JP2010080164A - Current measurement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve current measurement accuracy in a current measurement device equipped with a current measuring part structured including a platy resistor. <P>SOLUTION: The resistor 121 of a current measuring part includes an input part 121a with a first through-hole 101a formed, an output part 121b with a second through-hole 101b formed, and a resistor main part 121c being as a channel of current heading from the first through-hole 101a to the second through-hole 101b. When a direction perpendicular to a direction of electric current flow in the resistor body 121c is to be a current-flow perpendicular direction, a width of the resistor body 121c in the current-flow perpendicular direction is made to be narrower than those of a first electrode 111 and a second electrode 131. Thus, even if unevenness of electric current distribution is generated in the first electrode 111, unevenness of electric current distribution in the resistor body 121c is made smaller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a current measuring device that measures a current flowing inside a fuel cell.

  Conventionally, Patent Document 1 discloses a current measuring device that is applied to a fuel cell configured by laminating and arranging a plurality of cells that output electric energy, and measures the current flowing inside the fuel cell. The current measurement device of Patent Document 1 includes a first electrode that is in electrical contact with one of adjacent cells, a second electrode that is in electrical contact with the other cell, and a first electrode and a second electrode. And a current measuring unit configured to have a plate-like resistor that electrically connects the two.

  Then, the potential difference between the first connection part that connects the first electrode of the current measurement part and the resistor and the second connection part that connects the resistor and the second electrode is detected by the voltage sensor for current measurement. The current flowing inside the fuel cell is measured by dividing the measured potential difference by the electric resistance value of the resistor.

More specifically, in the current measurement unit of Patent Document 1, the first and second electrodes and the resistor are arranged on different printed circuit boards, and each printed circuit board is integrally formed as a laminated circuit board. The plurality of through-holes for through connection formed constitute the first connection portion and the second connection portion. The voltage sensor for current measurement measures a potential difference between one of the plurality of through holes constituting the first connection portion and one of the plurality of through holes constituting the second connection portion. .
JP 2007-280643 A

However, in the current measuring device of Patent Document 1, when the current does not flow uniformly in each part of the plate-like resistor (that is, the current distribution varies greatly), or when the current per surface is poor and the current flows only locally. For example, the current could not be measured accurately. This is because the measured potential difference changes depending on whether a large amount of current flows or a small amount of current flows in a portion close to the through hole to which the voltage sensor for current measurement is connected in order to measure the potential difference. In view of the above points, an object of the present invention is to improve current measurement accuracy in a current measurement device including a current measurement unit configured to have a plate-like resistor.

  In order to achieve the above object, according to the first aspect of the present invention, a fuel cell constructed by stacking and arranging a plurality of cells (10a) that output an electric energy by electrochemical reaction of an oxidant gas and a fuel gas. Applied to (10), disposed between adjacent cells (10a), and electrically contact one of the adjacent cells (10a), the first electrode (111), the adjacent cell (10a) The second electrode (131) that is in electrical contact with the other cell, and the plate-like electrode that electrically connects the first electrode (111) and the second electrode (131) and has a predetermined electric resistance value A current measurement unit (101) configured to include a resistor (121), a first connection unit (101a) that connects the first electrode (111) and the resistor (121), and a resistor (121); Second connecting portion for connecting the second electrode (131) 101b), a current flowing through the cell (10a) based on the potential difference detecting means (102) for detecting the potential difference between the two, and the detected potential difference detected by the potential difference detecting means (102) and the electric resistance value of the resistor (121). Current value detection means (51) for detecting the current value, and the resistor (121) is provided with an input part (121a) provided with the first connection part (101a) and a second connection part (101b). Output portion (121b), and resistor main body portion (121c) serving as a current path from the first connection portion (101a) to the second connection portion (101b), and in the resistor main body portion (121c) When the direction perpendicular to the current flow direction in FIG. 5 is defined as the current flow vertical direction, the width of the resistor main body portion 121c in the current flow vertical direction is the first electrode (111) and the second electrode (131). Current flow Is narrower than the straight direction of the width, the first connecting portion (101a) and a second connecting portion (101b) is characterized by being provided at a plurality of positions so as to respectively align the current flowing vertically.

  According to this, the width of the resistor main body portion (121c) in the vertical direction of current flow is made narrower than the width of the first electrode (111) and the second electrode (131) in the vertical direction of current flow. 121c), the current is collected and flowed in a narrow region. Therefore, even if the current distribution varies in the first electrode (111), the current distribution varies in the resistor main body (121c). Becomes smaller. Therefore, it is possible to suppress a measurement error from occurring in the detected potential difference of the potential difference detecting means (102). Since the current value detection means (51) detects the current flowing through the cell (10a) using the detected potential difference in which the measurement error is suppressed, the current measurement accuracy of the current measurement device can be improved.

