Fuel supply control device

Abstract

To provide a fuel supply control device capable of early closing a linear solenoid valve at the time of emergency stop.SOLUTION: A fuel supply control device includes pressure acquisition sections (S10, S40, S170), signal output sections (S30, S120), a first determination section (S50), an output stop section (S80), a second determination section (S20) and a duty drop section (S30). The signal output section generates a pulse width modulation signal and outputs the signal to a solenoid valve. The first determination section determines whether or not a pressure value is larger than an abnormality threshold value. When the pressure value is determined to be larger than the abnormality threshold value, the output stop section stops the output of the pulse width modulation signal. The second determination section determines whether or not the pressure value is larger than an abnormality sign threshold value that is smaller than the abnormality threshold value. When the pressure value is determined to be larger than the abnormality sign threshold value, the duty drop section lowers a duty of the pulse width modulation signal, compared to when the pressure value is determined to be equal to or smaller than the abnormality sign threshold value.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a control device for fuel supply to a fuel cell. [Background technology]

[0002] The fuel cell system described in Patent Document 1 includes a solenoid valve, a fuel cell, and a control device. The control device controls the injection time and timing of hydrogen gas into the fuel cell by opening and closing the solenoid valve using a control signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO2008 / 099905 Summary of the Invention [Problem to be solved by the invention]

[0004] When applying a fuel cell system to a commercial vehicle, the system must be durable enough to travel significantly longer distances than when applying a fuel cell system to a general vehicle. However, if an on / off controlled solenoid valve is used in the fuel cell system, the number of times the valve seats increases as the travel distance increases, causing the solenoid valve to deteriorate, resulting in a problem that the required durability cannot be met.

[0005] Therefore, it is conceivable to adopt a linear solenoid valve in a fuel cell system. The number of times the valve of a linear solenoid valve seats is reduced compared to an on / off control solenoid valve, so by adopting a linear solenoid valve, the required durability can be met. However, the inductance value of a linear solenoid valve is larger than that of an on / off control solenoid valve. Therefore, in the event of an emergency stop, even if the drive signal is stopped, the linear solenoid valve takes longer to close than an on / off control solenoid valve.

[0006] The present disclosure provides a fuel supply control device that is capable of closing a linear solenoid valve early during an emergency stop. [Means for solving the problem]

[0007] A fuel supply control device (30) according to the present disclosure is applied to a fuel cell system (100) including a fuel cell (15), a fuel tank (10), a fuel flow path (21) for supplying fuel from the fuel tank to the fuel cell, a linear solenoid valve (31) provided in the fuel flow path and having an opening adjusted in response to a pulse width modulation signal, and a pressure sensor (14) provided in the fuel flow path for detecting a pressure value in the fuel flow path. The fuel supply control device includes a pressure acquisition unit (S10, S40, S170), a signal output unit (S30, S120), a first determination unit (S50), an output stop unit (S80), a second determination unit (S20), and a duty reduction unit (S30). The pressure acquisition unit acquires the pressure value detected by the pressure sensor. The signal output unit generates a pulse width modulation signal and outputs it to the linear solenoid valve. The first determination unit determines whether the pressure value acquired by the pressure acquisition unit is greater than a preset abnormality threshold value. The output stopping unit stops output of the pulse width modulated signal from the signal output unit when the first determination unit determines that the pressure value is greater than the abnormality threshold. The second determination unit determines whether the pressure value acquired by the pressure acquisition unit is greater than an abnormality precursor threshold that is smaller than the abnormality threshold. The duty reducing unit reduces the duty of the pulse width modulated signal generated by the signal output unit when the second determination unit determines that the pressure value is greater than the abnormality precursor threshold compared to when the pressure value is determined to be equal to or less than the abnormality precursor threshold.

