Method of parameter fitting

Abstract

To reduce man-hours for tuning a control parameter in a fuel cell system.SOLUTION: A parameter fitting method of the fuel cell system includes a step of executing an iterative method using flow rate-pressure characteristic data indicating a pressure in the air supply flow path according to a flow rate of air into the air supply flow path for each of combinations of the opening and closing states of the first valve and the second valve, excluding a combination in which both the first valve and the second valve are in the closed state, for fitting of a control parameter related to piping, and a step of outputting the calculated control parameter when a repetition end condition related to the iterative method is satisfied.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for parameter fitting. [Background technology]

[0002] Patent Document 1 discloses a technique relating to the connection of air piping for supplying gas to a fuel cell stack in a fuel cell unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-116750 Summary of the Invention [Problem to be solved by the invention]

[0004] The basic configuration of the air piping of a fuel cell system may change depending on the application in which the fuel cell system is installed. In such cases, it is necessary to newly tune the gas flow rate and pressure adjustments to match the changed air piping configuration. For this reason, a technology that can reduce the amount of tuning work required has been desired. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided a method for parameter fitting of a fuel cell system, the fuel cell system including: a fuel cell; an air supply channel connected to the fuel cell for supplying air to the fuel cell; a bypass channel connected to the air supply channel for discharging air in the air supply channel to the outside of the fuel cell system without passing through the fuel cell; an air discharge channel connected to the fuel cell for discharging air from the fuel cell; a first valve provided at a first connection portion that connects the air supply channel and the bypass channel for opening and closing the bypass channel; a second valve provided at a second connection portion that connects the fuel cell and the air discharge channel for opening and closing the air discharge channel; a pressure sensor provided at the first connection portion that measures the pressure of air flowing into the air supply channel; and a confluence discharge channel that merges the bypass channel and the air discharge channel to discharge air discharged from the bypass channel and air discharged from the air discharge channel. The parameter fitting method includes the steps of: executing an iterative method using flow-pressure characteristic data indicating the pressure in the air supply flow path according to the flow rate of air into the air supply flow path for each combination of the open / closed states of the first valve and the second valve, excluding combinations in which both the first valve and the second valve are closed, in order to fit control parameters related to piping; and outputting the calculated control parameters when an iteration termination condition for the iterative method is satisfied. According to the above aspect, it is possible to perform fitting of control parameters relating to piping by executing an iterative method using flow rate-pressure characteristic data, thereby reducing the number of steps required for retuning. (2) In the parameter fitting method of the above aspect, the control parameters include a parameter related to pressure loss in the bypass flow path, a parameter related to pressure loss in the exhaust flow path, and a parameter related to pressure loss in the confluent exhaust flow path. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a fuel cell system. [Figure 2] 10 is a flowchart showing a tuning method for adjusting gas flow rates and pressures. [Figure 3] FIG. 4 is an explanatory diagram showing an example of measured values ​​obtained by an air flow meter and a pressure sensor. [Figure 4] FIG. 10 is an explanatory diagram showing a graph of the air pressure on the outlet side of the intercooler estimated using the control parameter k2 adjusted by the iterative process. [Figure 5] FIG. 10 is an explanatory diagram showing a graph of the air pressure on the outlet side of the intercooler estimated using the control parameter k3 adjusted by the iterative process. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. Embodiment 1 is a diagram showing a schematic configuration of a fuel cell system 10. The fuel cell system 10 is mounted on, for example, an electric vehicle and used as a power source for driving the electric vehicle, a power source for various devices, etc. The fuel cell system 10 includes a fuel cell stack 100, an anode gas supply system 200, a cathode gas supply system 300, an air flow meter 410, a pressure sensor 420, and an ECU (Electronic Control Unit) 500.

[0009] The fuel cell stack 100 generates electricity through a fuel cell reaction using a fuel gas and an oxidant gas. Hydrogen is used as the fuel gas, and a gas containing oxygen (air) is used as the oxidant gas. The fuel gas is also called an anode gas. The oxidant gas is also called a cathode gas. The anode gas supply system 200 supplies the fuel gas to the fuel cell stack 100.

