting means for detecting the remaining capacity of the battery; When the vehicle is in a running state, when the battery remaining capacity detected by the battery remaining capacity detecting means is equal to or less than a first predetermined value, power generation by the generator is started and the power take-out device is in a workable state. In some cases, when the remaining battery charge is equal to or less than a second predetermined value different from the first predetermined value, power generation by the generator is started. Power generation control apparatus for a hybrid electric vehicle; and a control means. 2. The power generation control device for a hybrid electric vehicle according to claim 1, wherein the operable state of the power take-out device has a standby state and an operating state, and the control means includes a step of setting the power take-off device to be in a standby state. A power generation control device for a hybrid electric vehicle, wherein when in a state, the power generation by the power generator is prohibited until the remaining battery capacity becomes equal to or less than a third predetermined value smaller than the second predetermined value.