[0008] The fuel supply control device of the present disclosure reduces the duty of the PWM signal when the pressure value exceeds the abnormality prediction threshold. Therefore, when the pressure value further increases and exceeds the abnormality threshold, the duty has been reduced in advance, so that the linear solenoid valve can be closed early. In other words, the linear solenoid valve can be closed early during an emergency stop. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing the configuration of a fuel cell system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram illustrating a configuration of a controller according to the present embodiment. [Diagram 3] FIG. 4 is a diagram showing a change in current over time when an on / off controlled solenoid valve is closed. [Figure 4] FIG. 4 is a diagram showing a change in current over time when the linear solenoid valve is closed. [Diagram 5] 4 is a flowchart showing a control process of the injector according to the embodiment. [Figure 6] 4 is a time chart of various parameters during normal operation of the fuel cell system according to the present embodiment. [Figure 7] 4 is a time chart of various parameters when an abnormality occurs in the fuel cell system according to the embodiment. [Figure 8] 4 is a time chart of various parameters during a loop in the fuel cell system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. <1. Configuration> <1-1. Overall composition> 1 shows the configuration of a fuel cell system 100 according to this embodiment. The fuel cell system 100 is applied, for example, to an on-board power generation system of a fuel cell vehicle, and generates power by chemically combining a fuel gas with an oxidizing gas. In this embodiment, hydrogen gas is used as the fuel gas, and oxygen gas is used as the oxidizing gas.

[0011] The fuel cell system 100 comprises a high-pressure hydrogen tank 10, a fuel cell stack (hereinafter referred to as FC stack) 15, a fuel supply passage 21, a drainage passage 22, a linear solenoid valve (hereinafter referred to as LSV) 31, an auxiliary injector 32, a controller 30, and a low-pressure sensor 14.

[0012] The high-pressure hydrogen tank 10 stores high-pressure hydrogen gas. The fuel supply flow path 21 connects the high-pressure hydrogen tank 10 and the FC stack 15, and is a pipe for supplying hydrogen gas from the high-pressure hydrogen tank 10 to the FC stack 15. The high-pressure hydrogen tank 10 corresponds to the fuel tank of this disclosure.

[0013] The FC stack 15 is configured by stacking multiple battery cells. Each battery cell generates electricity by chemically bonding hydrogen gas supplied via a fuel supply passage 21 with oxygen supplied via an air supply passage (not shown). The FC stack 15 corresponds to the fuel cell of the present disclosure.

[0014] The drainage flow path 22 is a pipe that passes through the inside of the FC stack 15 and extends to the outside of the FC stack 15. The drainage flow path 22 discharges water that is produced as electricity is generated in the FC stack 15, together with the air that has passed through the FC stack.

[0015] The LSV 31 is provided in the fuel supply flow path 21 as an injector that injects hydrogen gas supplied from the high-pressure hydrogen tank 10 into the fuel supply flow path 21. The LSV 31 includes a valve seat having an injection hole, a nozzle body that guides hydrogen gas to the injection hole, a valve element housed and held so as to be movable in the axial direction (i.e., the gas flow direction) relative to the nozzle body, and a solenoid coil 31a.

[0016] 2, the LSV 31 is an electromagnetically driven valve that separates the valve disc from the valve seat by electromagnetic force generated by supplying current to the solenoid coil 31a. More specifically, the LSV 31 is a continuously controlled solenoid valve that can adjust the amount of separation between the valve disc and the valve seat (i.e., the valve opening).

[0017] The LSV 31 is driven by a pulse width modulation signal (hereinafter, PWM signal) output from a controller 30 described later, and the opening degree of the valve is adjusted. By adjusting the opening degree of the valve of the LSV 31, the flow rate of hydrogen gas supplied to the FC stack 15 can be adjusted.

[0018] The auxiliary injector 32 is provided in the fuel supply flow path 21 as an injector that injects hydrogen gas supplied from the high-pressure hydrogen tank 10 into the fuel supply flow path 21. The auxiliary injector 32 is provided in the fuel supply flow path 21 parallel to the fuel supply flow path 21 in which the LSV 31 is provided. The auxiliary injector 32 is a solenoid valve equipped with a solenoid coil 32a, and may be an LSV or an on / off controlled solenoid valve. An on / off controlled solenoid valve cannot adjust the valve opening and can only control opening and closing. In this embodiment, the auxiliary injector 32 is an on / off controlled solenoid valve.