[0010] The cathode gas supply system 300 supplies oxidant gas taken in from the outside to the fuel cell stack 100. The cathode gas supply system 300 includes a supply pipe 310, an air compressor 320, an intercooler 330, an exhaust pipe 340, an outlet pipe 350, a bypass pipe 360, a flow dividing valve 370, and a pressure adjusting valve 380.

[0011] The supply pipe 310 is a flow path for supplying air to the fuel cell stack 100. The supply pipe 310 constitutes an "air supply flow path." The supply pipe 310 includes an upstream pipe 311, a downstream pipe 312, and an inlet pipe 313. Air is taken in from the inlet end of the upstream pipe 311. An air compressor 320 is provided between the upstream pipe 311 and the downstream pipe 312. An intercooler 330 is provided between the downstream pipe 312 and the inlet pipe 313. The outlet end of the inlet pipe 313 is connected to the fuel cell stack 100.

[0012] Air compressor 320 compresses air taken in from the outside under the control of ECU (Electronic Control Unit) 500 installed in the electric vehicle, and sends out the compressed air. The compressed air is sent to intercooler 330. Intercooler 330 cools the air compressed by air compressor 320. The cooled air is sent to fuel cell stack 100.

[0013] The inlet end of the outlet pipe 350 is connected to the fuel cell stack 100 via a pressure adjustment valve 380. The outlet pipe 350 constitutes an "air discharge flow path" for discharging air from within the fuel cell stack 100.

[0014] The bypass pipe 360 ​​is connected to the downstream pipe 312 via the intercooler 330. The bypass pipe 360 ​​constitutes a "bypass flow path" that discharges the air in the supply pipe 310 to the outside of the fuel cell system 10 without passing through the fuel cell stack 100.

[0015] An outlet end of the bypass pipe 360 ​​and an outlet end of the outlet pipe 350 are connected to an inlet end of the exhaust pipe 340. The exhaust pipe 340 forms a "junction exhaust flow path" for discharging the air discharged from the bypass pipe 360 ​​and the air discharged from the outlet pipe 350.

[0016] The flow diverter valve 370 is a valve provided at the connection (first connection) between the supply pipe 310 and the bypass pipe 360. The flow diverter valve 370 is used to open and close the bypass pipe 360. When the flow diverter valve 370 is open, air flows from the downstream pipe 312 into the bypass pipe 360. When the flow diverter valve 370 is closed, air does not flow from the downstream pipe 312 into the bypass pipe 360. The flow diverter valve 370 is also called the "first valve."

[0017] The pressure regulating valve 380 is a valve provided at the connection (second connection) between the fuel cell stack 100 and the outlet pipe 350. The pressure regulating valve 380 is used to open and close the outlet pipe 350. When the pressure regulating valve 380 is open, air inside the fuel cell stack 100 flows into the outlet pipe 350. When the pressure regulating valve 380 is closed, air does not flow from the fuel cell stack 100 into the outlet pipe 350. The pressure regulating valve 380 is also called the "second valve."

[0018] Air flow meter 410 is disposed near the end of the inlet side of upstream pipe 311. Air flow meter 410 measures the intake amount of air that has flowed into supply pipe 310. Pressure sensor 420 is disposed at the outlet of intercooler 330 on the inlet pipe 313 side. Pressure sensor 420 measures the pressure inside the flow path at the outlet of intercooler 330 on the inlet pipe 313 side.

