JP7437765B2 - Information processing device, power supply system, information processing method, and program - Google Patents

Description

The present invention relates to an information processing device, a power supply system, an information processing method, and a program.

Conventionally, the current-voltage characteristics of a fuel cell are obtained by measuring the output voltage while measuring the output current, and the current value is divided into large, medium, and small regions to determine concentration voltage loss, resistance voltage loss, and activation of the fuel cell. It is characterized by estimating the physical parameters of the diffusion layer, electrolyte membrane, and catalyst layer by calculating the voltage loss individually and fitting the fuel cell operation model equation to the concentration voltage loss, resistance voltage loss, and activation voltage loss characteristics. A method for estimating physical parameters of a fuel cell is disclosed (for example, see Patent Document 1).

JP2009-026567A Japanese Patent Application Publication No. 2010-123279 Japanese Patent Application Publication No. 2009-117110

However, the above technology estimates static physical parameters, and it is necessary to estimate parameters that dynamically change during fuel cell operation and derive a simple and appropriate method for improving operating performance. I couldn't do that.

The present invention has been made in consideration of such circumstances, and provides an information processing device, a power supply system, and a power supply system that can easily or appropriately derive a method for improving the operation of a fuel cell during actual operation. One of the purposes is to provide information processing methods and programs.

An information processing device, a power supply system, an information processing method, and a program according to the present invention employ the following configuration.
(1): An information processing device according to one aspect of the present invention includes an acquisition unit that acquires a current index related to a current output by a fuel cell cell and a voltage index related to a voltage, and a plurality of a processing unit that derives the polarization of the plurality of polarizations, and a difference between each of the reference polarizations set for each of the plurality of polarizations and each of the plurality of polarizations when the voltage index related to the voltage is less than a threshold; and a derivation unit that derives a method for increasing the voltage value output by the fuel cell based on the comparison result.

(2): In the aspect of (1) above, the plurality of polarizations include resistance polarization and concentration polarization, and the processing unit applies the current index to a first model for deriving resistance polarization to generate resistance polarization, The current index is applied to a second model for deriving concentration polarization to derive concentration polarization, and the derivation unit is set for the resistance polarization and the current index when the voltage index is less than a threshold value. The difference in resistance polarization from the reference resistance polarization set for the current index is compared with the difference in concentration polarization between the concentration polarization and the reference concentration polarization set for the current index, and based on the comparison result, the fuel cell outputs We will derive a method to increase the voltage value.

(3): In the aspect of (2) above, the plurality of polarizations further include activation polarization, and the processing unit applies the current index to a third model for deriving activation polarization to generate activation polarization. and the deriving unit calculates a reference activation polarization set for the resistance polarization difference, the concentration polarization difference, the activation polarization, and the current index when the voltage index is less than a threshold value. A method for increasing the voltage value output by the fuel cell is derived based on the comparison result.

(4): In any one of the above (1) to (3), the acquisition unit further acquires the temperature of the fuel cell, and some or all of the plurality of models are In this model, the polarization is derived using an index related to temperature acquired by the acquisition unit in addition to the current index.

(5): In any of the aspects (1) to (4) above, the derivation unit classifies the acquired current index and voltage index based on categories in which the current index is divided into predetermined ranges. , derive a plurality of polarizations based on one current index and one voltage index corresponding to the classification result, and when the voltage index regarding the voltage is less than a threshold, a plurality of polarizations corresponding to the classification result are derived. The method is derived by comparing each of the reference polarizations with each of the plurality of derived polarizations.

(6): In the aspect of (2) above, the derivation unit determines a method associated with a larger difference between the resistance polarization difference and the concentration polarization difference as the method for increasing the voltage value. do.

(7): In the aspect of (6) above, when the resistance polarization difference is large, control for cooling the fuel cell is executed, and when the concentration polarization difference is large, hydrogen is discharged from the fuel cell. The fuel cell apparatus further includes a control section that executes control to open the outlet and adjust the amount of air or oxygen flowing into the fuel cell.

(8): In the aspect of (3) above, the derivation unit calculates the voltage value using a method associated with the largest difference among the resistance polarization difference, the concentration polarization difference, and the activation polarization difference. Decided on a method to raise it.

(9): In the aspect of (8) above, when the resistance polarization difference is the largest, control for cooling the fuel cell is executed, and when the concentration polarization difference is the largest, the hydrogen in the fuel cell is control to open the exhaust port of the fuel cell and adjust the amount of air or oxygen flowing into the fuel cell, and when the activation polarization difference is the largest, increase the pressure of hydrogen supplied to the fuel cell. The apparatus further includes a control section that executes control to control the operation.

(10): A power supply system according to one aspect of the present invention includes the information processing device according to any one of the aspects (1) to (9) above, and a fuel cell stack in which a plurality of fuel cells are stacked. have

(11): In the aspect of (10) above, a first supply facility for supplying hydrogen to the fuel cell, a second supply facility for supplying air or oxygen to the fuel cell, and cooling the fuel cell. The apparatus further includes a cooling facility.

