WO2016139759A1 - 燃料電池の状態検出装置及び状態検出方法 - Google Patents
燃料電池の状態検出装置及び状態検出方法 Download PDFInfo
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- WO2016139759A1 WO2016139759A1 PCT/JP2015/056261 JP2015056261W WO2016139759A1 WO 2016139759 A1 WO2016139759 A1 WO 2016139759A1 JP 2015056261 W JP2015056261 W JP 2015056261W WO 2016139759 A1 WO2016139759 A1 WO 2016139759A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04492—Humidity; Ambient humidity; Water content
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/04—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant in circuits having distributed constants, e.g. having very long conductors or involving high frequencies
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04492—Humidity; Ambient humidity; Water content
- H01M8/04529—Humidity; Ambient humidity; Water content of the electrolyte
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04537—Electric variables
- H01M8/04634—Other electric variables, e.g. resistance or impedance
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04537—Electric variables
- H01M8/04634—Other electric variables, e.g. resistance or impedance
- H01M8/04641—Other electric variables, e.g. resistance or impedance of the individual fuel cell
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
- H01M8/04664—Failure or abnormal function
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04828—Humidity; Water content
- H01M8/0485—Humidity; Water content of the electrolyte
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
- H01M8/04858—Electric variables
- H01M8/04949—Electric variables other electric variables, e.g. resistance or impedance
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
- H01M8/1018—Polymeric electrolyte materials
- H01M8/1039—Polymeric electrolyte materials halogenated, e.g. sulfonated polyvinylidene fluorides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M2008/1095—Fuel cells with polymeric electrolytes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2250/00—Fuel cells for particular applications; Specific features of fuel cell system
- H01M2250/20—Fuel cells in motive systems, e.g. vehicle, ship, plane
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02T90/40—Application of hydrogen technology to transportation, e.g. using fuel cells
Definitions
- the present invention relates to a fuel cell state detection device and a state detection method.
- HFR High Frequency Frequency
- Patent Document 1 the first impedance in the first frequency region corresponding to the electrolyte membrane resistance and the first frequency region corresponding to the sum of the electrolyte membrane resistance and the catalyst layer resistance are disclosed.
- the second impedance in the second frequency region that is a lower frequency region is calculated, and the wetness index of the fuel cell is calculated based on the differential impedance that is the difference between the second impedance and the first impedance. It has been proposed to calculate the water content of the catalyst layer.
- Patent Document 2 calculates an ionomer resistance based on an assumed formula from an imaginary part of a measured impedance, and uses the ionomer resistance as a wet / dry index of a fuel cell. Has been proposed.
- the present invention has been made paying attention to such problems, and an object thereof is to provide a fuel cell state detection device and a state detection method capable of detecting the state of the fuel cell with high accuracy.
- a fuel cell state detection device that sets an assumed high frequency impedance value based on an impedance measurement value belonging to an arc region of an impedance curve of the fuel cell.
- Means a measured high frequency impedance value calculating means for obtaining a measured high frequency impedance value based on an impedance measured value belonging to a non-arc region of the impedance curve of the fuel cell, and the measured high frequency impedance value from the assumed high frequency impedance value.
- a fuel cell state detection device comprising ionomer resistance estimation means for estimating a subtracted value as an ionomer resistance value.
- the assumed high frequency impedance value setting means calculates the value of the intersection of the equivalent circuit impedance curve set based on the impedance measurement value belonging to the arc region and the real axis as the assumed high frequency. Set as impedance value.
- FIG. 1 is a perspective view of a fuel cell according to an embodiment of the present invention.
- 2 is a cross-sectional view of the fuel cell of FIG. 1 taken along the line II-II.
- FIG. 3 is a schematic configuration diagram of a fuel cell system according to an embodiment of the present invention.
- FIG. 4 is a diagram showing an equivalent circuit model of a fuel battery cell employed in an embodiment of the present invention.
- FIG. 5 is a diagram for explaining the principle that the ionomer resistance value increases as the thickness of the catalyst layer of the electrolyte membrane increases.
- FIG. 6 is an equivalent circuit of a distributed constant system in which the distribution in the thickness direction of the fuel cells is taken into consideration.
- FIG. 7 is a graph showing the frequency characteristics of the imaginary part impedance determined based on the simple equivalent circuit.
- FIG. 8 is a Nyquist diagram of a fuel cell according to an embodiment.
- FIG. 9 is a flowchart showing a flow of estimating the ionomer resistance value of the fuel cell.
- FIG. 10 is a flowchart showing a flow for obtaining the actually measured high frequency impedance value.
- FIG. 11 is a flowchart showing a flow of obtaining the assumed high frequency impedance value.
- FIG. 12 is a diagram showing the relationship between the ionomer resistance value and the wetness.
- FIG. 13 is a flowchart showing a flow of creating data for ionomer resistance value correction.
- FIG. 14 is a graph schematically showing how the ionomer resistance value increases due to deterioration of the catalyst layer.
- FIG. 15 is a flowchart showing a flow of correcting the ionomer resistance value.
- FIG. 16 is a graph showing the relationship between the electrolyte membrane resistance value and the wetness.
- FIG. 17 is a flowchart showing a flow of creating data for correcting the electrolyte membrane resistance value.
- FIG. 18 is a graph schematically showing an increase in the measured high frequency impedance value due to deterioration of the separator or the like.
- FIG. 19 is a flowchart showing a flow of correcting the electrolyte membrane resistance value.
- FIG. 20 is a flowchart illustrating a flow of determining whether a frequency belongs to an arc region or a non-arc region in one embodiment.
- FIG. 21 is a diagram for explaining a mode for determining whether a frequency belongs to an arc region or a non-arc region.
- FIG. 22 is a diagram for explaining a mode for determining whether a frequency belongs to an arc region or a non-arc region.
- FIG. 23 is a diagram for explaining a mode for determining whether a frequency belongs to an arc region or a non-arc region.
- FIG. 24 is a diagram for explaining impedance measurement by a so-called excitation current application method in the fuel cell system according to the embodiment.
- a fuel cell has a structure in which an electrolyte membrane is sandwiched between an anode electrode as a fuel electrode and a cathode electrode as an oxidant electrode.
- an anode gas containing hydrogen is supplied to the anode electrode, while a cathode gas containing oxygen is supplied to the cathode electrode, and electricity is generated by using these gases.
- the electrode reaction that proceeds at both the anode and cathode electrodes is as follows.
- Anode electrode 2H 2 ⁇ 4H + + 4e ⁇ (1)
- Cathode electrode 4H + + 4e ⁇ + O 2 ⁇ 2H 2 O (2)
- These electrode reactions (1) and (2) generate an electromotive force of about 1 V (volt) in the fuel cell.
- FIG. 1 and 2 are views for explaining the configuration of a fuel cell 10 according to an embodiment of the present invention.
- 1 is a perspective view of the fuel battery cell 10
- FIG. 2 is a cross-sectional view of the fuel battery cell 10 of FIG.
- the fuel cell 10 includes a membrane electrode assembly (MEA) 11 and an anode separator 12 and a cathode separator 13 that are arranged so as to sandwich the MEA 11 therebetween.
- MEA membrane electrode assembly
- the MEA 11 includes an electrolyte membrane 111, an anode electrode 112, and a cathode electrode 113.
- the MEA 11 has an anode electrode 112 on one surface side of the electrolyte membrane 111 and a cathode electrode 113 on the other surface side.
- the electrolyte membrane 111 is a proton-conductive ion exchange membrane formed of a fluorine-based resin.
- the electrolyte membrane 111 exhibits good electrical conductivity in a wet state.
- the electrolyte membrane 111 may be made of another material such as a material in which a predetermined matrix is impregnated with phosphoric acid (H 3 PO 4 ), for example, depending on the assumed fuel cell response.
- the anode electrode 112 includes a catalyst layer 112A and a gas diffusion layer 112B.
- the catalyst layer 112 ⁇ / b> A is a member formed of carbon black particles carrying Pt or Pt or the like, and is provided in contact with the electrolyte membrane 111.
- the gas diffusion layer 112B is disposed outside the catalyst layer 112A.
- the gas diffusion layer 112B is a member formed of carbon cloth having gas diffusibility and conductivity, and is provided in contact with the catalyst layer 112A and the anode separator 12.
- the cathode electrode 113 includes a catalyst layer 113A and a gas diffusion layer 113B.
- the catalyst layer 113A is disposed between the electrolyte membrane 111 and the gas diffusion layer 113B, and the gas diffusion layer 113B is disposed between the catalyst layer 113A and the cathode separator 13.
- the anode separator 12 is disposed outside the gas diffusion layer 112B.
- the anode separator 12 includes a plurality of anode gas passages 121 for supplying anode gas (hydrogen gas) to the anode electrode 112.
- the anode gas flow path 121 is formed as a groove-shaped passage.
- the cathode separator 13 is disposed outside the gas diffusion layer 113B.
- the cathode separator 13 includes a plurality of cathode gas passages 131 for supplying cathode gas (air) to the cathode electrode 113.
- the cathode gas channel 131 is formed as a groove-shaped passage.
- the anode separator 12 and the cathode separator 13 are configured such that the flow direction of the anode gas flowing through the anode gas flow path 121 and the flow direction of the cathode gas flowing through the cathode gas flow path 131 are opposite to each other.
- the anode separator 12 and the cathode separator 13 may be configured such that the flow directions of these gases flow in the same direction.
