KR101124984B1 - Emergency operating method of fuel cell vehicle - Google Patents

Abstract

The present invention relates to an emergency operation method of a fuel cell vehicle, and the emergency operation of the vehicle with a limited stack output without shutting down the fuel cell without a failure of the air supply controller or the inverter even in a communication failure state between the vehicle controller and the air supply controller. It is an object of the present invention to provide an emergency driving method of a fuel cell vehicle that enables the driver's safety to be possible. In order to achieve the above object, the vehicle controller and the air supply controller for confirming a communication state between each other; If the communication is disconnected for a predetermined time, controlling the operation of the air supply such that the air supply controller supplies air to the fuel cell stack at a set flow rate; Next, the vehicle controller receives the flow rate detection value of the air supplied to the fuel cell stack from the air flow rate sensor to determine whether the set air flow rate or more; When the air flow rate is greater than or equal to, the vehicle controller drives the driving motor to the output of the fuel cell stack to drive the vehicle in an emergency driving mode.

Description

Emergency operating method of fuel cell vehicle

The present invention relates to an emergency operation method of a fuel cell vehicle, and more particularly, to enable emergency operation of a vehicle at the output of the fuel cell stack without a system shutdown in a communication disconnection state between a vehicle controller and an air supply controller. It relates to an emergency operation method of a fuel cell vehicle.

A fuel cell system applied to a hydrogen fuel cell vehicle, which is one of environmentally friendly future vehicles, includes a fuel cell stack for generating electric energy from an electrochemical reaction of a reaction gas, a hydrogen supply device for supplying hydrogen as fuel to the fuel cell stack, An air supply device for supplying air containing oxygen, which is an oxidant for electrochemical reaction, to the fuel cell stack, and heat of the electrochemical reaction by-product of the fuel cell stack is released to the outside to optimally control the operating temperature of the fuel cell stack. It includes a thermal and water management system (TMS) that performs water management functions.

In the fuel cell vehicle equipped with such a fuel cell system, when only the fuel cell is used as a power source of the vehicle, the fuel cell is in charge of all the loads constituting the vehicle, which results in a decrease in performance in a low operating area of the fuel cell. There is this.

In addition, when a sudden load is applied to the vehicle, the fuel cell output voltage suddenly drops and the vehicle performance is deteriorated because it cannot supply enough power to the driving motor. Fall).

In addition, since the fuel cell has a unidirectional output characteristic, energy input from the driving motor may not be recovered when the vehicle is braked, thereby reducing the efficiency of the vehicle system.

In order to compensate for the above disadvantages, an energy storage device such as a charge / discharge high voltage battery or a supercapacitor (supercap) may be mounted as a separate auxiliary power source for providing power required for driving a motor in addition to the fuel cell as the main power source. have.

1 and 2 are diagrams illustrating a driving system of a fuel cell vehicle, and illustrates a fuel cell hybrid vehicle equipped with a battery or a supercapacitor. 1 is a normal operation state, Figure 2 is a view for explaining a problem in accordance with the prior art, the control period communication disconnection state.

As shown, a fuel cell stack 10 as a main power source and a battery (or supercapacitor) 20 as an auxiliary power source are mounted and driven by electric power supplied from a main power source or an auxiliary power source as a driving source of a vehicle. A drive motor controller (motor controller, MCU: Motor Control Unit) 31 is mounted that includes a motor 30 and an inverter for driving and controlling the drive motor 30.

In addition, an air blower 40, which is an air supply for supplying air, which is a reactive gas, to the fuel cell stack 10 as a component of an air supply device, and a motor of the air blower 40 (hereinafter, referred to as a blower motor) The controller 41 for an air supply including an inverter for driving and controlling the air flow, and the air flow sensor 42 for detecting the flow of air supplied to the fuel cell stack (10).

In addition, the vehicle controller 50 is provided as a top-level controller for controlling the overall operation of the fuel cell system and the vehicle, the vehicle controller 50 may be provided integrally with the controller for the drive motor.

The flow rate detection value signal output from the air flow rate sensor 42, that is, the air flow rate supplied to the fuel cell stack 10 by the air blower 40 is input to the vehicle controller 50.

In FIG. 1 and FIG. 2, the illustration of the hydrogen supply device and the heat and water management system (TMS) is omitted, and some of the components of the air supply device such as the humidifier are omitted.

