JPH11178116A - Hybrid electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable automatic charging of a secondary battery safely, in both case wherein a vehicle is in an unmanned stopping state after a key is off, and wherein a vehicle is in a manned stopping state while a key is on. SOLUTION: After a key-off state is detected, a secondary battery 6 is automatically charged by a controller 12. At the time of the automatic charging, a command to drive a fan a 11 of a radiator 10 is outputted from a fuel battery system controller 13 to the fan 11. An air stream which is weak but good enough to push remaining hydrogen to flow out is generated by the rotation of the fan 11. Therefore, if a very small quantity of hydrogen which cannot be detected by an existing hydrogen detector leaks, the leaking gas is exhausted with the stream of the air and does not stay on an engine hood, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid electric vehicle in which a secondary battery for supplying power to a vehicle drive motor is automatically (unmanned) charged by a fuel cell system when the vehicle is stopped, and more particularly to safety during the automatic charging. The present invention relates to a hybrid electric vehicle in which is secured.

[0002]

2. Description of the Related Art Conventionally, as a fuel cell system used in this kind of hybrid electric vehicle, for example,
One disclosed in JP-A-8-91804 is known. When such a fuel cell system operates, a gas such as hydrogen is generated during the power generation process. It is dangerous if such gas leaks out of the device due to malfunction,
In a conventional fuel cell system, when a gas leak is detected, the operation of the system is stopped to take safety measures.

[0003]

However, in the above-mentioned conventional fuel cell system, when the amount of gas leakage is very small, a failure cannot be detected, and the operation of the system can be stopped to take safety measures. May not be.

In a vehicle equipped with a fuel cell, even if a small amount of leakage occurs, the leaked gas diffuses into the outside air while the vehicle is running, so that there is no problem even if the operation of the fuel cell system is continued. . However, if the vehicle is stationary,
The leaked gas may accumulate inside the vehicle to cause a problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and comprises a secondary battery and a secondary battery.
A motor for driving a vehicle that is rotated by being supplied with power from a secondary battery, a fuel cell system for charging a secondary battery or supplying power to a motor for driving a vehicle, charging / discharging the secondary battery, and operating the fuel cell system. In a hybrid electric vehicle comprising a control device for controlling a vehicle, an automatic charging means for automatically charging a secondary battery after detecting a key OFF is provided, and a radiator fan is forcibly operated continuously during automatic charging by the automatic charging means. A gas flow generated by the fuel cell system is discharged along with the air flow.

An automatic charging means for automatically charging a secondary battery when a vehicle stopped state is continuously detected for a predetermined time or more, and a radiator fan forcibly continuously operating during automatic charging by the automatic charging means for air Exhaust means for creating a flow of gas and putting the gas generated in the fuel cell system on the flow of air, and charge release means for releasing the automatic charging by the automatic charging means when an accelerator operation is detected. I do.

[0007]

Next, an embodiment of a hybrid electric vehicle according to the present invention will be described.

FIG. 1 is a block diagram showing a schematic configuration of the hybrid electric vehicle according to the present embodiment.

The motor 7 is a main engine for driving the vehicle, that is, the wheel 8, and functions as a generator during regeneration. The regenerative power is charged and stored in the secondary battery 6 via the power converter 5. Driving power for driving the motor 7 is supplied from the secondary battery 6 via the power converter 5.
At this time, the secondary battery 6 is discharged. Further, the electric power generated by the fuel cell system 1 is also supplied to the motor 7 via the same power converter 5 and becomes the driving electric power of the motor 7. The fuel cell system 1 includes, for example, a fuel cell 2, a reformer 4 that reforms a fuel class to generate hydrogen, and a compressor 8 that pumps air to the fuel cell 2.

The control device 12 comprises, for example, a fuel cell system controller 13, a motor controller 14, and a battery controller 15. The fuel cell system controller 13 mainly includes the fuel cell system 1
To the fan 11 of the radiator 10 or an operation signal a. Motor controller 14
Controls the supply of drive power to the motor 7 and the charging of the secondary battery 6 with regenerative power via a command to the power converter 5. The battery controller 15 mainly includes
The state of the secondary battery 6 is detected based on the signal of the DOD sensor 9 and the charge / discharge of the secondary battery 6 is instructed to the power converter 5.
At the same time, the battery controller 15 detects whether or not the external charging device 17 is connected to the vehicle based on a signal from the coupler 16 connected to the external charging device 17,
It instructs power converter 5 to charge / discharge secondary battery 6.

