JP2010272458A - Electric connection structure of fuel cell system, and fuel cell system using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric connection structure of a fuel cell system for facilitating electric connection work between both terminals even in the case an output side terminal of the fuel cell and an input side terminal of a voltage converter are arranged nearby and position error is caused between both the terminals. <P>SOLUTION: The electric connection structure 10 of a fuel cell system includes a fuel cell 12 which generates power by receiving supply of a reaction gas, and a DC/DC converter 76 which converts the output voltage of the fuel cell 12, and includes an output side terminal 13 which extends from the fuel cell 12, an input side terminal 77 which extends from the DC/DC converter 76, and a braided flexible bus bar 16 which electrically connects between the output side terminal 13 and the input side terminal 77. The output side terminal 13 of the fuel cell 12 and the input side terminal 77 of the DC/DC converter 76 are arranged in a position relation in which they are separated in vertical direction but overlapping portions exist when viewed only in the extension direction of the terminals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electric connection structure of a fuel cell system and a fuel cell system using the same, and more particularly to an electric connection structure of a fuel cell and a voltage converter for converting an output voltage of the fuel cell and a fuel cell using the same. About the system.

  2. Description of the Related Art Conventionally, a fuel cell is known in which hydrogen, which is a fuel, and oxygen in the air, which is an oxidizing gas, is supplied as a reaction gas and generates power through an electrochemical reaction. A fuel cell is a clean power generation device that does not emit carbon dioxide, which is a cause of global warming, and is expected as a power supply device for an electric vehicle using a motor as a power source.

  When a fuel cell is used as an in-vehicle power source, the DC voltage output from the fuel cell is boosted by a DC / DC converter, the boosted DC voltage is converted to an AC voltage by an inverter, and this AC voltage is applied to the motor for driving. Thus, it is conceivable to obtain the driving force for traveling while charging the power storage device with regenerative power output from the motor during regenerative braking.

  For example, Patent Document 1 discloses a propulsion motor (16) mounted on a vehicle, a fuel cell (11) and a power storage device (13) connected in parallel to the motor (16), and a fuel cell ( 11) and a first DC / DC converter (12) disposed between the motor (16), a second DC / DC converter (14) disposed between the power storage device (13) and the motor (16), A second current sensor (35) for detecting an input current of the first DC / DC converter (12), a system voltage sensor (31) for detecting an output voltage of the second DC / DC converter (14), and a second current sensor ( 35) feedback control of the first DC / DC converter (12) so that the current value detected in 35) becomes the target current, and the feedback is performed so that the voltage value detected by the system voltage sensor (31) becomes the target voltage. Comprises a control device for click control and (22), the power supply system of a fuel cell vehicle is disclosed.

JP 2007-318938 A

  In a configuration in which a DC voltage supplied from a fuel cell is boosted by a DC / DC converter and used as a driving voltage of a motor as disclosed in Patent Document 1, the fuel cell and a reaction gas supply system for supplying a reaction gas to the fuel Since a vehicle-mounted space (for example, in the engine compartment) when a power system such as a DC / DC converter or a motor is mounted on a vehicle is limited, the fuel cell and the converter are disposed close to each other. The output side terminal and the input side terminal of the DC / DC converter may be provided in a close positional relationship.

  In order to electrically connect the output side terminal of the fuel cell and the input side terminal of the DC / DC converter, it is preferable to use power wiring. In general, power wiring is configured by connecting ring-shaped metal terminal pieces to both ends of a thick copper wire that is insulated and coated with enamel or the like.

  When the fuel cell and the DC / DC converter are fixed to a frame forming a part of the vehicle body, the fuel cell output side input and the DC / DC are caused by manufacturing errors of the fuel cell and the DC / DC converter, bending of the frame, and the like. An error (hereinafter referred to as “position error”) may occur between the input side terminal of the converter and a distance and an orientation. In this case, connection work must be performed while bending or twisting the power wiring in order to absorb the position error with the power wiring connecting between the two. Since the wiring is so rigid that it requires a considerable amount of force to bend, there is a problem that the electrical connection work between both terminals becomes difficult.

  In particular, the positional relationship between the fuel cell and the DC / DC converter is close, the space between them can be used as a work space, and the output side terminal of the fuel cell and the input side terminal of the DC / DC converter are close to each other. In this case, this problem becomes significant when a relatively short power wiring is used.

  The object of the present invention is to facilitate the electrical connection work between both terminals even when the output side terminal of the fuel cell and the input side terminal of the voltage conversion device are arranged close to each other and a positional error occurs between the both terminals. An object of the present invention is to provide an electric connection structure of a fuel cell system (hereinafter, simply referred to as “electric connection structure” where appropriate) and a fuel cell system using the same.

