JP2010078556A - Resistance distribution detector and fuel battery system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistance distribution detector capable of correctly detecting a resistance distribution of an actual fuel battery cell, and a fuel battery system using the same. <P>SOLUTION: The resistance distribution detector interposed in a fuel battery stack for detecting the resistance distribution of a cell 10, whose resistance distribution is to be detected, includes: an electrode plate 20, including a plurality of electrodes 22-1 to 22-4 formed on a surface of an electrically insulative base plate 21 and coming into contact with the cell 10; AC controllers 30-1 to 30-4 for making alternate current to flow so that respective potentials of the plurality of electrodes 22-1 to 22-4 become equipotential; and a resistance calculating means 70 for calculating a resistance value per area in contact with each electrode, based on the alternate current flowing to the plurality of electrodes 22-1 to 22-4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resistance distribution detection device and a fuel cell system using the resistance distribution detection device.

  In order to improve the output density of the fuel cell, it is desirable to increase the generated current density while making the generated current density uniform by eliminating the unevenness of the generated current density of the cells. The unevenness of the generated current density of the cell is caused by the distribution (variation) of the internal resistance of the cell. If the internal resistance of the cell is high, power loss occurs and the generated current density cannot be increased. Therefore, during power generation, it is desirable to reduce the internal resistance of the cell as much as possible while keeping the distribution (variation) of the internal resistance of the cell within a predetermined range.

  By the way, the cell which is the detection target of the resistance distribution has a configuration in which a pair of separators are arranged on the front and back surfaces of a membrane electrode assembly (hereinafter referred to as “MEA”) including an electrolyte membrane. The separator is made of carbon or stainless steel having a low volume resistivity so as to reduce power loss. Therefore, the internal resistance of the cell depends particularly on the internal resistance of the electrolyte membrane. The internal resistance of the electrolyte membrane is greatly affected by the ionic conductivity of the electrolyte membrane. As the ionic conductivity increases, the internal resistance of the electrolyte membrane decreases. The internal resistance of the entire cell is also reduced. The ionic conductivity becomes higher (easy to conduct) in proportion to the water content of the electrolyte membrane. Therefore, if the water content of the electrolyte membrane is appropriately controlled according to the power generation state, the generation current density of the cell is not uneven, the power generation current density of the cell is increased, and the output density is improved.

  For this reason, it is desirable to accurately detect the distribution of internal resistance of the electrolyte membrane.

  However, as described above, carbon or stainless steel having a low volume resistivity is used for the separator.Therefore, when the resistance distribution of the electrolyte membrane is detected from the outside of the separator, the current shunting effect (shunt effect) in the in-plane direction of the separator is used. ), The resistance distribution whose distribution is smoothed and becomes smaller is detected. Therefore, in order to accurately detect the resistance distribution, it is necessary to prevent the current shunting effect (shunt effect) of the separator.

For example, in Patent Document 1, in order to prevent a current from being diverted in the in-plane direction of the separator, the resistance distribution of the cell is detected using a dedicated separator that is divided into a plurality of partial regions by an electric insulating material.
JP 2003-77515 A

  However, in the conventional method described above, the separator is structurally divided (divided electrodes), so that the measurement result is different from that of an actual fuel cell. Therefore, it is necessary to verify the difference between such a measurement result and an actual separator that is not divided into electrodes. In addition, it is difficult to manufacture a structure for maintaining the original functions such as the gas seal and mechanical strength of the separator. Therefore, it is difficult to detect the resistance distribution by incorporating it into an actual fuel cell stack.

  The present invention has been made paying attention to such conventional problems, and provides a resistance distribution detection device capable of accurately detecting the resistance distribution of an actual fuel cell and a fuel cell system using the resistance distribution detection device. For the purpose.

  The present invention solves the above problems by the following means.

  The present invention provides an electrode plate that includes a plurality of electrodes that are formed on the surface of an electrically insulating base plate and that abuts against a resistance distribution detection target cell, and an alternating current that causes alternating current to flow so that each of the plurality of electrodes has the same potential. It is characterized by comprising: a controller; and resistance calculation means for calculating a resistance value for each region in contact with each electrode based on an alternating current applied to the plurality of electrodes.