  In addition, the “current flow direction” described in the claims does not mean only a direction that completely coincides with the direction of the current that actually flows through the resistor main body (121c), and is equivalent to this. This means that the direction includes a direction equivalent to the direction of the current, such as a direction physically going from the first connection part (101a) to the second connection part (101b).

  According to the second aspect of the present invention, in the current measuring device according to the first aspect, the width of the input portion (121a) and the output portion (121b) in the vertical direction of the current flow is the current flow of the resistor body portion (121c). It is characterized by being equal to the width in the vertical direction.

  According to this, the width of the input part (121a) provided with the first connection part (101a) and the output part (121b) provided with the second connection part (101b) in the current flow vertical direction is reduced. The currents flowing through the plurality of first connection parts (101a) are easily averaged (that is, the variation in current distribution is reduced), and the currents flowing through the plurality of second connection parts (101b) are averaged. It becomes easy. Therefore, the measurement error of the detected potential difference by the potential difference detecting means (102) is further reduced, and the current measurement accuracy of the current measuring device is further improved.

  According to a third aspect of the present invention, in the current measuring device according to the first aspect, the widths of the input part (121a) and the output part (121b) in the current flow vertical direction are the first electrode (111) and the second electrode. It is characterized by being equal to the width of the current flow (131) in the vertical direction.

  According to this, the size, number, arrangement, etc. of the first connection part (101a) and the second connection part (101b) can be made the same as the conventional one.

  According to a fourth aspect of the present invention, in the current measuring device according to any one of the first to third aspects, the first electrode (111) is disposed on the first printed circuit board (110), and the second electrode The electrode (131) is disposed on the second printed circuit board (130), the resistor (121) is disposed on the third printed circuit board (120), and the first to third printed circuit boards (110, 120). , 130) are integrally coupled as a multilayer substrate with the third printed circuit board (120) sandwiched between the first printed circuit board (110) and the second printed circuit board (130), and the resistor (121). The spacer (124) having the same thickness as that of the resistor (121) is arranged on the third printed circuit board (120) along with the resistor (121) in a state of being electrically disconnected from the resistor (121). To do.

  According to this, since the spacer (124) having the same thickness as the resistor (121) is provided, when the first to third printed boards (110, 120, 130) are stacked, the first printed board (110 ) And the second printed circuit board (130) can be prevented from being warped, and the contact state between the first electrode (111) and the second electrode (131) and the cell (10a) is improved. be able to.

  According to a fifth aspect of the present invention, in the current measuring device according to any one of the first to fourth aspects, a wiring (electrically connecting the first connecting portion (101a) and the potential difference detecting means (102) ( 122) is electrically connected to the first connection part (101a) located at the center of the first connection part (101a) in the vertical direction of the current flow, and is connected to the second connection part (101b) and the potential difference detection means (102). ) Is electrically connected to the second connection portion (101b) located at the center of the second connection portion (101b) in the vertical direction of the current flow. Features.

  According to this, even if there is a variation in the value of the current flowing through each of the plurality of first connection parts (101a), the first connection part (101a) located in the central part in the current flow vertical direction has an average value thereof. Even if there is a variation in the values of the current flowing through the plurality of second connection portions (101b), the second connection portion (101b) located at the center in the vertical direction of the current flow The current value tends to be close to their average value. Therefore, the measurement error of the detected potential difference by the potential difference detecting means (102) is further reduced, and the current measurement accuracy of the current measuring device is further improved.

  According to a sixth aspect of the invention, in the current measuring device according to any one of the first to fifth aspects, the resistor (121) is made of a metal foil. According to this, the thickness of the current measuring device can be reduced.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is an overall configuration diagram of a fuel cell system to which a current measuring device 100 of the present embodiment is applied. This fuel cell system is applied to a so-called fuel cell vehicle, which is a kind of electric vehicle, and supplies electric power to an electric load such as an electric motor for vehicle travel.

  First, as shown in FIG. 1, the fuel cell system includes a fuel cell 10 that generates electric power using an electrochemical reaction between hydrogen and oxygen. The fuel cell 10 outputs electric energy supplied to an electric load such as an electric motor for driving a vehicle (not shown), a secondary battery, and various auxiliary machines for vehicles. In this embodiment, a solid polymer electrolyte fuel The battery is adopted.