The fuel cell system controller 13, the motor controller 14, and the battery controller 15 are in communication with each other, so that there is no inconsistency in the overall instructions of the control device 12.

The control device 12 has a traveling key ON / OF.
An F signal, an accelerator signal, and a vehicle speed signal are provided. In addition, an automatic charge release switch 22, a display panel 23, a speaker 24 and an automatic charge external display lamp 25 are connected to the control device 12. When the automatic charge release switch 22 is turned on, an automatic charge release signal after the key is turned off is given to the control device 12. Also, the control device 1
2 outputs an automatic charging panel display signal to the display panel 23 in the vehicle at the time of automatic charging after the key is turned off, simultaneously outputs an automatic charging voice signal to the speaker 24 in the vehicle, and further outputs an automatic charging external display signal to the lamp 25 outside the vehicle. Output to Upon receiving this signal, the display panel 23 visually displays the automatic charging state, and upon receiving this signal, the speaker 24 audibly notifies that it is in the automatic charging state. The lamp 25 is turned on when receiving this signal.

FIG. 2 is a flowchart showing an automatic charging control process for the secondary battery 6 by the hybrid electric vehicle according to the present embodiment, which is shown as a key OFF subroutine. The main routine is the same as the control process of a normal hybrid electric vehicle except that a key OFF subroutine is entered by using a travel key OFF signal as a trigger.
It is omitted here.

When entering the key OFF subroutine, first,
It is determined whether the charged amount of the secondary battery 6 is larger or smaller than a predetermined amount (FIG. 2, step 101). The predetermined amount of this criterion is set to a value close to full charge, for example, 70% of full charge, leaving a margin for charging regenerative power. If the charge amount is larger than the predetermined amount, the determination result is No, and the process proceeds to a normal fuel cell stop routine (Step 102), and thereafter returns to the main routine (omitted). The fuel cell stop routine is not described in detail because it is not directly related to the present invention. However, the fuel cell stop routine is set to a state in which the fuel cell system 1 can be safely stopped by replacing hydrogen in the pipe with nitrogen.
This is a routine for stopping.

If the charge amount is smaller than the predetermined amount, the judgment result is Yes, and the control of the controller 12 controls the speaker 2.
4 outputs a voice signal to notify the driver of the start of automatic charging (step 103). Subsequently, a panel display signal is output from the control device 12 to the display panel 23,
The start of automatic charging is visually displayed on the display panel 23 in the vehicle (step 104).

Next, the state of the charge release switch 22 is checked by the controller 12 (step 105). If the charge release switch 22 is ON and a charge release signal is input to the control device 12, the determination result is Ye
s, and it is determined that the driver does not want automatic charging. Then, the process enters a fuel cell stop routine (step 102), and thereafter returns to the main routine.
On the other hand, if the charge release switch 22 is OFF, the determination result is No, and it is next determined whether or not the external charging device 17 is connected to the vehicle based on a signal from the coupler 16 (step 106). .

If the connection is made, the judgment result is Yes.
In this case, the charging of the secondary battery 6 by the external charging device 17 is prioritized, and the process enters a fuel cell stop routine (step 102) and returns to the main routine.
On the other hand, if the external charging device 17 is not connected to the vehicle, the determination result is No. Then, based on a fuel flow signal from a fuel flow meter (not shown), it is determined whether the fuel supply is normal. It is determined (step 107). This determination is made, for example, by comparing the fuel flow rate with a specified value and determining whether the deviation is within a predetermined value.

If it is determined that the fuel supply is not normal, the determination result is No, and the process enters a fuel cell stop routine (step 102) and returns to the main routine.
If the fuel supply is normal, the determination result is Yes, and then a power generation command is issued from the fuel cell system controller 13 to the fuel cell system 1 (step 108). At the same time, a command to charge the secondary battery 6 with the power generated by the fuel cell system 1 is output from the battery controller 15 to the power converter 5. Fuel cell system 1 at this time
Are selected such that the efficiency of the fuel cell system 1 becomes MAX.