  According to the present invention, an alternating current is made to flow so that each of the plurality of electrodes formed on the surface of the electrically insulating base plate and in contact with the resistance distribution detection target cell has the same potential. AC does not mix with the stack generation current (DC). Therefore, the internal resistance of the resistance distribution detection target cell can be accurately detected.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
First, in order to facilitate understanding of the present invention, a problem to be solved will be described with reference to FIGS. 13 and 14.

  The power generation cell 10 of the fuel cell has a structure in which separators 12 are stacked on the front and back surfaces of the MEA 11. FIG. 13 shows the internal resistance of the cell 10 as a model. The MEA 11 generates voltage E (1), E (2), E (3), E (4) depending on the location. Further, the internal resistances Rm (1), Rm (2), Rm (3), and Rm (4) are distributed depending on the location.

  As described above, since carbon, stainless steel, or the like having a low volume resistivity is used for the separator 12, if an attempt is made to detect the resistance distribution of the MEA 11 from the outside of the separator 12, the current Ip (1 ), Ip (2), Ip (3) are diverted.

  As shown in FIG. 14A, even if the internal resistances Rm (1), Rm (2), Rm (3), and Rm (4) are distributed, the currents Ip (1), Ip (2), Ip By dividing (3), the detected current value (solid line in FIG. 14B) is smoothed compared to the original value (broken line in FIG. 14B). For this reason, the detected value of internal resistance (solid line in FIG. 14C) is also smoothed compared to the original value (broken line in FIG. 14C).

  FIG. 1 is a view showing a fuel cell using a resistance distribution detection device according to the present invention, FIG. 1 (A) is an overall perspective view, and FIG. 1 (B) is a perspective view showing an extracted electrode plate. 1 (C) is an enlarged view showing a part of the cross section of the fuel cell.

  The fuel cell stack 1 has a configuration in which a plurality of power generation cells 10 are stacked and sandwiched between end plates 40 from both sides thereof.

  The power generation cell 10 is a unit cell of a fuel cell. Each power generation cell 10 generates an electromotive voltage of about 1 volt (V).

  As shown in FIG. 1C, the power generation cell 10 has a structure in which separators 12 are laminated on the front and back surfaces of a membrane electrode assembly (hereinafter referred to as “MEA”) 11.

  In the MEA 11, electrode catalyst layers 11b are formed on both surfaces of an electrolyte membrane 11a made of an ion exchange membrane. The separator 12 overlaps with the electrode catalyst layer 11b.

  As for the separator 12, an unevenness | corrugation is formed in the front and back, and the recessed part becomes the gas flow path 12a. Cathode gas flows through the gas channel 12a on one side, and anode gas flows through the gas channel 12a on the back side. A seal 13 is disposed to prevent leakage of the reaction gas. A cooling water channel 12 b is formed inside the separator 12.

  The end plate 40 is disposed at the outermost part of the stacked power generation cells 10. The end plate 40 is made of a rigid metal material such as steel.

  One end plate 40 (the left front end plate 40 in FIG. 1) includes an anode supply port 41a, an anode discharge port 41b, a cathode supply port 42a, a cathode discharge port 42b, and a cooling water supply port 43a. A cooling water discharge port 43b is provided. In the present embodiment, the anode supply port 41a, the cooling water supply port 43a, and the cathode supply port 42a are provided on the left side in the drawing. The anode discharge port 41b, the cooling water discharge port 43b, and the cathode discharge port 42b are provided on the right side in the figure.

  Although illustration is omitted, nuts are respectively arranged near the four corners of the end plate 40. The fuel cell stack 1 has a hole (not shown) penetrating therethrough. A tension rod (not shown) is inserted through this through hole. The tension rod is made of a rigid metal material such as steel. The tension rod is insulated on the surface in order to prevent electrical shorting between the power generation cells. The nut described above is screwed to both ends of the tension rod. The nut and the tension rod tighten the fuel cell stack 1 in the stacking direction.

