KR20240070266A - Fuel cell system and control method of fuel cell system - Google Patents

Abstract

An air flow line connected to the fuel cell stack and equipped with a flow sensor that measures pressure or flow rate; An air shutoff valve provided in the air flow line; It controls the air flow in the air flow line by controlling the air shutoff valve, and detects abnormalities in the air shutoff valve through whether output voltage is generated or changes in the measured value of the flow sensor when controlling the complete closure or full opening of the air shutoff valve. A fuel cell system including a control unit that corrects control is introduced.

Description

Fuel cell system and fuel cell system control method {FUEL CELL SYSTEM AND CONTROL METHOD OF FUEL CELL SYSTEM}

The present invention relates to a fuel cell system and a fuel cell system control method, which detects and corrects control abnormalities when the ACV (Air Cut-Off Valve) is fully closed and fully opened. It's about the technology to do it.

A fuel cell is a device that receives hydrogen and air from the outside and generates electrical energy through an electrochemistry reaction inside the fuel cell stack. It is a power source in various fields such as fuel cell vehicles (FCEV) and fuel cells for power generation. It can be used as

The fuel cell system includes a fuel cell stack that stacks a plurality of fuel cells used as a power source, a fuel supply system that supplies hydrogen, a fuel, etc. to the fuel cell stack, an air supply system that supplies oxygen, an oxidizing agent necessary for electrochemical reactions, It includes water and heat management systems that control the temperature of the fuel cell stack.

The fuel supply system depressurizes the compressed hydrogen inside the hydrogen tank and supplies it to the anode of the fuel cell stack, and the air supply system operates the air compressor to supply external air to the cathode of the fuel cell stack. ) is supplied.

When hydrogen is supplied to the anode of the fuel cell stack and oxygen is supplied to the air electrode, hydrogen ions are separated at the anode through a catalytic reaction. The separated hydrogen ions are transferred to the anode, which is the air electrode, through the electrolyte membrane, and at the anode, the hydrogen ions separated from the fuel electrode, electrons, and oxygen undergo an electrochemical reaction together, through which electrical energy can be obtained. Specifically, electrochemical oxidation of hydrogen occurs at the anode, and electrochemical reduction of oxygen occurs at the air electrode. Electricity and heat are generated due to the movement of electrons generated at this time, and water vapor or water is generated through the chemical reaction of hydrogen and oxygen combining. This is created.

An exhaust device is provided to discharge by-products such as water vapor, water and heat, and unreacted hydrogen and oxygen generated during the electric energy generation process of the fuel cell stack, and gases such as water vapor, hydrogen and oxygen are released into the atmosphere through the exhaust passage. is discharged into the stomach.

The electrochemical reaction that occurs inside a fuel cell is expressed in a reaction equation as follows.

[Reaction at anode] 2H ₂ (g) → 4H ⁺ (aq.) + 4e ^-

[Reaction at cathode] O ₂ (g) + 4H ⁺ (aq.) + 4e ^- → 2H ₂ O(l)

[Overall reaction] 2H ₂ (g) + O ₂ (g) → 2H ₂ O(l) + electrical energy + heat energy

As shown in the above reaction equation, hydrogen molecules are decomposed at the anode to generate 4 hydrogen ions and 4 electrons. Electrons move through an external circuit to generate current (electrical energy), and hydrogen ions move to the cathode through the electrolyte membrane to cause a cathode reaction, and water and heat are generated as by-products of the electrochemical reaction.

Meanwhile, Figure 1 shows a schematic diagram of a fuel cell system. Referring to FIG. 1, an air cut-off valve (ACV) is provided in the air flow line of the fuel cell stack to block air transported to the cathode when the fuel cell stack is shut down. ACV prevents air from flowing into the fuel cell stack when the fuel cell stack is shut down, reacting with the remaining hydrogen, and deteriorating the fuel cell stack.

The complete closing of the ACV is achieved by the rotation of the drive motor that drives the ACV. Generally, the number of revolutions of the drive motor that allows the ACV to be completely closed is set, and a sensor inside the ACV counts the number of revolutions of the drive motor and operates the ACV. It can be detected whether complete closure has been achieved.