Next, a command a for rotating the fan 11 of the radiator 10 is output from the fuel cell system controller 13 to the fan 11 (step 109). The fuel of the fuel cell 2 is hydrogen, or the reformer 4 reforms another fuel to generate hydrogen. The reason why the fuel cell system 1 rotates the fan 11 in this manner during power generation is to prevent a small amount of hydrogen that cannot be detected by the existing hydrogen detector from leaking and stopping on the upper surface of an engine hood or the like due to some abnormality. It is.

Since it is not the purpose of cooling the interior of the engine room, the fan 11 does not need to be rotated at full speed. The fan 11 is rotated on the upper surface of an engine hood or the like, but weak enough to generate a flow of air enough to flush accumulated hydrogen. Is good. The extent to which the number of revolutions can be reduced can be determined experimentally because it depends on the layout in the engine and the shape of the engine hood. Such a reduction in the rotation speed of the fan 11 is preferable not only from the viewpoint of reducing energy consumption, but also from the viewpoint of reducing fan noise.

Next, an external charging display signal is output from the control device 12 to the lamp 25, the lamp 25 is turned on, and processing is performed so that it can be recognized from outside the vehicle that automatic charging is being performed (step 110). The display device that indicates that the vehicle is being automatically charged outside the vehicle is described as a specific lamp 25, but may be a panel that displays that the vehicle is being charged. Next, the state of the key ON / OFF signal is
Checked by the key remains OFF or ON
Is determined (step 111).

If the key is changed to ON, the judgment result is No, and the process enters a fuel cell stop routine (step 102) and returns to the main routine. On the other hand, if the key remains OFF, the determination result is Yes, and it is determined again whether the charged amount of the secondary battery 6 is larger or smaller than a predetermined amount (step 112). If the charge amount of the secondary battery 6 is larger than the predetermined amount, the determination result is N
and the processing proceeds to the fuel cell stop routine (step 10).
Enter 2) and return to the main routine. On the other hand, if the charge amount is smaller than the predetermined amount, the determination result is Yes, the process returns to step 104, and the above-described control process is repeated.

Next, an automatic charging control process of the secondary battery 6 by the hybrid electric vehicle according to another embodiment of the present invention will be described.

In the embodiment described above, the travel key is turned off.
As a result, the vehicle stopped state was detected and automatic charging was performed. In the present embodiment, even if the traveling key is ON, if the vehicle is stopped for a certain period of time or more, the charging mode is automatically entered, and the charging mode is released by starting the vehicle. The state of charge of the secondary battery 6 is constantly monitored while the vehicle is running, and when the charged amount becomes smaller than a predetermined amount, the fuel cell system 1 operates to charge the secondary battery 6.

The system configuration according to the present embodiment is the same as the configuration shown in FIG. 1, and the automatic charging control process is shown in the flowchart of FIG.

The processing of the portion enclosed by the broken line in the flowchart is basically the same as the key OFF subroutine shown in FIG.
However, the processing in the broken line is different from the processing shown in FIG. 2 only in that the processing in step 206 is added after step 104. In step 206, the state of the accelerator signal (see FIG. 1) provided to the control device 12 is determined. If the accelerator signal is determined to be ON, the determination result is No, and the processing is performed in a fuel cell charging stop routine (step Step 102) and return to the main routine. on the other hand,
If the accelerator signal remains OFF, the judgment result is Yes.
, And the process proceeds to Step 105. That is, when the start of the vehicle is detected in step 206,
The automatic charging mode is released.

When the vehicle stop state is detected by the vehicle speed signal (see FIG. 1) input to the control device 12, the processing enters a vehicle stop subroutine. When entering this subroutine, first, in step 201, the vehicle stop time count flag is set to 0. In the next step 202, the value of the count flag is determined, and the count flag = 1
If so, the determination result is Yes, and the process proceeds to step 204.
Proceed to If the count flag is not 1, the determination result is No, and the process proceeds to Step 203. In the process of step 203, the count flag is set to 1 and a timer T (not shown) for counting the stop time is reset and started.