  As a method of supplying hydrogen as an anode gas to the anode supply port 41a, for example, a method of supplying hydrogen gas directly from a hydrogen storage device or a hydrogen-containing gas reformed by reforming a fuel containing hydrogen is supplied. There are methods. Examples of the hydrogen storage device include a high-pressure gas tank, a liquefied hydrogen tank, and a hydrogen storage alloy tank. Examples of the fuel containing hydrogen include natural gas, methanol, and gasoline. Air is generally used as the cathode gas supplied to the cathode supply port 42a.

  The MEA 11, the separator 12, and the electrode plate 20 are formed with holes 41a, 41b, 42a, 42b, 43a, 43b, respectively. For example, the state of the electrode plate 20 is shown in FIG. These are stacked to form an anode supply port 41a, an anode discharge port 41b, a cathode supply port 42a, a cathode discharge port 42b, a cooling water supply port 43a, and a cooling water discharge port 43b.

  In the fuel cell stack 1, an electrode plate 20 is laminated instead of a part (one sheet in FIG. 1) of MEAs 11. In FIG. 1, one electrode plate 20 is laminated, but two or more may be used.

  As shown in FIG. 1B, the electrode plate 20 includes a base plate 21 and electrodes 22 (electrode 22-1, electrode 22-2, electrode 22-3, and electrode 22-4).

  The base plate 21 is electrically insulating. The base plate 21 includes a connector edge 21a. The base plate 21 incorporates an AC generator 30 as shown in FIG. The AC generator 30 is connected to each electrode 22 (electrode 22-1, electrode 22-2, electrode via the signal line 21b (signal line 21b-1, signal line 21b-2, signal line 21b-3, signal line 21b). 22-3 and electrode 22-4) are connected. The alternating current generator 30 can adjust the alternating current for each electrode 22 (electrode 22-1, electrode 22-2, electrode 22-3, electrode 22-4).

  The electrode 22 is formed on one side of the base plate 21. In FIG. 1B, the case where four electrodes 22-1, 22-2, 22-3, and 22-4 are formed is shown as an example. Or 5 or more may be sufficient. What is necessary is just to set suitably in consideration of the precision, manufacturing cost, etc. which are requested | required. The electrode 22 contacts the resistance distribution detection target cell 10. In the present embodiment, the resistance distribution detection target cell 10 is the cell 10 on the left side of the drawing.

  The connector edge 21a of the electrode plate 20 and the resistance distribution detection target cell 10 on the opposite side of the electrode plate 20 with the MEA 11 in between are connected by a feedback current wiring 23.

  Although not shown in FIG. 1, as shown in FIG. 2, a detector 51 that detects a potential difference between one surface of the MEA 11 and the electrode 22 that contacts the opposite surface of the MEA 11 is provided.

  FIG. 2 is a diagram modeling the above configuration.

  The controller 70 inputs the potential differences Vs (1), Vs (2), Vs (3), Vs (4) detected by the detectors 51-1, 51-2, 51-3, 51-4, The alternating current generated by the AC generators 30-1, 30-2, 30-3, and 30-4 is controlled so that the potential differences Vs (1), Vs (2), Vs (3), and Vs (4) are equal. At this time, the alternating current Is (1) flows through the electrode 22-1, the internal resistance Rm (1) of the MEA 11, and the feedback current wiring 23-1. Alternating currents Is (2), Is (3), Is (4) flow in the same manner. Then, the controller 70 calculates the internal resistances Rm (1), Rm (2), Rm (3), and Rm (4) by applying Ohm's law to the AC signal.

  In this way, the alternating current generated by the AC generators 30-1, 30-2, 30-3, and 30-4 is set so that the potential differences Vs (1), Vs (2), Vs (3), and Vs (4) are equal. I tried to control it. By doing so, the potential difference between both ends of the in-plane resistance Rp of the separator 12 becomes zero, and the currents Ip (1), Ip (2), Ip (3) are shunted in the in-plane direction of the separator 12. Can be prevented.

  FIG. 3 is a diagram for explaining the effect of this embodiment.

  Therefore, the detection value (solid line in FIG. 3B) according to the present embodiment matches the original value. In FIG. 3B, the detected values in FIG. 14B are indicated by broken lines for reference. For this reason, the detected value of the internal resistance (solid line in FIG. 14C) also matches the original value. In FIG. 3C, the detected values in FIG. 14C are indicated by broken lines for reference.