[0019] The auxiliary injector 32 is driven by a PWM signal output from the controller 30. The auxiliary injector 32 is an auxiliary injector for the LSV 31. When the amount of hydrogen gas supplied is insufficient by driving only the LSV 31, when the fuel cell system 100 is driven at a low temperature, or when the fuel cell system 100 is started, the controller 30 drives the LSV 31 and also drives the auxiliary injector 32. Furthermore, when an abnormality occurs in the LSV 31, the controller 30 drives the auxiliary injector 32 instead of the LSV 31. Note that the number of auxiliary injectors 32 is not limited to one, but may be two or more.

[0020] The low pressure sensor 14 is provided in the fuel supply passage 21. More specifically, the low pressure sensor 14 is provided in the fuel supply passage 21 downstream of the LSV 31 and the auxiliary injector 32. The low pressure sensor 14 detects a low pressure value P L Detect.

[0021] The controller 30 detects the low pressure value P L The low pressure value P L Based on this, the controller 30 controls the driving of the LSV 31 and the auxiliary injector 32. The details of the controller 30 will be described later. The controller 30 corresponds to the fuel supply control device of the present disclosure.

[0022] <1-2. Controller configuration> Next, the configuration of the controller 30 will be described with reference to Fig. 2. The controller 30 includes a CPU 40, a first high-side switch 36, a differential amplifier circuit 33, a low-pass filter 39, a first low-side switch 38, a second high-side switch 34, a second low-side switch 35, resistors R1 and R2, and diodes D1, D2, D3, and D4. The CPU 40 executes a program stored in a memory (not shown) to realize various functions of a pressure acquisition unit, a signal output unit, a first determination unit, a second determination unit, a duty reduction unit, a count unit, a notification unit, and a drive unit.

[0023] The first high-side switch 36 has a first terminal, a second terminal, and a third terminal. The first high-side switch 36 is, for example, an n-type MOSFET. The first terminal is connected to the CPU 40, and a first high-side drive signal is input from the CPU 40. The second terminal is connected to a power source. The third terminal is connected to a first end of the solenoid coil 31a of the LSV 31. The resistor R1 is connected between the second terminal and the third terminal.

[0024] The first low-side switch 38 is an n-type MOSFET. The gate of the first low-side switch 38 is connected to the CPU 40 via a resistor R4, and a first low-side drive signal is input from the CPU 40. The drain of the first low-side switch 38 is connected to the second end of the solenoid coil 31a via a resistor R2. The source of the first low-side switch 38 is grounded.

[0025] The diode D1 is connected between the drain of the first low-side switch 38 and the first output terminal of the first high-side switch 36. The diode D1 is connected such that the anode is on the drain side of the first low-side switch 38, and returns current from the low-side side to the high-side side.

[0026] The diode D2 is connected between the source of the first low-side switch 38 and the second output terminal of the first high-side switch 36. The diode D2 is connected such that the anode is on the source side of the first low-side switch 38, and returns current from the low-side side to the high-side side.

[0027] The differential amplifier circuit 33 is connected to both ends of the resistor R2 and detects the current flowing through the resistor R2. That is, the differential amplifier circuit 33 detects the LSV current flowing through the solenoid coil 31a. The differential amplifier circuit 33 is provided because it is desirable to use a highly accurate current value for controlling the LSV 31, which is the main injector.

[0028] The low-pass filter 39 includes a resistor R3 and a capacitor C1, and is connected between the differential amplifier circuit 33 and the CPU 40. The low-pass filter 39 removes high-frequency components from the current detection value output from the differential amplifier circuit 33, and outputs the result to the CPU 40.

[0029] The CPU 40 outputs a first high-side drive signal to the first high-side switch 36. The high-side drive signal is a pulse signal. When the first high-side drive signal is output (i.e., when the first high-side drive signal is high), the first high-side switch 36 is turned on, and when the first high-side drive signal is not output (i.e., when the first high-side drive signal is low), the first high-side switch 36 is turned off.

[0030] The CPU 40 outputs a first low-side drive signal to the first low-side switch 38. The low-side drive signal is a first pulse width modulation signal (hereinafter, PWM signal). When the first PWM signal is high, the first low-side switch 38 is on, and when the first PWM signal is low, the first low-side switch 38 is off. When the first high-side switch 36 is on and the first low-side switch 38 is on, an LSV current flows through the solenoid coil 31a. As a result, an electromagnetic force is generated, and the valve of the LSV 31 opens.

