JPH03276573A - Control system for on-vehicle fuel cell - Google Patents

Abstract

PURPOSE:To reduce the capacity of a backup battery by calculating the proper feed quantity of the reaction gas based on the running load command fed to the accelerator of a vehicle for feed-forward control. CONSTITUTION:When the depression quantity of an accelerator pedal 5 is adjusted to change the running load command of a vehicle, the depression quantity of the accelerator pedal 5 is converted into an electric signal and inputted to an arithmetic unit 12. The arithmetic unit 12 adds the signal from a battery residual capacity meter 11 to the load command and calculates the required feed quantity of the reaction gas fed to a fuel cell 1. A controller 7 outputs a control command to a flow control servo valve 13 and an air blower 10 based on the calculated result and feed-forward-controls the feed quantity of the reaction gas to the fuel cell 1. The capacity of a backup battery is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel cell control method for driving a vehicle motor using the generated output of a fuel cell mounted on an electric vehicle.

[Conventional technology]

BACKGROUND ART Recently, electric vehicles equipped with batteries have become popular in order to prevent automobile exhaust gas pollution, and recently, vehicles equipped with fuel cells as batteries have also been developed.

Here, a conventional fuel cell power generation system mounted on a vehicle is shown in FIG. In the figure, 1 is the fuel cell, 2 is the Chitafupa, and 3 is the auxiliary power source at startup.

and a battery that functions as a backup power source for peak loads; 4 is a vehicle motor that drives the wheels 4a; 5 is an accelerator pedal as an accelerator; 6 is a potentiometer that converts mechanical position displacement into an electrical signal; 7 is a controller;
8 is a fuel gas pressure cylinder, 9 is a pressure regulating valve, and 10 is an air blower.

Here, the fuel cell 1 uses fuel gas as is well known.

Electric power is generated by supplying air to the anode and cathode, respectively, and the output is supplied to the vehicle motor 4 via the chopper 2.

When the vehicle is running, a load command is given to the controller 7 based on the amount of depression of the Arcel pedal 5, and the output of the chopper 2 is changed to control the speed of the vehicle motor 4. When the load suddenly increases, the insufficient output of the fuel cell 1 is compensated for by the power of the battery 2, and when the load is light, the battery 3 is charged with surplus power of the fuel cell 1. Note that the pressure regulating valve 10 operates by sensing pressure changes in the gas line due to increases and decreases in fuel gas consumption in the fuel cell 1, and functions to maintain a constant pressure of the fuel gas supplied to the fuel cell. .

(Problems to be Solved by the Invention) By the way, the above-described conventional system has the following problems.

(1) If the capacity of the backup battery 3 is sufficiently large, the necessary power can be supplied to the vehicle motor 4 even when the load suddenly increases, so that the fuel cell will not experience a drop in output due to insufficient supply of reactant gas. .

However, a large-capacity battery is very large in size and weight, so it is not suitable for practical use in a vehicle.

(2) Therefore, in order to reduce the capacity of the backup battery, it is necessary to increase the load followability of the fuel cell accordingly. Therefore, as shown in Fig. 5, the pressure regulating valve 9
In this method, it is inevitable that a large delay will occur in the response of the reactant gas supply due to load fluctuations, and this will cause a temporary fuel gas shortage, especially when the load suddenly increases. As a result, the output of the fuel cell decreases, making it impossible to provide the fuel cell with sufficient load followability.

The present invention has been made in consideration of the above points, and improves the responsiveness of reactant gas supply to the fuel cell as the load increases and decreases, thereby preventing a transient decrease in the fuel cell output due to fuel gas shortage, thereby providing a backup An object of the present invention is to provide a control method for a vehicle-mounted fuel cell that can reduce battery capacity.

[l! Means for Solving the Problem] In order to solve the above problem 111M, the present invention is provided with a calculation and control means for the amount of reactant gas supplied to the fuel cell, and a means for calculating and controlling the amount of reactant gas supplied to the fuel cell based on the running load command given to the accelerator of the vehicle. In addition, feedforward control is performed by calculating the appropriate supply amount of the reaction gas corresponding to the load command.

In addition, in order to further improve the controllability of the above-mentioned control method, it is possible to add a signal that uses the remaining capacity of the battery as a parameter to the load command to calculate the reaction gas supply amount, or to calculate the amount of reactant gas supplied when the vehicle is accelerating. It is preferable to add means such as calculating the reaction gas supply amount by multiplying the load command by a coefficient suitable for the acceleration load pattern of the vehicle.

[Effect]

According to the above, when the driver of the vehicle depresses the accelerator pedal, which is an accelerator, while the vehicle is running, for example, to accelerate the vehicle, the amount of depression is converted into an electrical signal and given to the computing unit as a load command for traveling. Then, the calculator calculates the appropriate amount of reactant gas to be supplied according to the amount of depression of the Arcel pedal, and the controller calculates the appropriate amount of reactant gas to be supplied to the reactor gas supply system of the fuel cell (the flow control servo valve connected to the fuel gas line, Feedforward control of the air blower (air blower connected to the air line). Note that the controller simultaneously controls the output of the chopper according to the load command. Therefore, the output of the fuel cell increases by following load fluctuations without response delay. Note that if the amount of depression of the accelerator pedal is reduced to reduce the traveling speed of the vehicle, the amount of reactant gas supplied will be throttled and the output of the fuel cell will be reduced, contrary to the above.