However, due to the high-output operation of the fuel cell stack, mechanical defects may occur in the ACV due to the influence of high-pressure air, and mechanical defects may also occur when the ACV is controlled with high torque to maintain airtightness. Additionally, mechanical defects may occur in the ACV due to accumulation of fuel cell stack operation. Accordingly, despite the ACV complete closure control command, the air tightness of the ACV may not be maintained due to a mechanical defect and air may leak into the fuel cell stack. Accordingly, voltage may be generated even after the fuel cell stack is turned off, causing deterioration of the fuel cell stack.

Meanwhile, since the sensor present inside the conventional ACV only counts the number of rotations of the drive motor to check whether the ACV is completely closed, there is a problem that the confidentiality of the ACV caused by a mechanical defect cannot be confirmed with the conventional sensor. there is.

The matters described as background technology above are only for the purpose of improving understanding of the background of the present invention, and should not be taken as recognition that they correspond to prior art already known to those skilled in the art.

KR 10-2018-0067276 A

The present invention was proposed to solve this problem. A fuel cell system and a fuel cell system control method that can prevent deterioration of the fuel cell stack by detecting and correcting a mechanical defect in the air shutoff valve. The purpose is to provide.

The fuel cell system according to the present invention for achieving the above object includes an air flow line connected to the fuel cell stack and equipped with a flow sensor for measuring pressure or flow rate; An air shutoff valve provided in the air flow line; It controls the air flow in the air flow line by controlling the air shutoff valve, and detects abnormalities in the air shutoff valve through whether output voltage is generated or changes in the measured value of the flow sensor when controlling the complete closure or full opening of the air shutoff valve. It includes a control unit that corrects the control.

The flow sensor may be provided in the air flow line at the entrance side of the fuel cell stack.

If the output voltage of the fuel cell stack is detected after controlling the air shutoff valve to be completely closed, the control unit can detect that there is a problem with the air shutoff valve.

When an abnormality is detected after controlling the complete closing of the air blocking valve, the control unit gradually rotates the driving motor of the air blocking valve in the closing direction and monitors the pressure value measured from the flow sensor to correct and control the complete closing of the air blocking valve. there is.

The control unit may determine that the air shutoff valve is completely closed when the pressure measured from the flow sensor shows a tendency to gradually increase after rotating the drive motor in the closing direction.

The control unit stores the rotational speed of the driving motor at which the pressure measured from the flow sensor begins to gradually increase, and in subsequent control, complete closure of the air shutoff valve can be controlled through the stored rotational speed of the driving motor. there is.

The control unit reduces the rotational speed of the drive motor and monitors the pressure value measured from the flow sensor to correct and control the complete closure of the air shutoff valve.

A plurality of flow sensors are provided in the air flow line, the first flow sensor is provided at the front of the air compressor provided in the air flow line, and the second flow sensor may be provided in the air flow line at the entrance to the fuel cell stack. .

The control unit may detect that there is a problem with the air shutoff valve if the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor are different from each other after controlling the full opening of the air shutoff valve.

When an abnormality is detected after controlling the full opening of the air shutoff valve, the control unit gradually rotates the driving motor of the air shutoff valve in the direction of opening and monitors the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor. Thus, the full opening of the air shutoff valve can be corrected and controlled.

The control unit may determine that the air shutoff valve is fully opened when the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor are the same after rotating the drive motor in the opening direction.

The control unit reduces the rotational speed of the drive motor and monitors the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor to correct and control the full opening of the air shutoff valve.

As a method for controlling the fuel cell system, the fuel cell system control method includes the steps of a control unit controlling fully closing or fully opening an air shutoff valve; A step where the control unit detects an abnormality in the air shutoff valve through a change in the measured value of the flow sensor; And a step of the control unit correcting the control of the air shutoff valve.

The step of detecting an abnormality in the air blocking valve when the air blocking valve is completely closed is to detect an abnormality in the air blocking valve when the output voltage of the fuel cell stack is detected after controlling the complete closing of the air blocking valve. In the step of detecting an abnormality in the air shutoff valve when fully opened, if the flow rate measured by a plurality of flow sensors provided in the air flow line is different after the air shutoff valve is fully opened, it can be detected that there is a control error in the air shutoff valve. there is.

The step of correcting the control of the air shutoff valve when the air shutoff valve is completely closed involves rotating the drive motor of the air shutoff valve in the direction of closing the air shutoff valve and monitoring the pressure value measured from the flow sensor to ensure that the air shutoff valve is completely closed. Closure control can be calibrated.