(12): In the information processing method according to one aspect of the present invention, a computer acquires a current index related to a current output by a fuel cell and a voltage index related to a voltage, and applies the current index to a plurality of models to generate a plurality of and when a voltage index related to the voltage is less than a threshold, compare each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations. Based on the comparison results, a method for increasing the voltage value output by the fuel cell is derived.

(13): The program according to one aspect of the present invention causes a computer to obtain a current index regarding the current output from a fuel cell and a voltage index regarding the voltage, and applies the current index to a plurality of models to obtain a plurality of polarizations. is derived, and when the voltage index regarding the voltage is less than a threshold, comparing each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations, Based on the comparison results, a method for increasing the voltage value output by the fuel cell is derived.

According to aspects (1) to (13) above, when the voltage index related to voltage is less than the threshold value, the information processing device selects each of the plurality of reference polarizations set for each of the plurality of polarizations, Improve the operation of the fuel cell by comparing the difference between each of the multiple polarizations actually measured and deriving a method for increasing the voltage value output by the fuel cell based on the comparison results. A control method can be derived simply or appropriately. In addition, the information processing device can derive a method for increasing the voltage value of a fuel cell whose voltage value has decreased, for example, among a plurality of fuel cells when the fuel cell stack is in operation. , it is possible to easily or appropriately derive a control method for improving the operation of the entire fuel cell stack.

According to the aspect (4) above, the information processing device derives polarization by applying a model that derives polarization using an index related to temperature, thereby generating a fuel cell that takes into account the state and environment of the fuel cell. Control techniques can be derived to improve performance.

According to the aspect (5) above, the information processing device stores each of the reference polarizations set for each of the plurality of polarizations and associated with the classified category, and each of the plurality of actually measured polarizations. By comparing and deriving the above method, a control method can be derived with higher accuracy. For example, even if the current output from the fuel cell changes due to the load connected to the fuel cell, this effect is suppressed.

According to (7) and (9) above, the control device can increase the voltage value output by the fuel cell by controlling various equipment.

1 is a diagram showing an example of the configuration of a fuel cell system 1 including an information processing device. 5 is a diagram showing an example of the contents of initial value information 152. FIG. 3 is a diagram showing an example of the contents of model information 154. FIG. FIG. 2 is a diagram showing an example of the relationship between a theoretical voltage, each polarization (activation loss, concentration loss, Ohmic loss), and a voltage output by a fuel cell. 15 is a diagram showing an example of the contents of detected value information 156. FIG. 5 is a flowchart illustrating an example of the flow of processing executed by the control device 100. FIG. 5 is a flowchart illustrating an example of the flow of processing executed by the control device 100. FIG. FIG. 7 is a diagram for explaining steps S204 to S208 and the like. It is a figure which shows an example of the comparison result of polarization. FIG. 3 is a diagram illustrating an example of a change in the voltage output by a fuel cell and a change in the difference between the detected concentration polarization and the reference activation polarization. It is a figure which shows the IV curve obtained by the process of this embodiment, and the IV curve obtained by other methods. FIG. 6 is a diagram showing plot data used to generate “All data,” “Reference,” and “Proposed.” It is a figure which shows the polarization of each method when a current density is 500 mA/cm ^<2> . It is a flowchart which shows an example of the flow of processing performed by control device 100 of a 2nd embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an information processing device, a power supply system, an information processing method, and a program according to the present invention will be described below with reference to the drawings.

<First embodiment>
FIG. 1 is a diagram showing an example of the configuration of a fuel cell system 1 including an information processing device. The fuel cell system 1 includes a fuel cell unit 10 and a control device 100. The fuel cell unit 10 and the control device 100 can communicate via a communication line or wireless communication.

[Fuel cell unit]
The fuel cell unit 10 includes, for example, a fuel cell stack 20, an air pump 30, an air flow control mechanism 32, a cooling fan 40, a hydrogen tank 50, a hydrogen flow control mechanism 52, and a sensor group 70.

The fuel cell stack 20 is, for example, a polymer electrolyte fuel cell. The fuel cell stack 20 includes, for example, a stacked body in which a plurality of fuel cells are stacked. A fuel cell generates an electromotive force by reacting an anode reaction gas (eg, hydrogen) and a cathode reaction gas (eg, oxygen). The fuel cell stack 20 outputs the generated power to a load (not shown).

The air pump 30 supplies air to the cathode reaction gas supply port of the fuel cell stack 20 . The air flow control mechanism 32 includes an air valve and an air flow controller, and controls the flow rate of air supplied to the fuel cell stack 20 based on the control of the control device 100.

The cooling fan 40 sends air to the fuel cell stack 20 under the control of the control device 100 to cool the fuel cell stack 20 .