[0019] The ECU 500 executes tuning processing for adjusting the gas flow rate and pressure, which will be described later. If the vehicle in which the fuel cell system 10 is to be installed is changed from the originally intended model of electric vehicle to another model of electric vehicle, the configuration of the piping constituting the flow path of the cathode gas supply system 300 may be changed from the configuration for the original model of electric vehicle. In this case, new tuning is required to adjust the gas flow rate and pressure to match the changed piping configuration. The targets of tuning are the control parameter k1 of the exhaust piping 340, the control parameter k2 of the outlet piping 350, and the control parameter k3 of the bypass piping 360. In the configuration shown in FIG. 1, the fuel cell system 10 has only one pressure sensor 420. It is not possible to measure the pressures inside the exhaust piping 340, the outlet piping 350, and the bypass piping 360. Therefore, the air flow rate and the pre-adjusted control parameter k1 are used to calculate the pressure loss in the exhaust piping 340. The air flow rate and the pre-adjusted control parameter k2 are used to calculate the pressure loss in the outlet piping 350. When calculating the pressure loss of the bypass piping 360, the air flow rate and a control parameter k3 that has been adjusted in advance are used. Therefore, it is necessary to tune the control parameters k1 to k3 to match the changed piping configuration. The control parameters are pressure loss coefficients. Note that the control parameters k1 to k3 are scalar quantities.

[0020] 2 is a flowchart showing a tuning method for adjusting the gas flow rate and pressure in this embodiment. The process shown in FIG.

[0021] In step S101, flow rate-pressure characteristic data indicating the pressure inside the supply pipe 310 is acquired for each pattern of flow path configurations assumed by opening and closing the valves. Hereinafter, opening the flow diversion valve 370 or the pressure regulation valve 380 refers to fully opening the valve. Closing the flow diversion valve 370 or the pressure regulation valve 380 shown in FIG. 1 refers to fully closing the valve. The assumed flow path configurations based on the combination of opening and closing the flow diversion valve 370 and the pressure regulation valve 380 are as follows. Note that, since it is assumed that the fuel cell system 10 is operating, a state in which both the flow diversion valve 370 and the pressure regulation valve 380 are closed is not included. (1) Only the fuel cell stack 100 side is open (2) Open only the bypass side (3) Open everything

[0022] In the case of (1) where only the fuel cell stack 100 side is opened, the flow dividing valve 370 is closed and the pressure adjusting valve 380 is open. In this case, the air flows through the upstream pipe 311, downstream pipe 312, inlet pipe 313, fuel cell stack 100, outlet pipe 350, and exhaust pipe 340 in this order.

[0023] When only the bypass side is opened (2), the flow dividing valve 370 is opened and the pressure adjusting valve 380 is closed. In this case, the air flows through the upstream pipe 311, downstream pipe 312, bypass pipe 360, and exhaust pipe 340 in this order.

[0024] When all of (3) are opened, the flow dividing valve 370 is opened and the pressure adjusting valve 380 is opened. In this case, the air flows through the upstream pipe 311, downstream pipe 312, inlet pipe 313, fuel cell stack 100, outlet pipe 350, and exhaust pipe 340 in this order. Furthermore, the air flows through the upstream pipe 311, downstream pipe 312, bypass pipe 360, and exhaust pipe 340 in this order.

[0025] As shown in FIG. 2, in step S101, the open / close states of the flow dividing valve 370 and the pressure adjusting valve 380 are switched to acquire flow rate / pressure characteristic data for each of the above states (1) to (3).

[0026] The flow rate-pressure characteristic data is composed of measurements by the air flow meter 410 and the pressure sensor 420. Specifically, the air compressor 320 is operated, and the rotation speed of the motor of the air compressor 320 is increased stepwise at regular intervals. When the rotation speed of the motor reaches a certain value, the air compressor 320 is stopped. During the period from when the air compressor 320 starts to when it stops, the measurement values ​​by the air flow meter 410 and the pressure sensor 420 are acquired. The operation period of the air compressor 320 when acquiring the flow rate-pressure characteristic data for each of the states (1) to (3) is the same. FIG. 3 is an explanatory diagram showing an example of the measurement values ​​by the air flow meter 410 and the pressure sensor 420. In FIG. 3, the upper row shows the measurement values ​​by the air flow meter 410, and the lower row shows the measurement values ​​by the pressure sensor 420. In step S101, a process is executed to acquire the measurement values ​​of the air flow meter 410 and the pressure sensor 420 for each of the above states (1) to (3). Hereinafter, the flow rate-pressure characteristic data in state (1) will be referred to as first flow rate-pressure characteristic data D1. The flow rate-pressure characteristic data in state (2) will be referred to as second flow rate-pressure characteristic data D2. The flow rate-pressure characteristic data in state (3) will be referred to as third flow rate-pressure characteristic data D3.

