Cell voltage measurement device and cell voltage measurement method for fuel cell

Abstract

The present invention provides a cell voltage measurement device capable of quickly detecting, in parallel, the voltage values of a plurality of cells constituting a fuel cell stack. A cell voltage measurement device according to the present disclosure is capable of measuring cell voltages of a cell stack in which electrode pins for voltage measurement are provided in correspondence with a plurality of cells, by bringing measurement pads into contact with the electrode pins, said cell voltage measurement device comprising: a plurality of measurement pads, at least three of which are provided in correspondence with both terminals of two adjacent electrode pins; and a control device that measures the voltages of the plurality of cells via the measurement pads.

Description

Fuel cell cell voltage measuring device and cell voltage measuring method

[0001] The present disclosure relates to a cell voltage measuring device capable of measuring the cell voltage of each fuel cell that constitutes a fuel cell stack.

[0002] In recent years, development of fuel cell vehicles equipped with fuel cells that have a relatively small environmental impact has been progressing. Fuel cell vehicles obtain the necessary driving force by supplying electrical energy generated by the fuel cell to an electric motor. Therefore, in order to obtain the desired power generation capacity corresponding to this driving force, such fuel cells are used as a fuel cell stack, which is composed of multiple fuel cells (hereinafter also referred to as "cells") stacked one on top of the other.

[0003] As described above, since multiple cells are stacked and mounted on a vehicle, it is necessary to detect whether each cell in the fuel cell stack has the desired power generation performance. While it is conceivable to detect the voltage value of each cell individually, it has also been proposed to detect the voltage values ​​of multiple cells in parallel using a flat harness, as exemplified in the following patent document:

[0004] JP 2018-63880 A

[0005] However, current technologies, including those described in the above-mentioned patent documents, do not adequately meet market needs, and the following problems exist. For example, in Patent Document 1, a flat harness is used to detect the voltage values ​​of multiple cells in parallel, but connectors must be connected individually to the cell voltage detection terminals, which requires a considerable amount of time for assembly preparation. Furthermore, because connectors must be connected individually to the cell voltage detection terminals, there is a risk that an inexperienced worker will incorrectly connect the connectors to the cell voltage detection terminals.

[0006] The present disclosure has been made in consideration of the above-mentioned problems as an example, and aims to provide a fuel cell voltage measuring device that can quickly detect the voltage values ​​of multiple cells that make up a fuel cell stack in parallel.

[0007] In order to solve the above problem, according to one aspect of the present disclosure, there is provided a cell voltage measuring device for a fuel cell, which is capable of measuring each cell voltage by contacting measurement pads with electrode pins for voltage measurement provided for each of a plurality of cells in a battery stack, the cell voltage measuring device including a plurality of measurement pads, at least three of which are provided corresponding to the ends of two adjacent electrode pins, and a control device that measures the voltages of each of the plurality of cells via the measurement pads.

[0008] The cell voltage measuring device of the present disclosure can quickly detect the voltage values ​​of the multiple cells that make up a fuel cell stack in parallel.

[0009] FIG. 1 is a schematic diagram showing a fuel cell stack in an embodiment. FIG. 1 is a schematic diagram showing a cell voltage measuring device for a fuel cell in an embodiment. FIG. 2 is a schematic diagram explaining the positional and arrangement relationship between electrode pins in a fuel cell stack and measurement pads in a cell voltage measuring device. FIG. 3 is a functional block diagram explaining each function of a cell voltage measuring device in an embodiment. FIG. 4 is a flowchart showing a cell voltage measuring method for a fuel cell in an embodiment. FIG. 5 is a schematic diagram showing a state when each voltage value (initial voltage value) is detected from an electrode pin in the cell voltage measuring method. FIG. 6 is a schematic diagram showing a state when measurement pads corresponding to electrode pins are defined in the cell voltage measuring method. FIG. 7 is a schematic diagram showing a cell voltage measuring device for a fuel cell in a modified example. FIG. 8 is a schematic diagram showing a state when voltage values ​​are obtained from electrode pins of a fuel cell stack using a cell voltage measuring device in a modified example.

[0010] Next, preferred embodiments of the present disclosure will be described. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted. Furthermore, configurations other than those described in detail below may be supplemented appropriately with elemental technologies and configurations related to known fuel cell stacks and cells, including those described in the patent documents mentioned above.