  An electrical connection structure of a fuel cell system according to the present invention is an electrical connection structure of a fuel cell system that includes a fuel cell that generates power upon supply of a reaction gas, and a voltage converter that converts an output voltage of the fuel cell. An output side terminal extending from the fuel cell, an input side terminal extending from the voltage converter, and a braided flexible bus bar that electrically connects the output side terminal and the input side terminal. The output side terminal and the input side terminal of the voltage converter are arranged in a positional relationship where they are separated from each other but overlap when viewed only in the terminal extending direction.

  In the electrical connection structure of the fuel cell system according to the present invention, the fuel cell and the voltage conversion device are arranged close to each other in the lateral direction, and an output side terminal projecting from a side end surface facing the voltage conversion device of the fuel cell And an input-side terminal projecting from a side end surface facing the fuel cell of the voltage conversion device may be formed to extend in a facing direction.

  Further, in the electrical connection structure of the fuel cell system of the present invention, the fuel cell and the voltage conversion device are disposed close to each other in the vertical direction, an output side terminal projecting from the side end surface of the fuel cell, and the fuel cell The input side terminal protruding from the side end face of the voltage converter in the same direction as the side end face may be formed extending in the same direction.

  Further, in the electrical connection structure of the fuel cell system of the present invention, the output side terminal of the fuel cell, the input side terminal of the voltage converter, and the braided flexible bus bar are covered with an insulating and waterproof cover member. preferable. In this case, a conductive layer may be formed on the inner surface of the cover member.

  Further, in the electrical connection structure of the fuel cell system of the present invention, the voltage converter is a DC / DC converter capable of boosting a DC voltage output from the fuel cell, or a DC voltage output from the fuel cell is an AC voltage. It may be an inverter that can be converted into

  Furthermore, the fuel cell system according to the present invention includes a fuel cell and an electrical converter connected by the electrical connection structure of the fuel cell having any one of the above configurations, and a load connected to the electrical converter and supplied with power. And a power storage device connected in parallel to the fuel cell so as to be able to be charged and discharged with respect to the load.

  According to the electrical connection structure of the fuel cell system and the fuel cell system using the same according to the present invention, the fuel cell system disposed apart from each other in a positional relationship in which overlapping portions exist only when viewed in the terminal extending direction. The output side terminal and the input side terminal of the voltage converter are electrically connected by a braided flexible bus bar. Since the braided flexible bus bar has excellent flexibility against bending and twisting, even if a positional error occurs between the output side terminal and the input side terminal that are spaced apart from each other as described above, the positional error is reduced. It can be easily absorbed and electrical connection work between both terminals can be easily performed.

FIG. 1 is a schematic configuration diagram of a fuel cell system to which an electrical connection structure according to an embodiment of the present invention is applied. FIG. 2 is a perspective view showing an electrical connection structure according to an embodiment of the present invention. FIG. 3 is a side view of the electrical connection structure shown in FIG. 4 is a plan view of the electrical connection structure shown in FIG. FIG. 5 is a diagram showing a braided flexible bus bar and waterproof boots included in the electrical connection structure. FIG. 6 is a view similar to FIG. 5 showing an example in which a conductive layer is formed on the inner surface of the waterproof boot. FIG. 7 is a view showing a state in which the braided flexible bus bar is bent at about 90 degrees. FIG. 8 is a view showing a state in which the braided flexible bus bar is further twisted by a predetermined angle from the state shown in FIG. FIG. 9 is a side view showing the electrical connection structure when the fuel cell and the DC / DC converter are arranged in the vertical direction.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  FIG. 1 is a schematic configuration diagram of an entire system showing an example in which a fuel cell system 1 to which an electrical connection structure 10 of a fuel cell system according to an embodiment of the present invention is applied is used as an in-vehicle power supply system of a fuel cell vehicle. is there.

  The fuel cell system 1 includes a fuel cell stack (fuel cell) 12 that generates power by receiving supply of hydrogen and oxygen (air) as reaction gases, an air supply system 40 for supplying air to the fuel cell stack 12, A hydrogen supply system 50 for supplying hydrogen as a fuel to the fuel cell stack 12, a power system 70 for controlling charging / discharging of power, and a control device 100 for overall control of the entire system are provided.