  In this embodiment, alternating current is controlled using alternating current generators 30-1, 30-2, 30-3, and 30-4. Therefore, it does not mix with the stack generated current (DC). And from the alternating currents Is (1), Is (2), Is (3), Is (4) and the alternating potentials Vs (1), Vs (2), Vs (3), Vs (4) according to Ohm's law, The internal resistances Rm (1), Rm (2), Rm (3), Rm (4) of each electrode region can be accurately calculated. DC pulse waves (voltage level is periodically turned ON / OFF) can work in the same way, but a circuit that drives large power (several kW) equivalent to the amount of stack power generation is required, especially for automobiles In the fuel cell, the circuit becomes larger than the stack, which is unrealistic. In addition, resistance distribution can be measured with quasi-direct current (1 Hz or less) even with existing FRA (frequency response analysis method), but there are limitations such that detection is not possible unless the specimen is generated to some extent. Therefore, it is optimal to control alternating current as in this embodiment.

(Second Embodiment)
FIG. 4 is a model circuit diagram showing a second embodiment of the resistance distribution detecting device according to the present invention. FIG. 4 corresponds to FIG. 2 of the first embodiment, and only the main configuration is taken out. In the following description, the same reference numerals are given to portions that perform the same functions as those described above, and redundant descriptions are omitted as appropriate.

  The resistance distribution detection device of this embodiment includes a reference potential generator 52. Further, a comparator 53 for comparing the potentials of the adjacent electrodes 22 is included. The AC generator 30 adjusts the generated AC so that the potential difference is fed back to zero.

  The comparator 53-1 detects the potential difference between the reference potential Vs (0) of the reference potential generator 52 and the potential Vs (1) of the electrode 22-1, and the AC generator 30-1 so that this potential difference becomes zero. Feedback control of AC generated. Further, the generated AC signal Sis (1) at this time is transmitted to the controller 70. The controller 70 calculates the internal resistance Rm (1) by applying Ohm's law to the AC signal Sis (1).

  The comparator 53-2 detects the potential difference between the potential Vs (1) of the electrode 22-1 and the potential Vs (2) of the electrode 22-2, and generates the AC generator 30-2 so that this potential difference becomes zero. Feedback control of alternating current. Further, the generated AC signal Sis (2) at this time is transmitted to the controller 70. The controller 70 calculates the internal resistance Rm (2) by applying Ohm's law to the AC signal Sis (2). The same applies to the comparator 53-3 and the comparator 53-4.

  According to the present embodiment, the potential difference between the adjacent electrodes 22 is detected, and the AC is controlled so that the potentials of the adjacent electrodes 22 are the same by feeding back the detected potential difference. In this way, each electrode 22 is always controlled to the output potential of the reference potential generator 52 after a predetermined time has elapsed since the power was turned on (after the feedback has been converged). As a result, the potential difference between both ends of the in-plane resistance Rp of the separator is kept at zero, and no current flows through the in-plane resistance Rp. That is, it is possible to prevent the current from being shunted in the in-plane direction of the separator 12.

  The output signal Sis of each comparator 53 is a value proportional to each alternating current Is. Accordingly, the output signal Sis of each comparator 53 is input to the controller 70 and multiplied by the proportional coefficient of the output signal to obtain the alternating current Is. The resistance value of each electrode region can be accurately obtained from the alternating current Is and the output voltage Vs (0) of the reference potential generator 52 based on Ohm's law.

  Furthermore, according to the present embodiment, the circuit can be assembled more simply than in the first embodiment, and the manufacturing cost can be reduced.

(Third embodiment)
FIG. 5 is a model circuit diagram showing a third embodiment of the resistance distribution detecting device according to the present invention. FIG. 5 (A) is an overall view, and FIG. 5 (B) is an equivalent circuit within a broken line in FIG. FIG.

  The resistance distribution detection device of this embodiment includes a reference potential generator 52. Further, a comparator 54 for comparing the reference potential with the potential of each electrode 22 is included. The AC generator 30 adjusts the generated AC so that the potential difference is fed back to zero.