[0027] In step S102, a search range is set for a control parameter k1 of the exhaust pipe 340. For example, k1={0.1, 0.2, ..., 0.9, 1, 2, 3, ..., 20} is set as the search range for k1. The search range for the control parameter k1 is determined, for example, based on the perspective of how many times the pressure loss in the changed pipe configuration is likely to be compared to the pressure loss in the old pipe configuration.

[0028] In step S103, an arbitrary value within the search range is set as the control parameter k1, for example, the first value 0.1 within the search range is set as k1.

[0029] In step S104, the first flow rate / pressure characteristic data D1 is used to perform parameter fitting of a control parameter k2 of the outlet pipe 350. For example, the initial value of the control parameter k2 is set to k2=1.

[0030] [Process 11] Using the actual measured value of the flow rate of the air compressor 320, control parameters k1 and k2 as inputs, the pressure of the air on the outlet side of the intercooler 330 is estimated by a preset mathematical formula (M1). Q(t) is a measurement value by the air flow meter 410 in the first flow rate-pressure characteristic data D1, and represents the actual measured value of the flow rate of the air compressor 320. P ICet (t) is an estimated value of the pressure of the air on the outlet side of the intercooler 330 at time t. Time t represents the elapsed time from the start of operation of the air compressor 320. fa1(Q(t), k1, k2) is a function for calculating an estimated value of the pressure of the air on the outlet side of the intercooler 330. This process is performed for all measurement values ​​during the measurement period of the first flow-pressure characteristic data D1. P ICet (t)=fa1(Q(t),k1,k2) (M1)

[0031] [Process 12] The pressure loss in the outlet pipe 350 is estimated by a preset formula (M2) using the actual measured value Q(t) of the flow rate of the air compressor 320 and the control parameter k2. 2et (t) is the estimated value of the pressure loss in the outlet pipe 350 at time t. fb(Q(t)) is a function for calculating the estimated value of the pressure loss. This process is performed for all the measured values ​​during the measurement period of the first flow rate pressure characteristic data D1. As a result, ΔP 2et (t) is obtained. ΔP 2et(t)=k2×fb(Q(t)) (M2)

[0032] [Process 13] Estimated pressure loss ΔP in the outlet pipe 350 2et (t) average value ΔP 2et_ave is calculated.

[0033] [Process 14] As shown in formula (M3), the actual measured value P of the air pressure on the outlet side of the intercooler 330 IC (t) and the estimated value P of the air pressure on the outlet side of the intercooler 330 ICet The difference between (t) and (t) is the error P ICerr The actual measured value P of the air pressure on the outlet side of the intercooler 330 is calculated as (t). IC (t) is the measurement value of the first flow rate / pressure characteristic data D1 measured by the pressure sensor 420. This process is executed for all measurement values ​​during the measurement period of the first flow rate / pressure characteristic data D1. P ICerr (t)=P IC (t)-P ICet (t) (M3)

[0034] [Process 15] Estimated value P of the air pressure on the outlet side of the intercooler 330 ICet Error P of (t) ICerr (t) average value P ICerr_ave When the estimated pressure loss in the outlet pipe 350 is smaller than the actual pressure loss in the outlet pipe 350, the average value P ICerr_ave takes a positive value. When the estimated pressure loss in the outlet pipe 350 is larger than the actual pressure loss in the outlet pipe 350, the average value P ICerr_ave takes a negative value.