The step of correcting the control of the air shutoff valve when the air shutoff valve is fully opened involves rotating the drive motor of the air shutoff valve in the direction of opening the air shutoff valve and the first flow provided at the front of the air compressor provided in the air flow line. Fully open control of the air shutoff valve can be corrected by monitoring the flow rate measured by the sensor and the flow rate measured by the second flow sensor provided in the air flow line at the inlet side of the fuel cell stack.

According to the fuel cell system and fuel cell system control method of the present invention, even if a mechanical defect occurs in the air shutoff valve, it can be detected and corrected for, thereby preventing deterioration of the fuel cell stack. In addition, it is advantageous in terms of economic efficiency because mechanical defects are detected through sensors existing in the existing system without any special sensors to detect mechanical defects.

1 is a schematic diagram of a fuel cell system.
Figure 2 is a fuel cell system according to an embodiment of the present invention.
Figure 3 is a graph to explain the principle of abnormality detection when controlling the complete closure of the air shutoff valve.
Figure 4 is a graph to explain the principle of full closure correction control of the air shutoff valve.
Figure 5 is to explain the principle of abnormality detection when controlling the full opening of the air shutoff valve.
Figure 6 is a flowchart of a fuel cell system control method according to an embodiment of the present invention.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

In describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that it does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

The fuel cell system according to the present invention is intended to solve the problem of not being able to completely close or fully open due to mechanical defects that may occur in the air shutoff valve (ACV).

The fuel cell system according to the present invention for achieving the above object includes an air flow line 300 connected to the fuel cell stack 100 and equipped with a flow sensor 200 that measures pressure or flow rate; An air blocking valve 400 provided in the air flow line 300; And the air flow in the air flow line 300 is controlled by controlling the air shutoff valve 400, through whether or not voltage is generated or the measured value of the flow sensor when controlling the complete closing or fully opening of the air shutoff valve 400. It includes a control unit 500 that detects abnormalities in the air shutoff valve and corrects the control.

Figure 2 is a fuel cell system according to an embodiment of the present invention. Specifically, to describe each configuration, the flow sensor 200 is a sensor that measures the pressure or flow rate of air pressurized by the air compressor 600 provided in the air flow line 300. The flow sensor 200 may be provided at the inlet of the fuel cell stack 100, more specifically, at the air flow line 300 at the cathode inlet side. The flow sensor 200 measures the pressure or flow rate of air flowing into the cathode inlet.

The air blocking valve 400 prevents residual air from flowing into the cathode from the air flow line 300 when the fuel cell stack 100 is shut down, so that the voltage remains even after the fuel cell stack 100 is shut down. This is a configuration to prevent deterioration of the fuel cell stack 100. When the air shutoff valve 400 is completely closed, the air in the air flow line 300 is discharged into the atmosphere along the bypass line 350.

The control unit 500 is configured to control complete closure of the air shutoff valve 400. For example, the control unit may be a fuel-cell control unit (FCU). The controller is a communication device that communicates with other controllers or sensors to control the function in charge, a memory that stores the operating system, logic commands, input/output information, etc., and a unit that performs the judgments, calculations, and decisions necessary to control the function in charge. It may include more than one processor.

Meanwhile, the control unit 500 communicates with the air shutoff valve 400 to control the air shutoff valve 400. Specifically, control of the air shutoff valve 400 is performed by controlling a drive motor (not shown) that drives the air shutoff valve 400 by the control unit 500, thereby ensuring complete closure of the air shutoff valve 400. It can be done.

For example, when the fuel cell stack 100 is turned off, the control unit 500 can block the air flowing into the air flow line 300 by rotating the drive motor in the direction in which the air shutoff valve 400 is closed. .

However, as mentioned above, mechanical defects may occur in the air shutoff valve 400 due to the accumulation of high pressure air or the operation of the fuel cell stack 100, resulting in air shutoff despite the complete closing control of the control unit 500. The valve 400 may not be completely closed.

If complete closure is not achieved, a gap may be formed in the air flow line 300, and air from the outside may flow into the cathode through the gap formed, causing voltage to be generated even after the engine is turned off.

To solve this problem, the fuel cell system of the present invention detects abnormalities in the air shutoff valve 400 through changes in the measured value of the flow sensor 200. If an abnormality is detected, the control of the air shutoff valve 400 is corrected so that the air shutoff valve 400 can be completely closed.

Meanwhile, the control unit 500 may detect that there is a problem with the air shutoff valve 400 when the output voltage of the fuel cell stack 100 is detected after controlling the complete closure of the air shutoff valve 400.