  As shown in FIG. 5B, only the amplitude information of the potential of the electrode 22 is fed back. Then, the amplitude of the output waveform Vs (0) of the reference potential generator 52 is adjusted by the output (feedback amount) of the comparator 54 using a voltage gain control amplifier (VGA). Then, the output of the voltage gain control amplifier (VGA) is caused to generate an alternating current Is (x) through a voltage / current conversion circuit.

  Even in the configuration of the present embodiment, each electrode 22 is always controlled to the output potential of the reference potential generator 52 after a predetermined time has elapsed since the power was turned on (after the feedback has converged). As a result, the potential difference between both ends of the in-plane resistance Rp of the separator is kept at zero, and no current flows through the in-plane resistance Rp. That is, it is possible to prevent the current from being shunted in the in-plane direction of the separator 12.

  Further, since an alternating current having the same phase as that of the output waveform Vs (0) of the reference potential generator 52 is generated, only the amplitude information may be matched with the output waveform Vs (0). Therefore, according to this embodiment, the alternating current can be precisely controlled with a small number of circuit elements.

  Further, the reference potential generator 52 is provided with a frequency sweep function, and the AC impedance of the resistance distribution detection target cell 10 can be measured by sweeping the frequency of the AC waveform within a predetermined range. In addition to the resistance (ion + electron transfer resistance) of the resistance distribution detection target cell 10, the charge transfer resistance at the electrochemical interface of the electrolyte membrane can be derived from the measured AC impedance. Since this charge transfer resistance indicates the state of electrochemical reaction, it is possible to estimate the supply state of the reaction gas in the plane of the resistance distribution detection target cell 10 as the distribution from this charge transfer resistance. Furthermore, it is possible to improve the power generation efficiency of the fuel cell by controlling the reaction gas supply amount and the like based on the reaction gas supply state estimation.

(Internal structure of electrode plate)
FIG. 6 shows the internal structure of the electrode plate.

  The base plate 21 has an electrode 22 formed on one surface (bottom surface in FIG. 6), a back electrode 24 formed on the opposite surface (top surface in FIG. 6), and the electrode 22 and the back electrode 24 are made of a conductor 25. Connected with. The conductor 25 allows a generated current including the resistance distribution detection target cell 10 to pass therethrough. The conductors 25 connect the electrodes 22 and the back electrodes 24 in the number corresponding to the maximum through current capacity. An AC generator (AC generation circuit) 30 is built in the back surface of the electrode 22 of the base plate 21. The electrode plate 20 having such a structure can be manufactured by a manufacturing process of a multilayer printed board.

  By incorporating the AC generator 30, external wiring is eliminated, the resistance distribution detection target cell 10 and the other power generation cells have the same size, and can be interposed without changing the size of the fuel cell stack.

  Further, by forming the AC generator (AC generation circuit) 30 directly under the electrode 22, detection errors due to electrical noise and wiring resistance can be reduced.

  Furthermore, since the electrode 22 and the back electrode 24 are connected by the conductor 25, the generated current can be freely passed between the front and back surfaces of the electrode plate 20. Therefore, it is possible to stack the electrode plate 20 on the fuel cell stack at an arbitrary place. Therefore, the design freedom of the fuel cell system is improved.

  Furthermore, a plurality of electrode plates 20 may be interposed. In this way, it is also possible to always exert the maximum power generation output density by performing appropriate power generation control on the power generation cells in the entire area of the fuel cell stack.

  The electrode 22 is divided into, for example, four sheets, but is electrically connected to the back electrode 24 by the conductor 25, so that the flow of the generated current (DC) of the fuel cell stack is not disturbed, and the electrode plate 20 It can reproduce the original stack power generation phenomenon without intervening.

(Fuel cell system using resistance distribution detector)
FIG. 7 is a diagram showing a fuel cell system using the resistance distribution detection device according to the present invention.

  The fuel cell stack 1 of the fuel cell system 100 includes the electrode plate 20 described above.

  A blower 111 is provided on the upstream side of the cathode channel 110 of the fuel cell system 100. Air (cathode gas C) is supplied to the fuel cell stack 1 by the blower 111. The cathode gas flow rate can be adjusted by controlling the blower 111. An exhaust valve 112 and a cathode pressure sensor 113 are provided on the downstream side of the cathode channel 110. The cathode gas pressure can be adjusted by controlling the exhaust valve 112.