  More specifically, the fuel cell 10 is configured by electrically connecting a plurality of fuel cell cells 10a (hereinafter simply referred to as cells 10a) as basic units in series. In each cell 10a, as shown below, hydrogen and oxygen are electrochemically reacted to output electric energy.

(Negative electrode side) H ₂ → 2H ⁺ + 2e ⁻
(Positive electrode side) 2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O
Furthermore, the electrical energy output from the fuel cell 10 is measured by a voltage sensor 11 that detects a voltage output as the entire fuel cell 10 and a current sensor 12 that detects a current output as the entire fuel cell 10. . The detection signals of the voltage sensor 11 and the current sensor 12 are input to the control device 50 described later.

  Further, on the air electrode (positive electrode) side of the fuel cell 10, an air supply pipe 20 a for supplying air (oxygen) as an oxidant gas to the fuel cell 10, and the electrochemical reaction in the fuel cell 10 are finished. An air discharge pipe 20b for discharging the surplus air and generated water generated by the air electrode from the fuel cell 10 to the outside air is connected.

  An air pump 21 is provided at the most upstream portion of the air supply pipe 20a to pump air sucked from the atmosphere to the fuel cell 10, and an air discharge pipe 20b adjusts the pressure of the air in the fuel cell 10. An air pressure regulating valve 23 is provided.

  Further, the air supply pipe 20 a and the air discharge pipe 20 b are provided with a humidifier 22 for moving the humidity (water vapor) of the air flowing out from the air pressure regulating valve 23 to the air pumped from the air pump 21. . The humidifier 22 is composed of a plurality of hollow fibers and functions to humidify the air supplied to the fuel cell 10.

  On the hydrogen electrode (negative electrode) side of the fuel cell 10, a hydrogen supply pipe 30 a for supplying hydrogen, which is a fuel gas, to the fuel cell 10, and the generated water accumulated on the hydrogen electrode side together with a small amount of hydrogen from the fuel cell 10 to the outside air A hydrogen discharge pipe 30b is connected to discharge. Furthermore, the hydrogen supply pipe 30a and the hydrogen discharge pipe 30b are connected via a hydrogen circulation pipe 30c.

  A high-pressure hydrogen tank 31 filled with high-pressure hydrogen is provided at the most upstream portion of the hydrogen supply pipe 30a, and is supplied to the fuel cell 10 between the high-pressure hydrogen tank 31 and the fuel cell 10 in the hydrogen supply pipe 30a. A hydrogen pressure regulating valve 32 for adjusting the pressure of hydrogen is provided.

  The hydrogen discharge pipe 30b is provided with an electromagnetic valve 34 that opens and closes at predetermined time intervals in order to discharge the produced water together with a small amount of hydrogen to the outside air. In the above-described electrochemical reaction, generated water is not generated on the hydrogen electrode side, but generated water that has permeated the electrolyte membrane of each cell 10a from the oxygen electrode side may accumulate on the hydrogen electrode side. Therefore, in this embodiment, the hydrogen discharge pipe 30b and the electromagnetic valve 34 are provided.

  The hydrogen circulation pipe 30c is provided to connect the downstream side of the hydrogen pressure regulating valve 32 of the hydrogen supply pipe 30a and the upstream side of the electromagnetic valve 34 of the hydrogen discharge pipe 30b. Thereby, the unreacted hydrogen flowing out from the fuel cell 10 is circulated to the fuel cell 10 and re-supplied. A hydrogen pump 33 for circulating hydrogen is disposed in the hydrogen circulation pipe 30c.

  By the way, the fuel cell 10 needs to be maintained at a constant temperature (for example, about 80 ° C.) during operation in order to ensure power generation efficiency. Therefore, a cooling water circuit 40 for cooling the fuel cell 10 is connected to the fuel cell 10. The coolant circuit 40 is provided with a water pump 41 that circulates coolant (heat medium) in the fuel cell 10 and a radiator 43 that includes an electric fan 42.

  Further, the cooling water circuit 40 is provided with a bypass flow path 44 through which the cooling water flows so as to bypass the radiator 43. A flow path switching valve 45 for adjusting the flow rate of the cooling water flowing through the bypass flow path 44 is provided at the junction of the cooling water circuit 40 and the bypass flow path 44. The cooling capacity of the cooling water circuit 40 is adjusted by adjusting the valve opening degree of the flow path switching valve 45.