[0035] [Process 16] In order to reduce the error, the control parameter k2 is updated using the formula (M4). In this way, in step S104, the control parameter k2 is adjusted while the value of the control parameter k1 is kept fixed. The average value P ICerr_aveWhen the average value P is a positive value, the value of the control parameter k2 after updating becomes larger than the value of the control parameter k2 before updating. ICerr_ave When k2 is a negative value, the value of the control parameter k2 after updating is smaller than the value of the control parameter k2 before updating. k2=k2×(ΔP 2et_ave +P ICerr_ave ) / ΔP 2et_ave ···(M4)

[0036] [Process 17] It is determined whether or not the parameter fitting of the control parameter k2 of the outlet pipe 350 is completed. Specifically, it is determined whether or not a preset termination condition is satisfied. Here, the average value P calculated in [Process 15] is ICerr_ave is equal to or less than a preset threshold, the termination condition is determined to be satisfied. The satisfaction of the termination condition means that the estimated value of the pressure of the air on the outlet side of the intercooler 330 has converged to a correct value. The correct value is a value that is likely to be the estimated value of the pressure of the air on the outlet side of the intercooler 330. If the termination condition is not satisfied, [Process 11] to [Process 17] are executed again. FIG. 4 is a graph showing the pressure of the air on the outlet side of the intercooler 330 estimated by Equation (M1) using the control parameter k2 adjusted by repeating the above-mentioned processes. The dashed line represents the measurement value of the first flow-rate-pressure characteristic data D1 by the pressure sensor 420. The solid line represents the estimated value of the pressure of the air on the outlet side of the intercooler 330. FIG. 4 shows an example in which multiple estimated values ​​are obtained by repeating [Process 11] to [Process 17].

[0037] In step S105, the second flow rate / pressure characteristic data D2 is used to perform parameter fitting of the control parameter k3 of the bypass pipe 360. The initial value of the control parameter k3 is set to k3=1.

[0038] [Process 21] Using the actual measured value of the air compressor flow rate, control parameter k1, and control parameter k3 as inputs, the pressure of the air on the outlet side of the intercooler 330 is estimated by a preset mathematical formula (M5). Q(t) is a measurement value by the air flow meter 410 in the second flow rate-pressure characteristic data D2, and represents the actual measured value of the air compressor 320 flow rate. P ICet (t) is an estimated value of the pressure of the air on the outlet side of the intercooler 330 at time t. fa2(Q(t), k1, k3) is a function for calculating an estimated value of the pressure of the air on the outlet side of the intercooler 330. This process is executed for all measurement values ​​during the measurement period of the second flow-pressure characteristic data D2. P ICet (t)=fa2(Q(t),k1,k3) (M5)

[0039] [Process 22] The pressure loss in the bypass pipe 360 ​​is estimated by a preset formula (M6) using the actual measured value Q(t) of the flow rate of the air compressor 320 and the control parameter k3. ΔP 3et (t) is the estimated value of the pressure loss in the bypass pipe 360 ​​at time t. fc(Q(t)) is a function for calculating the estimated value of the pressure loss. This process is performed for all the measured values ​​during the measurement period of the second flow rate pressure characteristic data D2. As a result, the number of ΔP 2et (t) is obtained. ΔP 3et (t) = k3 × fc(Q(t)) (M6)

[0040] [Process 23] Estimated pressure loss ΔP in the bypass piping 360 3et (t) average value ΔP 3et_ave is calculated.

[0041] [Process 24] As shown in formula (M7), the actual measured value P of the air pressure on the outlet side of the intercooler 330 IC (t) and the estimated value P of the air pressure on the outlet side of the intercooler 330 ICet The difference between (t) and (t) is the error PICerr The actual measured value P of the air pressure on the outlet side of the intercooler 330 is calculated as (t). IC (t) is the measurement value of the second flow rate / pressure characteristic data D2 measured by the pressure sensor 420. This process is executed for all measurement values ​​during the measurement period of the second flow rate / pressure characteristic data D2. P ICerr (t)=P IC (t)-P ICet (t) (M7)

[0042] [Process 25] Estimated value P of the air pressure on the outlet side of the intercooler 330 ICet Error P of (t) ICerr (t) average value P ICerr_ave When the estimated pressure loss of the bypass pipe 360 ​​is smaller than the actual pressure loss of the bypass pipe 360, the average value P ICerr_ave takes a positive value. When the estimated pressure loss of the bypass pipe 360 ​​is larger than the actual pressure loss of the bypass pipe 360, the average value P ICerr_ave takes a negative value.