[0011] <Fuel Cell Stack 200> Figure 1 shows a fuel cell stack 200 according to this embodiment. The fuel cell stack 200 according to this embodiment is mounted on, for example, a known fuel cell vehicle (FCV). Such a fuel cell stack 200 is configured by stacking a plurality of cells 210. Each cell 210 has a structure in which a known MEA (membrane electrode assembly) is interposed between a pair of known separators disposed on the fuel electrode side and the air electrode side, respectively.

[0012] The membrane electrode assembly may include at least a known cathode catalyst layer, a known anode catalyst layer facing the cathode catalyst layer, and a known polymer electrolyte membrane disposed between the cathode catalyst layer and the anode catalyst layer. The membrane electrode assembly may further include a known air electrode-side gas diffusion layer and a known fuel electrode-side gas diffusion layer. As an example, the cell 210 of this embodiment may be a polymer electrolyte fuel cell (PEFC) having an individual electromotive force of about 1 V.

[0013] 1, the fuel cell stack 200 may include a known terminal plate 220 and an insulating plate 230 at both ends of the stacked multiple cells 210. The fuel cell stack 200 may also include a known end plate 240 that holds the multiple cells 210 together with a predetermined pressure.

[0014] The above-described fuel cell stack 200 is capable of detecting whether each of the stacked cells 210 has the desired power generation performance. Specifically, each of the cells 210 constituting the fuel cell stack is provided with an electrode pin 211 capable of detecting a voltage value. Therefore, the control device 20, which will be described later, can detect the voltage value of each of the cells 210 via the electrode pin 211.

[0015] <Cell voltage measuring device 100> Next, the fuel cell voltage measuring device 100 of this embodiment will be described with reference to Figures 2 and 3. As can be seen from the figures, the cell voltage measuring device 100 is configured to be able to measure cell voltages for a fuel cell stack 200 in which electrode pins 211 for voltage measurement are provided corresponding to a plurality of cells 210, by bringing measurement pads 12, which will be described later, into contact with the electrode pins 211.

[0016] More specifically, the cell voltage measuring device 100 of this embodiment is configured to include a measurement terminal unit 10 and a control device 20. As shown in the figure, the measurement terminal unit 10 covers a surface of the fuel cell stack 200 on which a plurality of electrode pins 211 are arranged, thereby enabling detection of cell voltages via the electrode pins 211. Such a measurement terminal unit 10 is configured to include a base plate 11 provided with wiring (not shown), a plurality of measurement pads 12 each connected to the wiring, and an insulating layer 13 interposed between adjacent measurement pads 12.

[0017] 2 and 3, at least three measurement pads 12 are provided corresponding to the distance between both ends of two adjacent electrode pins 211. In this manner, in this embodiment, the measurement pads 12 and the electrode pins 211 do not correspond one-to-one, and the number of measurement pads 12 is configured to be greater than the number of electrode pins 211.

[0018] In other words, as shown in these figures, when the distance between adjacent electrode pins (e.g., center-to-center distance) is L2 and the distance between adjacent measurement pads (similarly, center-to-center distance) is L1, L2 > L1. In other words, it is preferable that the multiple measurement pads 12 are each installed on the base plate 11 so that at least one measurement pad 12 partitioned by the insulating layer 13 is disposed between adjacent electrode pins 211. Note that in this embodiment, the pitch of the electrode pins and measurement pads is defined using the center-to-center distance, but the pitch may also be defined using a parameter other than the center-to-center distance, such as the distance based on either the left or right end.

[0019] 3, the gap W1 between adjacent measurement pads 12 (i.e., the width of the insulating layer 13) may be set smaller than the width W3 of the tip of the electrode pin 211 that contacts the measurement pad 12. This makes it possible to easily and quickly detect the voltages of multiple cells without making the cell voltage measuring device 100 excessively large.

[0020] Also, as an example, the elements constituting the cell voltage measuring device 100 in this embodiment may have the following relationships: Width W2 of the measurement pad 12 > Gap W1 (width of the insulating layer 13 sandwiched between the measurement pads) Width W2 of the measurement pad 12 > Tip width W3 of the electrode pin 211 Tip width W3 of the electrode pin 211 > Gap W1 (width of the insulating layer 13) By having these characteristics, it is possible to easily and quickly detect multiple cell voltages without the cell voltage measuring device 100 becoming excessively large. Note that it is preferable that the width W2 of the measurement pad 12 is the same between multiple measurement pads.