  Further, a temperature sensor 46 as a temperature detecting means for detecting the temperature of the cooling water flowing out from the fuel cell 10 is provided in the vicinity of the outlet side of the fuel cell 10 in the cooling water circuit 40. By detecting the cooling water temperature by the temperature sensor 46, the temperature of the fuel cell 10 can be indirectly detected. The detection signal of the temperature sensor 46 is also input to the control device 50.

  The control device 50 controls the operation of various electric actuators constituting the fuel cell system on the basis of input signals, and is composed of a well-known microcomputer comprising a CPU, ROM, RAM, etc. and its peripheral circuits. Yes.

  Specifically, on the input side of the control device 50, in addition to the detection signals of the voltage sensor 11, the current sensor 12, and the temperature sensor 46 described above, the current is output from a current detection circuit 51 of the current measurement device 100 described later. A current signal is input. On the other hand, on the output side, various electric actuators such as the air pump 21, the air pressure regulating valve 23, the hydrogen pressure regulating valve 32, the hydrogen pump 33, the electromagnetic valve 34, the water pump 41, and the flow path switching valve 45 are connected. Yes.

  Next, details of the current measuring apparatus 100 of the present embodiment will be described. The current measuring device 100 includes a current measuring unit assembly plate 100a in which a plurality of current measuring units 101 are integrally configured as a plate member, and a current measuring voltage sensor 102 that detects a potential difference between predetermined portions of each current measuring unit 101. And a current detection circuit 51 that detects a current of a portion corresponding to the arrangement position of each current measurement unit 101 in the plate surface of the cell 10a and outputs the current to the control device 50.

  The current measuring unit assembly plate 100a will be described with reference to FIGS. 2 is an external perspective view of the fuel cell 10, and FIG. 3 is an exploded perspective view of the current measurement unit assembly plate 100a. As shown in FIG. 2, a plurality of current measurement unit assembly plates 100a are provided, and are arranged between adjacent cells 10a.

  Further, as shown in FIG. 3, the current measurement unit assembly board 100 a includes three printed boards, that is, a first printed board 110, a second printed board 130, and a third printed board 120 on which a wiring pattern is formed (printed). Have. And these printed circuit boards 110-130 are comprised as a laminated board integrated by the hot press in the state which interposed the insulating adhesive agent.

  In addition, as a 1st-3rd printed circuit board 110-130, a general glass epoxy board | substrate is employable. In addition, in the current measurement unit assembly plate 100a configured as a multilayer substrate, three through-holes penetrating the front and back of the multilayer substrate are formed in the vicinity of two opposing sides (left and right sides in FIG. 3). Yes. These through holes function as a manifold for circulating air, hydrogen, and cooling water when the cells 10a are stacked.

  Furthermore, between the manifolds on both sides, a plurality of current measuring units 101 are arranged in a matrix (lattice) in two orthogonal directions. More specifically, as shown in FIG. 3, the current measuring units 101 of this embodiment are arranged in a matrix of six in the vertical direction on the paper and seven in the horizontal direction on the paper.

  That is, in the present embodiment, a plurality of current measuring units 101 are arranged between the same adjacent cells 10a. As a result, the plurality of current measurement units 101 are arranged over the entire plate surface of the current measurement unit assembly plate 100a. Therefore, in the current measurement device 100 of the present embodiment, the current in the plane of the cell 10a. The density distribution can be measured.

  The current measurement unit 101 includes a first electrode 111 that is in electrical contact with one of the adjacent cells 10a, a second electrode 131 that is in electrical contact with the other cell 10a of the adjacent cells 10a, and The first electrode 111 and the second electrode 131 are electrically connected and have a plate-like resistor 121 having a predetermined electric resistance value.

  Therefore, the 1st electrode 111 and the 2nd electrode 131 are comprised as a pair of electrode, and are arrange | positioned at the both plate | board surface of the plate-shaped electric current measurement part assembly board 100a. Specifically, the first electrode 111 is disposed on the surface of the first printed circuit board 110 facing the one cell 10a (the front side in FIG. 3), and the second electrode 131 is disposed on the other side of the second printed circuit board 130. It is arrange | positioned in the surface (back side of the paper surface of FIG. 3) which opposes the cell 10a.

  The resistor 121 is disposed on the surface of the third printed circuit board 120 that faces the first printed circuit board 110 (the front side in FIG. 3). On the other hand, a current measurement wiring 122 is provided on the surface of the third printed circuit board 120 opposite to the side on which the resistor 121 is formed (the back side in FIG. 3).