Among the illustrated components, the driving motor 30 and the blower motor are driven by receiving power from the fuel cell stack 10 or the battery (or supercapacitor) 20, and the battery 20 is driven from the fuel cell stack 10. The generated power and the regenerative power generated by the driving motor 30 are stored.

In addition, the inverter for the drive motor and the inverter for the air supply may be a PWM inverter that applies three-phase alternating current to the driving motor 30 and the blower motor, respectively, and the PWM inverter is a semiconductor switch capable of high-speed switching (eg, IGBT). And a power module (not shown) consisting of a diode forming a current loop during power generation.

The PWM inverter uses pulse width modulation (PWM) to change the width of the switching pulse for switching the semiconductor switch for controlling the three-phase current applied to the motor.

When the drive motor 30 and the blower motor are driven, the vehicle controller 50 transmits a control command to the drive motor controller 31 and the air supply controller 41 and receives a status feedback. The drive motor inverter and The inverter for the air supply phase-shifts the power supplied from the fuel cell stack 10 or the battery (or supercapacitor) 20 through PWM switching to drive the motor.

That is, each inverter generates a three-phase current according to the control command applied from the vehicle controller 41 to control the driving speed of the motor, and the drive motor controller 31 and the air supply controller 41 are absolute motors. Each positional information and each phase current is fed back and used to control the inverter.

However, if the communication between the vehicle controller 50 and the air supply controller 41 is interrupted during normal driving of the fuel cell vehicle, the air supply controller may not receive the control command, and thus the power supply capable of driving the air blower 40. Even if this is supplied, the air supply to the fuel cell stack 10 is stopped, which causes the fuel cell stack to stop generating power.

Referring to FIG. 2, it is shown that air cannot be supplied to the fuel cell stack 10 while driving of the air blower 40 is stopped while communication between the vehicle controller 50 and the controller 41 for the air supply is cut off. Giving.

As a result, when power generation of the fuel cell stack 10 is stopped, the driving motor 30 cannot be driven by the stack power, and residual energy is used only in a vehicle equipped with an energy storage device such as a battery 20 or a supercapacitor. It is possible to travel in a limp home mode such as pulling a vehicle off the shoulder.

However, in a vehicle that lacks residual energy or is not equipped with an energy storage device, a fuel cell stoppage (or shutdown) may lead to a shutdown of the vehicle, which may cause a vehicle driver to face a dangerous situation.

Accordingly, the present invention has been invented to solve the above problems, and even when the communication between the vehicle controller and the air supply controller is lost, the vehicle is limited to the stack output without shutting down the fuel cell unless the air supply controller or the inverter has failed. It is an object of the present invention to provide an emergency operation method of a fuel cell vehicle that enables the emergency operation of the driver to ensure the safety of the driver.

Another object of the present invention is to provide an emergency driving method of a fuel cell vehicle capable of implementing an emergency driving mode of an additional vehicle in addition to an emergency driving mode using power of an energy storage device without improving a system or adding hardware. There is this.

In order to achieve the above object, the present invention includes the steps of checking the communication state between the vehicle controller and the controller for the air supply; If the communication is disconnected for a predetermined time, controlling the operation of the air supply such that the air supply controller supplies air to the fuel cell stack at a set flow rate; Next, the vehicle controller receives the flow rate detection value of the air supplied to the fuel cell stack from the air flow rate sensor to determine whether the set air flow rate or more; When the air flow rate is greater than or equal to, the vehicle controller drives the driving motor to the output of the fuel cell stack to drive the vehicle in the emergency operation mode; provides an emergency operation method for a fuel cell vehicle comprising a.

Here, the air supply is an air blower, the rotational speed of the air blower is preset and input to the air supply controller to the air supply at the set flow rate by the air blower, the controller for the air supply is When the communication disconnection state is confirmed, the air blower is controlled at the set rotation speed.

In addition, when the vehicle controller determines that the flow rate detection value of the air flow sensor is less than the set air flow rate, it is determined that the controller for the air supply or the inverter for the air supply is faulty, and the driving motor is driven by the power stored in the energy storage device. Characterized in that the vehicle is driven in the emergency operation mode.

In addition, the vehicle controller is characterized in that to inform the driver by operating the warning means in the emergency operation mode.