[0043] [Process 26] In order to reduce the error, the control parameter k3 is updated by the formula (M8). In this way, in step S105, the control parameter k3 is adjusted while the value of the control parameter k1 is kept fixed. The average value P ICerr_ave When the average value P is a positive value, the value of the control parameter k3 after updating is larger than the value of the control parameter k3 before updating. ICerr_ave When takes a negative value, the value of the control parameter k3 after updating becomes smaller than the value of the control parameter k3 before updating. k3=k3×(ΔP 3et_ave +P ICerr_ave ) / ΔP 3et_ave ···(M8)

[0044] [Process 27] It is determined whether the parameter fitting of the control parameter k3 of the bypass pipe 360 ​​is completed. Specifically, it is determined whether a preset termination condition is satisfied. Here, the average value P calculated in [Process 25] is ICerr_ave is equal to or less than a preset threshold, the termination condition is determined to be satisfied. The satisfaction of the termination condition means that the estimated value of the outlet air pressure of the intercooler 330 has converged to a correct value. The correct value is a value that is likely to be the estimated value of the outlet air pressure of the intercooler 330. If the termination condition is not satisfied, [Process 21] to [Process 27] are executed again. FIG. 5 is a graph showing the outlet air pressure of the intercooler 330 estimated by Equation (M5) using the control parameter k3 adjusted by repeating the above-mentioned process. The dashed line represents the measurement value of the second flow-rate-pressure characteristic data D2 by the pressure sensor 420. The solid line represents the estimated value of the outlet air pressure of the intercooler 330. FIG. 5 shows an example in which multiple estimated values ​​are obtained by repeating [Process 21] to [Process 27].

[0045] In step S106, the fitting accuracy for the third flow rate pressure characteristic data D3 is quantified using the control parameters k2 and k3 for which parameter fitting has been completed. The closer the estimated pressure loss is to the actual pressure loss, the higher the fitting accuracy.

[0046] [Process 31] Using the actual measured value of the flow rate of the air compressor 320, control parameters k1, k2, and k3 as inputs, the pressure of the air on the outlet side of the intercooler 330 is estimated using a preset mathematical formula (M9). Q(t) is a measurement value by the air flow meter 410 in the third flow rate-pressure characteristic data D3, and represents the actual measured value of the flow rate of the air compressor 320. P ICet(t) is an estimated value of the pressure of the air on the outlet side of the intercooler 330 at time t. fa3(Q(t), k1, k2, k3) is a function for calculating an estimated value of the pressure of the air on the outlet side of the intercooler 330. This process is performed for all measurement values ​​during the measurement period of the third flow rate-pressure characteristic data D3. P ICet (t)=fa3(Q(t),k1,k2,k3)...(M9)

[0047] [Process 32] As shown in formula (M10), the actual measured value P of the air pressure on the outlet side of the intercooler 330 IC (t) and the estimated value P of the air pressure on the outlet side of the intercooler 330 ICet The difference between (t) and (t) is the error P ICerr The actual measured value P of the air pressure on the outlet side of the intercooler 330 is calculated as (t). IC (t) is the measurement value of the third flow rate pressure characteristic data D3 measured by the pressure sensor 420. This process is executed for all measurement values ​​during the measurement period of the third flow rate pressure characteristic data D3. P ICerr (t)=P IC (t)-P ICet (t) (M10)

[0048] [Process 33] Estimated value P of the air pressure on the outlet side of the intercooler 330 ICet Error P of (t) ICerr (t) average value P ICerr_ave is calculated.

[0049] In step S107, it is determined whether the fitting accuracy is as desired. Specifically, the average value P ICerr_aveis equal to or greater than a preset threshold, it is determined that the fitting accuracy is the desired accuracy. When the fitting accuracy has reached the desired accuracy, it means that fitting of the control parameters k1 to k3 has been completed. When the termination condition is satisfied (step S107; YES), the process of step S108 is executed. When the termination condition is not satisfied (step S107; NO), the process of step S103 is executed again.

[0050] When the process of step S103 is performed for the second time or later, a value different from the previously set value within the search range is set to the control parameter k1. For example, a value next to the currently set value within the search range is set. Then, the process from step S104 onwards is executed again.