  Further, on one side of the third printed circuit board 120, a signal extracting connector 123 to which a current measuring wiring 122 is connected is provided. In FIG. 3, the current measurement wiring 122 is indicated by diagonal lines surrounded by a broken line. The first electrode 111, the second electrode 131, the resistor 121, and the current measurement wiring 122 are wired to the first to third printed boards 110 to 130 with metal foil (specifically, copper foil). It is formed as a pattern.

  Next, referring to FIGS. 4 and 5, specific stacking modes of the first to third printed circuit boards 110 to 130, the first electrode 111, the second electrode 131, the resistor 121, and the current measurement constituting the current measuring unit 101 An electrical connection mode of the wiring 122 will be described. 4 is a cross-sectional view of the current measuring unit 101, and FIG. 5 is an explanatory diagram showing the flow of current in the current measuring unit 101. As will be described later, in the present embodiment, the first and second through holes 101a and 101b are arranged in a matrix. However, in FIGS. 4 and 5, the first and second through holes 101a and 101b are simplified to facilitate understanding. Only one second through hole 101a, 101b or one row is shown.

  As shown in FIG. 4, insulating adhesives 112 and 124 having electrical insulation are provided between the first printed circuit board 110 and the third printed circuit board 120 and between the third printed circuit board 120 and the second printed circuit board 130. Is arranged. The first to third printed boards 110 to 130 are provided with a plurality of first and second through holes 101a and 101b having a round hole shape.

  On the inner peripheral surfaces of the first and second through holes 101a and 101b, a conductor made of the same metal foil as the first and second electrodes 111 and 131 is formed. The first electrode 111, the resistor 121, and the current measurement wiring 122 are connected through the first through hole 101a, and the resistor 121, the second electrode 131, and the current measurement are connected through the second through hole 101b. A wiring 122 is connected. Therefore, the first and second through holes 101a and 101b constitute the first and second connection portions of this embodiment, respectively.

  Further, since the first electrode 111 is connected to one end side of the resistor 121 and the second electrode 131 is connected to the other end side of the resistor 121, the resistor 121 has one end side as shown in FIG. And current flows between the other end side.

  4 and 5, a current measuring voltage sensor 102 is connected to the first and second through holes 101a and 101b via a current measuring wiring 122 and an external wiring, respectively. The voltage sensor for current measurement 102 is a potential difference detection unit that detects a potential difference between two points of the first through hole 101a and the second through hole 101b and outputs a detection signal to the current detection circuit 51.

  The current detection circuit 51 performs an arithmetic process using the detection potential difference of the voltage sensor 102 for current measurement and the electric resistance value of the resistor 121 between the first through hole 101a and the second through hole 101b. It is a current value detection means for calculating a current flowing through a portion corresponding to each current measurement unit 101 in the plane.

  Next, specific configurations of the first electrode 111, the second electrode 131, and the resistor 121 will be described with reference to FIG. FIG. 6 is an exploded view of the first electrode 111, the second electrode 131, and the resistor 121.

  As shown in FIG. 6, the resistor 121 includes an input part 121a provided with the first through hole 101a, an output part 121b provided with the second through hole 101b, and the second through hole from the first through hole 101a. The resistor body 121c is a current path toward the current 101b.

  Here, in the resistor body 121c, a current flows from the first through hole 101a side to the second through hole 101b side, in other words, from the input unit 121a side to the output unit 121b side. When the direction perpendicular to the current flow direction in the resistor body 121c (hereinafter simply referred to as the current flow direction in the resistor) (the left-right direction in FIG. 6) is the current flow vertical direction, the resistor 121 The width in the vertical direction of the current flow is narrower than the width in the vertical direction of the current flow of the first electrode 111 and the second electrode 131. More specifically, the width of the input part 121a and the output part 121b in the current flow vertical direction is equal to the width of the resistor main body part 121c in the current flow vertical direction.

  The first and second through holes 101a and 101b are arranged in a matrix (lattice) in the current flow direction in the resistor and in the direction perpendicular to the current flow. The current measurement wiring 122 that electrically connects the first through hole 101a and the current measurement voltage sensor 102 is a first through located in the center of the plurality of first through holes 101a in the vertical direction of the current flow. It is electrically connected to the hole 101a. In addition, the current measurement wiring 122 that electrically connects the second through hole 101b and the current measurement voltage sensor 102 is the second through hole located at the center of the plurality of second through holes 101b in the vertical direction of the current flow. It is electrically connected to the hole 101b.

  The diameter and number of the first and second through holes 101a and 101b and the width and thickness of the resistor 121 are determined based on the maximum current value of power generated by the fuel cell 10. Incidentally, when it is desired to further reduce the width of the resistor 121, the thickness of the resistor 121 is increased.