- a fuel cell 10 When such a fuel cell 10 is used as a power source for automobiles, since a required power is large, it is used as a fuel cell stack in which several hundred fuel cells 10 are laminated. Then, a fuel cell system for supplying anode gas and cathode gas to the fuel cell stack is configured, and electric power for driving the vehicle is taken out.
- FIG. 3 is a schematic diagram of a fuel cell system 100 according to an embodiment of the present invention.
- the fuel cell system 100 includes a fuel cell 1, a cathode gas supply / discharge device 2, an anode gas supply / discharge device 3, a power system 5, and a controller 6.
- the fuel cell 1 is a stacked battery in which a plurality of fuel cells 10 (unit cells) are stacked as described above.
- the fuel cell 1 receives supply of anode gas and cathode gas and generates electric power necessary for traveling of the vehicle.
- the fuel cell 1 has an anode electrode side terminal 1A and a cathode electrode side terminal 1B as output terminals for extracting electric power.
- the cathode gas supply / discharge device 2 supplies cathode gas to the fuel cell 1 and discharges cathode off-gas discharged from the fuel cell 1 to the outside.
- the cathode gas supply / discharge device 2 includes a cathode gas supply passage 21, a cathode gas discharge passage 22, a filter 23, an air flow sensor 24, a cathode compressor 25, a cathode pressure sensor 26, and a water recovery device (WRD; Water ⁇ Recovery). Device) 27 and a cathode pressure regulating valve 28.
- the cathode gas supply passage 21 is a passage through which the cathode gas supplied to the fuel cell 1 flows. One end of the cathode gas supply passage 21 is connected to the filter 23, and the other end is connected to the cathode gas inlet of the fuel cell 1.
- the cathode gas discharge passage 22 is a passage through which the cathode off gas discharged from the fuel cell 1 flows. One end of the cathode gas discharge passage 22 is connected to the cathode gas outlet of the fuel cell 1, and the other end is formed as an open end.
- the cathode off gas is a mixed gas containing cathode gas and water vapor generated by electrode reaction.
- the filter 23 is a member that removes dust and dirt contained in the cathode gas taken into the cathode gas supply passage 21.
- the cathode compressor 25 is provided in the cathode gas supply passage 21 on the downstream side of the filter 23.
- the cathode compressor 25 pumps the cathode gas in the cathode gas supply passage 21 and supplies it to the fuel cell 1.
- the air flow sensor 24 is provided in the cathode gas supply passage 21 between the filter 23 and the cathode compressor 25.
- the air flow sensor 24 detects the flow rate of the cathode gas supplied to the fuel cell 1.
- the cathode pressure sensor 26 is provided in the cathode gas supply passage 21 between the cathode compressor 25 and the WRD 27.
- the cathode pressure sensor 26 detects the pressure of the cathode gas supplied to the fuel cell 1.
- the cathode gas pressure detected by the cathode pressure sensor 26 represents the pressure of the entire cathode system including the cathode gas flow path and the like of the fuel cell 1.
- the WRD 27 is connected across the cathode gas supply passage 21 and the cathode gas discharge passage 22.
- the WRD 27 is a device that collects moisture in the cathode off-gas flowing through the cathode gas discharge passage 22 and humidifies the cathode gas flowing through the cathode gas supply passage 21 using the collected moisture.
- the cathode pressure regulating valve 28 is provided in the cathode gas discharge passage 22 downstream of the WRD 27.
- the cathode pressure regulating valve 28 is controlled to be opened and closed by the controller 6 and adjusts the pressure of the cathode gas supplied to the fuel cell 1.
- the anode gas supply / discharge device 3 supplies anode gas to the fuel cell 1 and discharges anode off-gas discharged from the fuel cell 1 to the cathode gas discharge passage 22.
- the anode gas supply / discharge device 3 includes a high pressure tank 31, an anode gas supply passage 32, an anode pressure regulating valve 33, an anode pressure sensor 34, an anode gas discharge passage 35, a buffer tank 36, a purge passage 37, and a purge. And a valve 38.
- the high-pressure tank 31 is a container that stores the anode gas supplied to the fuel cell 1 while maintaining the high-pressure state.
- the anode gas supply passage 32 is a passage for supplying the anode gas discharged from the high-pressure tank 31 to the fuel cell 1.
- One end of the anode gas supply passage 32 is connected to the high-pressure tank 31, and the other end is connected to the anode gas inlet of the fuel cell 1.
- the anode pressure regulating valve 33 is provided in the anode gas supply passage 32 downstream of the high pressure tank 31.
- the anode pressure regulating valve 33 is controlled to be opened and closed by the controller 6 and adjusts the pressure of the anode gas supplied to the fuel cell 1.
- the anode pressure sensor 34 is provided in the anode gas supply passage 32 downstream of the anode pressure regulating valve 33.
- the anode pressure sensor 34 detects the pressure of the anode gas supplied to the fuel cell 1.
- the anode gas pressure detected by the anode pressure sensor 34 represents the pressure of the entire anode system including the buffer tank 36 and the anode gas flow path of the fuel cell 1.
- the anode gas discharge passage 35 is a passage through which the anode off gas discharged from the fuel cell 1 flows. One end of the anode gas discharge passage 35 is connected to the anode gas outlet of the fuel cell 1, and the other end is connected to the buffer tank 36.
- the anode off gas includes an anode gas that has not been used in the electrode reaction, an impurity gas such as nitrogen that has leaked from the cathode gas channel 131 to the anode gas channel 121, moisture, and the like.
- the buffer tank 36 is a container for temporarily storing the anode off gas flowing through the anode gas discharge passage 35.
- the anode off gas stored in the buffer tank 36 is discharged to the cathode gas discharge passage 22 through the purge passage 37 when the purge valve 38 is opened.
- the purge passage 37 is a passage for discharging the anode off gas. One end of the purge passage 37 is connected to the anode gas discharge passage 35, and the other end is connected to the cathode gas discharge passage 22 downstream of the cathode pressure regulating valve 28.
- the purge valve 38 is provided in the purge passage 37.
- the purge valve 38 is controlled to be opened and closed by the controller 6 and controls the purge flow rate of the anode off gas discharged from the anode gas discharge passage 35 to the cathode gas discharge passage 22.
- the anode off gas is discharged to the outside through the purge passage 37 and the cathode gas discharge passage 22. At this time, the anode off gas is mixed with the cathode off gas in the cathode gas discharge passage 22.
- the anode off gas and the cathode off gas are mixed and discharged to the outside, whereby the anode gas concentration (hydrogen concentration) in the mixed gas is determined to be a value equal to or lower than the discharge allowable concentration.
- the power system 5 includes a current sensor 51, a voltage sensor 52, a traveling motor 53, an inverter 54, a battery 55, and a DC / DC converter 56.
- the current sensor 51 detects the output current taken out from the fuel cell 1.
- the voltage sensor 52 detects the output voltage of the fuel cell 1, that is, the inter-terminal voltage between the anode electrode side terminal 1A and the cathode electrode side terminal 1B.
- the voltage sensor 52 may be configured to detect a voltage for each of the fuel cells 10 or may be configured to detect a voltage for each of the plurality of fuel cells 10.
- the traveling motor 53 is a three-phase AC synchronous motor, and is a drive source for driving the wheels.
- the travel motor 53 has a function as an electric motor that rotates by receiving power supplied from the fuel cell 1 and the battery 55 and a function as a generator that generates electric power by being driven to rotate by an external force.
- the inverter 54 includes a plurality of semiconductor switches such as IGBTs.
- the semiconductor switch of the inverter 54 is switching-controlled by the controller 6, thereby converting DC power into AC power or AC power into DC power.
- the traveling motor 53 functions as an electric motor
- the inverter 54 converts the combined DC power of the output power of the fuel cell 1 and the output power of the battery 55 into three-phase AC power and supplies it to the traveling motor 53.
- the traveling motor 53 functions as a generator
- the inverter 54 converts the regenerative power (three-phase alternating current power) of the traveling motor 53 into direct current power and supplies the direct current power to the battery 55.
- the battery 55 is configured such that the surplus output power of the fuel cell 1 and the regenerative power of the traveling motor 53 are charged.
- the electric power charged in the battery 55 is supplied to auxiliary equipment such as the cathode compressor 25 and the traveling motor 53 as necessary.
- the DC / DC converter 56 is a bidirectional voltage converter that raises and lowers the output voltage of the fuel cell 1.
- the output current of the fuel cell 1 is adjusted by controlling the output voltage of the fuel cell 1 by the DC / DC converter 56.
- the controller 6 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface).
- CPU central processing unit
- ROM read only memory
- RAM random access memory
- I / O interface input / output interface
- a signal from a sensor such as an accelerator stroke sensor (not shown) that detects the amount of depression of the accelerator pedal is input to the controller 6.
- the controller 6 controls the anode pressure regulating valve 33, the cathode pressure regulating valve 28, the cathode compressor 25, etc. according to the operating state of the fuel cell system 100, and controls the pressure and flow rate of the anode gas and cathode gas supplied to the fuel cell 1. adjust.
- the controller 6 calculates the target output power of the fuel cell 1 based on the operation state of the fuel cell system 100. Furthermore, the controller 6 calculates the target output power based on the required power of the travel motor 53, the required power of auxiliary equipment such as the cathode compressor 25, the charge / discharge request of the battery 55, and the like.