[0051] In step S108, the control parameters k1 to k3 stored in a predetermined area of ​​a memory (not shown) included in ECU 500 are updated with the control parameters k1 to k3 for which fitting has been completed. This process is also referred to as a "step of outputting control parameters." Thereafter, the process shown in FIG. 2 ends.

[0052] In this embodiment, the fuel cell system 10 has only one pressure sensor 420. If the configuration of the piping constituting the flow paths of the cathode gas supply system 300 is changed from the original configuration, the control parameters k1 to K3 must be adjusted. As described above, the control parameters k1 to k3 can be fitted by performing an iterative method using flow-pressure characteristic data, thereby reducing the labor required for retuning. Conventionally, pressure measurements of each piping were performed using a separate airflow meter and pressure sensor before the piping constituting the flow paths of the cathode gas supply system 300 was assembled, and tuning was performed based on the measurement results. Then, the piping was assembled after tuning was completed. In this embodiment, tuning can be performed after the piping constituting the flow paths of the cathode gas supply system 300 is assembled, thereby reducing the labor required for tuning compared to conventional methods. Furthermore, there is no need to prepare a separate airflow meter and pressure sensor.

[0053] In the above embodiment, the search for the control parameter k1 is stopped when the desired fitting accuracy is achieved. However, the entire search range may be searched, and then the control parameter with the best fitting accuracy may be selected.

[0054] In the above embodiment, an example has been described in which all of the control parameters k1 to k3 are fitted. When one of the multiple pipes constituting the flow path of the cathode gas supply system 300 is changed, it is sufficient to fit only the control parameters for the changed pipe. When all of the multiple pipes constituting the flow path of the cathode gas supply system 300 are changed, it is necessary to fit all of the control parameters corresponding to each pipe.

[0055] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0056] D1...first flow rate pressure characteristic data, D2...second flow rate pressure characteristic data, D3...third flow rate pressure characteristic data, k1 to k3...control parameters, 10...fuel cell system, 100...fuel cell stack, 200...anode gas supply system, 300...cathode gas supply system, 310...supply piping, 311...upstream piping, 312...downstream piping, 313...inlet piping, 320...air compressor, 330...intercooler, 340...exhaust piping, 350...outlet piping, 360...bypass piping, 370...diverter valve, 380...pressure regulating valve, 410...air flow meter, 420...pressure sensor

Claims

1. 1. A method for parameter fitting of a fuel cell system, comprising: The fuel cell system includes: A fuel cell; an air supply flow path connected to the fuel cell for supplying air to the fuel cell; a bypass flow path connected to the air supply flow path for discharging air in the air supply flow path to the outside of the fuel cell system without passing through the fuel cell; an air exhaust flow path connected to the fuel cell for exhausting air from within the fuel cell; a first valve provided at a first connection portion that is a connection portion between the air supply flow path and the bypass flow path, the first valve opening and closing the bypass flow path; a second valve provided at a second connection portion that is a connection portion between the fuel cell and the air discharge flow path, the second valve opening and closing the air discharge flow path; a pressure sensor provided in the first connection portion, the pressure sensor measuring the pressure of air flowing into the air supply channel; a confluence discharge flow path that merges the bypass flow path and the air discharge flow path to discharge the air discharged from the bypass flow path and the air discharged from the air discharge flow path; It is equipped with The parameter fitting method includes: performing an iterative method using flow-pressure characteristic data indicating the pressure in the air supply passage according to the flow rate of air into the air supply passage for each combination of open / closed states of the first valve and the second valve, excluding a combination in which both the first valve and the second valve are closed, in order to fit control parameters related to the piping; outputting the calculated control parameters when an iteration termination condition for the iterative method is satisfied; A method of parameter fitting, including:

2. 2. A method of parameter fitting according to claim 1, comprising: The control parameters include: a parameter relating to a pressure loss in the bypass flow path; a parameter relating to a pressure loss in the air discharge flow path; a parameter relating to a pressure loss in the confluence discharge flow path; Included are methods of parameter fitting.

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