[0031] The CPU 40 detects the low pressure value P L Based on this time series, the FC stack 15 calculates the amount of hydrogen gas required, and controls the opening of the LSV 31 so that the calculated amount of hydrogen gas is supplied to the FC stack 15. The CPU 40 adjusts the duty of the first PWM signal based on the LSV current value to control the electromagnetic force generated in the LSV, thereby controlling the opening of the LSV 31. When the LSV 31 alone cannot supply the required amount of hydrogen gas, the CPU 40 opens the auxiliary injector 32 to cause hydrogen gas to be supplied from the auxiliary injector 32 as well.

[0032] Here, the LSV 31 has a larger inductance value than an on / off controlled solenoid valve, so that even if the output of the first high side drive signal and the first low side drive signal is stopped, the LSV current does not immediately become 0, and it takes time for the LSV current to be cut off after the output of the first high side drive signal and the second low side drive signal is stopped.

[0033] FIG. 3 shows the time T1 required to cut off the current in an on / off controlled solenoid valve, and FIG. 4 shows the time T2 required to cut off the current in a linear solenoid valve. Time T2 is much longer than time T1. Therefore, in the LSV 31, even if the output of the first high side drive signal and the first low side drive signal is stopped, it takes time to close the valve. However, when an abnormality occurs in the fuel cell system 100, it is necessary to close the LSV 31 early. Therefore, in the control process of the injector according to this embodiment, when the CPU 40 detects a sign of an abnormality, it reduces the duty of the first PWM signal. As a result, when an abnormality actually occurs, the LSV 31 can be closed early. The details of the control process of the injector according to this embodiment will be described later.

[0034] The second high-side switch 34 has a first terminal, a second terminal, and a third terminal. The second high-side switch 34 is, for example, an n-type MOSFET. The first terminal is connected to the CPU 40, and a second high-side drive signal is input from the CPU 40. The second terminal is connected to a power source. The third terminal is connected to a first end of the solenoid coil 32a of the auxiliary injector 32. The second high-side switch 34 also detects the current flowing through the solenoid coil 32a and outputs it to the CPU 40.

[0035] The second low-side switch 35 has a first terminal, a second terminal, and a third terminal. The second low-side switch 35 is, for example, an n-type MOSFET. The first terminal is connected to the CPU 40, and a second low-side drive signal is input from the CPU 40. The second terminal is connected to the second end of the solenoid coil 32a. The third terminal is grounded.

[0036] The diode D3 is connected between the second terminal of the second low-side switch 35 and the second terminal of the second high-side switch 34. The diode D3 is connected such that the anode is on the second terminal side of the second low-side switch 35, and returns current from the low-side side to the high-side side.

[0037] The diode D4 is connected between the third terminal of the second low-side switch 35 and the third terminal of the second high-side switch 34. The diode D3 is connected such that the anode is on the third terminal side of the second low-side switch 35, and returns current from the low-side side to the high-side side.

[0038] The CPU 40 outputs a second high-side drive signal to the second high-side switch 34, and outputs a second low-side drive signal to the second low-side switch 35. The second high-side drive signal is a pulse signal, and the second low-side drive signal is a second PWM signal. When the second high-side drive signal is output, the second high-side switch 34 is turned on, and when the second high-side drive signal is not output, the second high-side switch 34 is turned off. Furthermore, when the second PWM signal is high, the second low-side switch 35 is turned on, and when the second PWM signal is low, the second low-side switch 35 is turned off.

[0039] When the second high-side switch 34 is on and the second low-side switch 35 is on, a current flows through the solenoid coil 32a to open the valve of the auxiliary injector 32. The CPU 40 adjusts the duty of the second PWM signal to control the current flowing through the solenoid coil 32a to be constant.

[0040] <2. Processing> Next, the injector control process executed by the CPU 40 will be described with reference to the flowchart of Fig. 5. The CPU 40 receives a drive command from the FC stack 15 and starts the injector control process.