- the controller 6 calculates the target output current of the fuel cell 1 with reference to the predetermined IV characteristic (current-voltage characteristic) of the fuel cell 1 based on the calculated target output power. Then, the controller 6 controls the output voltage of the fuel cell 1 by the DC / DC converter 56 so that the output current of the fuel cell 1 becomes the target output current, and supplies the necessary current to the traveling motor 53 and the auxiliary machinery. Control.
- controller 6 controls the cathode compressor 25 and the like so that the wetness (water content) of each electrolyte membrane 111 and catalyst layers 112A and 113A of the fuel cell 1 is suitable for power generation.
- the controller 6 in the present embodiment has a function of calculating an ionomer resistance value that correlates particularly with the wetness of the catalyst layers 112A and 113A.
- the controller 6 superimposes an AC signal having a predetermined frequency on the output current and output voltage of the fuel cell 1 when measuring the impedance of the fuel cell 1.
- the controller 6 is configured such that a voltage value obtained by performing Fourier transform on a value obtained by superimposing an AC signal having a predetermined frequency on the output voltage of the fuel cell 1 and an AC signal having the same frequency superimposed on the output current.
- the impedance value Z of the fuel cell 1 at a predetermined frequency is calculated by dividing the current value obtained by performing Fourier transform on the value.
- FIG. 4 is a schematic diagram showing a simple equivalent circuit of the fuel cell 10.
- This simple equivalent circuit is a circuit in which circuit elements such as electron transport resistance and contact resistance in the actual fuel cell 1 are omitted.
- the main circuit elements of the fuel cell 1 are the electrolyte membrane resistance and the reaction of the cathode electrode 113.
- This is a circuit in which the model is simplified considering only the resistance and the electric double layer capacitance.
- reaction resistance and electric double layer capacity at the anode electrode 112 are ignored.
- the reaction resistance value on the anode electrode 112 side is compared with the reaction resistance value R act of the cathode electrode 113. This is because even if this is ignored, it is considered that a large error is not given to the state detection of the fuel cell 1.
- reaction resistance value on the anode electrode 112 side is very small as described above, a current easily flows through the reaction resistance portion on the anode electrode 112 side. That is, this means that almost no current flows through the electric double layer capacitive component arranged in parallel with the reaction resistance. Therefore, sufficient accuracy can be maintained even if the electric double layer capacitance component of the anode 112 is ignored in impedance measurement.
- Z re and Z im are the real part and imaginary part of the impedance of the fuel cell 1, respectively, ⁇ is the angular frequency of the AC signal, R act is the reaction resistance value of the cathode electrode, and C dl is the electric double layer of the cathode electrode 113 It means capacity value.
- an impedance curve on the complex plane (hereinafter also referred to as an equivalent circuit impedance curve) determined based on Equation (1) is on the complex plane having a center of R m + R act / 2 and a radius of R act / 2. Since it represents a circle, the intersection of the circle and the real axis is R m . This means that if the high frequency ⁇ H having a sufficiently large value is also used for impedance measurement, the actual impedance measurement value Z re ( ⁇ H ) matches the electrolyte membrane resistance value R m . This is also clear from the fact that if the value of ⁇ is sufficiently large in Equation (2), the second term on the right side approaches 0 and R m ⁇ Z re .
- the ionomer resistance value and the electron transport resistance value in the electrolyte membrane 111, the gas diffusion layer 113 ⁇ / b> B, and the catalyst layer 113 ⁇ / b> A (hereinafter simply referred to as the electron transport of the electrolyte membrane 111).
- the inventors of the present invention determined that the electrolyte membrane resistance value R m determined based on the above-described simplified equivalent circuit is actually the true electrolyte membrane resistance value of the fuel cell 1, the ionomer resistance component, and the electron transport of the electrolyte membrane 111. It was found that it corresponds to a value obtained by adding a resistance component (hereinafter referred to as an assumed high frequency impedance value R cell, sup ).
- the electrolyte membrane resistance value R m determined based on the simple equivalent circuit will be described as an assumed high frequency impedance value R cell, sup, and “R mem ” represents the true electrolyte membrane resistance of the fuel cell 1.
- the assumed high frequency impedance value R cell, sup is equal to the sum of the true electrolyte membrane resistance value R mem , the ionomer resistance value R ion , and the electron transport resistance value of the electrolyte membrane 111.
- the ionomer resistance value R ion is known to be a resistance generated due to the movement of the proton H + in the catalyst layer 113A.
- the catalyst layer 113A The distribution of Pt (reaction sites) in the thickness direction must be considered.
- FIG. 5 is a diagram illustrating the principle that the ionomer resistance value increases as the thickness of the catalyst layer 113A of the electrolyte membrane 111 increases.
- Pt platinum
- FIG. 5 is a diagram illustrating the principle that the ionomer resistance value increases as the thickness of the catalyst layer 113A of the electrolyte membrane 111 increases.
- reaction efficiency decreases when the proton H + moves through the ionomer for a long distance or concentrates on Pt close to the electrolyte membrane 111, the reaction does not seem to cause such a decrease in efficiency. It tends to progress so as to have a uniform distribution of a certain degree in the thickness direction.
- the movement distance in the ionomer is increased based on the action of the proton H + exhibiting a uniform distribution in the thickness direction. Is understood to be large.
- FIG. 6 shows an equivalent circuit of a distributed constant system in which the distribution in the thickness direction of the fuel cell 10 is also taken into consideration. That is, the equivalent circuit is a circuit that more accurately represents the characteristics of the actual fuel cell 10 in consideration of the effects of ionomer resistance, electron transport resistance of the electrolyte membrane 111, and the like.
- reaction sites A1 to An each having a reaction resistance element and an electric double layer capacitance element are set in the cathode electrode 113. That is, a plurality of reaction sites A1 to An are set corresponding to the thickness of the cathode electrode 113, so that the accuracy of the model is improved.
- the ionomer resistance and the electron transport resistance of the electrolyte membrane 111 are also taken into consideration, and the thickness of the fuel cell 10 is taken into consideration similarly to the cathode electrode 113, and each of the equivalent circuits includes a plurality of resistance elements (in the drawing). n-1)).
- the reaction resistance values corresponding to the respective reaction resistance elements in the cathode electrode 113 are denoted by R act, a1 , R act, a2 ,... R act, an and correspond to the electric double layer capacitance elements.
- the electric double layer capacity values denoted C dl, a1, C dl, a2, ⁇ C dl, a sign of an.
- the ionomer resistance value is labeled with R ion, a 1 , R ion, a 2 ,... R ion, an ⁇ 1
- the electron transport resistance value of the electrolyte membrane 111 is represented by R m, ele . A sign is attached.
- R g, ele, a1 , R g, ele, a2 ,... R g, ele, an-1 are attributed to the structure formed by the carbon supporting Pt in the catalyst layer 113A. Means electron transport resistance.
- the impedance value in the electric double layer capacitive element is expressed by an expression of 1 / ( ⁇ C dl ). Therefore, as apparent from this equation, the impedance value in the electric double layer capacitive element becomes smaller as the frequency is higher.
- the impedance that is , the combined resistance of R act, a1 and C dl, a1
- the impedance that is , the combined resistance of R act, a1 and C dl, a1
- the current that flows to the reaction site An far from the electrolyte membrane 111 passes through all the ionomer resistance elements. Therefore, as described above, in the case of a high frequency at which current is likely to flow relatively to the reaction site A1, the current hardly flows to the reaction site An.
- FIG. 7 is a graph showing the frequency characteristics of the imaginary part impedance value determined based on the simple equivalent circuit of FIG.
- a straight line indicated by a broken line in the drawing illustrates the expression (3) based on the above-described simple equivalent circuit. That is, the slope of this line is given by 1 / C dl R 2 act and the intercept is given by C dl .
- the curve shown in the figure is drawn by plotting and connecting imaginary part impedance measurement values Z im ( ⁇ ) measured in advance at the plurality of frequencies ⁇ in the fuel cell 1.
- the imaginary part impedance measurement value Z im ( ⁇ ) measured at a plurality of frequency points is used in this way, based on the imaginary part impedance Z im obtained from the above-described simplified equivalent circuit equation (1),
- the multilayer capacitance value C dl and the reaction resistance value R act can be obtained.
- the slope 1 / C dl R 2 act and the intercept C dl of the straight line are also obtained using the electric double layer capacitance value C dl and the reaction resistance value R act thus obtained.
- the line connecting the square plots matches the straight line based on the simple equivalent circuit in the relatively low frequency range, but does not match in the high frequency range, and the value decreases rapidly. It is a divergence.
- the simple equivalent circuit shown in FIG. 4 is a good model of an actual fuel cell in a relatively low frequency region, but is not well modeled in a relatively high frequency region. means.
- the reason why the simple equivalent circuit shown in FIG. 4 has a low accuracy as a model in a relatively high frequency region is that the inventors of the present invention have considered that the electrons of the electrolyte membrane 111 considered in the equivalent circuit of the distributed constant system in FIG. It is considered that the cause is that the influence of the transport resistance value R m, ele and the ionomer resistance values R ion, a1 to R ion, an becomes so large that it cannot be ignored in the high frequency region.
- the electron transport resistance values R g, ele, a1 , R g, ele, a2 ,... R g, ele, an-1 due to the carbon in the catalyst layer 113A are the electron transport resistance values of the electrolyte membrane 111.