  The fuel cell stack 12 is a cell stack in which a large number of fuel cells are stacked in an electrically connected state. The fuel cell is composed of a solid polymer electrolyte membrane, an anode side electrode, a cathode side electrode, and a separator. The anode side electrode and the cathode side electrode are diffusion electrodes having a sandwich structure by sandwiching the polymer electrolyte membrane from both sides. The separator composed of a gas-impermeable conductive member is a hydrogen and air flow path comprising a plurality of groove-shaped recesses between the anode side electrode and the cathode side electrode while further sandwiching the sandwich structure from both sides. Is forming.

  The anode electrode of the fuel cell is mainly composed of carbon powder supporting a platinum-based metal catalyst, and is formed on the surface of the catalyst layer in contact with the solid polymer electrolyte membrane, and has air permeability and electronic conductivity. And a gas diffusion layer. Similarly, the cathode side electrode has a catalyst layer and a gas diffusion layer. For example, for the catalyst layer, carbon powder carrying platinum or an alloy composed of platinum and other metals is dispersed in a suitable organic solvent, an appropriate amount of electrolyte solution is added to form a paste, and screen printing is performed on the polymer electrolyte membrane. Is formed. The gas diffusion layer is formed of, for example, carbon cloth, carbon paper, or carbon felt woven with carbon fiber yarns. The polymer electrolyte membrane is a proton conductive ion exchange membrane formed of a solid polymer material, for example, a fluororesin, and exhibits good electrical conductivity in a wet state.

  In each fuel cell configured as described above, hydrogen is supplied to the anode side electrode to cause an oxidation reaction represented by H2 → 2H ++ 2e-, and air is supplied to the cathode side electrode (1/2). A reduction reaction represented by O 2 + 2H + 2e − → H 2 O occurs, and an electrochemical reaction represented by H 2 + (1/2) O 2 → H 2 O occurs in the entire fuel cell. Then, electrons released from hydrogen are collected at the anode side electrode of each fuel cell, and supplied as power generation power from the fuel cell stack 12 to the power system 70 via an electrical connection structure 10 described later.

  The air supply system 40 includes an air supply passage 41 through which air supplied to the air electrode of the fuel cell stack 12 flows and an air discharge passage 42 through which air discharged from the fuel cell stack 12 flows. In the air supply passage 41, an air compressor 44 that takes in air from the atmosphere via an air filter 43, a humidifier 45 for appropriately humidifying air compressed and pressurized by the air compressor 44, and the fuel cell stack 12 And a shut-off valve 46 for shutting off the air supply. On the other hand, the air discharge passage 42 is provided with a shutoff valve 47 for shutting off the discharge of air from the fuel cell stack 12 and a pressure regulating valve 48 for adjusting the air supply pressure. Further, the air discharge passage 42 is provided through the humidifier 45, and the generated water discharged together with the air from the fuel cell stack 12 is collected by the porous body when flowing through the humidifier 45, The air supply passage 41 is configured to be used for humidification of air supplied through the air supply passage 41.

  The hydrogen supply system 50 includes, for example, a hydrogen supply source 52 including a high-pressure hydrogen tank, a hydrogen supply passage 54 through which hydrogen gas supplied from the hydrogen supply source 52 to the fuel electrode of the fuel cell stack 12 flows, and the fuel cell stack 12. A hydrogen discharge passage 56 through which discharged hydrogen off-gas flows, a circulation passage 58 branched from the hydrogen discharge passage 56 and connected to the hydrogen supply passage 54, and hydrogen off-gas discharged from the fuel cell stack 12 from the hydrogen discharge passage 56 And a circulation pump 60 for circulating and supplying the hydrogen supply passage 54 via the circulation passage 58.

  In the hydrogen supply passage 54 connected to the fuel cell stack 12 from the hydrogen supply source 52, a shutoff valve 61 for blocking outflow of hydrogen gas from the hydrogen supply source 52 in order from the upstream side in the hydrogen gas supply direction, and a hydrogen supply source The hydrogen gas ejected from 52 is appropriately depressurized and the injector 62 for controlling the hydrogen supply amount, the shut-off valve 63 for shutting off the hydrogen gas supply to the fuel cell stack 12, and the hydrogen supplied to the fuel cell stack 12 A pressure sensor 64 for detecting the gas pressure is installed. On the other hand, in the hydrogen discharge passage 56, a shutoff valve 66 for shutting off the hydrogen offgas from the fuel cell stack 12 in order from the upstream side in the hydrogen offgas discharge direction, and a valve open when discharging the hydrogen offgas to the outside of the system. A hydrogen off-gas discharge shutoff valve 68 is installed.

  The shutoff valves 46, 47, 48, 61, 63, 66, 68 included in the air supply system 40 and the hydrogen supply system 50 include electromagnetic valves that open or close in response to a command from the control device 100. Preferably used. Further, the pressure regulating valve 48 and the injector 62 are preferably constituted by an electromagnetic on-off valve having a valve body that can be opened and closed by an electromagnetic driving force, and the valve is passed by controlling the opening degree and valve opening time of the valve body. The gas flow rate and gas pressure of air and hydrogen can be adjusted.