In addition, the vehicle controller determines that the communication between the controllers is disconnected when the flow rate detection value of the air flow rate sensor is greater than or equal to the set flow rate, and that the controller state for the air supply controller or the inverter for the air supply is determined to be broken when the flow rate detection value of the air flow rate sensor is less than the set flow rate. It is characterized in that to operate the warning means so that each state can be distinguished.

In addition, if the communication between the vehicle controller and the controller for the air supply is resumed after entering the emergency operation mode, characterized in that to release the emergency operation mode.

Accordingly, according to the emergency operation method of the fuel cell vehicle according to the present invention, even if the communication between the vehicle controller and the air supply controller is not in operation, the operation of the vehicle is limited to the stack output without shutdown unless the air supply controller or the inverter has failed. It is possible to secure the driver's safety by making it possible.

In addition, the present invention can implement the emergency driving mode of the vehicle in addition to the emergency driving mode using the power of the energy storage device only by improving the control logic without changing the system or adding hardware.

In particular, an additional mode of emergency operation of the vehicle at the stack output, rather than shutting down the system or using the power of the energy storage device in case of communication loss, has been added even when the energy storage device is not mounted or the energy remaining in the energy storage device is consumed. The vehicle can be moved to a safe place.

1 and 2 are diagrams illustrating a driving system of a general fuel cell vehicle, in which FIG. 1 shows a normal driving state, and FIG. 2 shows a communication disconnection state between a vehicle controller and an air supply controller.
3 is a system configuration for explaining an emergency operation method of a fuel cell vehicle according to the present invention.
4 is a flowchart illustrating an emergency driving method of a fuel cell vehicle according to the present invention.
5 is a view showing a state when performing the emergency operation mode due to communication disconnection between the controller in the present invention.
6 is a view illustrating a state in which a failure of the controller or inverter for the air supply in the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains.

3 is a block diagram showing a driving system of a fuel cell vehicle to which an emergency driving method of a fuel cell vehicle according to the present invention is applied, and supplying air in a communication disconnected state between the vehicle controller 50 and the air supply controller 41. It is a figure which shows the state which the controller 41 controls the drive of the air supply 40 so that the air flow volume which set itself may be supplied.

As shown, the present invention implements an additional vehicle emergency driving mode (lymph home mode) only by improving the control logic without changing the system or adding hardware.

In particular, in the present invention, even if a problem of communication disconnection occurs between the vehicle controller 50 and the controller 41 for the air supply, if there is no problem in the controller 41 for the air supply itself, the vehicle is limited to the output of the fuel cell stack 10. The main focus is to ensure the driver's safety by enabling the operation of.

4 is a flowchart illustrating an emergency driving method of a fuel cell vehicle according to the present invention, with reference to this will be described in detail the emergency driving method according to the present invention.

First, the communication state between the vehicle controller 50 and the air supply controller 41 is always checked in real time during fuel cell operation. If there is a problem in the communication between the vehicle controller 50 and the air supply controller 41, In the case where the communication between the controllers is disconnected, the controller 41 for the air supply waits for resumption of communication with the vehicle controller 50 for a predetermined time.

If the communication is resumed within a certain waiting time, since there is no problem in the communication state between the controllers, the air supply (air blower) 40 is driven and controlled in the normal operation mode, and thus the air supply device and the hydrogen supply device normally operate. As the reaction gas (air and hydrogen) is supplied, normal power generation operation of the fuel cell stack 10 and vehicle driving (drive motor driving) are performed.

On the other hand, when communication is not resumed even during a predetermined waiting time, the controller 41 for the air supply controls the driving of the air supply 40 so that air of a set flow rate is supplied to the fuel cell stack 10.

At this time, the controller 41 for the air supply emergencyly drives the air supply 40 such that a predetermined air flow rate is supplied to the fuel cell stack 10. The air supply 40, for example, a specific air flow rate by the air blower A predetermined rotation speed (rpm) for emergency driving the air blower 40 to the air supply controller 41 itself may be preset and input to be supplied to the battery stack 10.

When the communication is not resumed for a predetermined waiting time, the air supply controller 41 emergencyly drives the air blower 40 at a predetermined rotational speed so that a predetermined air flow rate is supplied to the fuel cell stack 10.