High-pressure hydrogen is stored in the hydrogen tank 50 and is supplied to the anode reaction gas supply port of the fuel cell stack 20 . The hydrogen flow control mechanism 52 includes a hydrogen valve and a hydrogen flow controller, and controls the flow rate of hydrogen supplied from the hydrogen tank 50 to the fuel cell stack 20 based on the control of the control device 100.

The sensor group 70 includes, for example, a current sensor, a voltage sensor, a temperature sensor, and the like. The current sensor detects the current value output by each fuel cell. The voltage sensor detects the voltage value output by each fuel cell. The temperature sensor detects the temperature of each fuel cell.

[Control device]
The control device 100 includes, for example, an acquisition section 110, a processing section 120, a derivation section 130, a control section 140, and a storage section 150. The acquisition unit 110, the processing unit 120, the derivation unit 130, and the control unit 140 are realized, for example, by a computer processor such as an ECU (Electronic Control Unit) or a CPU (Central Processing Unit) executing a program (software). . These functional units are realized by calculation hardware (including circuits) that contribute to calculations, such as ASSP (Application Specific Standard Product), ASIC (Application Specific Integrated Circuit), and FPGA (Field-Programmable Gate Array). It may be implemented by a combination of software and hardware.

The storage unit 150 is, for example, a storage device including a nonvolatile storage medium such as an HDD (Hard Disk Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), or a ROM (Read Only Memory), or a RAM (Random Access Memory). This is realized by a storage device equipped with a volatile storage medium such as memory. The storage unit 150 stores, for example, initial value information 152, model information 154, and detected value information 156. Details of this information will be described later.

[Initial value information]
FIG. 2 is a diagram showing an example of the contents of the initial value information 152. The initial value information 152 indicates the initial state of the fuel cell stack 20 (for example, at the time of shipment or at the reference time of starting use). The initial value information 152 includes, for example, current density (mA/cm ² ), voltage (V), temperature (° C.), and information based on a model formula described later for a category that is a range of current density (mA/cm ² ). This is information in which voltage (V), activation polarization (V), resistance polarization (V), and concentration polarization (V) are associated. Here, "current density" is used as an example of "current index". For example, as shown in FIG. 2, when categorizing, a small current range (2 mA/cm ² ) is set for a range where the current density is low, and a large current range (25 mA/cm 2 ) is set for a range where the current density is high ^. ) is set. The reason for this is to make the number of samples (number of sample data) of each range approximately the same.

[Model information]
The model information 154 includes, for example, a model for deriving the voltage etc. output by the fuel cell shown in equation (1) below. "V" is the fitting voltage and "E ₀ " is the theoretical voltage. “η _act ” is the activation polarization, “η _оhmic ” is the resistive polarization, and “η _con ” is the concentration polarization.

For the model information 154, for example, instead of (or in addition to) the above equation (1), a model for deriving the voltage etc. output by the fuel cell shown in the following equation (2) may be used. This embodiment will be described using the following equation (2). “E _(T) ” is a theoretical voltage with temperature information taken into consideration. "η _act(T) " is the activation polarization with temperature information taken into consideration, "η _оhmic(T) " is the resistance polarization with temperature information taken into account, and "η _con(T) " is the activation polarization with temperature information added. It is the concentration polarization that has been taken into account. [T] is, for example, the temperature (operating temperature) of the fuel cell. [T] is the temperature detected by the temperature sensor or an index based on the temperature.

The above equation (2) can be expressed as the following equation (3). "T[b+aln{i}-A" is a term for deriving activation polarization, "R _(T)・i" is a term for deriving resistance polarization, and "m _(T) exp{n・i} ” is a term for deriving concentration polarization. As shown in FIG. 3, various parameters used in the model are stored in the storage unit 150 as model information 154. [Reference 1] Akimoto Y, Okajima K. Semi-Empirical Equation of PEMFC Considering Operation Temperature. Energy Technology Policy. 2014; 1(1):91-96

FIG. 4 is a diagram showing an example of the relationship between the theoretical voltage E (Theoretical voltage), each polarization (Activation loss, Concentration loss, Ohmic loss), and the output voltage output from the fuel cell. The vertical axis in FIG. 4 indicates the voltage [V] output by the fuel cell, and the horizontal axis in FIG. 4 indicates the current [A] output by the fuel cell. The one-dot chain line in FIG. 4 is a voltage obtained by removing activation polarization (activation loss) from the theoretical voltage E. The two-dot chain line in FIG. 4 is a voltage obtained by removing activation polarization and concentration loss from the theoretical voltage E. The solid line in FIG. 4 is the output voltage, which is the voltage obtained by removing activation polarization, concentration polarization, and resistance polarization (Ohmic loss) from the theoretical voltage E. As shown in FIG. 4, in the region where the current is small, the influence of activation polarization is dominant, and the influence of resistance polarization and concentration polarization is small. Further, in a region where the current is small, the activation polarization changes, but in other regions, the change in the influence of the activation polarization is small. On the other hand, in a region where the current is large, the influence of resistance polarization or concentration polarization tends to increase. As shown in FIG. 4, the fitting voltage is derived by taking into account the effects of activation polarization, resistance polarization, and concentration polarization.