  A fuel supply valve 121 and an anode pressure sensor 122 are provided on the upstream side of the anode flow path 120 of the fuel cell system 100. The amount of power generation can be adjusted by controlling the fuel supply valve 121. A circulation pump 123 and a purge valve 124 are provided on the downstream side of the anode channel 120. A circulation flow path 120 a branches from between the circulation pump 123 and the purge valve 124.

  A flow valve 131 is provided on the upstream side of the refrigerant flow path 130 of the fuel cell system 100. The cooling amount can be adjusted by controlling the flow valve 131.

  Based on the current density distribution signal, temperature distribution signal, cathode pressure signal, anode pressure signal and the like of the current density distribution sensor 20, the FC operation controller 150 includes a blower 111, an exhaust valve 112, a fuel supply valve 121, a circulation pump 123, a flow rate. The valve 131, the power adjustment device 140, and the like are controlled. The FC operation controller 150 is constituted by 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). The controller 150 may be composed of a plurality of microcomputers.

  FIG. 8 is a diagram summarizing the control contents of the fuel cell system according to the present invention.

  The fuel cell system executes the control as shown in FIG. Specific contents will be described with reference to the flowcharts in FIG.

(Dry-out avoidance control)
FIG. 9 is a flowchart showing dryout avoidance control of the fuel cell system according to the present invention.

  In step S100, the controller detects the resistance value of the resistance distribution detection target cell and its distribution.

  In step S210, the controller determines whether or not the resistance value has increased. If the resistance value does not increase, the possibility of dryout is not high, so the process proceeds to step S800 and normal operation control is executed. If the resistance value increases, the process proceeds to step S220.

  In step S220, the controller determines whether the detected resistance distribution is excessive and exceeds an allowable range. If the allowable range is exceeded, the process proceeds to step S230, and then the process proceeds to step S240. If the allowable range is not exceeded, the process directly proceeds to step S240.

  In step S230, the controller sets an output restriction flag.

  In step S240, the controller executes dryout avoidance control.

  FIG. 10 is a flowchart showing a subroutine of dryout avoidance control.

  In step S241, the controller opens the flow valve 131. Then, the flow rate of the cooling water increases and the cell temperature decreases.

  In step S242, the controller increases the humidification amount of the humidifier. Then, the humidification amount of the cathode gas is increased and a high humidification state is obtained.

  In step S243, the controller determines whether the output restriction flag is set. If it is set, the process proceeds to step S244, and if it is not set, the process proceeds to step S245.

  In step S244, the controller limits the output.

  In step S245, the controller opens the fuel supply valve 121 and increases the rotation of the blower 111. As a result, the flow rates of the anode gas and the cathode gas increase.

  In step S246, the controller increases the output of the power adjustment device 140. Then, the amount of power generation increases. The electrolyte membrane is wetted by the generated water and high humidification, and dryout can be avoided.

(Flooding avoidance control)
FIG. 11 is a flowchart showing flooding avoidance control of the fuel cell system according to the present invention.

  In step S100, the controller detects the resistance value of the resistance distribution detection target cell and its distribution.

  In step S310, the controller determines whether or not the resistance value has decreased. If the resistance value does not decrease, the possibility of flooding is not high. Therefore, the process proceeds to step S800, and normal operation control is executed. If the resistance value decreases, the process proceeds to step S320.

  In step S320, the controller determines whether or not the detected resistance distribution is excessive and exceeds an allowable range. If the allowable range is exceeded, the process proceeds to step S330, and then the process proceeds to step S340. If the allowable range is not exceeded, the process directly proceeds to step S340.

  In step S330, the controller sets an output restriction flag.

  In step S340, the controller executes flooding avoidance control.

  FIG. 12 is a flowchart illustrating a subroutine for flooding avoidance control.

  In step S341, the controller decreases the humidification amount of the humidifier. Alternatively, when the resistance value / distribution indicating the flooding state has already been detected, the humidified gas is bypassed and the dried cathode gas is supplied to the stack. As a result, the dew point in the cell is lowered to a dry state.

  In step S342, the controller closes the flow valve 131. Then, the flow rate of the cooling water decreases and the cell temperature rises.