  Next, a current measurement method using the current measurement apparatus 100 will be described. By supplying hydrogen and air to the fuel cell 10, power generation in the fuel cell 10 is started. In each current measurement unit 101 of the current measurement device 100, a current flows from the cell 10 a upstream in the current flow direction to the plate surface of the first electrode 111.

  Then, current flows in the order of the first electrode 111 → the first through hole 101a → the resistor 121 → the second through hole 101b → the second electrode 131, and flows from the plate surface of the second electrode 131 to the cell 10a downstream in the current flow direction. Current flows.

  At this time, the current measurement voltage sensor 102 measures the potential difference between the two points of the first through hole 101a and the second through hole 101b. As described above, in this embodiment, since the resistor 121 having a predetermined electric resistance value is used, the electric resistance value of the resistor 121 between the first and second through holes 101a and 101b is also a known value. .

  Therefore, the current detection circuit 51 divides the detected potential difference by the current measurement voltage sensor 102 by the electrical resistance value of the resistor 121 between the first and second through holes 101a and 101b stored in advance as known information. As a result, the value of the current flowing through the resistor 121 is calculated. Then, the current detection circuit 51 outputs the current value obtained by the calculation process to the control device 50.

  Further, the control device 50 detects the current distribution in the plane of the cell 10a, estimates the power generation state of the fuel cell 10 based on the detected current distribution, and supplies the air supply amount and supply pressure, the hydrogen supply pressure, and the cooling water circulation. The amount is controlled. This improves the efficiency and reliability of the fuel cell system.

  At this time, in the present embodiment, the width of the resistor main body 121c in the vertical direction of the current flow is made narrower than the width of the first electrode 111 and the second electrode 131 in the vertical direction of the current flow. Since the current is collected and flowed in a narrow region, even if the current distribution varies in the first electrode 111, the current distribution variation in the resistor body 121c becomes small. Therefore, it is possible to suppress a measurement error from occurring in the detection potential difference of the current measuring voltage sensor 102. Since the current detection circuit 51 detects the current flowing through each part of the cell 10a using the detection potential difference in which the measurement error is suppressed, the current measurement accuracy of the current measurement device 100 can be improved, and the fuel cell system. Efficiency and reliability can be further improved.

  In addition, since the width of the input portion 121a provided with the first through-hole 101a and the output portion 121b provided with the second through-hole 101b in the vertical direction of the current flow is narrowed, the plurality of first through-holes 101a are respectively provided. The flowing current is easily averaged (that is, the variation in current distribution is reduced), and the current flowing through each of the plurality of second through holes 101b is easily averaged. Therefore, the measurement error of the detected potential difference by the current measurement voltage sensor 102 is further reduced, and the current measurement accuracy of the current measurement device 100 is further improved.

  Furthermore, even if there is a variation in the value of the current flowing through each of the plurality of first through holes 101a, the first through hole 101a located at the center in the vertical direction of the current flow tends to have a current value close to the average value thereof. In addition, even if there are variations in the values of the currents flowing through the plurality of second through holes 101b, the current values in the second through holes 101b located at the center in the vertical direction of the current flow are close to their average values. easy. In the present embodiment, the current measurement wiring 122 is electrically connected to the first through hole 101a located at the center in the vertical direction of the current flow among the plurality of first through holes 101a, and the plurality of first through holes 101a. Since the two through-holes 101b are electrically connected to the second through-hole 101b located at the center in the vertical direction of the current flow, the measurement error of the detected potential difference by the current measuring voltage sensor 102 is further reduced. The current measurement accuracy of the current measuring device 100 is further improved.

  Moreover, since the 1st electrode 111, the 2nd electrode 131, the resistor 121, and the electric current measurement wiring 122 are comprised from metal foil, the thickness of the electric current measurement apparatus 100 can be made thin.

(Modification of the first embodiment)
FIG. 7 shows a first variation of the first embodiment. As shown in FIG. 7, a spacer 124 having the same thickness as the resistor 121 is electrically disconnected from the resistor 121. The resistors 121 may be arranged on the third printed circuit board 120 side by side on both sides of the current flow in the vertical direction. The spacer 124 is formed of the same metal foil as that of the resistor 121.

  According to this, since the spacer having the same thickness as the resistor 121 is provided, the first printed board 110 and the second printed board 130 are warped when the first to third printed boards 110 to 130 are stacked. In other words, the contact state between the first electrode 111 and the second electrode 131 and the cell 10a can be improved.