[Detection value information]
FIG. 5 is a diagram showing an example of the contents of the detected value information 156. The detected value information 156 is information in which the current density (mA/cm ² ) of the current output by each fuel cell, the voltage (V), and the temperature (° C.) are associated with each other. The detected value information 156 is information detected by the sensor group 70 at predetermined intervals.

[Functional part]
The acquisition unit 110 acquires the current value, voltage value, and temperature output by the fuel cell. When temperature is not applied to the model, the acquisition unit 110 may omit temperature acquisition. The acquisition unit 110 acquires information detected by the sensor group 70 from the sensor group 70, and stores the acquired information (detected value information 156) in the storage unit 150.

The processing unit 120 applies current indicators and temperature-based indicators to a plurality of models to derive a plurality of polarizations. The processing unit 120 derives resistance polarization by applying the current value-based index and the temperature-based index of the detected value information 156 to the model included in the model information 154, and applies the current value-based index and temperature-based index of the detected value information 156 to the model included in the model information 154. The concentration polarization is derived by applying the index based on the model information 154 to the model included in the model information 154. The processing unit 120 applies the current value-based index and the temperature-based index of the detected value information 156 to the model included in the model information 154 to derive activation polarization. The current index or the index based on the current value is, for example, a current value, a current density, or an index obtained based on these. A specific example will be described later. The temperature-based index is, for example, the operating temperature of the fuel cell or an index obtained from the operating temperature. The processing unit 120 may omit the temperature and derive each polarization.

When the voltage index related to voltage is less than the threshold value, the derivation unit 130 compares each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations, and calculates the comparison result. Based on this, we will derive a method for increasing the voltage value output by the fuel cell. The voltage index will be described later.

When the voltage value of the detected value information 156 is less than the threshold voltage, the derivation unit 130 compares the resistance polarization difference, the concentration polarization difference, and the activation polarization difference, and based on the comparison result, determines whether the fuel cell is We will derive a method to increase the voltage value output by. The resistance polarization difference is the difference between the resistance polarization and the reference resistance polarization set for the current index (for example, the resistance polarization of the initial value information 152 corresponding to the current density category of the detected value information 156). The concentration polarization difference is the difference between the concentration polarization and the reference concentration polarization set for the current index (for example, the concentration polarization of the initial value information 152 corresponding to the current density category of the detected value information 156). The activation polarization difference is the difference between the activation polarization and the reference activation polarization set for the current index (for example, the activation polarization of the initial value information 152 corresponding to the current density category of the detected value information 156). .

"Methods" include cooling techniques, purging techniques, and hydrogen pressure raising techniques. The cooling method is to operate the cooling fan 40 to cool the fuel cell. The purge method is to perform purge control. Purge control is control that opens the hydrogen discharge port of the fuel cell and adjusts the flow rate of the air pump 30 according to the amount of hydrogen. The hydrogen pressure increasing method is to increase the pressure when hydrogen, which is the fuel supplied by the hydrogen tank 50, is supplied. "Deriving a method" includes determining which method to apply among the cooling method, purge method, and hydrogen pressure increase method, and determining which method to apply in which order. .

"Threshold voltage" means that the voltage output by the fuel cell does not become zero when a process is performed to derive a method for increasing the voltage value output by the fuel cell based on the above comparison results. This value is determined based on the following conditions. The "threshold voltage" is a value set with a margin such that the voltage output from the fuel cell does not become zero, taking into account the control cycle.

The control unit 140 executes control based on the method derived by the derivation unit 130. When executing the cooling method, the control unit 140 controls the cooling fan 40. When executing the purge method, the control unit 140 executes control to open a discharge port (not shown), and also controls the air flow rate control mechanism 32. When executing the hydrogen pressure increase method, the control unit 140 controls the hydrogen flow rate control mechanism 52.

The processing executed by the control device 100 will be described below with reference to a flowchart.

[Flowchart (Part 1)]
FIG. 6 is a flowchart illustrating an example of the flow of processing executed by the control device 100. This process is a process executed before the fuel cell stack 20 starts operating. First, the control device 100 sets initial value information 152 (step S100). Next, the control device 100 sets a threshold voltage Va (step S102).

One or both of the initial value information 152 and the threshold voltage Va may be set by a user's operation, or may be embedded in a program executed by the control device 100. Further, the control device 100 may set the initial value information obtained via the network as the initial value information 152, and may set the threshold voltage obtained via the network as the threshold voltage Va. Networks include the Internet, LAN (Local Area Network), WAN (Wide Area Network), cellular network, and the like. As a result, the initial value information 152 and the threshold voltage Va are set, and the processing of this flowchart ends.