At this time, the air flow rate sensor 42 detects the flow rate of air actually supplied to the fuel cell stack 10 by the emergency driving of the air blower 40. The flow rate detection value signal output from the air flow rate sensor 42, That is, the air flow rate signal according to the emergency driving of the air blower 40 is transmitted to the vehicle controller 50 and input.

In addition, the vehicle controller 50 also waits for resumption of communication for a predetermined waiting time when communication with the air supply controller 41 is interrupted, and if the communication is not resumed, the flow rate detection value signal output from the air flow sensor 42. From the air blower 40, it is confirmed whether or not the air flow rate at the time of emergency driving is supplied to the fuel cell stack 10.

Here, when it is confirmed that the air is supplied to the fuel cell stack 10 above the air flow rate during the air blower 40 emergency driving, the air blower 40 is emergency driven by the controller 41 / inverter for the air supply. Since the air is supplied to the fuel cell stack 10, the vehicle controller 50 determines that the air supply controller 41 and the inverter are in a normal operating state rather than a failure condition.

Therefore, it is determined that the air supply controller 41 enters the emergency operation mode due to the communication disconnection in the state in which the air supply controller 41 and the inverter operate normally, and the vehicle controller 50 also enters the emergency operation mode. Then, the vehicle performs emergency operation (lymph home mode operation) (emergency operation mode 1).

That is, since the air is being supplied by the emergency drive of the air blower 40 while the hydrogen supply to the fuel cell stack 10 is maintained (the power generation state of the fuel cell is maintained), the vehicle controller 50 Lymph groove driving such as driving the motor 30 to emergency driving with limited output of the fuel cell stack 10 while limiting the output of the fuel cell stack 10 to the level at which the lymph groove driving is possible, is performed. do.

In this case, since the vehicle travels to the limp home, the vehicle controller 50 operates in-vehicle warning means 60 such as a warning light of a driver's seat cluster or a device capable of sound output, and enters the emergency driving mode. And alert the user that the vehicle is traveling in an emergency driving state.

In addition, when communication between the controllers is resumed during emergency driving, the vehicle controller 50 may release the emergency driving mode and transition back to the normal driving mode. In this case, the vehicle controller 50 is in the normal driving mode. 60 may be informed to the driver.

However, if the flow rate of the air supplied to the fuel cell stack 10 is less than the flow rate at the time of emergency supply of the air supply 40 without the communication between the controllers being resumed, a failure has occurred in the controller 41 or the inverter for the air supply. Judgment shuts down the fuel cell system.

Even in this case, the vehicle controller 50 operates the warning means 60 to warn the user that the fuel cell system is shut down due to a failure of the controller 41 or the inverter for the air supply, and the fuel cell system is shut down. Even if the energy storage device 20, that is, a vehicle equipped with a battery or a supercapacitor, the driving motor 30 is driven by using the residual energy stored therein to drive the vehicle in an emergency driving (lymph home mode driving) state. (Emergency operation mode 2).

In the case of a fuel cell vehicle using only the fuel cell stack 10 as a power source without the energy storage device 20, the vehicle is inevitably shut down in this situation.

In the control process during the emergency operation as described above, during the emergency operation of the air blower 40 set to supply air to the air flow rate, or the air flow rate is set to be supplied to the fuel cell stack 10 when the communication between the controller is disconnected The rotational speed (rpm) may be larger than the actual amount required for driving the vehicle. In this case, since the supply flow rate of the dry air is increased by the air blower 40, the fuel cell stack 10 may be dried.

Therefore, although the output speed may be increased to extract a lot of output from the fuel cell stack 10, the proper rotation speed to prevent drying may be selected and applied even if the output is reduced.

In addition, since the vehicle controller 50 may determine the communication disconnection state between the controller and the failure state of the controller 41 or the inverter for the air supply, the controller 50 distinguishes the two situations through the warning means 60. It is possible to warn by.

That is, when the flow rate detection value of the air flow sensor 42 is greater than or equal to the set flow rate, the vehicle controller 50 disconnects communication between the controllers. When the flow rate detection value of the air flow sensor 42 is less than the set flow rate, the controller for the air supply (41) or by determining the failure state of the inverter, it is possible to operate the warning means 60 so that each situation can be distinguished, in this case the operator or the operator at the time of maintenance through the operation of the warning means 60 You can know by separating.