Further, by constantly monitoring the remaining capacity of the battery that functions as a buffer, and adding the remaining capacity as a parameter to the load command described above to determine the reactant gas supply amount, more fine-grained control becomes possible.

Furthermore, when accelerating the vehicle, a coefficient (coefficient value: l to 2) corresponding to the acceleration load pattern is applied for a predetermined period of time (
The acceleration performance of the vehicle is further improved by increasing the amount of reactant gas supplied by multiplying the load command by a fraction of a few seconds).

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Note that the same equipment corresponding to FIG. 5 is given the same reference numeral.

First, in the circuit of FIG. 1, a battery remaining capacity meter 11 that monitors the remaining capacity of the battery 3 as a control system of the fuel cell;
A computing unit 12 is newly added to the circuit shown in Fig. 5, and a flow rate control servo valve 13 that increases/decreases the valve opening in response to commands from the controller 7 is installed in the fuel gas line instead of the pressure regulating valve shown in Fig. 5. connected.

When such a control circuit adjusts the amount of depression of the accelerator pedal 5 to change the load command for running the vehicle, the amount of depression of the accelerator pedal is converted into an electrical signal and input to the calculator 12. On the other hand, the arithmetic unit 12 adds the signal from the battery remaining capacity meter 11 to the load command and adds the signal from the fuel cell l
Calculate the required supply amount of reactant gas to be supplied to. In other words,
When the remaining capacity of the battery 3 is low, the output of the fuel cell 1 is increased above the load command, and the remaining capacity of the battery is reduced to 100.
%, on the other hand, adjustments are made to suppress the increase in fuel cell output. Based on this calculation result, the controller 7 also controls the flow rate control servo valve 13. A control command is output to the air blower 10 to perform feedforward control of the amount of reactant gas supplied to the fuel cell. At the same time, the controller 7 controls the output of the chigoppa 2 to control the speed of the vehicle motor 4.

Here, the amount of depression of the accelerator pedal 5 and the opening degree of the flow rate control servo valve 13 connected to the fuel gas line.

The relationship between this and the output of the fuel cell l is set as shown in FIG. 2, for example. Note that A in the figure is a bias amount corresponding to idling.

On the other hand, in order to accelerate the vehicle by depressing the accelerator pedal 5, a peak load is transiently applied to the vehicle motor 4. Therefore, in order to make the output of the fuel cell follow the peak load that occurs when the vehicle accelerates, it is necessary to wait for a predetermined period of time (for example, about 7 seconds) from the time the load command is received, as shown in Figure 3. The load command is multiplied by a coefficient (coefficient value: 1 to 2) corresponding to the acceleration load pattern of the vehicle.
Based on this, the reactant gas supply amount and the vehicle motor 4 can be appropriately controlled.

Incidentally, FIG. 4 is a time chart showing the above control.

〔Effect of the invention〕

As described above, the control method of the present invention provides the following effects.

(1) Equipped with a calculation control means for the amount of reactive gas supplied to the fuel cell, which calculates an appropriate amount of reactive gas to be supplied corresponding to the load command given to the accelerator of the vehicle based on the load command for running. By performing feedforward control, the followability of the fuel cell output to load fluctuations can be significantly improved compared to the conventional method.

(2) Therefore, there is no reduction in the output of the fuel cell due to a shortage of reactant gas, and as a result, the capacity of the bank-up battery combined with the fuel cell can be reduced, making it significantly smaller and more compact. It is extremely advantageous as a power source.

(3) Furthermore, when controlling the reactant gas supply to the fuel cell, the reactant gas supply amount is calculated by adding a signal that uses the battery's remaining capacity as a parameter to the load command, or when the vehicle is accelerating, the acceleration load of the vehicle is calculated. More fine control can be achieved by adding means such as calculating the amount of reactant gas supplied by multiplying the load command by a coefficient appropriate to the pattern.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of an embodiment of the present invention, Figure 2 is a diagram of the relationship between the accelerator pedal depression amount, fuel cell output, and flow rate control servo valve opening, and Figure 3 is a diagram of the coefficient by which the load command is multiplied during vehicle acceleration. In the pattern diagram, Fig. 4 is a time chart diagram showing the control operation according to Fig. 1, and Fig. 5 is an operating circuit diagram of a conventional fuel cell-equipped vehicle. : Battery, 4: Vehicle motor, 5: Accelerator pedal (accelerator), 7: Controller, 11: Battery remaining capacity meter, 12 Two computing units, 13
:Flow control servo valve, /Sung, Fig. 3 Fig. 4

Claims (1)

[Claims] 1) A fuel cell control method for driving a vehicle motor by combining a fuel cell mounted on a vehicle with a battery, comprising calculation control means for the amount of reactant gas supplied to the fuel cell,
Based on the driving load command given to the vehicle's accelerator,
A control method for a vehicle-mounted fuel cell, characterized in that feedforward control is performed by calculating an appropriate supply amount of a reactant gas corresponding to the load command. 2) A control method for a vehicle-mounted fuel cell according to claim 1, characterized in that the reactant gas supply amount is calculated by adding a signal having the remaining capacity of the battery as a parameter to the load command. 3) In the control method according to claim 1, when the vehicle is running under acceleration, the amount of reactant gas supplied is calculated by multiplying the load command by a coefficient commensurate with the acceleration load pattern of the vehicle. control method.