- FIG. 8 shows an impedance curve (also referred to as an equivalent circuit impedance curve C1) determined by applying a measured value of the state quantity of the fuel cell 1 to a simple equivalent circuit, based on an actual impedance value measured in advance under a predetermined condition.
- Impedance curve hereinafter also referred to as measured impedance curve C2
- impedance curve when it is assumed that the effect of electron transport resistance R m, ele of electrolyte membrane 111 is excluded in the measured impedance curve (hereinafter referred to as “electron transport resistance excluded impedance curve”) C3)).
- the equivalent circuit impedance curve C1 is indicated by a broken line
- the measured impedance curve C2 is indicated by a solid line
- the electron transport resistance exclusion impedance curve C3 is indicated by a one-dot chain line.
- only a part of each impedance curve is shown for simplification of the drawing.
- the equivalent circuit impedance curve C1 is, for example, measured impedance values Z ( ⁇ L1 ) and Z ( ⁇ L2 ) at two frequencies ⁇ L1 and ⁇ L2 in the low frequency region, in particular its real part Z re ( ⁇ L1 ) And Z re ( ⁇ L2 ) and imaginary part Z im ( ⁇ L1 ) and Z im ( ⁇ L2 ) are applied to the impedance equations (2) and (3) based on the simplified equivalent circuit, and thus obtained From the four equations, the electric double layer capacitance C dl , reaction resistance R act , and assumed high frequency impedance value R cell, sup are obtained, and these arc values are obtained by substituting these values into equation (1). That is, in particular, as understood with reference to FIG. 8, the value of the intersection of the equivalent circuit impedance curve C1 and the real axis corresponds to the assumed high frequency impedance value R cell, sup .
- the measured impedance curve C2 is a curve drawn by plotting impedance measurements at a plurality of frequencies on the fuel cell 1 obtained from the equivalent circuit impedance curve C1 and plotting the obtained impedance measurements on a complex plane. is there.
- this measured impedance curve C2 normally requires impedance measurement values at a large number of frequencies, it is difficult to create the fuel cell 1 in a state where it is mounted on the vehicle. Therefore, as the measured impedance curve C2, for example, data created by experimentally measuring impedance in advance for the same type of fuel cell as the fuel cell 1 is used.
- the electron transport resistance exclusion impedance curve C3 is a curve in which the influence of the electron transport resistance value R m, ele is excluded from the measured impedance curve C2.
- the present inventors have found that there is only a difference that the electron transport resistance exclusion impedance curve C3 is translated in the negative direction of the actual axis by the influence of the electron transport resistance value R m, ele with respect to the measured impedance curve C2. That is, the measured high frequency impedance value R cell, act , which is the value of the intersection between the measured impedance curve C 2 and the real axis, is a value obtained by adding the electron transport resistance value R m, ele to the electrolyte membrane resistance value R mem . .
- the actually measured impedance curve C2 substantially matches the equivalent circuit impedance curve C1 in a relatively low-frequency arc region. However, the actually measured impedance curve C2 forms a linear portion in the relatively high frequency non-arc region L2, and deviates from the equivalent circuit impedance curve C1.
- sup and the measured high frequency impedance value R cell act which is the value of the intersection of the measured impedance curve C2 and the real axis, the electron transport resistance value R m, ele of the electrolyte membrane 111 and the electrolyte membrane resistance It has been found that the value R mem is canceled and ionomer resistance values R ion, a1 to R ion, an (hereinafter collectively referred to as R ion ) are obtained.
- the ionomer resistance value R ion thus obtained does not include other resistance components and is highly accurate.
- the highly accurate ionomer resistance value R ion can be used for estimating the wet state of the fuel cell 1, and the wet state is high. The accuracy can be estimated.
- FIG. 9 is a flowchart showing a flow of estimating the ionomer resistance value R ion of the fuel cell 1 according to the first embodiment. The following steps S101 to S103 are executed by the controller 6.
- step S101 the above-described measured high frequency impedance value R cell, act is obtained using the impedance measurement value of the frequency in the non-arc region L2.
- FIG. 10 is a flowchart showing a detailed flow for obtaining the measured high frequency impedance value R cell, act .
- Found high frequency impedance value R cell of the present embodiment, estimation of the act is performed in accordance with steps S1011 ⁇ step S1014 shown in FIG.
- step S1011 the controller 6 sets the output current and output voltage output from the fuel cell 1 to the frequency ⁇ H (several kHz to several tens kHz) of the non-arc region L2 (high frequency region) at the impedance measurement timing.
- the DC / DC converter 56 is controlled so that the signal is superimposed.
- the frequency ⁇ H is more preferably as large as possible, and is preferably several tens of kHz.
- the higher the frequency value the closer the point on the complex plane represented by the frequency approaches the intersection of the measured impedance curve C2 and the real axis.
- step S1012 the controller 6 performs a Fourier transform process on the current value I out of the output current measured by the current sensor 51, calculates the current amplitude value I out ( ⁇ H).
- step S1013 it performs a Fourier transform process on the output voltage V out measured by the voltage sensor 52, and calculates the voltage amplitude value V out ( ⁇ H).
- step S1014 by dividing the voltage amplitude value V out the (omega H) at a current amplitude value I out ( ⁇ H) is calculated impedance Z ( ⁇ H), a fuel cell the real component Z re ( ⁇ H) 1 measured high frequency impedance value R cell, act is determined.
- step S102 the above-described assumed high frequency impedance value R cell, sup is obtained using the impedance measurement value of the frequency in the arc region which is the low frequency region.
- the measured impedance curve C2 substantially coincides with the equivalent circuit impedance curve C1 in the arc region as described above.
- FIG. 11 is a flowchart showing a flow for obtaining the assumed high frequency impedance value R cell, sup .
- the actually measured high frequency impedance value according to this embodiment is estimated according to steps S1021 to S1025 shown in the figure.
- step S1021 the controller 6 receives signals of two frequencies ⁇ L1 and ⁇ L2 (several Hz to several tens Hz) in the arc region in the output current and output voltage output from the fuel cell 1 at the impedance measurement timing.
- the DC / DC converter 56 is controlled so as to be superimposed on each other.
- step S1022 the controller 6 performs a Fourier transform process on the current value I out of the output current measured by the current sensor 51 when the AC signal of frequency omega L1 is superimposed, the current amplitude value I out (omega L1) Is calculated.
- the current value I out of the output current measured by the current sensor 51 is subjected to Fourier transform processing to calculate a current amplitude value I out ( ⁇ L2 ).
- step S1023 the controller 6 performs a Fourier transform process to the value V out of the output voltage measured by the voltage sensor 52 when the AC signal of frequency omega L1 is superimposed, the voltage amplitude value V out (omega L1) calculate. Further, when an AC signal of frequency ⁇ L2 is superimposed, the output voltage value V out measured by the voltage sensor 52 is subjected to Fourier transform processing to calculate a current amplitude value V out ( ⁇ L2 ).
- step S1024 it calculates the impedance Z ( ⁇ L1) by dividing the voltage amplitude value V out ( ⁇ L1) with a current amplitude value I out ( ⁇ L1), the voltage amplitude value V out ( ⁇ L2) the current amplitude value
- the impedance Z ( ⁇ L2 ) is calculated by dividing by I out ( ⁇ L2 ).
- step S1025 an assumed high frequency impedance value R cell, sup is obtained based on the two impedances Z ( ⁇ L1 ) and impedance Z ( ⁇ L2 ). Specifically, solving the equations obtained by applying the measured impedance Z ( ⁇ L1 ) and impedance Z ( ⁇ L2 ) to the impedance equations (2) and (3) based on the simple equivalent circuit, R cell, sup (R m in equation (2)), which is one of the unknowns, is obtained.
- the slope is (1 / C dl R act 2 ) on the coordinate plane with (1 / ⁇ 2 ) as the horizontal axis and ( ⁇ 1 / ⁇ Z im ) as the vertical axis.
- an electric double layer capacitor C dl and reaction resistance R act are calculated.
- the assumed high frequency impedance value R cell, sup obtained as described above coincides with the value of the intersection between the equivalent circuit impedance curve C1 and the real axis (see FIG. 8).
- step S103 the controller 6 estimates the ionomer resistance value R ion based on the measured high frequency impedance value R cell, act and the assumed high frequency impedance value R cell, sup . Specifically, the controller 6 subtracts the measured high frequency impedance value R cell, act from the assumed high frequency impedance value R cell, sup , that is, R cell, sup ⁇ R cell, act is the ionomer resistance value R ion. Estimated.
- the ionomer resistance value R ion estimated in this way is used to estimate the wetness w of the fuel cell 1.
- FIG. 12 shows the relationship between the ionomer resistance value R ion and the wetness w of the fuel cell 1. As illustrated, there is a negative correlation between the ionomer resistance value R ion and the wetness w of the fuel cell 1. That is, the wet state of the fuel cell 1 can be detected by monitoring the ionomer resistance value R ion .
- the state detection device of the fuel cell 1 that is, the state detection device including the controller 6, the current sensor 51, the voltage sensor 52, and the DC / DC converter 56, the following effects can be obtained. Can do.
- the controller 6 determines the assumed height based on the impedance measurement values Z ( ⁇ L1 ) and Z ( ⁇ L2 ) belonging to the arc region of the impedance curve C 2 of the fuel cell 1.