[0021] The control device 20 is configured to have the function of measuring the cell voltages of the multiple cells 210 via the measurement pads 12 when measuring the cell voltage of each cell in the fuel cell stack 200. As an example, the control device 20 may be configured to include one or more processors (CPUs (Central Processing Units)) and one or more known storage devices 30 such as memories communicatively connected to the one or more processors. As an example, the control device 20 may be configured to be connectable to a known network such as the Internet via a known communication device 40 such as a smartphone.

[0022] 4, such a control device 20 may include a voltage measurement unit 21, an unconnected pad determination unit 22, a simultaneously connected pad determination unit 23, an electrode pad determination unit 24, and a notification control unit 25. These units are typically functions realized by a processor such as a CPU executing a computer program, but some or all of these units may be implemented as analog circuits.

[0023] The voltage measurement unit 21 is configured to have the function of measuring the cell voltage from the electrode pins 211 that contact the measurement pads 12. The function of the voltage measurement unit 21 is not particularly limited as long as it can measure the cell voltage of each cell that makes up the fuel cell stack 200, and for example, a known voltage detection function such as that disclosed in the above-mentioned patent documents may be applied.

[0024] The unconnected pad determination unit 22 is configured to have the function of determining, during the above-mentioned cell voltage measurement, measurement pads 12 (also referred to as "unconnected pads") that are not in contact with the electrode pins 211 provided on each cell that constitutes the fuel cell stack 200. As an example, the unconnected pad determination unit 22 may determine the presence or absence of the above-mentioned unconnected pads based on the voltage values ​​of each measurement pad measured by the voltage measurement unit 21.

[0025] The threshold voltage value for determining whether or not there is an unconnected pad can be determined in advance by prior experiments or simulations depending on the type and electromotive force of the fuel cell used. As an example, the unconnected pad determination unit 22 may determine that a measurement pad whose voltage value measured by the voltage measurement unit 21 is 0 V is an "unconnected pad."

[0026] The simultaneous connection pad determination unit 23 is configured to have the function of determining, during the above-mentioned cell voltage measurement, a plurality of measurement pads 12 (also referred to as "simultaneous connection pads") that are simultaneously in contact with one electrode pin 211 that constitutes the fuel cell stack 200. As an example, the simultaneous connection pad determination unit 23 may determine the presence or absence of the above-mentioned simultaneously connection pads based on the voltage value of each measurement pad measured by the voltage measurement unit 21.

[0027] In this case, the conditions for determining whether or not there are simultaneously connected pads include whether a voltage equal to or greater than a predetermined value is measured simultaneously between adjacent measurement pads 12, or whether the same voltage value is detected between adjacent measurement pads 12. The "voltage equal to or greater than a predetermined value" can be determined in advance by prior experiments or simulations depending on the type and electromotive force of the fuel cell used.

[0028] The electrode pad determination unit 24 is configured to have the function of determining the measurement pads (also referred to as "electrode pads") corresponding to the electrode pins 211 of each cell that constitutes the fuel cell stack 200. Specifically, the electrode pad determination unit 24 excludes the measurement pads 12 that detected 0 V during the above-mentioned cell voltage measurement. Furthermore, the electrode pad determination unit 24 can set adjacent measurement pads 12 that detected a voltage value equal to or greater than a predetermined value as the electrode pads corresponding to one electrode pin 211 that at least a portion of these pads face.

[0029] The notification control unit 25 executes a process of presenting various information such as the power generation state of the fuel cell stack 200 and the voltages of individual cells via a known notification device 50 (speaker 51 and display 52) electrically connected to the control device 20. The notification control unit 25 may also perform control to present the various information described above on an external terminal such as a smartphone carried by an operator or the like.

[0030] <Cell Voltage Measurement Method> Next, a method for measuring the cell voltage of each cell constituting the fuel cell stack 200 in this embodiment will be described with reference to Figures 5 to 7. Below, a flow for measuring each cell voltage of the fuel cell stack 200 in which electrode pins 211 for voltage measurement are provided corresponding to each of the stacked cells 210 will be described.

[0031] First, as a preparation step, for example, an operator exposes the electrode pins 211 in the fuel cell stack 200 in order to inspect the power generation state of the fuel cell stack 200 mounted on a known fuel cell vehicle (FCV). The fuel cell stack 200 to be inspected at this time may be removed from the FCV, or may remain mounted on the FCV.