[0041] In S10, the low pressure value P detected by the low pressure sensor 14 is L Get the. Next, in S20, the low pressure value P obtained in S10 is L is the abnormality prediction threshold P LF It is determined whether the abnormality prediction threshold P LF is preset and stored in the controller 30. LF is the threshold for detecting signs before an abnormality occurs, and the abnormality threshold P LH The abnormal threshold P LH is a threshold value for detecting the occurrence of an abnormality, and is preset and stored in the controller 30. In S20, the low pressure value P L is the abnormality prediction threshold P LFIf it is determined that the difference is greater than 1, the process proceeds to S30.

[0042] In S30, the duty of the first PWM signal output to the LSV 31 is reduced. In detail, the target pressure value is calculated from the amount of hydrogen gas required by the FC stack 15, and the target pressure value and the low pressure value P L The reference value of the duty is calculated according to the difference between the low pressure value P L and abnormality prediction threshold P LF The amount of decrease corresponding to the difference between the low pressure value P L and abnormality prediction threshold P LF The larger the difference between the low pressure and the low pressure value P L is the abnormality prediction threshold P LF The duty is calculated by greatly reducing the duty from the duty when it is equal to or less than 0.05 V. Then, the first PWM signal in which the calculated duty is set is output to the first low-side switch .

[0043] Next, in S40, the low pressure value P detected by the low pressure sensor 14 is L Get the. Next, in S50, the low pressure value P obtained in S40 is L is the abnormal threshold P LH In S50, it is determined whether the low pressure value P L is the abnormal threshold P LH If it is determined that the number is equal to or less than the predetermined number, the process proceeds to S60.

[0044] In S60, the loop counter Rc is incremented by 1. The loop counter Rc is incremented by 1 when the low pressure value P L is the abnormality prediction threshold P LF A pressure value P that is greater than or equal to the lower pressure L is the abnormal threshold P LH The loop counter Rc counts the number of consecutive processes that determine that the low pressure value P L is the abnormality prediction threshold P LF A pressure value P that is greater than or equal to the lower pressure L is the abnormal threshold P LHThe number of determination loops in which the determination that the value is equal to or less than the threshold is repeated is counted.

[0045] Low pressure value P L is the abnormality prediction threshold P LF A pressure value P that is greater than or equal to the lower pressure L is the abnormal threshold P LH If it is determined that the duty of the first PWM signal is equal to or less than this, the duty of the first PWM signal is reduced, but the driving of the LSV 31 is not stopped. However, if the above determination loop continues, it is possible that some abnormality has occurred in the LSV 31, so it is desirable to stop the LSV 31. Therefore, the number of determination loops is counted.

[0046] Next, in S70, it is determined whether the loop counter Rc is greater than a set value Rcn. The set value Rcn is a fixed value that is set in advance and stored in the controller 30. The set value Rcn is, for example, 5. If it is determined in S70 that the loop counter Rc is equal to or less than the set value Rcn, the process returns to S10.

[0047] In addition, in S50, the low pressure value P obtained in S40 L is the abnormal threshold P LH If it is determined that the difference is greater than 1, the process proceeds to S80. In S80, the output of the first high side drive signal and the first PWM signal is stopped to urgently stop the LSV 31. At this time, since the duty of the first PWM signal has already decreased below the reference value, the LSV 31 can be closed early.

[0048] Next, in S90, since the determination loop has ended, the loop counter Rc is reset to 0 and this process ends. In addition, in S20, the low pressure value P L is the abnormality prediction threshold P LF If it is determined that the number is equal to or less than the predetermined number, the process proceeds to S100.

[0049] In S100, since the determination loop has ended, the loop counter Rc is reset to 0. Next, in S110, it is determined whether the duty of the first PWM signal has been reduced from the reference value. If it is determined that the duty has been reduced from the reference value, the process proceeds to S120. If it is determined that the duty has not been reduced from the reference value, the process skips S120 and proceeds to S130.