- the assumed high frequency impedance value setting means assumes the value of the intersection between the equivalent circuit impedance curve C1 set based on the impedance measurement values Z ( ⁇ L1 ) and Z ( ⁇ L2 ) in the arc region and the real axis.
- the high frequency impedance value R cell, sup is set (step S102).
- the equivalent circuit impedance curve C1 set based on the impedance measurement values Z ( ⁇ L1 ) and Z ( ⁇ L2 ) belonging to the arc region of the impedance curve C2 of the fuel cell 1, the equivalent circuit impedance curve C1 and the actual
- the assumed high frequency impedance value R cell, sup determined as the value of the intersection with the axis includes the ionomer resistance value R ion in addition to the electrolyte membrane resistance value R mem and the electron transport resistance value R m, ele of the electrolyte membrane 111. ing.
- the measured high frequency impedance value R cell act set based on the impedance measurement value Z ( ⁇ H ) belonging to the non-arc region L2 of the impedance curve C2 of the fuel cell 1 includes the electrolyte membrane resistance value R mem and The electron transport resistance value R m, ele of the electrolyte membrane 111 is included.
- the highly accurate ionomer resistance value R ion obtained in this way can be used for detecting the state of the fuel cell 1, and as a result, contributes to detecting the state of the fuel cell 1 with high accuracy.
- the equivalent circuit impedance curve C1 is an impedance measurement value belonging to the arc region in the equations (1) to (3) of the impedance obtained from the simple equivalent circuit of the fuel cell 1 (see FIG. 4). It is set by applying Z ( ⁇ L1 ) and Z ( ⁇ L2 ).
- Z ( ⁇ L1 ) and Z ( ⁇ L2 ) the amount of calculation related to the setting of the equivalent circuit impedance curve C1 is reduced.
- R cell sup that is the value of the intersection between the equivalent circuit impedance curve C1 and the real axis.
- the equivalent circuit impedance curve C1 is obtained by changing the frequency of two points in the circular arc region to the equation (2) of the real impedance part and the equation (3) of the imaginary impedance part obtained from the simple equivalent circuit of FIG. omega L1, and omega impedance measurements in L2 Z ( ⁇ L1), Z real part Z re ( ⁇ L1) of ( ⁇ L2), Z re ( ⁇ L2) and the imaginary part Z im ( ⁇ L1), Z im ( It is set by applying ⁇ L2 ).
- the amount of calculation for obtaining the assumed high frequency impedance value R cell, sup can be further reduced.
- the assumed high frequency impedance value setting means is based on two or more impedances Z ( ⁇ L1 ) and Z ( ⁇ L2 ) belonging to the arc region, and each of two or more assumed high frequency impedance value candidates R cell, sup-1 and Rcell, sup-2 are obtained, and an average value (R cell, sup-1 + R cell ) of candidate R cell, sup-1 and R cell, sup-2 of two or more assumed high frequency impedance values is obtained.
- sup ⁇ 2 ) / 2 is set as the assumed high frequency impedance value R cell, sup . Thereby, the measurement error of the assumed high frequency impedance value R cell, sup is reduced.
- ⁇ H is selected as the frequency in the non-arc region L2, and the impedance Z ( ⁇ H ) of this frequency ⁇ H is used.
- the measured height is measured using impedance measured values Z ( ⁇ H ′) and Z ( ⁇ H ′′) of two frequencies ⁇ H ′ and ⁇ H ′′ smaller than ⁇ H.
- the frequency impedance value R cell, act may be calculated. In this case, the calculation can be performed by the same process as the calculation of the assumed high frequency impedance value using the equations (1) to (3) of the impedance obtained from the simple equivalent circuit of FIG.
- the actually measured high-frequency impedance value calculation means includes two or more impedances Z ( ⁇ H ′), Z belonging to the non-arc region L2. Based on ( ⁇ H ′′ ), two or more measured high-frequency impedance value candidates R cell, act-1 , R cell, act-2 are obtained, and the average value (R cell, act-1 + R cell, act-2 ) / 2 may be estimated as the measured high frequency impedance value R cell, act . Thereby, the measurement error of the measured high frequency impedance value R cell, act is reduced.
- the higher value of the above-mentioned two or more assumed high frequency impedance value candidates R cell, sup-1 , R cell, sup-2 is set as the assumed high frequency impedance value R cell, sup. May be.
- the assumed high frequency impedance value R cell, sup is estimated to be relatively high, so that the ionomer resistance value R ion estimated as R cell, sup ⁇ R cell, act is also estimated to be relatively high. It will be. Therefore, referring to the relationship shown in the graph of FIG. 12, since the wetness w is estimated to be relatively low, measures to prevent overdrying by quickly grasping the dry state of the fuel cell are taken. Can do.
- two or more measured high frequency impedance value candidates R cell, act-1, respectively. , R cell, act-2 is obtained, the lower value of the two or more measured high frequency impedance value candidates R cell, act-1 , R cell, act-2 obtained is the measured high frequency impedance value.
- R cell, act may be estimated.
- the measured high frequency impedance value R cell, act is estimated to be relatively low, so that the ionomer resistance value R ion calculated as R cell, sup ⁇ R cell, act is estimated to be higher.
- the wetness w is estimated to be relatively low, and therefore, measures are taken to quickly grasp the dry state of the fuel cell 1 and prevent overdrying. be able to.
- the lower one of the above two or more assumed high frequency impedance value candidates (R cell, sup-1 , R cell, sup-2 ) is estimated as the assumed high frequency impedance value R cell, sup .
- the assumed high frequency impedance value R cell, sup is estimated to be relatively low, so that the ionomer resistance value R ion calculated as R cell, sup ⁇ R cell, act is also estimated to be relatively low. It will be.
- the wetness w is estimated to be relatively high, and therefore, measures to prevent flooding and the like by quickly grasping the wet state of the fuel cell are taken. Can do.
- each of two or more measured high frequency impedance value candidates (R cell, act ⁇ 1 , R cell, act-2 )
- the higher one of the two or more measured high frequency impedance value candidates (R cell, act-1 , R cell, act-2 ) obtained is actually measured
- the high frequency impedance value R cell, act may be estimated.
- the measured high frequency impedance value R cell, act is estimated to be relatively high, and therefore the ionomer resistance value R ion estimated as R cell, sup ⁇ R cell, act is estimated to be lower.
- the wetness w is estimated to be relatively high, so that measures to prevent flooding by quickly grasping the wet state of the fuel cell can be taken. it can.
- the selection low and the selection high while roughly determining whether the fuel cell 1 is in a state close to overdrying or in a state close to flooding (that is, overwetting).
- the wet state of the fuel cell 1 may be roughly estimated by existing HFR measurement or the like, and the selection low and the selection high may be determined based on the result of the rough estimation. . Furthermore, the wet state is roughly estimated based on the operating conditions of the fuel cell 1 such as the cathode gas flow rate, the anode gas flow rate, and the temperature, and the selection low and the selection high are determined based on the result of the rough estimation. May be.
- the second embodiment will be described.
- symbol is attached
- the estimated ionomer resistance value R ion is corrected in consideration of the deterioration state of the fuel cell 1.
- the estimated value of the ionomer resistance value R ion increases due to deterioration of the catalyst layer 113A.
- the relationship between the ionomer resistance value R ion and the wetness w is inherently a negative correlation shown in FIG. 12, if the ionomer resistance value R ion can be estimated, the wetness is based on the estimated value. It is also possible to estimate the degree w.
- the ionomer resistance value R ion may increase regardless of the wetness value w.
- correction is performed to exclude an increase in ionomer resistance value R ion due to deterioration of the catalyst layer 113A so that the ionomer resistance value R ion accurately corresponds to the wetness w.
- FIG. 13 is a flowchart showing a flow of creating data for ionomer resistance value correction in the present embodiment.
- the data for correcting the ionomer resistance value is generated before the fuel cell 1 is mounted on the vehicle, for example.
- FIG. 14 is a graph schematically showing how the ionomer resistance value R ion changes with time.
- step S1101 the controller 6 estimates the ionomer resistance value under the reference operating condition.
- the “reference operation condition” is a power generation condition of the fuel cell 1 that assumes a normal load state such as normal traveling or a low load state such as inertial traveling rather than a high load state such as acceleration.
- a normal load state such as normal traveling or a low load state such as inertial traveling rather than a high load state such as acceleration.
- this reference operating condition is set. Can be realized.
- the ionomer resistance value R ion estimated at this time t is also referred to as “degraded ionomer resistance value (R ion ) t ”.
- step S1102 and step S1103 are executed over time, and the increment ⁇ R ion (t) is obtained as a function of time.
- step S1104 the obtained increment ⁇ R ion (t) is stored in a memory (not shown) of the controller 6 or the like.
- this increment ⁇ R ion (t) is used as data for ionomer resistance value correction.
- the stored increment ⁇ R ion (t) is corrected without calculating the increment of the ionomer resistance value R ion due to deterioration.
- the ionomer resistance value R ion is corrected by using it as data.
- details of the correction of the ionomer resistance value using the data for correcting the ionomer resistance value will be described.
- FIG. 15 is a flowchart showing the flow of correcting the ionomer resistance value.
- step S ⁇ b> 1111 the controller 6 estimates the ionomer resistance value R ion after the predetermined time t has elapsed after operating the fuel cell 1.
- this estimated value is also referred to as “current ionomer resistance value (R ion ) cur ”.