  In step S343, the controller determines whether an output restriction flag is set. If it is set, the process proceeds to step S344, and if it is not set, the process proceeds to step S346.

  In step S344, the controller purges.

  In step S345, the controller limits the output.

  In step S346, the controller increases the rotation of the circulation pump 123 and the blower 111. Then, the flow rates of the anode gas and the cathode gas are increased, the gas flow rate is increased, and the drainage property in the cell is promoted.

  In step S347, the controller increases the output of the power adjustment device 140. Then, the amount of power generation increases. The electrolyte membrane is dried by the synergistic effect of the cell temperature rise and the supply gas drying, and flooding can be avoided.

  Without being limited to the embodiments described above, various modifications and changes are possible within the scope of the technical idea, and it is obvious that these are also included in the technical scope of the present invention.

  For example, in the above-described embodiment, the electrode formed on one side of the base plate is shown as an example in which the number of electrodes 22-1, 22-2, 22-3, and 22-4 is four. It may be one sheet, three sheets, or five or more sheets. What is necessary is just to set suitably in consideration of the precision, manufacturing cost, etc. which are requested | required.

It is a figure which shows the fuel cell which uses the resistance distribution detection apparatus by this invention. It is the figure which modeled the main structures of the resistance distribution detection apparatus. It is a figure explaining the effect of this embodiment. It is a model circuit diagram which shows 2nd Embodiment of the resistance distribution detection apparatus by this invention. It is a model circuit diagram which shows 3rd Embodiment of the resistance distribution detection apparatus by this invention. It is a figure which shows the internal structure of an electrode plate. It is a figure which shows the fuel cell system which uses the resistance distribution detection apparatus by this invention. It is the figure which summarized the control content of the fuel cell system by this invention. 4 is a flowchart showing dryout avoidance control of the fuel cell system according to the present invention. It is a flowchart which shows the subroutine of dryout avoidance control. 5 is a flowchart showing flooding avoidance control of the fuel cell system according to the present invention. It is a flowchart which shows the subroutine of flooding avoidance control. It is the figure which showed the model for demonstrating a solution subject. It is a figure explaining a solution subject.

Explanation of symbols

10 resistance distribution detection target cell 20 electrode plate 21 base plate 22 electrode 30 AC controller 51 detector 52 reference potential generator 53 comparator (adjacent electrode comparator)
54 Comparator (reference comparator)
70 Controller (resistance calculation means)

Claims (6)

A resistance distribution detection device that is interposed in a fuel cell stack and detects a resistance distribution of a resistance distribution detection target cell,
An electrode plate including a plurality of electrodes formed on the surface of the electrically insulating base plate and in contact with the resistance distribution detection target cell;
An alternating current controller for causing alternating current to flow so that each of the plurality of electrodes has the same potential;
A resistance calculating means for calculating a resistance value for each region in contact with each electrode based on an alternating current passed through the plurality of electrodes;
A resistance distribution detection device comprising: The resistance distribution detection device according to claim 1,
Having a potential detection means for detecting the potential of each of the plurality of electrodes;
The alternating current controller feeds back alternating current so that the potential of each electrode becomes the same potential by feeding back each detected potential.
A resistance distribution detecting device. The resistance distribution detection device according to claim 1,
An adjacent electrode comparator for detecting a potential difference between adjacent electrodes among the plurality of electrodes;
The AC controller feeds an alternating current so that the potential of the adjacent electrode is the same potential by feeding back the potential difference between the adjacent electrodes.
A resistance distribution detecting device. The resistance distribution detection device according to claim 1,
A reference comparator for detecting a potential difference between the reference potential and each electrode;
The AC controller feeds an alternating current so that the potential of each electrode becomes the same potential by feeding back the potential difference from the reference.
A resistance distribution detecting device. In the resistance distribution detection device according to any one of claims 1 to 4,
The electrode plate is
A back electrode disposed on a surface opposite to the surface on which the electrode is disposed;
A conductor connecting the electrode and the back electrode,
A resistance distribution detecting device. In the fuel cell system using the resistance distribution detection device according to any one of claims 1 to 5,
Control the water content of the electrolyte membrane of the fuel cell so that the detected resistance value and resistance distribution are as intended.
A fuel cell system.

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