[0050] In S120, the duty of the first PWM signal to be output to the LSV 31 is returned to the reference value. In S130, it is determined whether or not a normal off command has been received from the FC stack 15. When the supply of hydrogen gas is not required, the FC stack 15 outputs a normal off command to the controller 30. If it is determined that a normal off command has been received, the operation of the LSV 31 is stopped and this process ends. If it is determined that a normal off command has not been received, the process returns to S10.

[0051] If it is determined in S70 that the loop counter Rc is greater than the set value Rcn, the process proceeds to S140. In S140, the abnormality is notified to the user by sound, light, display, etc. In detail, a warning sound is output from a speaker in the vehicle, or a voice notifying the abnormality is output, or an indicator in the vehicle is turned on or flashes, or text or a figure notifying the abnormality is displayed on a display in the vehicle.

[0052] Next, in S150, the driving of the LSV 31 is stopped. Next, in S160, the second high side drive signal and the second low side drive signal are output to the auxiliary injector 32 to drive the auxiliary injector 32. At this time, the low pressure value P L is the abnormal threshold P LH Since the above condition is met, the supply of hydrogen gas will continue even if the LSV31 is stopped.

[0053] Next, in S170, the low pressure value P detected by the low pressure sensor 14 is L Get the. Next, in S180, the low pressure value P obtained in S170 is L is the abnormal threshold PLH In step S180, it is determined whether the low pressure value P L is the abnormal threshold P LH If it is determined that the number is equal to or less than the predetermined number, the process proceeds to S190.

[0054] In S190, it is determined whether or not there is a normal off command from the FC stack 15. If it is determined that there is a normal off command, the process proceeds to S210, and if it is determined that there is no normal off command, the process returns to S170.

[0055] In S200, the output of the second high side drive signal and the second PWM signal is stopped to bring the auxiliary injector 32 to an emergency stop. At this time, since the auxiliary injector 32 is an on / off controlled solenoid valve, it can be closed early even if the duty of the second PWM signal has not been reduced in advance. If the auxiliary injector 32 is an LSV, the low pressure value P L is the abnormality prediction threshold P LF When the duty of the second PWM signal exceeds this limit, the duty of the second PWM signal is reduced.

[0056] Next, in S210, since the determination loop has been ended and the auxiliary injector 32 has been driven, the loop counter Rc is reset to 0 and this process ends.

[0057] <3.Operation> 6 shows an example of a timing chart when the fuel cell system 100 is normal. At time t1, in response to a request for hydrogen gas from the FC stack 15, a command to drive the LSV is issued, and in response to the command to drive the LSV, a first high side drive signal and a first low side drive signal are output to the LSV 31. As a result, the LSV 31 opens, hydrogen gas is supplied to the fuel supply flow path 21, and the LSV current value and low pressure value P L begins to increase.

[0058] And the low pressure value P L is the abnormality prediction threshold P LFAt time t2, without exceeding , the LSV drive command is turned off in response to a normal off command from the FC stack 15, and the output of the first high side drive signal and the first low side drive signal is stopped. Accordingly, the LSV current value starts to decrease from time t2, and when a time T2 has elapsed from time t2, the LSV current is shut off (i.e., becomes 0).

[0059] In this example, the low pressure value P L is the abnormality prediction threshold P LF Since the duty of the first low side drive signal does not exceed , the duty of the first low side drive signal does not decrease. Therefore, when a normal off command is received, the LSV31 does not close early, and it takes time T2 from when the output of the first high side drive signal and the first low side drive signal is stopped until the valve closes. However, since the valve closes when a normal off command is received, and not when an abnormality occurs, no problem occurs even if the time required to close the valve is longer.

[0060] 7 shows an example of a time chart when an abnormality occurs in the fuel cell system 100. At time t11, in response to a command to drive the LSV, the first high side drive signal and the second high side drive signal are output to the LSV 31, and the LSV current value and the low pressure value P L begins to increase.

[0061] At time t12, the low pressure value P L is the abnormality prediction threshold P LF , and the duty of the first low side drive signal decreases. Accordingly, the LSV current value gradually decreases. In addition, the low pressure value P L The rate of increase in the low pressure value P L continues to increase.