- the current ionomer resistance value (R ion ) cur is also estimated by the same method as in steps S101 to S103 shown in FIG.
- the operating time t of the fuel cell 1 when the current ionomer resistance value (R ion ) cur is estimated is stored in a memory (not shown) or the like.
- step S1112 the increment ⁇ R ion (t) stored in step S1204 is read from the memory of the controller 6 or the like.
- the increment ⁇ R ion (t) corresponding to the operating time t of the fuel cell 1 is read from the memory or the like of the controller 6.
- step S1113 the corrected true ionomer resistance value (R ion ) tru is calculated by subtracting the increment ⁇ R ion (t) from the current ionomer resistance value (R ion ) cur described above.
- the controller 6 further functions as an ionomer resistance correction unit.
- the ionomer resistance value (R ion ) t is compared to obtain the ionomer resistance value increment ⁇ R ion (t), and the current estimated value (R ion ) cur of the ionomer resistance value is subtracted from this increment ⁇ R ion (t). To determine the true ionomer resistance value (R ion ) tru .
- the true ionomer resistance value (R ion ) tru corresponding to the degree of wetness w can be obtained with high accuracy, excluding the increase in the ionomer resistance value R ion due to deterioration.
- the estimation accuracy of the wet state of the battery 1 is further improved.
- the above correction ensures the influence of the deterioration state of the catalyst layer 113A that promotes the increase of the ionomer resistance value R ion. Can be removed.
- the present invention is not limited to this.
- the cause of the electron transport resistance such as the gas diffusion layer and the separator
- the true ionomer resistance value (R ion ) tru may be obtained by subtracting from the value (R ion ) cur .
- the estimated electrolyte membrane is considered in consideration of an increase in the electrolyte membrane resistance value R mem due to deterioration of elements that contribute greatly to the electronic resistance, such as the gas diffusion layer 113B and the separator 13 of the fuel cell 1.
- the resistance value R mem is corrected.
- FIG. 16 shows the relationship between the electrolyte membrane resistance value R mem and the wetness w.
- the relationship between the electrolyte membrane resistance value R mem and the wetness w is a negative correlation shown in the figure. Therefore, if the wetness w can be estimated using the ionomer resistance value R ion as described above, the electrolyte membrane resistance value R mem can be estimated based on the estimated value of the wetness w.
- the measured high frequency impedance value R cell act obtained in steps S1011 to S1014 in FIG.
- the measured high frequency impedance value R cell act includes the electron transport resistance component as described above, the value increases when the elements such as the gas diffusion layer 113B and the separator 13 are deteriorated. It will be.
- the measured high frequency impedance value R cell, act is measured using the electrolyte membrane resistance value R mem estimated using the wetness w based on the ionomer resistance value R ion described above. Correction is performed so as to exclude the increase in electron transport resistance due to deterioration.
- FIG. 17 is a flowchart showing a flow of creating the electrolyte membrane resistance value correction data in the present embodiment.
- the creation of the electrolyte membrane resistance value correction data is performed, for example, before the fuel cell 1 is mounted on the vehicle.
- Each estimation and measurement are performed under the reference operating conditions described in the second embodiment. Preferably.
- FIG. 18 is a graph schematically showing how the measured high frequency impedance value R cell, act changes with time.
- step S1201 the controller 6 determines the electrolyte membrane resistance value shown in FIG. 16 and the wetness level w of the fuel cell 1 from the wetness level w estimated based on the ionomer resistance value R ion at the start of operation of the fuel cell 1. Based on the relationship, the electrolyte membrane resistance value R mem is estimated.
- the ionomer resistance value R ion used for estimation may be the value estimated in step S103 in FIG. 9 or the true ionomer resistance value (R ion ) tru obtained in step S1113 in FIG. .
- the estimated electrolyte membrane resistance value R mem is set as the reference electrolyte membrane resistance value (R mem ) cri .
- step S1202 after the estimation of the reference electrolyte membrane resistance value (R mem ) cri , the controller 6 operates the fuel cell 1 and after time t has elapsed, obtains the measured high frequency impedance value R cell, act . .
- the degradation of elements such as the gas diffusion layer 113B and the separator 13 proceeds with the operation of the fuel cell 1, so that the measured high frequency impedance value R cell, act is Ascend (see FIG. 18).
- the actually measured high frequency impedance value R cell, act that has risen at time t is estimated.
- the actually measured high frequency impedance value R cell, act estimated at this time t is also referred to as “degraded actually measured high frequency impedance value (R cell, act ) t ”.
- the specific method for obtaining the measured high frequency impedance value R cell, act is the same as the method described in steps S1011 to S1014 in FIG.
- step S1203 the controller 6 subtracts the reference electrolyte membrane resistance value (R mem ) cri from the estimated post-degradation measured high frequency impedance value (R cell, act ) t to obtain a difference ⁇ R e (t) due to degradation.
- step S1202 and step S1203 are executed over time, and this difference ⁇ R e (t) is obtained as a function of time.
- step S1204 the obtained difference ⁇ R e (t) is stored in a memory (not shown) of the controller 6 or the like.
- this difference ⁇ R e (t) is used as data for correcting the electrolyte membrane resistance value.
- the stored difference ⁇ R e () is calculated without calculating the increment of the actually measured high frequency impedance value R cell, act due to deterioration.
- ⁇ R e (t) is corrected using t) as correction data.
- FIG. 19 is a flowchart showing the flow of correcting the ionomer resistance value.
- step S1211 the controller 6 calculates the measured high frequency impedance value R cell, act after the predetermined time t has elapsed after the fuel cell 1 is operated.
- the obtained value is also referred to as “current high frequency impedance value (R cell, act ) cur ”.
- the operating time t of the fuel cell 1 when the current high frequency impedance value (R cell, act ) cur is estimated is stored in a memory or the like (not shown).
- step S ⁇ b > 1212 the controller 6 reads the difference ⁇ R e (t) stored in step S ⁇ b > 1204 from the memory or the like of the controller 6.
- the difference ⁇ R e (t) corresponding to the operating time t of the fuel cell 1 is read from the memory or the like of the controller 6.
- step S1213 the controller 6 calculates the corrected true electrolyte membrane resistance value (R mem ) tru by subtracting the difference ⁇ R e (t) from the current high frequency impedance value (R cell, act ) cur described above. To do.
- the current high frequency impedance value (R cell, act ) cur after the operation time t of the fuel cell 1 has elapsed includes the influence of deterioration of elements such as the gas diffusion layer 113B and the separator 13. Also, by subtracting the difference ⁇ R e (t) from the current high frequency impedance value (R cell, act ) cur, the true electrolyte membrane resistance value (R mem ) tru that does not include the effects of the above deterioration is obtained. Can do.
- the controller 6 further functions as an electrolyte membrane resistance estimation unit that estimates the electrolyte membrane resistance value R mem . Then, the controller 6 determines a reference electrolyte membrane resistance value (R mem ) cri set based on the relationship between the estimated ionomer resistance value R ion or (R ion ) tru and the wetness w of the fuel cell 1, The difference ⁇ R e (t) of the actually measured high frequency impedance value is obtained by comparing the measured actual high frequency impedance value (R cell, act ) t after deterioration after the fuel cell 1 has been operated for a predetermined time from the setting time. The true electrolyte membrane resistance value (R mem ) tru is obtained by subtracting this difference ⁇ R e (t) from the current measured value (R cell, act ) cur of the actually measured high frequency impedance value.
- the difference ⁇ R e (t) in the electrolyte membrane resistance value due to the increase in the electron transport resistance caused by the deterioration of the electronic components such as the gas diffusion layer 113B and the separator 13 of the fuel cell 1 can be estimated with high accuracy.
- the measured high frequency impedance value can be matched with the actual electrolyte membrane resistance value with high accuracy.
- various controls of the fuel cell 1 can be more suitably performed by using the actually measured high frequency impedance value corrected in this way as the true electrolyte membrane resistance value.
- the frequency for impedance measurement used when obtaining the assumed high frequency impedance value R cell, sup or the measured high frequency impedance value R cell, act belongs to the arc region of the measured impedance curve C2. It is determined appropriately whether it exists or belongs to a non-arc region. As a result, the accuracy of the ionomer resistance value R ion obtained using these impedance values can be improved.
- two frequencies ⁇ 1 and ⁇ 2 ( ⁇ 1 ⁇ 2) belong to the arc region of the actually measured impedance curve C2 or belong to the non-arc region L2 of the actually measured impedance curve C2.
- a process for determining whether or not will be described.
- the method of the present embodiment can be similarly applied to three or more frequencies.
- FIG. 20 is a flowchart showing a flow of determining whether two frequencies ⁇ 1 and ⁇ 2 used for impedance measurement belong to the arc region of the measured impedance curve C2 or belong to the non-arc region of the measured impedance curve C2.
- the processes in steps S1301 to S1308 are executed by the controller 6.
- step S130 impedances Z ( ⁇ 1) and Z ( ⁇ 2) at two frequencies ⁇ 1 and ⁇ 2 are measured. Note that a specific method of impedance measurement is performed by the same method as the impedance measurement in steps S1021 to S1024 in FIG. 10, for example.
- step S1302 a straight line L connecting the impedance values Z ( ⁇ 1) and Z ( ⁇ 2) is set on the complex plane.
- step S1303 the size of the coordinate ⁇ of the intersection point of the straight line L with the real axis and the actually measured high frequency impedance value R cell, act are compared.
