Fuel cell stack

Abstract

To provide a fuel cell stack that allows a user to select whether to enable a termination resistor.SOLUTION: A fuel cell stack 1 includes a cell stack 3 in which a number of fuel cells are stacked, and is equipped with a cell monitor 4 that monitors the voltage of the cell stack 3, a communication wire harness 5 connected to the cell monitor 4, and an IF connector 6 that can be connected to the communication wire harness 5 from outside the fuel cell stack 1. The communication wire harness 5 includes a termination resistor 7. The IF connector 6 includes a connection pin that can be electrically connected to the termination resistor 7.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fuel cell stack.

Background Art

[0002] Conventionally, in such a technical field, for example, there is one described in Patent Document 1. The fuel cell stack described in Patent Document 1 includes a cell stack in which a plurality of fuel cells are stacked, a cell monitor that monitors the cell stack, a control device that communicates with the cell monitor via a communication wire harness, a first case that houses the cell stack, and a second case that houses the control device. In this fuel cell stack, the communication connector of the communication wire harness connecting the control device and the cell monitor is connected to the connection connector provided at the connector portion of the cell monitor through the connector opening of the second case, so that the connection between the cell monitor and the control device can be facilitated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When selling a fuel cell stack, there are users who desire one-to-one CAN communication with the fuel cell stack, and there are also users who desire multiple CAN communications. It is required that the termination resistance on the fuel cell stack side can be freely selected to be effective or invalid according to the communication requirements of the user. However, in the above-described fuel cell stack, a termination resistance is mounted on the cell monitor and is fixed as having a termination resistance as a fuel cell stack, so there is a problem that it cannot be applied to the above-described selection.

[0005] The present invention was made to solve these technical problems and aims to provide a fuel cell stack in which the terminating resistor can be selected to be enabled or disabled. [Means for solving the problem]

[0006] The fuel cell stack according to the present invention is a fuel cell stack including a cell stack in which a plurality of fuel cell cells are stacked, comprising: a cell monitor for monitoring the voltage of the cell stack; a communication wire harness connected to the cell monitor; and a connector that can be connected to the communication wire harness from outside the fuel cell stack, wherein the communication wire harness has a termination resistor, and the connector has connection pins that can be electrically connected to the termination resistor.

[0007] In the fuel cell stack according to the present invention, the communication wire harness has a termination resistor, and the connector has a connection pin that can be electrically connected to the termination resistor. Therefore, if the user wants to enable the termination resistor on the fuel cell stack side, this can be achieved by connecting to the connection pin in the connector that is electrically connected to the termination resistor. In this way, for example, it becomes possible to use the termination resistor on the fuel cell stack side and the termination resistor provided in the user's system, enabling one-to-one communication with the fuel cell stack. On the other hand, if the user wants to disable the termination resistor on the fuel cell stack side, multiple communications with the fuel cell stack can be achieved by not connecting to the connection pin in the connector that is electrically connected to the termination resistor, for example, by using the termination resistor provided in the user's system. [Effects of the Invention]

[0008] According to the present invention, it is possible to select whether to enable or disable the termination resistor on the fuel cell stack side. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the structure of a fuel cell stack according to the embodiment. [Figure 2A]This is a schematic diagram illustrating one-to-one CAN communication. [Figure 2B] This is a schematic diagram illustrating a one-to-one CAN communication connection. [Figure 3A] This is a schematic diagram illustrating multiple CAN communications. [Figure 3B] This is a schematic diagram illustrating the connection of multiple CAN communications. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the fuel cell stack according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, in the CAN (Controller Area Network) communication described below, a differential transmission path equipped with a high-potential side signal line and a low-potential side signal line is used, with the potential of the high-potential side signal line indicated by "CANH" and the potential of the low-potential side signal line indicated by "CANL".