  FIG. 8 shows a second modification of the first embodiment. As shown in FIG. 8, a resistor 121 is arranged on one end side in the current flow vertical direction on the third printed circuit board 120, and the current is changed. A spacer 124 having the same thickness as that of the resistor 121 may be disposed on the other end side in the flow vertical direction while being electrically disconnected from the resistor 121. The spacer 124 is formed of the same metal foil as that of the resistor 121. Also by this, the same effect as the first modified example can be obtained.

(Second Embodiment)
A second embodiment of the present invention will be described. FIG. 9 is an exploded view of the first electrode 111, the second electrode 131, and the resistor 121 in the current measuring device according to the second embodiment. In the present embodiment, the specific configurations of the first electrode 111, the second electrode 131, and the resistor 121 are changed, and the other parts are the same as those of the first embodiment, and therefore only different parts will be described.

  As shown in FIG. 9, the width of the resistor body 121 c in the vertical direction of the current flow of the resistor 121 is the width of the first electrode 111 and the second electrode 131 in the vertical direction of the current flow, as in the first embodiment. It is narrower than. Also, the width of the input part 121a and the output part 121b in the current flow vertical direction of the resistor 121 is equal to the width of the first electrode 111 and the second electrode 131 in the current flow vertical direction.

  The first and second through holes 101a and 101b extend across the entire width of the input part 121a and the output part 121b in the vertical direction of the current flow, and in the vertical direction of the current flow of the first electrode 111 and the second electrode 131. They are arranged in a line in the vertical direction of the current flow over the entire width.

  The current measurement wiring 122 that electrically connects the first through-hole 101a and the current-measurement voltage sensor 102 is the first through-hole 101a located at the center of the plurality of first through-holes 101a in the current flow vertical direction. Is electrically connected. In addition, the current measurement wiring 122 that electrically connects the second through hole 101b and the current measurement voltage sensor 102 is the second through hole located at the center of the plurality of second through holes 101b in the vertical direction of the current flow. It is electrically connected to the hole 101b.

  According to this, the size, number, arrangement, etc. of the first through hole 101a and the second through hole 101b can be made the same as the conventional one.

  Further, in the present embodiment, as in the first embodiment, the current is collected in a narrow region in the resistor main body 121c and flows, so that the current distribution varies in the first electrode 111. However, the variation in the current distribution is reduced in the resistor body 121c, and the current measurement accuracy of the current measuring device 100 can be improved.

(Modification of the second embodiment)
FIG. 10 shows a first modification of the second embodiment. As shown in FIG. 10, a spacer 124 having the same thickness as the resistor 121 is electrically disconnected from the resistor 121. You may arrange | position on the 3rd printed circuit board 120 along with the current flow vertical direction both sides of the resistor main body part 121c. The spacer 124 is formed of the same metal foil as that of the resistor 121.

  According to this, since the spacer having the same thickness as the resistor 121 is provided, the first printed board 110 and the second printed board 130 are warped when the first to third printed boards 110 to 130 are stacked. In other words, the contact state between the first electrode 111 and the second electrode 131 and the cell 10a can be improved.

  In the case of the first modified example, in the second through hole 101b on the output side, the current may concentrate on the through hole in the central portion in the vertical direction of the current flow, so the second modified example of the second embodiment. As shown in FIG. 11 showing an example, the width of the output portion 121b in the vertical direction of the current flow is made equal to the width of the resistor main body portion 121c in the vertical direction of the current flow, and the second through hole 101b They may be arranged in a matrix (lattice) in the direction perpendicular to the current flow.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows.

  (1) In the above-described embodiment, the plurality of current measurement units 101 are provided on the current measurement unit assembly plate 100a so as to be arranged over the entire surface of the cell 10a. However, at least one current measurement unit 101 is provided. What is necessary is just to be provided. Thereby, the local current of the site | part corresponding to the electric current measurement part 101 in the cell 10a can be measured.

  (2) In the above-described embodiment, the example in which the first electrode 111, the second electrode 131, the resistor 121, and the current measurement wiring 122 are formed of copper foil has been described. Alternatively, the second electrode 111 or 131 may be formed of a material having a higher resistance value (for example, nickel foil). As a result, the potential difference of the resistor 121 between the two points of the first through hole 101a and the second through hole 101b is increased, and the potential difference is easily measured.

  (3) In the above-described embodiment, the example in which the resistor 121 and the current measurement wiring 122 are formed on the third printed circuit board 120 has been described. However, the resistor 121 and the current measurement wiring 122 are formed on different printed circuit boards. May be. In this case, each printed board may be integrated as a laminated board with the first and second printed boards sandwiched therebetween.