5 is a view showing the state when performing the emergency operation mode due to the communication disconnection between the controller, the air supply controller 41 at the time of the communication error occurs the air blower 40 at the set rotation speed of its own emergency (self-set After the emergency operation (at the start of the emergency operation of the controller for the air supply) is started to emergencyly drive the air supply with the air flow rate, the vehicle controller 50 may limit the output of the fuel cell stack 10 to operate the vehicle in the limp home mode. It is shown that the emergency driving state of the vehicle controller 50 for driving in the road is started.

In addition, since the controller 41 for the air supply enters the emergency operation mode, the rotation speed of the air blower 40 is constantly controlled at a preset rotation speed (the air blower is driven in an emergency), so that the controller for the air supply 41 It can be seen that the air flow rate supplied to the fuel cell stack 10 is constantly controlled at a level corresponding to the rotational speed at the time when the emergency operation of the vehicle is started.

In addition, it can be seen that the output of the fuel cell stack 10 is limited at the time when the emergency operation of the vehicle controller 50 is started, and the vehicle controller 50 operates the warning means 60 at the time when the emergency operation is started. The driver will be warned of an emergency operation.

6 illustrates a state where a failure of the controller 41 for the air supply or the inverter occurs, and the vehicle controller 50 confirms that the communication with the controller 41 for the air supply is impossible and then connects the air blower 40 to the air blower 40. By checking the situation in which the air supply corresponding to the rotational speed (flow rate) set at the time of emergency drive is not made | formed, it is finally determined that the air supply controller 41 or an inverter is in a failure state.

In this case, when the energy storage device 20 such as a battery or a supercapacitor is mounted, the vehicle is emergencyly driven by driving the driving motor 30 using the power stored in the energy storage device, but the energy storage device 20 is mounted. In the vehicle not being shut down, the vehicle controller 50 is shut down and the warning means 60 is operated to inform the driver of the failure of the controller 41 or the inverter for the air supply.

Thus, in the present invention, even if the communication between the vehicle controller 50 and the air supply controller 41 is disconnected, the vehicle can be operated with limited power without shutting down unless the air supply controller 41 or the inverter is in a fault condition. As a result, the driver's safety can be secured.

The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are provided. Also included in the scope of the present invention.

10: fuel cell stack
20: battery (or supercapacitor) (energy storage device)
30: drive motor 31: drive motor controller / inverter
40: air blower (air supply) 41: air supply controller
42: air flow sensor 50: vehicle controller

Claims (6)

Confirming a communication state between the vehicle controller and the air supply controller;
If the communication is disconnected for a predetermined time, controlling the operation of the air supply such that the air supply controller supplies air to the fuel cell stack at a set flow rate;
Next, the vehicle controller receives the flow rate detection value of the air supplied to the fuel cell stack from the air flow rate sensor to determine whether the set air flow rate or more;
Driving the vehicle in an emergency driving mode by driving the driving motor to the output of the fuel cell stack when the air flow rate is equal to or greater than the set air flow rate;
Emergency operation method of a fuel cell vehicle comprising a.
The method according to claim 1,
The air supply is an air blower,
The rotation speed of the air blower is preset and input to the controller for the air supply so that the air is supplied at the set flow rate by the air blower.
And when the controller for the air supply checks the communication disconnection state, controls the driving of the air blower at the set rotation speed.
The method according to claim 1,
If the vehicle controller determines that the flow rate detection value of the air flow rate sensor is less than the set air flow rate, it is determined that the controller for the air supply or the inverter for the air supply is faulty, and the driving motor is driven by the power stored in the energy storage device. Emergency driving method of a fuel cell vehicle, characterized in that for driving in the emergency operation mode.
The method according to claim 1 or 3,
The vehicle controller is an emergency driving method for a fuel cell vehicle, characterized in that to inform the driver by operating the warning means in the emergency operation mode.
The method of claim 4,
If the flow rate detection value of the air flow rate sensor is more than the set flow rate, the vehicle controller determines that the communication is disconnected between the controllers. If the flow rate detection value of the air flow rate sensor is less than the set flow rate, the vehicle controller determines that the controller for the air supply or the inverter for the air supply Emergency operation method of a fuel cell vehicle, characterized in that to operate the warning means to distinguish each state.
The method according to claim 1,
And emergency mode is released when communication between the vehicle controller and the controller for the air supply is resumed after entering the emergency mode.

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