[0011] Figure 1 is a schematic diagram showing the structure of a fuel cell stack according to an embodiment. As shown in Figure 1, the fuel cell stack 1 of this embodiment comprises a box-shaped stack case 2, a cell stack 3, a cell monitor 4, and a communication wire harness 5 housed inside the stack case 2, and an IF (Interface) connector 6 attached to the side wall of the stack case 2.

[0012] The cell stack 3 is a cell stack formed by stacking multiple fuel cell cells, and constitutes a solid polymer electrolyte fuel cell. Although not shown in the figure, a fuel cell cell has a membrane / electrode assembly in which a polymer electrolyte membrane is sandwiched between an anode electrode and a cathode electrode, and a pair of separators that sandwich the membrane / electrode assembly from both sides. The fuel cell cell generates electricity through an oxidation-reduction reaction between oxygen gas from the air supplied via the separator on the cathode electrode side and hydrogen gas supplied via the separator on the anode electrode side.

[0013] The stack case 2 is formed in the shape of a rectangular box from a metal material such as aluminum. The cell monitor 4 is for monitoring the voltage of the cell stack 3. In this embodiment, there are two cell monitors 4 (first cell monitor 4a, second cell monitor 4b). An ECU (Electronic Control Unit) is located in each cell monitor. Termination resistors are not implemented in the ECUs within each cell monitor.

[0014] The communication wire harness 5 is electrically connected to the ECU of the first cell monitor 4a and the ECU of the second cell monitor 4b, respectively, via connectors, for example. One end of the communication wire harness 5 extends to the side wall of the stack case 2 and is electrically connected to the IF connector 6. In this embodiment, the communication wire harness 5 is configured to have a termination resistor 7.

[0015] The IF connector 6 is fixed to the side wall of the stack case 2, penetrating the side wall of the stack case 2, so that it can be connected to the communication wire harness 5 from outside the fuel cell stack 1. This IF connector 6 is a connector provided to connect the communication wire harness 5 to the user's system, and is configured to have a power connection pin, a GND (Ground) connection pin, a CAN communication connection pin for each cell monitor, and a termination resistor connection pin.

[0016] More specifically, as shown in Figures 2B and 3B, the IF connector 6 has eight connection pins: a power connection pin, a GND connection pin, an ECU(1)CANH connection pin, an ECU(1)CANL connection pin, an ECU(2)CANH connection pin, an ECU(2)CANL connection pin, a termination resistor CANH connection pin, and a termination resistor CANL connection pin. These pins protrude outward from the IF connector 6.

[0017] The end part of the power supply connection pin (i.e., the end part opposite to the end part protruding outward from the IF connector 6) is electrically connected to the power supplies of the first cell monitor 4a and the second cell monitor 4b via the communication wire harness 5, respectively. The end part of the GND connection pin is electrically connected to the GND of the first cell monitor 4a and the GND of the second cell monitor 4b via the communication wire harness 5, respectively. Further, the end part of this GND connection pin is also electrically connected to the GND of the termination resistor 7 of the communication wire harness 5.

[0018] The end part of the ECU(1) CANH connection pin is electrically connected to the CANH of the ECU of the first cell monitor 4a (displayed as "ECU(1) CANH" in FIGS. 2B and 3B) via the communication wire harness 5. The end part of the ECU(1) CANL connection pin is electrically connected to the CANL of the ECU of the first cell monitor 4a (displayed as "ECU(1) CANL" in FIGS. 2B and 3B) via the communication wire harness 5.

[0019] The end part of the ECU(2) CANH connection pin is electrically connected to the CANH of the ECU of the second cell monitor 4b (displayed as "ECU(2) CANH" in FIGS. 2B and 3B) via the communication wire harness 5. The end part of the ECU(2) CANL pin is electrically connected to the CANL of the ECU of the second cell monitor 4b (displayed as "ECU(2) CANL" in FIGS. 2B and 3B) via the communication wire harness 5.