[Flowchart (Part 2)]
FIG. 7 is a flowchart illustrating an example of the flow of processing executed by the control device 100. This process is a process executed after the process in the flowchart of FIG.

First, the control device 100 determines whether or not the operation of the fuel cell stack 20 has started (step S200). When the operation of the fuel cell stack 20 is started, the acquisition unit 110 acquires the current value, voltage value, and temperature of each fuel cell from the sensor group 70, and uses the acquired information to determine the current index and voltage index used for processing. (voltage value V1) and temperature are acquired. (Step S202).

Here, the acquisition unit 110 obtains, for example, one voltage index and one temperature for each category of current index from the detected values of current, voltage, and temperature acquired at predetermined intervals. One voltage indicator and one temperature for each category of current indicators are, for example, values obtained by statistically processing detected values corresponding to current indicators within the range of the category, and correspond to each current indicator within the range of the category. These include the average value of the attached voltage index, the average value of temperature, the median value of voltage index, the median value of temperature, and a statistically obtained value excluding outlier values. These values are used in subsequent processing (processing to obtain polarization). For example, in the process of step S202, when a current index outside the category range is obtained, the acquisition unit 110 uses the current index within the category range obtained before the current index outside the category range is obtained. Statistical processing is performed on the corresponding detected values to obtain the voltage index and temperature of the category. The current index and temperature may also be determined in the same manner as above. The current index may be an index set for a category. This process suppresses bias in detected values and improves the accuracy of results obtained in subsequent processes (for example, derived polarization). Note that the voltage index, voltage index, or temperature used in subsequent processing may be a detected value.

Next, the processing unit 120 determines whether the voltage value V1 acquired in step S202 is less than the threshold voltage Va (step S204). That is, it is determined whether there is a fuel cell whose voltage value V1 is less than the threshold voltage Va. If the voltage value V1 is not less than the threshold voltage Va, the process returns to step S202. Note that the voltage value V1 may be a detected value or may be a voltage value corresponding to the category of the current index obtained in step S202.

If the voltage value V1 is less than the threshold voltage Va, the processing unit 120 calculates each polarization (step S206). Each polarization is derived, for example, based on each index (current index and temperature) obtained in step S202. Next, the derivation unit 130 derives the difference between each of the obtained polarizations and the polarization of the initial value information 152 (step S208). The processes in step S206 and step S208 may be performed between step S202 and step S204. The above [steps S204 to S208 and subsequent determination processing (steps S210, S214, S218)] will be described later with reference to FIGS. 8 and 9.

Next, the deriving unit 130 compares the resistance polarization difference, the concentration polarization difference, and the activation polarization difference, which are the differences derived in step S208, and determines whether the activation polarization difference is the largest among them. (Step S210). When the activation polarization difference is the maximum, the control unit 140 controls the hydrogen flow rate control mechanism 52 to increase the pressure when supplying hydrogen (step S212). Since activation polarization is reduced by an increase in operating temperature and pressure due to catalyst activity, control is performed to increase the fuel supply pressure.

If the activation polarization difference is not the maximum, the derivation unit 130 compares the resistance polarization difference, the concentration polarization difference, and the activation polarization difference, and determines whether the resistance polarization difference is the maximum among them. (Step S214). If the resistance polarization difference is the maximum, the control unit 140 operates the cooling fan 40 to cool the fuel cell (step S216). Since resistance polarization occurs due to drying (dryout) of the ion exchange membrane, a process of lowering the operating temperature is performed to alleviate the drying.

If the resistance polarization difference is not the maximum, the derivation unit 130 compares the resistance polarization difference, the concentration polarization difference, and the activation polarization difference, and determines whether the concentration polarization difference is the maximum among them ( Step S210). If the concentration polarization difference is the maximum, the control unit 140 executes purge control (step S220). Concentration polarization occurs due to a deviation between the reaction of the reactant gas and the flow rate of the reactant gas, or a reduction in the reaction surface area (flooding). Therefore, control is performed to open the hydrogen exhaust port and adjust the flow rate of the reactant gas. It is reduced by

After the processing in step S218 or S220, the control unit 140 determines whether or not the operation of the fuel cell stack 20 has ended (step S222). If the operation of the fuel cell stack 20 has not ended, the process returns to step S202, and if the operation of the fuel cell stack 20 has ended, the process of this flowchart ends.

In addition, in the above process, when the activation polarization difference is equal to or higher than the first threshold value, control is executed to increase the pressure when supplying hydrogen, and when the resistance polarization difference is equal to or higher than the second threshold value, the cooling Purge control may be executed when the control for operating the fan 40 is executed and the concentration polarization difference is equal to or greater than a third threshold value. Further, the order of processing in the above flowchart may be changed as appropriate.

[Step S204-Step S208 and subsequent determination processing (Steps S210, S214, S218)] will be explained.