Specifically, referring to FIG. 3, after the fuel cell stack 100 is turned off, the control unit 500 controls the air shutoff valve 400 to be completely closed. Even immediately after complete closure, residual air and residual hydrogen remain in the cathode and anode of the fuel cell stack 100 to generate output, so the residual output generated may be consumed by a COD heater, etc.

However, if the air shutoff valve 400 is not completely closed even after the remaining output is consumed, air flows into the cathode from the outside and reacts with the remaining hydrogen to generate an output voltage. Accordingly, if the output voltage is generated from the fuel cell stack 100 even after a certain period of time has elapsed after the air shutoff valve 400 is completely closed, it can be detected that there is a problem with the air shutoff valve 400.

Meanwhile, when an abnormality is detected after controlling the complete closure of the air shutoff valve 400, the control unit gradually rotates the drive motor of the air shutoff valve 400 in the closing direction and monitors the pressure value measured from the flow sensor 200. Complete closure of the air shutoff valve 400 can be corrected and controlled.

Specifically, if an abnormality is detected when the air shutoff valve 400 is completely closed, it can be seen that the air shutoff valve 400 is not completely closed, creating a gap in the air flow line 300. Therefore, in order to completely close the air shutoff valve 400, the drive motor that drives the air shutoff valve 400 can be rotated in the direction of closing the air shutoff valve 400 to completely close the air shutoff valve 400. .

At this time, it is necessary to measure the rotation speed of the drive motor that causes the air shutoff valve 400 to be completely closed and compensate for the rotation speed during subsequent complete closing control. Therefore, by gradually rotating the drive motor, the pressure value measured from the flow sensor 200 can be monitored to obtain the rotation speed of the drive motor at which the air shutoff valve 400 is completely closed.

Meanwhile, the control unit 500 may determine that the air shutoff valve 400 is completely closed when the pressure measured from the flow sensor 200 shows a tendency to gradually increase after rotating the drive motor in the closing direction. there is.

Specifically, referring to FIG. 4, when the air shutoff valve 400 is not completely closed, the hydrogen present in the fuel cell stack 100 flows out of the flow sensor due to a gap formed in the air flow line 300. The pressure measured at (200) may show the same pressure as atmospheric pressure.

However, from the point where the air shutoff valve 400 is completely closed, hydrogen crosses over to the cathode, and the pressure measured by the flow sensor 200 tends to gradually increase.

Therefore, if the pressure measured from the flow sensor 200 shows a tendency to gradually increase after rotating the drive motor in the closing direction, it can be determined that the air shutoff valve 400 is completely closed.

Meanwhile, the control unit 500 stores the rotational speed of the driving motor at which the pressure measured from the flow sensor 200 begins to gradually increase, and in subsequent control, air blocking is performed through the stored rotational speed of the driving motor. Full closure of the valve 400 can be controlled.

Specifically, the rotation speed previously set to completely block the air shutoff valve 400 is 1000, and the rotation speed of the drive motor at which the pressure measured from the flow sensor 200 begins to gradually increase is 1250. Then, the value to be compensated is 250. Therefore, in this case, 250 can be stored in addition to the previously set number of revolutions, and the stored value can be used to control complete closure of the air shutoff valve 400 in subsequent control.

To elaborate, if an abnormality is detected in the air shutoff valve 400 even during the complete closing control of the air shutoff valve due to the fuel cell stack 100 being turned off after correction control, the number of revolutions to be compensated can be obtained using the same method. . Through this, the complete closing control of the air shutoff valve 400 can be continuously performed.

Meanwhile, in order to reduce the concentration of hydrogen gas accumulated in the air flow line 300 at the start of the fuel cell, there are cases where the air shutoff valve 400 must be slightly opened. At this time, the number of revolutions (compensation value) stored through the control unit 500 can be used as data to slightly open the air shutoff valve 400.

Meanwhile, the control unit 500 can control the complete closure of the air shutoff valve 400 by reducing the rotational speed of the drive motor and monitoring the pressure value measured from the flow sensor 200.

Specifically, the control unit 500 can determine the initial rotation speed of the drive motor, and can determine the rotation speed of the drive motor according to the magnitude of the output voltage detected after the remaining voltage of the fuel cell stack 100 is consumed. That is, if the sensed output voltage is large, the size of the gap formed in the air flow line 300 is relatively large, and the rotation speed of the drive motor can be increased.