[0020] The end part of the termination resistor CANH connection pin is electrically connected to the CANH of the termination resistor 7 of the communication wire harness 5, and the end part of the termination resistor CANL connection pin is electrically connected to the CANL of the termination resistor 7 of the communication wire harness 5.

[0021] Hereinafter, based on FIGS. 2A to 3B, it will be described that the fuel cell stack 1 of the present embodiment can correspond to one-to-one CAN communication and multiple CAN communications, respectively.

[0022] [One-to-one CAN communication] Figure 2A is a schematic diagram illustrating one-to-one CAN communication, and Figure 2B is a schematic diagram illustrating the connection of one-to-one CAN communication. As shown in Figure 2A, for example, in the user-side system of the fuel cell stack 1, when performing one-to-one CAN communication with the fuel cell stack 1, the user electrically connects the IF connector 6 of the fuel cell stack 1 and the ECU 11 of the user-side ECU assembly 10 via the CAN communication bus 8. The ECU 11 of the user-side ECU assembly 10 is equipped with a termination resistor 12. The CAN communication bus 8 can be electrically connected to the IF connector 6 via, for example, a connector (not shown) that can be mated with the IF connector 6.

[0023] As shown in Figure 2B, the ECU 11 of the user-side ECU assembly 10 is equipped with, for example, a power supply, GND, ECU(1)CANH, ECU(1)CANL, ECU(2)CANH, ECU(2)CANL, termination resistor CANH, termination resistor CANL, etc.

[0024] At this time, the power supply, GND, ECU(1)CANH, ECU(1)CANL, ECU(2)CANH, and ECU(2)CANL pins of the user-side ECU assembly 10's ECU 11 are electrically connected via the CAN communication bus 8 to the power connection pin, GND connection pin, ECU(1)CANH connection pin, ECU(1)CANL connection pin, ECU(2)CANH connection pin, and ECU(2)CANL connection pin of the IF connector 6, respectively.

[0025] Furthermore, the termination resistors CANH and CANL on the user-side ECU assembly 10 are electrically connected to the termination resistor CANH connection pin and termination resistor CANL connection pin of the IF connector 6, respectively. In other words, at this time, the termination resistor 7 on the fuel cell stack 1 side is selected as enabled. This makes it possible to perform one-to-one CAN communication between the fuel cell stack 1 and the user-side system.

[0026] Furthermore, in CAN communication, two termination resistors are always required to prevent communication errors. As mentioned above, by using both the termination resistor 7 on the fuel cell stack 1 side and the termination resistor 12 on the user side ECU assembly 10, the quality of CAN communication between the fuel cell stack 1 and the user system can be maintained.

[0027] [Multiple CAN communications] Figure 3A is a schematic diagram showing multiple CAN communications, and Figure 3B is a schematic diagram for explaining the connection of multiple CAN communications. As shown in Figures 3A and 3B, for example, in the user-side system of the fuel cell stack 1, when multiple CAN communications are performed with the fuel cell stack 1, when the user electrically connects the IF connector 6 of the fuel cell stack 1 and the ECU 11 of the user-side ECU assembly 10 via the CAN communication bus 8, the power supply, GND, ECU(1)CANH, ECU(1)CANL, ECU(2)CANH, and ECU(2)CANL of the user-side ECU 11 are electrically connected to the power connection pin, GND connection pin, ECU(1)CANH connection pin, ECU(1)CANL connection pin, ECU(2)CANH connection pin, and ECU(2)CANL connection pin of the IF connector 6 via the CAN communication bus 8. However, the termination resistors CANH and CANL of the user-side ECU 11 are not electrically connected to the termination resistor CANH connection pin and termination resistor CANL connection pin of the IF connector 6. In other words, the termination resistor 7 on the fuel cell stack 1 side is selected as inactive.

[0028] This allows for multiple CAN communications between the fuel cell stack 1 and the user's system. Since the user's ECU 11 has two termination resistors 12, using these termination resistors 12 helps maintain the quality of CAN communications between the fuel cell stack 1 and the user's system.