[0032] Next, in step 1, the above-mentioned cell voltage measuring device 100 is used to determine whether or not the measurement terminal unit 10 is connected to the electrode pin 211 by covering the electrode pin 211 of the fuel cell stack 200 with the measurement terminal unit 10 so that the measurement pad 12 faces the electrode pin 211.

[0033] In this way, in step 1, at least three measurement pads 12 are provided corresponding to the ends of two adjacent electrode pins 211, and these measurement pads 12 are brought into contact with the electrode pins 211. As a more specific method for determining whether or not the connection is complete, the worker may visually determine whether or not the contact is complete, or the contact may be determined via a known optical sensor (not shown) or the like.

[0034] If it is determined in step 1 that the measurement terminal unit 10 (specifically, the measurement pad 12) is connected to the electrode pin 211, the control device 20 acquires the cell voltage as a primary measurement value from the electrode pin 211 that is in contact with the measurement pad 12 via the voltage measurement unit 21 described above in the subsequent step 2.

[0035] As an example, the cell voltage (primary measurement value) measured at this time from the electrode pin 211 is shown in Fig. 6. That is, in Fig. 6, the n measurement pads 12 arranged from the left edge to the right edge of the paper are numbered in order from 1 to n, and the electrode pins 211 of the fuel cell stack 200 arranged opposite to them are similarly numbered from 1 to m.

[0036] As can be seen from Figure 6, for example, the first electrode pin 211 is in contact with the first measurement pad 12. The second electrode pin 211 is in contact with the third and fourth measurement pads. The third electrode pin 211 is in contact with the sixth measurement pad 12. Similarly, the mth electrode pin 211 is in contact with the (n-1)th and nth measurement pads 12. At this time, the control device 20 acquires the following primary measurement values ​​via the voltage measurement unit 21, and stores these values ​​in the storage device 30, such as the memory described above.

[0037] Measured value at 1st measurement pad: 0.6V Measured value at 2nd measurement pad: 0V Measured value at 3rd measurement pad: 0.5V Measured value at 4th measurement pad: 0.5V Measured value at 5th measurement pad: 0V Measured value at 6th measurement pad: 0.7V Measured value at 7th measurement pad: 0V Measured value at 8th measurement pad: 0.7V Measured value at 9th measurement pad: 0.7V Measured value at 10th measurement pad: 0V Measured value at 11th measurement pad: 0.5V Measured value at n-1th measurement pad: 0.6V Measured value at nth measurement pad: 0.6V

[0038] Next, in step 3, the control device 20 determines which pads are unconnected via the unconnected pad determination unit 22. In the case shown in Fig. 6 as an example, the control device 20 can determine that the second, fifth, seventh, and tenth measurement pads 12 are unconnected pads.

[0039] Next, in step 4, the control device 20 determines which pads are simultaneous connection pads via the above-mentioned simultaneous connection pad determination unit 23. In the case shown in FIG. 6 as an example, the control device 20 can determine that the third and fourth, eighth and ninth, and n-1th and nth measurement pads 12 are simultaneous connection pads connected to one electrode pin. In this way, when a voltage equal to or greater than a predetermined value is measured between adjacent measurement pads 12, the control device 20 can integrate the adjacent measurement pads 12 and set them as a single pad corresponding to the electrode pin 211 facing them.

[0040] Next, in step 5, the control device 20 determines, via the electrode pad determination unit 24, electrode pads for measuring cell voltages that correspond to the electrode pins 211 of each cell that constitutes the fuel cell stack 200. As an example, as shown in Fig. 7, the control device 20 determines the electrode pads as follows via the electrode pad determination unit 24, and stores this information in the storage device 30, such as the memory described above.

[0041] 1st electrode pin: Set the 1st measurement pad as the electrode pad for measuring cell voltage. 2nd electrode pin: Set the 3rd and 4th measurement pads as the electrode pad for measuring cell voltage. 3rd electrode pin: Set the 6th measurement pad as the electrode pad for measuring cell voltage. 4th electrode pin: Set the 8th and 9th measurement pads as the electrode pad for measuring cell voltage. 5th electrode pin: Set the 11th measurement pad as the electrode pad for measuring cell voltage. mth electrode pin: Set the n-1th and nth measurement pads as the electrode pad for measuring cell voltage.