[0062] At time t13, the low pressure value P L is the abnormal threshold P LHand an abnormality in the low pressure is detected. As a result, the LSV drive command is turned off earlier than the timing of the normal off command. Accordingly, the output of the first high side drive signal and the first low side drive signal is stopped, the LSV current value starts to decrease further from time t13, and is cut off when the time T3 has elapsed from time t3.

[0063] In this example, the duty of the first low side drive signal is reduced from time t12, so the LSV 31 closes in a time T3 that is shorter than the time T2 required to close the valve when a normal off command is received. In other words, when an abnormality occurs, the LSV 31 closes early, and the supply of hydrogen gas stops.

[0064] 8 shows an example of a time chart when the judgment loop continues in the fuel cell system 100. At time t21, in response to a command to drive the LSV, the first high side drive signal and the second high side drive signal are output to the LSV 31, and the LSV current value and the low pressure value P L begins to increase.

[0065] At time t22, the low pressure value P L is the abnormality prediction threshold P LF , and the duty of the first low side drive signal decreases. Accordingly, the LSV current value gradually decreases. In addition, the low pressure value P L The rate of increase in the low pressure value P L continues to increase.

[0066] At time t23, the low pressure value P L starts to decrease. This is because the amount of hydrogen gas consumed by the FC stack 15 becomes greater than the amount of hydrogen gas supplied by the LSV 31. Therefore, the duty of the first low side drive signal starts to increase. However, the low pressure value P L is the abnormality prediction threshold P LF Since the duty of the first low-side drive signal is greater than the low-side pressure value P L is the abnormality prediction threshold P LF The duty is smaller than that when:

[0067] In addition, the low pressure value P L is the abnormality prediction threshold P LF and the abnormal threshold P LH The loop counter Rc continues to increment because it remains between Then, at time t24, the low pressure value P L starts to increase. Accordingly, the duty of the first low side drive signal starts to decrease.

[0068] At time t25, the low pressure value P L is the abnormal threshold P LH The loop counter Rc reaches a set value Rcn before the LSV current value exceeds t25. As a result, the LSV drive command is turned off. Accordingly, the output of the first high side drive signal and the first low side drive signal is stopped, and the LSV current value starts to decrease further from time t25.

[0069] In this case, the low pressure value P L is the abnormal threshold P LH Since the low pressure is equal to or lower than t26, the abnormality in the low pressure is not detected. Therefore, the auxiliary injector 32 starts to be driven instead of the LSV 31. As a result, at time t26, the value of the current flowing through the auxiliary injector 32 starts to increase.

[0070] <4. Effects> According to the first embodiment described above in detail, the following effects are achieved. (1) The controller 30 detects the low pressure value P L is the abnormality prediction threshold P LF If the low pressure value P L increases further and the abnormal threshold P LH In other words, the LSV 31 can be closed early during an emergency stop.

[0071] (2) A low pressure value P due to momentary electrical noise L is the abnormality prediction threshold P LFThe low pressure value P L is the abnormality prediction threshold P LF and the abnormal threshold P LH By counting the number of consecutive times that the pressure is judged to be equal to or lower than the low pressure value P L It can be determined whether the rise in the low pressure value P is due to momentary electrical noise. L When the increase in is caused by momentary electrical noise, it is possible to avoid executing unnecessary control.

[0072] (3) Low pressure value P L is the abnormality prediction threshold P LF Even if it exceeds the abnormal threshold P LH If the low pressure value P L is the abnormality prediction threshold P LF and the abnormal threshold P LH If it is repeatedly determined that the difference is equal to or less than this, there is a possibility that some abnormality has occurred in the LSV 31. In such a case, the LSV 31 can be closed to protect the fuel cell system 100.

[0073] (4) Low pressure value P L is the abnormality prediction threshold P LF and the abnormal threshold P LH If it is repeatedly determined that the above condition is met, the user is notified of the occurrence of an abnormality. This allows the user to recognize that some abnormality has occurred in the LSV 31. As a result, the user can ensure his or her own safety.

[0074] (5) When the loop counter Rc reaches the set value Rcn and the LSV 31 is closed, the auxiliary injector 32 is driven to supply hydrogen gas to the FC stack 15. In other words, fuel supply to the vehicle can be continued.