- step S1304 If it is determined in step S1304 that the coordinate ⁇ of the intersection point substantially matches the measured high frequency impedance value R cell, act , the process proceeds to step S1305, and both the frequencies ⁇ 1 and ⁇ 2 belong to the non-arc region L2. It is determined.
- FIG. 21 shows a mode in which the coordinate ⁇ of the intersection point of the straight line L with the real axis matches the measured high frequency impedance value R cell, act .
- the non-arc region L2 of the actually measured impedance curve C2 is formed as a straight portion, the coordinates ⁇ and R cell, act of the intersection with the real axis of the straight line L are substantially equal.
- the straight line L connecting the impedance values Z ( ⁇ 1) and Z ( ⁇ 2) coincides with the non-arc region L2. Therefore, the impedance values Z ( ⁇ 1) and Z ( ⁇ 2) on the straight line L inevitably exist on the non-arc region L2.
- the coordinate ⁇ is measured high-frequency impedance value R cell in the step S1304, when it is determined not to act substantially coincident, the process proceeds to step S1306, coordinate ⁇ is measured high-frequency impedance value R cell, than act It is determined whether it is large.
- step S1307 If it is determined that the coordinate ⁇ of the intersection is larger than the actually measured high frequency impedance value R cell, act , the process proceeds to step S1307, where it is determined that the relatively small value of frequency ⁇ 1 belongs to at least the arc region.
- FIG. 22 shows an aspect in which the coordinate ⁇ of the intersection point of the straight line L with the real axis is larger than the actually measured high frequency impedance value R cell, act .
- the frequency ⁇ 1 belongs to the arc region.
- the frequency ⁇ 2 is on the non-arc region L2, but if the value of the coordinate ⁇ of the intersection point with the real axis of the straight line L becomes larger than a certain value, it exists on the arc region.
- step S1306 determines whether the coordinate ⁇ of the intersection point is smaller than the actually measured high frequency impedance value R cell, act . If it is determined in step S1306 that the coordinate ⁇ of the intersection point is smaller than the actually measured high frequency impedance value R cell, act , the process proceeds to step S1308, where it is determined that both the frequencies ⁇ 1 and ⁇ 2 belong to the arc region.
- FIG. 23 shows a mode in which the coordinate ⁇ of the intersection point with the real axis of the straight line L is smaller than the actually measured high frequency impedance value R cell, act .
- the frequency ⁇ 2 belongs to the arc region. Therefore, although not shown in the drawing, ⁇ 1 smaller than the frequency ⁇ 2 naturally belongs to the arc region, and therefore both the frequencies ⁇ 1 and ⁇ 2 belong to the arc region.
- the controller 6 has an intersection ⁇ between the straight line L connecting the impedance measurement values Z ( ⁇ 1) and Z ( ⁇ 2) measured at two frequencies ⁇ 1 and ⁇ 2 and the real axis, and an actual high frequency impedance value.
- the two frequencies ⁇ 1 and ⁇ 2 function as frequency region determination means for determining whether the two frequencies ⁇ 1 and ⁇ 2 belong to the non-arc region or the arc region, respectively.
- one frequency belonging to the non-arc region (high frequency band) is used, and two frequencies belonging to the arc region (low frequency band) are used.
- the frequency is used.
- the frequency domain determination means for example, it is determined whether each of a plurality of frequencies belongs to a non-arc area or an arc area, one frequency belonging to the non-arc area is selected, and the arc area By selecting two frequencies belonging to, the ionomer resistance value R ion can be estimated with higher accuracy.
- the frequency domain determination unit is configured to detect all of the two frequencies ⁇ 1 and ⁇ 2 when the intersection ⁇ of the straight line L and the real axis substantially matches the measured high frequency impedance value R cell, act. Is determined to belong to the non-arc region (see step S1305).
- the frequency domain determination means when the intersection ⁇ between the straight line L and the real axis does not substantially match the measured high frequency impedance value R cell, act , at least two frequencies ⁇ 1 and ⁇ 2 Is determined to belong to the arc region (see steps S1307 and S1308).
- the frequency domain determination means is configured such that when the intersection ⁇ between the straight line L and the real axis is smaller than the measured high frequency impedance value R cell, act , both of the two frequencies ⁇ 1 and ⁇ 2 are in the arc domain. (See step S1308 and FIG. 23).
- the fuel cell 1 in the measurement of the impedance of the fuel cell 1 performed in the first embodiment or the like, instead of the configuration in which the output current I and the output voltage V on which the AC signal is superimposed are measured, the fuel cell 1 is used for a predetermined measurement.
- FIG. 24 is a block diagram schematically showing a main part related to impedance measurement in the fuel cell system 100 of the present embodiment.
- an applied alternating current adjusting unit 200 that applies an alternating current to the fuel cell 1 while adjusting the alternating current is provided.
- the applied AC current adjustment unit 200 is connected to the intermediate terminal 1C in addition to the positive terminal (cathode pole side terminal) 1B and the negative terminal (anode pole side terminal) 1A of the fuel cell 1 configured as a stack.
- the part connected to the midway terminal 1C is grounded as shown in the figure.
- the applied AC current adjustment unit 200 measures the positive-side voltage measurement sensor 210 that measures the positive-side AC potential difference V1 of the positive-electrode terminal 1B with respect to the intermediate terminal 1C, and the negative-side AC potential difference V2 of the negative-electrode terminal 1A with respect to the intermediate terminal 1C. And a negative electrode side voltage measurement sensor 212.
- the applied AC current adjusting unit 200 applies the AC current I2 to the circuit including the positive terminal 1B and the intermediate terminal 1C, and the AC power source 214 applying the AC current I1 to the circuit including the positive terminal 1B and the intermediate terminal 1C.
- Impedance of the fuel cell 1 based on the negative electrode side AC power supply unit 216 to be applied, the controller 6 for adjusting the amplitude and phase of the AC current I1 and the AC current I2, and the positive side AC potential differences V1 and V2 and the AC currents I1 and I2.
- an operation unit 220 that performs an operation of Z.
- the controller 6 adjusts the amplitude and phase of the alternating current I1 and the alternating current I2 so that the positive AC potential difference V1 and the negative AC potential difference V2 are equal.
- the arithmetic unit 220 includes hardware such as an A / D converter and a microcomputer chip (not shown) and a software configuration such as a program for calculating impedance, and the positive terminal AC potential difference V1 is divided by the AC current I1, and the halfway terminal 1C Is calculated by dividing the negative electrode side AC potential difference V2 by the AC current I2, and calculating the impedance Z2 from the intermediate terminal 1C to the negative electrode terminal 1A. Further, the calculation unit 220 calculates the total impedance Z of the fuel cell 1 by taking the sum of the impedance Z1 and the impedance Z2.
- the fuel cell state detection device is connected to the fuel cell 1 and outputs AC power sources 214 and 216 that output AC currents I1 and I2 to the fuel cell 1, and the positive side 1B of the fuel cell 1
- the positive side AC potential difference V1 which is a potential difference obtained by subtracting the potential of the midway part 1C from the potential
- the negative side AC potential difference V2 which is a potential difference obtained by subtracting the potential of the midway part 1C from the potential of the negative electrode side 1A of the fuel cell 1.
- controller 6 as an AC adjusting unit that adjusts the AC currents I1 and I2 based on the above, and the impedance of the fuel cell 1 based on the adjusted AC currents I1 and I2 and the positive-side AC potential difference V1 and the negative-side AC potential difference V2.
- the controller 6 is configured so that the positive-side AC potential difference V1 on the positive side of the fuel cell 1 is substantially equal to the negative-side AC potential difference V2 on the negative side.
- the amplitude and phase of the alternating current I2 applied by the alternating current power supply unit 216 are adjusted.
- the amplitude of the positive-side AC potential difference V1 and the amplitude of the negative-side AC potential difference V2 become equal, so that the positive terminal 1B and the negative terminal 1A are substantially equipotential. Therefore, the alternating currents I1 and I2 for impedance measurement are prevented from flowing to the traveling motor 53, so that the power generation by the fuel cell 1 is prevented from being affected.
- the measurement AC potential is superimposed on the voltage generated by the power generation.
- V1 and the negative-side AC potential difference V2 themselves increase, the phase and amplitude of the positive-side AC potential difference V1 and the negative-side AC potential difference V2 do not change, so that the fuel cell 1 is not in the power generation state. Highly accurate impedance measurement can be performed.