FIG. 8 is a diagram for explaining steps S204 to S208, etc. The control device 100 classifies the detected value information 156 into categories. When the control device 100 determines that the voltage value V1 corresponding to the category is less than the threshold voltage Va (for example, less than 0.25V), the control device 100 sets the current index and temperature corresponding to the category to the model formula of the model information 154 (for example, the above-mentioned formula). (3)) is applied to obtain activation polarization (detection activation polarization), resistance polarization (detection resistance polarization), and concentration polarization (detection concentration polarization). The control device 100 determines the category corresponding to the current index when the voltage value V1 becomes less than the threshold voltage Va, and based on the current index, voltage index, and temperature corresponding to the category (100-125 in FIG. 8). Derive each polarization. The control device 100 obtains the reference activation polarization, reference resistance polarization, and reference concentration polarization corresponding to the above categories from the initial value information 152. Then, the control device 100 compares the polarizations of the same type and derives the difference between the polarizations. The control device 100 derives the difference between the detected activation polarization and the reference activation polarization, the difference between the detected resistance polarization and the reference resistance polarization, and the difference between the detected concentration polarization and the reference concentration polarization. Hereinafter, when detection activation polarization, detection resistance polarization, and detection concentration polarization are not distinguished, they are referred to as "detection polarization," and when reference activation polarization, reference resistance polarization, and reference concentration polarization are not distinguished, they are referred to as "reference polarization." ” is sometimes called.

FIG. 9 is a diagram showing an example of polarization comparison results. In the illustrated example, the voltage [V] obtained by subtracting the reference polarization from the detected polarization is shown. For example, when the difference between the detected concentration polarization and the reference concentration polarization is larger than other differences as in this example, the control unit 140 executes purge control as described above.

FIG. 10 is a diagram showing an example of a change in the voltage (cell voltage [V]) output by a fuel cell and a change in concentration polarization [V]. For example, an experiment was conducted in which the control for the fuel cell was kept constant (current 20 A) and the fuel cell was operated at a low flow rate and low operating temperature so that flooding would occur over time. Flooding is a phenomenon in which water generated during power generation remains in the fuel cell and inhibits the supply and reaction of anode gas. In this case, the voltage output by the fuel cell decreased over time. At the time Tx when the voltage output by the fuel cell (CELL 5) becomes lower than the threshold voltage Va (for example, 0.25V), the processes from step S206 onward in the flowchart of FIG. 7 described above are executed, and the processes in FIG. As shown, it was determined that the voltage (concentration overpotential) obtained by subtracting the reference concentration polarization from the detected concentration polarization was the maximum, and the control unit 140 executed purge control. When purge control was executed, the concentration polarization tended to decrease, and the voltage output from the fuel cell increased. Thus, in the experimental results, the flooding obstacle was removed.

As described above, the control device 100 compares the difference between the detected polarization for each type and the reference polarization, and derives a method for increasing the voltage value output by the fuel cell based on the comparison result. Accordingly, a control method for improving the operation of the fuel cell can be easily or appropriately derived. Furthermore, the control device 100 can improve the operation of the fuel cell by executing the derived method.

[Explanation of the process of classifying current indicators into categories]
FIG. 11 is a diagram showing an IV curve obtained by the process of this embodiment and an IV curve obtained by another method. The vertical axis in FIG. 10 indicates the cell voltage [V] output by the fuel cell, and the horizontal axis in FIG. 10 indicates the current density [A/cm ² ] output by the fuel cell. In the figure, "Reference" is obtained by experiment using equation (2) in the above-mentioned [Reference Document 1]. The IV curve indicated by "Reference" is an IV curve that serves as a reference indicating the characteristics of the fuel cell. Specifically, "Reference" measures the fuel cell voltage and temperature at an arbitrary current value without applying the process of the flowchart of FIG. 7 of this embodiment, and when a predetermined temperature is reached, , is an IV curve obtained when a cooling fan is operated to cool the fuel cell. "All data" indicates an IV curve generated by executing the processes from step S204 in FIG. 7 of this embodiment using all data obtained at a predetermined period. "Proposed" is an IV curve obtained by performing the process shown in the flowchart of FIG. 7 described above. As shown in the present embodiment, "Proposed" is an IV curve obtained by plotting the relationship between voltage and current in a predetermined current density range. These IV curves are curves made of current-voltage data obtained by statistically processing plot data shown in FIG. 12, which will be described later, using a method such as the least squares method.

The I-V curve of "All data" is largely deviated from the IV curve of "Reference", but the I-V curve of "Proоposed" is similar to the I-V curve of "Reference". It shows a trend. This is due to the following reasons.

FIG. 12 is a diagram showing plot data used to generate "All data," "Reference," and "Proposed." There is more plot data of "All data" particularly in the low current density region than in other current density regions. Therefore, when generating a curve, the influence of plot data such as plot data in the low current density region and outliers becomes large, so as shown in FIG. 11, the I-V curve of "All data" is There is a large deviation from the IV curve of "Reference". On the other hand, in this embodiment, since data for each range (category) of current density is used, the I-V curve of "Proposed" is the I-V curve of "Reference" which is a standard indicating the characteristics of the fuel cell. It shows the same tendency as the V curve.