Conversely, if the sensed output voltage is small, the size of the gap formed in the air flow line 300 is relatively small, so the rotation speed of the driving motor can be relatively low.

In addition, after controlling the rotation of the drive motor, the control unit 500 monitors the pressure measured from the flow sensor 200 and, if the air shutoff valve 400 has not been completely closed, returns to the previous drive motor rotation. By reducing the rotational speed rather than the speed, the complete closure of the air shutoff valve 400 can be corrected and controlled.

In other words, an accurate compensation value for the drive motor can be obtained when the complete closing of the air shutoff valve 400 is controlled while reducing the rotation speed rather than maintaining a constant rotation speed.

On the other hand, if there is a problem with the air shutoff valve 400, it is highly likely that a problem occurs not only in fully closed control but also in fully open control. Therefore, not only when a problem occurs in fully closed control, but also when a problem occurs in fully open control, it is necessary to detect an abnormality in the air shutoff valve 400 and perform correction control.

During fully open control, in order to detect an abnormality in the air shutoff valve 400, the flow rate of air flowing through the air flow line 300 is compared with the flow rate of air flowing into the fuel cell stack 100.

For this purpose, a plurality of flow sensors 200 are provided in the air flow line 300, and the first flow sensor 200-1 is provided at the front of the air compressor 600 provided in the air flow line 300. , the second flow sensor 200-2 may be provided in the air flow line 300 at the inlet side of the fuel cell stack 100.

Meanwhile, the control unit 500 determines that the flow rate measured by the first flow sensor 200-1 and the flow rate measured by the second flow sensor 200-2 are different from each other after controlling the full opening of the air shutoff valve 400. In this case, it can be detected that there is a problem with the air shutoff valve 400.

Specifically, referring to FIG. 5, when the flow rate measured by the first flow sensor 200-1 and the flow rate measured by the second flow sensor 200-2 are different from each other, the air compressor 600 This means that some of the pressurized air is leaking out through the bypass line 350, which can be determined to indicate that an abnormality has occurred in the air shutoff valve 400.

That is, if the flow rate value measured by the first flow sensor 200-1 is greater than the flow rate value measured by the second flow sensor 200-2, the air shutoff valve 400 is not fully opened. A flow rate flowing out to the bypass line 350 occurs.

Meanwhile, when an abnormality is detected after controlling the full opening of the air shutoff valve 400, the control unit 500 gradually rotates the drive motor of the air shutoff valve 400 in the opening direction and transmits the signal to the first flow sensor 200-1. Full opening of the air shutoff valve 400 can be corrected and controlled by monitoring the flow rate measured by and the flow rate measured by the second flow sensor 200-2.

Specifically, if an abnormality is detected when the air shutoff valve 400 is fully opened, the air shutoff valve 400 does not completely open and a gap is formed at the point where the air flow line 300 branches off to the bypass line 350. It can be seen that this has occurred. Therefore, in order to completely open the air shutoff valve 400, the drive motor that drives the air shutoff valve 400 can be rotated in the direction of opening the air shutoff valve 400 to completely open the air shutoff valve 400. .

At this time, it is necessary to measure the rotation speed of the drive motor that causes the air shutoff valve 400 to be completely opened and compensate for the rotation speed during subsequent full opening control. Therefore, the air shutoff valve 400 is completely opened by gradually rotating the drive motor and monitoring the flow rate measured from the first flow sensor 200-1 and the second flow sensor 200-2. You can obtain the number of revolutions of the motor.

Meanwhile, the control unit rotates the drive motor in the opening direction, and when the flow rate measured by the first flow sensor (200-1) and the flow rate measured by the second flow sensor (200-2) are the same, the air shutoff valve (400) ) can be judged to have been completely opened.

Specifically, it is assumed that the number of revolutions previously set to fully open the air shutoff valve 400 is 1000, and the flow rate measured by the first flow sensor 200-1 and the second flow sensor 200-2 is If the number of revolutions of the driving motor that starts to become equal is 1250, the value that needs to be compensated is 250. Therefore, in this case, 250 can be stored in addition to the previously set number of revolutions, and the stored value can be used to control the full opening of the air shutoff valve 400 in subsequent control.

Furthermore, when an abnormality in the air shutoff valve 400 is detected, both the fully open and fully closed controls of the air shutoff valve 400 are affected, so the number of revolutions of the drive motor used in the fully closed correction control is changed to the fully open correction control. It can be used.