Abstract
Description
カソード極: 4H++4e-+O2 → 2H2O ・・・(2)
これら(1)、(2)の電極反応によって、燃料電池のセルは1V(ボルト)程度の起電力を生じる。
図9は、第1実施形態に係る燃料電池1のアイオノマ抵抗値Rionの推定の流れを示すフローチャートである。なお、以下のステップS101~ステップS103は、コントローラ6により実行される。
以下では、第2の実施形態について説明する。なお、第1の実施形態と同様の要素には同一の符号を付し、その説明を省略する。本実施形態では、特に、燃料電池1の劣化状態を考慮して、推定されたアイオノマ抵抗値Rionを補正する。
以下、第3の実施形態について説明する。なお、第1又は第2の実施形態と同様の要素には同一の符号を付し、その説明を省略する。本実施形態では、燃料電池1のガス拡散層113Bやセパレータ13等の電子抵抗への寄与の大きい要素が劣化することによる電解質膜抵抗値Rmemの上昇分を考慮して、推定された電解質膜抵抗値Rmemを補正する。
以下、第4の実施形態について説明する。なお、第1、第2、又は第3の実施形態と同様の要素には同一の符号を付し、その説明を省略する。本実施形態では、インピーダンス計測に用いる2以上の周波数が、実測インピーダンス曲線C2の円弧領域に属するものであるのか、又は非円弧領域に属するものであるかを判定する処理が行われる。
以下、第5の実施形態について説明する。なお、第1、第2、第3、又は第4の実施形態と同様の要素には同一の符号を付し、その説明を省略する。本実施形態では、インピーダンス計測にあたり、燃料電池1の出力電流及び出力電圧に交流信号を重畳する構成に代えて、燃料電池1に測定用電流源から電流Iを供給し、当該供給電流Iと出力される電圧Vとに基づいてインピーダンスZ=V/Iを計測するいわゆる励起電流印加法を行う。
Claims (18)
- 燃料電池の状態検出装置であって、
前記燃料電池のインピーダンス曲線の円弧領域に属するインピーダンス計測値に基づいて、仮定高周波数インピーダンス値を設定する仮定高周波数インピーダンス値設定手段と、
前記燃料電池のインピーダンス曲線の非円弧領域に属するインピーダンス計測値に基づいて、実測高周波数インピーダンス値を求める実測高周波数インピーダンス値算出手段と、
前記仮定高周波数インピーダンス値から前記実測高周波数インピーダンス値を減算した値をアイオノマ抵抗値と推定するアイオノマ抵抗推定手段と、
を有し、
前記仮定高周波数インピーダンス値設定手段は、
前記円弧領域に属するインピーダンス計測値に基づいて設定される等価回路インピーダンス曲線と実軸との交点の値を前記仮定高周波数インピーダンス値として設定する燃料電池の状態検出装置。 - 請求項1に記載の燃料電池の状態検出装置において、
前記等価回路インピーダンス曲線は、
前記燃料電池の等価回路から得られるインピーダンスの式に前記円弧領域に属するインピーダンス計測値を適用することで設定される燃料電池の状態検出装置。 - 請求項1~請求項3のいずれか1項に記載の燃料電池の状態検出装置において、
アイオノマ抵抗補正手段をさらに有し、
前記アイオノマ抵抗補正手段は、
基準運転条件下で推定されたアイオノマ抵抗値の基準値と、該基準運転条件下における推定値から前記燃料電池を所定時間稼動させた後に推定された劣化後アイオノマ抵抗値を比較することでアイオノマ抵抗値の増分を求め、
前記アイオノマ抵抗値の現在推定値に対し前記増分を減算することで補正を行う燃料電池の状態検出装置。 - 請求項4に記載の燃料電池の状態検出装置において、
前記燃料電池の劣化状態は、
触媒層の劣化状態である燃料電池の状態検出装置。 - 請求項1~請求項4のいずれか1項に記載の燃料電池の状態検出装置において、
電解質膜抵抗値を推定する電解質膜抵抗推定手段をさらに有し、
前記電解質膜抵抗推定手段は、
前記推定されたアイオノマ抵抗値と前記燃料電池の湿潤状態との関係に基づいて設定された基準電解質膜抵抗値と、該設定値から前記燃料電池を所定時間稼動させた後に推定された劣化後実測高周波数インピーダンス値と、を比較することでこれらの差分を求め、
前記実測高周波数インピーダンス値の現在測定値に対して前記差分を減算することで補正を行う燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記仮定高周波数インピーダンス値設定手段は、
前記円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の仮定高周波数インピーダンス値の候補を求め、
前記2以上の仮定高周波数インピーダンス値の候補の平均値を前記仮定高周波数インピーダンス値に設定する燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記実測高周波数インピーダンス値算出手段は、
前記非円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の実測高周波数インピーダンス値の候補を求め、
前記2以上の実測高周波数インピーダンス値の候補の平均値を前記実測高周波数インピーダンス値に設定する燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記仮定高周波数インピーダンス値設定手段は、
前記円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の仮定高周波数インピーダンス値の候補を求め、
前記2以上の仮定高周波数インピーダンス値の候補のうちの高い値を、それぞれ仮定高周波数インピーダンス値に設定する燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記実測高周波数インピーダンス値算出手段は、
前記非円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の実測高周波数インピーダンス値の候補を求め、
前記2以上の実測高周波数インピーダンス値の候補のうちの低い値を、前記実測高周波数インピーダンス値と推定する燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記仮定高周波数インピーダンス値設定手段は、
前記円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の仮定高周波数インピーダンス値の候補を求め、
前記2以上の仮定高周波数インピーダンス値の候補のうちの低い値を、それぞれ仮定高周波数インピーダンス値と推定する燃料電池の状態検出装置。 - 請求項1~請求項6のいずれか1項に記載の燃料電池の状態検出装置において、
前記実測高周波数インピーダンス値算出手段は、
前記非円弧領域に属する2以上のインピーダンス計測値に基づき、2以上の実測高周波数インピーダンス値の候補を求め、
前記2以上の実測高周波数インピーダンス値の候補のうちの高い値を、前記実測高周波数インピーダンス値と推定する燃料電池の状態検出装置。 - 請求項1~請求項12に記載の燃料電池の状態検出装置において、
2以上の周波数にて計測されたインピーダンス計測値を結ぶ直線と実軸との交点の値と、前記実測高周波数インピーダンス値と、を比較することで前記2以上の周波数が、それぞれ、前記非円弧領域に属するのか又は前記円弧領域に属するのかを判定する周波数領域判定手段をさらに有する燃料電池の状態検出装置。 - 請求項13に記載の燃料電池の状態検出装置において、
前記周波数領域判定手段は、
前記直線と実軸との交点の値と前記実測高周波数インピーダンス値が実質的に一致する場合に、前記2以上の周波数の全てが前記非円弧領域に属すると判定する燃料電池の状態検出装置。 - 請求項13に記載の燃料電池の状態検出装置において、
前記周波数領域判定手段は、
前記直線と実軸との交点の値と前記実測高周波数インピーダンス値が実質的に一致しない場合に、前記2以上の周波数のうちの少なくとも一つの相対的に値の小さい周波数が前記円弧領域に属すると判定する燃料電池の状態検出装置。 - 請求項15に記載の燃料電池の状態検出装置において、
前記周波数領域判定手段は、
前記交点の値が、前記実測高周波数インピーダンス値よりも小さい場合に、前記2以上の周波数の全てが前記円弧領域に属すると判定する燃料電池の状態検出装置。 - 請求項1~請求項16に記載の燃料電池の状態検出装置において、
前記燃料電池が積層電池として構成され、
前記積層電池に接続されて該積層電池に交流電流を出力する交流電源部と、
前記積層電池の正極側の電位から該積層電池の中途部分の電位を引いて求めた電位差である正極側交流電位差と、前記燃料電池の負極側の電位から前記中途部分の電位を引いて求めた電位差である負極側交流電位差と、に基づいて交流電流を調整する交流調整部と、
前記調整された交流電流並びに前記正極側交流電位差及び前記負極側交流電位差に基づいて前記燃料電池の前記インピーダンス計測値を演算するインピーダンス演算部と、
を有する燃料電池の状態検出装置。 - 燃料電池の状態検出方法であって、
前記燃料電池のインピーダンス曲線の円弧領域に属するインピーダンス計測値に基づいて、仮定高周波数インピーダンス値を設定する仮定高周波数インピーダンス値設定工程と、
前記燃料電池のインピーダンス曲線の非円弧領域に属するインピーダンス計測値に基づいて、実測高周波数インピーダンス値を求める実測高周波数インピーダンス値算出手段と、
前記仮定高周波数インピーダンス値から前記実測高周波数インピーダンス値を減算した値をアイオノマ抵抗値と推定するアイオノマ抵抗推定工程と、
を有し、
前記仮定高周波数インピーダンス値設定高低では、
前記円弧領域に属するインピーダンス計測値に基づいて設定される等価回路インピーダンス曲線と実軸との交点の値を前記仮定高周波数インピーダンス値として設定する燃料電池の状態検出方法。
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KR1020177024774A KR101830044B1 (ko) | 2015-03-03 | 2015-03-03 | 연료 전지의 상태 검출 장치 및 상태 검출 방법 |
EP15883927.4A EP3267522B1 (en) | 2015-03-03 | 2015-03-03 | Status detection device and status detection method for fuel cell |
JP2017503259A JP6394779B2 (ja) | 2015-03-03 | 2015-03-03 | 燃料電池の状態検出装置及び状態検出方法 |
CA2978525A CA2978525C (en) | 2015-03-03 | 2015-03-03 | State detection device and method for fuel cell |
US15/554,242 US10115987B2 (en) | 2015-03-03 | 2015-03-03 | State detection device and method for fuel cell |
PCT/JP2015/056261 WO2016139759A1 (ja) | 2015-03-03 | 2015-03-03 | 燃料電池の状態検出装置及び状態検出方法 |
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CN114243054B (zh) * | 2021-12-13 | 2023-11-07 | 中国科学院大连化学物理研究所 | 一种燃料电池催化剂浆料的储存方法 |
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CA2978525C (en) | 2019-04-23 |
EP3267522A4 (en) | 2018-02-14 |
CA2978525A1 (en) | 2016-09-09 |
EP3267522A1 (en) | 2018-01-10 |
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