FIG. 13 is a diagram showing the polarization of each method when the current density is 500 mA/cm ² . The activation polarization of "All data" was overestimated, and the other polarizations were underestimated. The maximum difference between the polarization of "Reference" and the polarization of "Proposed" is 0.05. In this way, the polarization tendency of "Proposed" is similar to that of the standard "Reference", and the polarization separation accuracy of "Proposed" is maintained.

In this embodiment, the current density is classified into categories, and control for increasing the voltage is executed based on the comparison result of comparing each polarization using the classification results. As a result, even if the plot data is biased as described above, the control device 100 of the present embodiment equalizes the number of sample data for each current range and compensates for the difference between the detected polarization and the reference polarization. By performing control based on this, it is possible to improve accuracy and reduce processing load.

According to the first embodiment described above, the control device 100 derives the plurality of polarizations by applying the current index to the plurality of models, and when the voltage index regarding the voltage is less than the threshold value, the control device 100 Comparing the difference between each of the reference polarizations set for the reference polarization and each of the plurality of polarizations, and deriving a method for increasing the voltage value output by the fuel cell based on the comparison result. Accordingly, a control method for improving the operation of the fuel cell can be easily or appropriately derived. More specifically, the control device 100 can derive each detected polarization with higher accuracy by incorporating the temperature at which the fuel cell is operating as a parameter of the model for deriving each polarization. Further, the control device 100 categorizes the current density and derives an appropriate method for increasing the voltage value output by the fuel cell while the fuel cell is in operation using the voltage and temperature corresponding to the categorized current density. , apply the derived method. Thereby, the control device 100 can suppress the calculation cost, more appropriately diagnose the state of the fuel cell in operation, and increase the voltage value output by the fuel cell.

<Second embodiment>
The second embodiment will be described below. In the first embodiment, activation polarization, resistance polarization, and concentration polarization were determined, these polarizations were compared with the corresponding initial value polarization, and control was executed based on the comparison results. In contrast, in the second embodiment, the process of determining the activation polarization and the process of comparing the activation polarization with the corresponding initial value activation polarization are omitted. Hereinafter, differences from the first embodiment will be mainly explained.

[flowchart]
FIG. 14 is a flowchart illustrating an example of the flow of processing executed by the control device 100 of the second embodiment. The explanation will focus on the differences from the flowchart of FIG. 7 described above. In FIG. 14, the process in step S207 is executed instead of the process in step S206 in FIG. 7, and the processes in step S210 and step S212 are omitted.

If it is determined in step S204 that the voltage value V1 is less than the threshold voltage Va, the processing unit 120 calculates resistance polarization and concentration polarization (step S207). Next, the processing unit 120 derives the difference between the obtained polarization and the polarization of the initial value information 152. The processing unit 120 derives the difference between the obtained resistance polarization and the resistance polarization of the initial value information 152 and the difference between the obtained concentration polarization and the concentration polarization of the initial value information 152. Then, the processes of steps S214-S222 are executed.

In a situation where the voltage value V1 is determined to be less than the threshold voltage Va in step S204, a resistance polarization difference or a concentration polarization difference tends to occur relatively easily, and an activation polarization difference tends to occur less easily. Therefore, as shown in the flowchart of FIG. 14, the process of deriving the difference in activation polarization and the process of determining whether the difference in activation polarization is the maximum may be omitted.

According to the second embodiment described above, a control method for improving the operation of the fuel cell can be easily or appropriately derived.

Note that although this embodiment has been described as being applied to a polymer electrolyte fuel cell as an example, the process of this embodiment may be applied to fuel cells other than polymer electrolyte fuel cells. In this case, the control device 100 acquires a current index related to the current and a voltage index related to the voltage output by the fuel cell other than the polymer electrolyte fuel cell, and applies the acquired current index to a plurality of models to generate a plurality of Derive polarization. Then, when the voltage index related to the voltage is less than the threshold value, the control device 100 compares each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations, Based on the comparison results, we will derive a method for increasing the voltage value output by the fuel cell.

[summary]
Until now, achieving stable operation of fuel cells required a large number of sensors and high-precision measurements, which was expensive. Furthermore, in order to evaluate polarization, it was necessary to stop operation and use a dedicated device such as an impedance analyzer. In contrast, in this embodiment, the information to be acquired is the current, voltage, and temperature detected by many fuel cells, and there is no need to additionally provide sensors or measuring instruments, reducing costs while reducing costs. , it is possible to easily or appropriately derive a control method for improving the operation of a fuel cell. Furthermore, since a voltage threshold is provided in this embodiment, it is possible to suppress an increase in power consumption due to frequent control. In this way, this embodiment can realize stable operation and improve the lifetime of the fuel cell, contributing to improved system reliability and widespread use.