Additionally, since this is the same in the case of fully open, the rotational speed of the drive motor used for fully open correction control can be used for fully closed correction control.

Meanwhile, the control unit 500 reduces the rotation speed of the drive motor and monitors the flow rate measured by the first flow sensor 200-1 and the flow rate measured by the second flow sensor 200-2 to control the air shutoff valve. The full opening of (400) can be corrected and controlled.

Specifically, the control unit 500 can determine the initial rotation speed of the driving motor, which is controlled by the first flow sensor 200-1 after starting the fuel cell stack 100 and controlling the full opening of the air shutoff valve 400. The rotational speed of the driving motor can be determined according to the size of the difference between the measured flow rate and the flow rate measured from the second flow sensor 200-2.

That is, if the difference between the flow rate measured by the first flow sensor 200-1 and the flow rate measured by the second flow sensor 200-2 is large, the rotation speed of the drive motor can be increased, and the difference value is large. If it is small, the rotation speed of the drive motor can be relatively small.

In addition, after controlling the rotation of the drive motor, the control unit 500 monitors the flow rate measured from the first flow sensor 200-1 and the flow rate measured from the second flow sensor 200-2, while still blocking the air. If the valve 400 is not fully opened, the complete closure of the air shutoff valve 400 can be corrected and controlled by reducing the rotation speed from the previous driving motor rotation speed.

Through this, it is possible to obtain an accurate compensation value for the drive motor and correct and control the complete closure of the air shutoff valve 400.

Meanwhile, referring to FIG. 6, as a method for controlling the fuel cell system, the fuel cell system control method includes steps (S110, S120) of the control unit controlling fully closing or fully opening the air shutoff valve 400; Steps (S111, S121) where the control unit 500 detects an abnormality in the air shutoff valve 400 through a change in the measured value of the flow sensor 200; and steps in which the control unit 500 corrects the control of the air shutoff valve 400 (S112, S122).

Specifically, the step (S111) of detecting an abnormality in the air shutoff valve 400 when the air shutoff valve 400 is completely closed is the output voltage of the fuel cell stack 100 after controlling the complete closure of the air shutoff valve 400. When this is detected, it is detected that there is an abnormality in the air blocking valve 400, and when the air blocking valve 400 is fully opened, the step (S121) of detecting an abnormality in the air blocking valve 400 is performed. ), if the flow rate measured by the plurality of flow sensors 200 provided in the air flow line 300 is different, it can be detected that there is a problem with the air shutoff valve 400.

Specifically, in the step (S112) of correcting the control of the air shutoff valve 400 when the air shutoff valve 400 is completely closed, the drive motor of the air shutoff valve 400 is moved in the direction of closing the air shutoff valve 400. By rotating and monitoring the pressure value measured from the flow sensor 200, the complete closing control of the air shutoff valve 400 can be corrected.

Specifically, in the step (S122) of correcting the control of the air shutoff valve 400 when the air shutoff valve 400 is fully opened, the drive motor of the air shutoff valve 400 is moved in the direction of opening the air shutoff valve 400. The flow rate measured by the first flow sensor 200-1 provided at the front of the air compressor 600 provided in the air flow line 300 and the air flow line 300 on the inlet side of the fuel cell stack 100 are rotated. ) The full opening control of the air shutoff valve 400 can be corrected by monitoring the flow rate measured by the second flow sensor 200-2 provided in the.

Meanwhile, when the correction control (S112, S122) of the air shutoff valve 400 is completed, the control unit 500 may further perform steps (S113, S123) of storing the rotation speed of the driving motor.

Specifically, if a mechanical defect occurs in the air shutoff valve 400 and a problem occurs in fully closing or fully opening, correction control is necessary in the subsequent fully closed or fully opened control. Therefore, the control unit 500 stores the rotation speed of the driving motor obtained in the correction control step (S112, 122) as a compensation value and this value can be used for the subsequent fully closed or fully opened control of the air shutoff valve 400. will be.

Although the present invention has been shown and described in relation to specific embodiments, it is known in the art that the present invention can be modified and changed in various ways without departing from the technical spirit of the present invention as provided by the following claims. This will be self-evident to those with ordinary knowledge.