1 is an overall configuration diagram of a fuel cell system to which a current measuring device according to a first embodiment of the present invention is applied. It is a perspective view of the fuel cell of a 1st embodiment. It is a disassembled perspective view of the current measurement part assembly board of 1st Embodiment. It is sectional drawing of the electric current measurement part of 1st Embodiment. It is a perspective view which shows the flow of the electric current of the electric current measurement part of 1st Embodiment. It is an exploded view of the 1st electrode, the 2nd electrode, and a resistor in a 1st embodiment. It is a figure which shows the 1st modification of 1st Embodiment. It is a figure which shows the 2nd modification of 1st Embodiment. It is an exploded view of the 1st electrode, the 2nd electrode, and a resistor in the current measuring device concerning a 2nd embodiment of the present invention. It is a figure which shows the 1st modification of 2nd Embodiment. It is a figure which shows the 2nd modification of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel cell 51 Current value detection means 10a Cell 101 Current measurement part 102 Current measurement voltage sensor (potential difference detection means)
111 1st electrode 121 Resistor 131 2nd electrode 101a 1st through hole (1st connection part)
101b 2nd through hole (2nd connection part)
121a input unit 121b output unit 121c resistor body unit

Claims (6)

Applied to a fuel cell (10) configured by stacking a plurality of cells (10a) that output an electric energy by electrochemical reaction of an oxidant gas and a fuel gas,
A first electrode (111) disposed between the adjacent cells (10a) and electrically contacting one of the adjacent cells (10a), and the other cell of the adjacent cells (10a) A second electrode (131) that is in electrical contact with the plate, and a plate-like resistor that electrically connects the first electrode (111) and the second electrode (131) and has a predetermined electric resistance value A current measuring unit (101) configured to include (121);
A first connection part (101a) connecting the first electrode (111) and the resistor (121) and a second connection part (101b) connecting the resistor (121) and the second electrode (131). ) A potential difference detection means (102) for detecting a potential difference between
Current value detection means (51) for detecting the value of the current flowing through the cell (10a) based on the detected potential difference detected by the potential difference detection means (102) and the electric resistance value of the resistor (121); With
The resistor (121) includes an input part (121a) provided with the first connection part (101a), an output part (121b) provided with the second connection part (101b), and the first connection. A resistor body portion (121c) that serves as a current path from the portion (101a) to the second connection portion (101b),
When the direction perpendicular to the direction of current flow in the resistor body (121c) is defined as the direction of current flow vertical,
The width of the resistor body portion (121c) in the vertical direction of current flow is narrower than the width of the first electrode (111) and the second electrode (131) in the vertical direction of current flow.
The current measuring device is characterized in that the first connecting portion (101a) and the second connecting portion (101b) are provided at a plurality of locations so as to be aligned in the current flow vertical direction.   The width of the input part (121a) and the output part (121b) in the current flow vertical direction is equal to the width of the resistor body part (121c) in the current flow vertical direction. The current measuring device according to 1.   The width of the input part (121a) and the output part (121b) in the current flow vertical direction is equal to the width of the first electrode (111) and the second electrode (131) in the current flow vertical direction. The current measuring device according to claim 1. The first electrode (111) is disposed on the first printed circuit board (110),
The second electrode (131) is disposed on the second printed circuit board (130),
The resistor (121) is disposed on the third printed circuit board (120),
The first to third printed circuit boards (110, 120, 130) sandwich the third printed circuit board (120) between the first printed circuit board (110) and the second printed circuit board (130). So, it is integrally bonded as a laminated substrate,
A spacer (124) having the same thickness as the resistor (121) is electrically disconnected from the resistor (121), and is aligned with the resistor (121) to the third printed circuit board (120). The current measuring device according to any one of claims 1 to 3, wherein the current measuring device is arranged in a vertical direction. A wiring (122) for electrically connecting the first connection part (101a) and the potential difference detecting means (102) is located in a central part of the first connection part (101a) in the vertical direction of current flow. 1 electrically connected to the connecting part (101a),
A wiring (122) for electrically connecting the second connection part (101b) and the potential difference detecting means (102) is a first part of the second connection part (101b) located at the center in the vertical direction of current flow. The current measuring device according to any one of claims 1 to 4, wherein the current measuring device is electrically connected to the two connecting portions (101b).   6. The current measuring device according to claim 1, wherein the resistor (121) is made of a metal foil.

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