[0075] (6) Low pressure value P L is the abnormality prediction threshold P LF Exceeds the abnormal threshold P LHThe duty of the first PWM signal is set smaller as the low pressure value P L is the abnormal threshold P LH When this value is exceeded, the LSV31 can be closed immediately.

[0076] (Other embodiments) Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0077] (a) In the above embodiment, the fuel is hydrogen gas, but the fuel is not limited to hydrogen gas. The fuel may be a gas other than hydrogen gas. In addition, the oxidizing gas may be a gas other than oxygen. (b) The controller 30 and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the controller 30 and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the controller 30 and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. The method for realizing the functions of each unit included in the controller 30 does not necessarily need to include software, and all of the functions may be realized using one or more hardware.

[0078] (c) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0079] (d) In addition to the fuel supply control device described above, the present disclosure can be realized in various forms, such as a system that includes the fuel supply control device as a component, a program for causing a computer to function as the fuel supply control device, a non-transient physical recording medium such as a semiconductor memory on which the program is recorded, and a fuel supply control method. [Explanation of symbols]

[0080] 10...high-pressure hydrogen tank, 14...low-pressure pressure sensor, 15...FC stack, 21...fuel supply passage, 30...controller, 31...LSV, 31a, 32a...solenoid coil, 32...auxiliary injector.

Claims

1. A fuel supply control device (30) applied to a fuel cell system (100) including a fuel cell (15), a fuel tank (10), a fuel flow path (21) for supplying fuel from the fuel tank to the fuel cell, a linear solenoid valve (31) provided in the fuel flow path and having an opening adjusted in response to a pulse width modulation signal, and a pressure sensor (14) provided in the fuel flow path and detecting a pressure value within the fuel flow path, a pressure acquisition unit (S10, S40, S170) that acquires the pressure value detected by the pressure sensor; A signal output unit (S30, S120) that generates the pulse width modulation signal and outputs it to the linear solenoid valve; a first determination unit (S50) that determines whether the pressure value acquired by the pressure acquisition unit is greater than a preset abnormality threshold value; an output stopping unit (S80) that stops output of the pulse width modulation signal from the signal output unit when the first determination unit determines that the pressure value is greater than the abnormality threshold value; a second determination unit (S20) that determines whether the pressure value acquired by the pressure acquisition unit is greater than an abnormality prediction threshold that is smaller than the abnormality threshold; a duty reducing unit (S30) that, when the second determination unit determines that the pressure value is greater than the abnormality sign threshold, reduces the duty of the pulse width modulation signal generated by the signal output unit to a value lower than that when the pressure value is determined to be equal to or less than the abnormality sign threshold. Fuel supply control device.

2. the first determination unit determines whether the pressure value is greater than the abnormality threshold value when the second determination unit determines that the pressure value is greater than the abnormality threshold value; the second determination unit determines whether the pressure value is greater than the abnormality prediction threshold when the first determination unit determines that the pressure value is equal to or less than the abnormality threshold; a counting unit (S60) that counts the number of consecutive times that the first determination unit determines that the pressure value is greater than the abnormality prediction threshold and the second determination unit determines that the pressure value is equal to or less than the abnormality threshold, The fuel supply control device according to claim 1.

3. The output stopping unit (S150) further stops the output of the pulse width modulation signal from the signal output unit in response to the continuous number of times counted by the counting unit exceeding a set number of times. The fuel supply control device according to claim 2.

4. The method further includes a notification unit (S140) that notifies the occurrence of an abnormality when the consecutive number of times counted by the count unit exceeds a set number of times.

4. The fuel supply control device according to claim 2 or 3.

5. The fuel cell system further includes an auxiliary injector (32) provided in the fuel flow path, a drive unit (S160) that drives the auxiliary injector when the output stop unit stops the output of the pulse width modulation signal in response to the number of consecutive occurrences exceeding the predetermined number of times.

4. The fuel supply control device according to claim 3.

6. the duty reducing unit reduces the duty of the pulse width modulation signal by a larger amount as a difference between the pressure value acquired by the pressure acquiring unit and the abnormality sign threshold becomes larger. The fuel supply control device according to any one of claims 1 to 5.

Images