In the process of step 204, it is determined whether the value of the timer T is larger than a predetermined value. If the value of the timer T is smaller than the predetermined value, the determination result is No, and the process returns to Step 202. On the other hand, timer T
Is larger than the predetermined value, that is, if a state in which the vehicle has been stopped for a predetermined time is detected, the determination result is Yes, and the process proceeds to Step 205.

In step 205, it is determined whether the fuel cell system 1 is operating. If it is not in operation, the determination result is No, and the process proceeds to step 1 in the broken line.
Go to 01. If the fuel cell system 1 is operating, the determination result is Yes, and the process proceeds to step 109 in the broken line, in which the fan 11 is rotated to generate a weak air flow on the upper surface of the engine hood or the like. Can be

In the above-described embodiment, the mode in which the secondary battery 6 is automatically charged when the vehicle is completely stopped has been described. However, even in a situation where the vehicle is not completely stopped and the vehicle is traveling at a low speed on a congested road, the configuration may be such that the fan 11 is rotated in the same manner as in the above embodiment. With such a configuration, the same effect as in the above embodiment can be obtained.

[0031]

As described above, according to the present invention, the key O
At the time of automatic charging after FF detection or when the vehicle is stopped, the radiator fan is forcibly rotated to prevent gas such as hydrogen leaked from the fuel cell system from accumulating on the upper surface of the engine such as the engine hood. Configured. For this reason, the secondary battery can be automatically charged safely even when the vehicle is stopped unattended, such as during automatic charging after the key is turned off, or when the vehicle is stopped with the driver on while the key is turned on. Thus, the effect is obtained that the vehicle can always be started from the optimum state.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an automatic charging system for a hybrid electric vehicle according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of an automatic charging control process according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of an automatic charging control process according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel cell system 2 ... Fuel cell 5 ... Power converter 6 ... Secondary battery 7 ... Vehicle driving motor 8 ... Wheel 9 ... DOD sensor 10 ... Radiator 11 ... Fan 12 ... Control device 17 ... External charging device 25 ... External Charge indicator lamp

Claims (7)

[Claims] 1. A secondary battery, a vehicle driving motor that is rotated by being supplied with power from the secondary battery, and a fuel cell system for charging the secondary battery or supplying power to the vehicle driving motor. A hybrid electric vehicle comprising: a control device that controls charging / discharging of the secondary battery and operation of the fuel cell system; and an automatic charging unit that automatically charges the secondary battery after detecting a key OFF, A hybrid electric vehicle wherein the radiator fan is forcibly and continuously operated during the automatic charging by the automatic charging means to generate an air flow, and the gas generated in the fuel cell system is exhausted by the air flow. . 2. A secondary battery, a motor for driving a vehicle that is rotated by being supplied with power from the secondary battery, and a fuel cell system for charging the secondary battery or supplying power to the motor for driving the vehicle. A control device for controlling the charging and discharging of the secondary battery and the operation of the fuel cell system.
Automatic charging means for automatically charging the next battery, and forcibly continuously operating the radiator fan during automatic charging by the automatic charging means to create an air flow, and generating the gas generated in the fuel cell system by the air flow. Exhaust means to put on the
A hybrid electric vehicle comprising: a charge canceling unit that cancels automatic charging by the automatic charging unit when an accelerator operation is detected. 3. The hybrid electric vehicle according to claim 1, wherein the rotation speed of the continuously operated radiator fan is set lower than the rotation speed during engine cooling during automatic charging. 4. The fuel cell system according to claim 1, wherein the fuel cell system operates at a point where an operating condition reaches an efficiency MAX.
Or the hybrid electric vehicle according to claim 2. 5. The vehicle according to claim 1, further comprising an external charging display device for displaying that the vehicle is being automatically charged when the secondary battery is being automatically charged by the automatic charging means. The hybrid electric vehicle according to claim 2. 6. A charge canceling means for canceling automatic charging by said automatic charging means when abnormality is detected in fuel supply to a fuel cell in said fuel cell system. Item 3. A hybrid electric vehicle according to Item 2. 7. The hybrid electric vehicle according to claim 1, further comprising a charge canceling means for canceling the automatic charging by the automatic charging means when detecting that the vehicle is connected to the external charging device.