[0029] In the fuel cell stack 1 according to this embodiment, the communication wire harness 5 has a termination resistor 7, and the IF connector 6 has connection pins (termination resistor CANH connection pin, termination resistor CANL connection pin) that can be electrically connected to the termination resistor 7. Therefore, if the user wants to enable the termination resistor 7 on the fuel cell stack 1 side, this can be achieved by connecting the termination resistors CANH and CANL of the user's ECU 11 to the termination resistor CANH connection pin and termination resistor CANL connection pin of the IF connector 6. Thus, it becomes possible to use the termination resistor 7 on the fuel cell stack 1 side and the termination resistor 12 of the user's ECU 11, enabling one-to-one CAN communication with the fuel cell stack 1. On the other hand, if the user wants to disable the termination resistor 7 on the fuel cell stack 1 side, multiple CAN communications with the fuel cell stack 1 can be achieved by not connecting the termination resistors CANH and CANL of the ECU 11 to the termination resistor CANH connection pin and termination resistor CANL connection pin of the IF connector 6, for example, by using two termination resistors 12 on the user's side.

[0030] Furthermore, since a fuel cell stack 1 having such a uniform structure can be used to support either one-to-one or multiple CAN communications from the user side, costs can be reduced compared to, for example, developing a fuel cell stack with a termination resistor that is exclusively suited to one-to-one CAN communications and a fuel cell stack without a termination resistor that is exclusively suited to multiple CAN communications.

[0031] Furthermore, in the fuel cell stack 1 according to this embodiment, the cell monitors 4 (first cell monitor 4a and second cell monitor 4b) do not have termination resistors installed; in other words, no termination resistors are provided on the cell monitors. This allows the wiring from the first cell monitor 4a to the second cell monitor 4b within the fuel cell stack to be treated as branch lines, so that the user can freely set the main line and improve the robustness of the wiring required for component mounting and other purposes.

[0032] Specifically, the main lines should be arranged with a maximum wiring length of less than 15m, and the branch lines should be arranged with a maximum wiring length of less than 5m. In a fuel cell stack, the wiring from a component with a termination resistor (e.g., the first cell monitor 4a with a termination resistor) to another component with a termination resistor (e.g., the second cell monitor 4b with a termination resistor) is considered the main line, and the wiring from a component without a termination resistor to the CAN communication bus is considered the branch line.

[0033] For example, if a termination resistor is provided on the cell monitor as in the conventional method, the wiring between the two cell monitors (first cell monitor 4a and second cell monitor 4b) within the fuel cell stack constitutes the main line. As a result, the wiring of the user's system is treated as a branch line, and only wiring less than 5m in length is possible. On the other hand, as in this embodiment, if a termination resistor is not provided on the cell monitor and is provided on the communication wire harness 5, the wiring from the fuel cell stack 1 to the user's system can be configured as the main line, or the wiring within the user's system can be configured as the main line, allowing the user to freely set the main line according to their system. As a result, the robustness of the wiring required for component mounting and other purposes can be improved.

[0034] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. [Explanation of Symbols]

[0035] 1: Fuel cell stack, 2: Stack case, 3: Cell stack, 4: Cell monitor, 4a: First cell monitor, 4b: Second cell monitor, 5: Communication wire harness, 6: IF connector, 7: Termination resistor, 8: CAN communication bus, 10: User-side ECU assembly, 11: ECU, 12: Termination resistor

Claims

[Claim 1] A fuel cell stack including a cell stack in which multiple fuel cell cells are stacked, A cell monitor that monitors the voltage of the cell stack, A communication wire harness connected to the cell monitor, A connector that can be connected to the communication wire harness from outside the fuel cell stack, Equipped with, The aforementioned communication wire harness has a termination resistor, The fuel cell stack is characterized in that the connector has a connection pin that is electrically connectable to the termination resistor and can be selected to be enabled or disabled.

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