Although the mode for implementing the present invention has been described above using embodiments, the present invention is not limited to these embodiments in any way, and various modifications and substitutions can be made without departing from the gist of the present invention. can be added.

1‥Fuel cell system, 10‥Fuel cell unit, 20‥Fuel cell stack, 30‥Air pump, 32‥Air flow control mechanism, 40‥Cooling fan, 50‥Hydrogen tank, 52‥Hydrogen flow rate control mechanism, 70‥Sensor group , 100...Control device, 110...Acquisition unit, 120...Processing unit, 130...Derivation unit, 140...Control unit, 150...Storage unit, 152...Initial value information, 154...Model information, 156...Detected value information

Claims (13)

an acquisition unit that acquires a current index regarding the current output by the fuel cell and a voltage index regarding the voltage;
a processing unit that derives a plurality of polarizations by applying the current index to a plurality of models;
When the voltage index related to the voltage is less than a threshold, compare each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations, and based on the comparison result. a derivation unit that derives a method for increasing the voltage value output by the fuel cell;
An information processing device comprising: The plurality of polarizations include resistance polarization and concentration polarization,
The processing unit derives concentration polarization by applying the current index to a second model that derives resistance polarization and concentration polarization by applying the current index to a first model that derives resistance polarization,
The derivation unit is configured to calculate a resistance polarization difference between the resistance polarization and a reference resistance polarization set for the current index, and a resistance polarization difference set for the concentration polarization and the current index when the voltage index is less than a threshold value. comparing the concentration polarization difference with the reference concentration polarization obtained, and deriving a method for increasing the voltage value output by the fuel cell based on the comparison result;
The information processing device according to claim 1. The plurality of polarizations further include activation polarization,
The processing unit derives activation polarization by applying the current index to a third model for deriving activation polarization,
The derivation unit is configured to activate the resistance polarization difference, the concentration polarization difference, the activation polarization, and a reference activation polarization set for the current index when the voltage index is less than a threshold value. and deriving a method for increasing the voltage value output by the fuel cell based on the comparison result.
The information processing device according to claim 2. The acquisition unit further acquires the temperature of the fuel cell,
Some or all of the plurality of models are models that derive the polarization using an index related to temperature acquired by the acquisition unit in addition to the current index,
The information processing device according to any one of claims 1 to 3. The derivation unit is
The obtained current index and voltage index are classified based on categories in which the current index is divided into predetermined ranges, and a plurality of polarizations are determined based on one current index and one voltage index corresponding to the result of the classification. Derive,
deriving the method by comparing each of the plurality of reference polarizations associated with the classification result with each of the plurality of derived polarizations when the voltage index regarding the voltage is less than a threshold;
The information processing device according to any one of claims 1 to 4. The deriving unit determines a method associated with a larger difference between the resistance polarization difference and the concentration polarization difference as a method for increasing the voltage value.
The information processing device according to claim 2. If the resistance polarization difference is large, performing control to cool the fuel cell,
If the concentration polarization difference is large, the fuel cell further includes a control unit that executes control to open a hydrogen discharge port of the fuel cell and adjust the amount of air or oxygen flowing into the fuel cell.
The information processing device according to claim 6. The derivation unit determines a method associated with the largest difference among the resistance polarization difference, the concentration polarization difference, and the activation polarization difference as a method for increasing the voltage value.
The information processing device according to claim 3. If the resistance polarization difference is the largest, performing control to cool the fuel cell;
If the concentration polarization difference is the largest, opening the hydrogen outlet of the fuel cell and controlling the amount of air or oxygen flowing into the fuel cell,
further comprising a control unit that executes control to increase the pressure of hydrogen supplied to the fuel cell when the activation polarization difference is the largest;
The information processing device according to claim 8. An information processing device according to any one of claims 1 to 9,
A fuel cell stack in which multiple fuel cells are stacked,
Power supply system with. a first supply facility that supplies hydrogen to the fuel cell;
a second supply facility that supplies air or oxygen to the fuel cell;
further comprising a cooling facility that cools the fuel cell;
The power supply system according to claim 10. The computer is
Obtaining a current index regarding the current output by the fuel cell and a voltage index regarding the voltage,
applying the current index to multiple models to derive multiple polarizations;
When the voltage index related to the voltage is less than a threshold, compare each of the reference polarizations set for each of the plurality of polarizations with the difference between each of the plurality of polarizations, and based on the comparison result. deriving a method for increasing the voltage value output by the fuel cell;
Information processing method. to the computer,
obtain a current index regarding the current output by the fuel cell and a voltage index regarding the voltage;
applying the current index to multiple models to derive multiple polarizations;
When the voltage index related to the voltage is less than a threshold, each of the reference polarizations set for each of the plurality of polarizations is compared with the difference between each of the plurality of polarizations, and based on the comparison result. and deriving a method for increasing the voltage value output by the fuel cell,
program.

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