[0042] Then, in step 5, the control device 20 detects the cell voltage of the corresponding cell from the electrode pad set above via the electrode pin 211. At this time, as the detected value from the electrode pad determined as the simultaneously connected pad, if the detected values ​​are the same, either one may be selected, or if the detected values ​​are different, the average value of these may be used as the detected value. Thus, in step 5, the voltages of the multiple cells constituting the fuel cell stack 200 are measured via the above-mentioned measurement pad 12.

[0043] As described above, the cell voltage measuring device of this embodiment uses a plurality of measurement pads, at least three of which are provided corresponding to the distance between both ends of two adjacent electrode pins (in other words, at least one measurement pad separated by an insulating layer between adjacent electrode pins). This allows for a one-to-one correspondence between the electrode pins and the measurement pads, thereby absorbing assembly errors between adjacent electrode pins and enabling rapid parallel detection of the cell voltages of multiple cells constituting a fuel cell stack.

[0044] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technology of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the technology to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0045] <Modifications> An example of the above-described modification or correction will be described below with reference to Figures 8 and 9. Note that in the following modification, the characteristic parts will be mainly described, and the same reference numerals will be used to designate the same components as in the embodiment already described, and descriptions thereof will be omitted as appropriate.

[0046] 8, a cell voltage measuring device 110 according to this modification is configured by adding an anisotropic conductive layer 60 to the cell voltage measuring device 100 described in the embodiment. As an example, the anisotropic conductive layer 60 may have a width W5 corresponding to the overall width W4 of the multiple measurement pads arranged in a planar direction on the base plate 11. In other words, the anisotropic conductive layer 60 may have a width in the planar direction that is substantially equal to the overall width W4 of the multiple measurement pads.

[0047] The anisotropic conductive layer 60 is disposed on the measurement pad 12 so as to be interposed between the measurement pad 12 and the electrode pin 211. The anisotropic conductive layer 60 may be fixed to the measurement pad 12 via a known conductive adhesive or the like. Such anisotropic conductive layer 60 is divided into a plurality of insulating regions 61 and conductive regions 62 arranged side by side in the planar direction (a plane parallel to the surface of the electrode pad).

[0048] Specifically, the anisotropic conductive layer 60 of this embodiment preferably has the insulating regions 61 and conductive regions 62 arranged alternately, as shown in Fig. 8. As a result, during the cell voltage measurement described above, when the multiple electrode pins 211 come into contact with the anisotropic conductive layer 60, the conductive regions 62 in contact with the electrode pins 211 form a conductive path, and the cell voltage is detected via the measurement pads 12 in contact with these conductive regions 62. The cell voltage measuring device according to the modified example described above also makes it possible to quickly detect the cell voltages of the multiple cells constituting the fuel cell stack in parallel.

[0049] 10: Measurement terminal unit 20: Control device 30: Storage device 40: Communication device 50: Notification device 60: Anisotropic conductive layer 100: Cell voltage measuring device 200: Fuel cell stack

Claims

1. A cell voltage measuring device for a fuel cell, which is capable of measuring the cell voltages of a battery stack in which electrode pins for voltage measurement are provided corresponding to each of a number of cells by contacting measurement pads with the electrode pins, comprising: a number of measurement pads, at least three of which are provided corresponding to the ends of two adjacent electrode pins; and a control device which measures the voltages of each of the multiple cells via the measurement pads.

2. The cell voltage measuring device of claim 1, wherein the control device, when a voltage equal to or greater than a predetermined value is measured at adjacent measurement pads among the plurality of measurement pads, sets the adjacent measurement pads as one pad corresponding to the opposing electrode pin.

3. The cell voltage measuring device according to claim 2, wherein the gap between the adjacent measurement pads is smaller than the width of the tip of the electrode pin that contacts the measurement pad.

4. The cell voltage measuring device according to claim 1, wherein an anisotropic conductive layer, which is divided into a plurality of insulating regions and conductive regions in a planar direction, is disposed between the measurement pad and the electrode pin.

5. A cell voltage measurement method for measuring the cell voltage of a battery stack in which electrode pins for voltage measurement are provided corresponding to a plurality of cells, the method comprising the steps of: contacting a plurality of measurement pads, at least three of which are provided corresponding to the ends of two adjacent electrode pins, with the electrode pins; and measuring the voltages of the plurality of cells via the measurement pads.

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