100: Fuel cell stack
200: Flow sensor
300: Air flow line
400: Air shutoff valve

Claims (16)

An air flow line connected to the fuel cell stack and equipped with a flow sensor that measures pressure or flow rate;
An air shutoff valve provided in the air flow line; and
Controls the air flow in the air flow line by controlling the air shutoff valve, and detects and controls abnormalities in the air shutoff valve through whether output voltage is generated or changes in the measured value of the flow sensor when controlling the complete closure or full opening of the air shutoff valve. A fuel cell system including a control unit that corrects. In claim 1,
A fuel cell system characterized in that the flow sensor is provided in the air flow line at the entrance to the fuel cell stack. In claim 1,
A fuel cell system characterized in that the control unit detects that there is a problem with the air shutoff valve when the output voltage of the fuel cell stack is detected after controlling the complete closure of the air shutoff valve. In claim 3,
When an abnormality is detected after controlling the complete closing of the air blocking valve, the control unit gradually rotates the driving motor of the air blocking valve in the closing direction and monitors the pressure value measured from the flow sensor to correct and control the complete closing of the air blocking valve. Characterized by a fuel cell system. In claim 4,
A fuel cell system characterized in that the control unit determines that the air shutoff valve is completely closed when the pressure measured from the flow sensor shows a tendency to gradually increase after rotating the drive motor in the closing direction. In claim 5,
The control unit stores the rotation speed of the driving motor at which the pressure measured from the flow sensor begins to gradually increase, and in subsequent control, controls the complete closing of the air shutoff valve through the stored rotation speed of the driving motor. Characterized by a fuel cell system. In claim 4,
A fuel cell system characterized in that the control unit reduces the rotational speed of the drive motor and monitors the pressure value measured from the flow sensor to correct and control the complete closure of the air shutoff valve. In claim 1,
A plurality of flow sensors are provided in the air flow line, the first flow sensor is provided at the front of the air compressor provided in the air flow line, and the second flow sensor is provided in the air flow line at the entrance of the fuel cell stack. fuel cell system. In claim 8,
A fuel cell system characterized in that the control unit detects that there is a problem with the air shutoff valve if the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor are different from each other after controlling the full opening of the air cutoff valve. . In claim 9,
When an abnormality is detected after controlling the full opening of the air shutoff valve, the control unit gradually rotates the driving motor of the air shutoff valve in the direction of opening and monitors the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor. A fuel cell system characterized in that the full opening of the air shutoff valve is corrected and controlled. In claim 10,
A fuel cell characterized in that the control unit rotates the drive motor in the opening direction and determines that the air shutoff valve is fully opened when the flow rate measured by the first flow sensor is the same as the flow rate measured by the second flow sensor. system. In claim 10,
A fuel cell system characterized in that the control unit reduces the rotational speed of the drive motor and monitors the flow rate measured by the first flow sensor and the flow rate measured by the second flow sensor to correct and control the full opening of the air shutoff valve. A control method for a fuel cell system according to claim 1, comprising:
A step where the control unit controls the complete closing or fully opening of the air shutoff valve;
A step where the control unit detects an abnormality in the air shutoff valve through a change in the measured value of the flow sensor; and
A fuel cell system control method including a step of the control unit correcting the control of the air shutoff valve. In claim 12,
In the step of detecting an abnormality in the air blocking valve when the air blocking valve is completely closed, if the output voltage of the fuel cell stack is detected after controlling the complete closing of the air blocking valve, it is detected that there is an abnormality in the air blocking valve,
When the air shutoff valve is fully opened, the step of detecting an abnormality in the air shutoff valve is that if the flow rate measured by a plurality of flow sensors provided in the air flow line is different after the air shutoff valve is fully opened, there is an abnormality in the air shutoff valve. A fuel cell system control method characterized by sensing. In claim 13,
The step of correcting the control of the air shutoff valve when the air shutoff valve is completely closed involves rotating the drive motor of the air shutoff valve in the direction of closing the air shutoff valve and monitoring the pressure value measured from the flow sensor to ensure that the air shutoff valve is completely closed. A fuel cell system control method characterized by correcting closure control. In claim 13,
The step of correcting the control of the air shutoff valve when the air shutoff valve is fully opened involves rotating the drive motor of the air shutoff valve in the direction of opening the air shutoff valve and the first flow provided at the front of the air compressor provided in the air flow line. A fuel cell system control method characterized by monitoring the flow rate measured by the sensor and the flow rate measured by the second flow sensor provided in the air flow line at the entrance of the fuel cell stack and correcting the full opening control of the air shutoff valve.

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