  The power system 70 includes a current sensor 72 and a voltage sensor 74 that detect the output current and output voltage of the fuel cell stack 12, a first DC / DC converter (voltage converter) 76, a battery (power storage device) 78, a battery current and a battery voltage. A current sensor 80 and a voltage sensor 82 for detecting the voltage, a second DC / DC converter (voltage converter) 84, a smoothing capacitor 86, and an inverter input voltage (sometimes referred to as a "system voltage") that is a voltage between terminals of the smoothing capacitor 86. A voltage sensor 88 to detect, an inverter 90, and a motor (load) 92 are included. The fuel cell 12 and the first DC / DC converter 76, and the battery 78 and the second DC / DC converter 84 are connected in parallel to the inverter 90 and the motor 92.

  The first DC / DC converter 76 has a function of boosting and outputting a DC voltage supplied from the fuel cell stack 12, and is electrically connected to the output side terminal of the fuel cell stack 12 by the electrical connection structure 10. The second DC / DC converter 84 boosts and outputs a DC voltage supplied from the battery 78, DC power supplied from the fuel cell stack 12 via the first DC / DC converter 76, or regenerative braking. Thus, the regenerative power collected by the motor 92 is stepped down to charge the battery 78. The first and second DC / DC converters 76 and 84 operate according to the control signal received from the control device 100, and perform the step-up or step-down function as described above.

  The battery 78 functions as a surplus power storage source, a regenerative energy storage source during regenerative braking, and an energy buffer during load fluctuations associated with acceleration or deceleration of the fuel cell vehicle. As the battery 78, for example, a secondary battery such as a nickel metal hydride battery or a lithium secondary battery is preferably used. However, instead of the battery, a capacitor that can store electricity without an internal chemical reaction may be used as the power storage device. The SOC (State of charge) of the battery 78 is monitored by integrating the battery current by the control device 100 to which the detection value of the current sensor 80 is input.

  The direct current voltage output from the first DC / DC converter 76 and / or the second DC / DC converter 84 is charged in the smoothing capacitor 86 and smoothed, and then supplied to the inverter 90 as a system voltage. The inverter 90 is an inverter driven by, for example, a pulse width modulation control method or a rectangular wave control method, and an internal power switching element (for example, IGBT) is controlled to be turned on / off according to a control signal from the control device 100. Thus, the DC voltage output from the fuel cell stack 12 or the battery 78 is converted into a three-phase AC voltage, and the rotational torque of the motor 92 is controlled. The motor 92 is a three-phase synchronous AC motor, for example, and constitutes a power source of the fuel cell vehicle. The output shaft of the motor 92 is connected to a power transmission mechanism 94 such as a speed reducer or a differential gear mechanism, and the power of the motor 92 is transmitted to the axle 96 through the power transmission mechanism, whereby the wheels 98 are rotationally driven. It has come to be.

  The control device 100 is a computer system including a central processing unit (CPU), ROM, RAM, and an input / output interface, and controls each part of the fuel cell system 1. For example, the control device 100 starts the operation of the fuel cell system 1 when receiving the activation signal IG output from the ignition switch by the on operation by the user. Then, based on the accelerator opening signal ACC output from the accelerator sensor, the vehicle speed signal SV output from the vehicle speed sensor, etc., the required power of the entire system is obtained. The required power of the entire system is the total value of the power required for driving the motor 92 that outputs the vehicle driving power and the power consumed by the in-vehicle accessories. The in-vehicle accessories include, for example, an air compressor, a hydrogen pump, a transmission, a wheel control device, a steering device, a suspension device, and a vehicle interior device (such as an air conditioner, a lighting device, and an audio).

  The control device 100 determines the distribution of the output power of each of the fuel cell stack 12 and the battery 78, and sets the air supply system 40 and the hydrogen supply system 50 so that the power generation amount of the fuel cell stack 12 matches the target power. At the same time, the first DC / DC converter 76 is boosted to adjust the output voltage of the fuel cell stack 12. Moreover, the control apparatus 100 outputs each AC voltage command value of U phase, V phase, and W phase to the inverter 90 as a switching command, for example so that the target torque according to an accelerator opening degree may be obtained, and a motor The output torque and rotation speed of 92 are controlled.

  Next, the electrical connection structure 10 of the present embodiment will be described with reference to FIGS. 2 is a perspective view showing the electrical connection structure 10, FIG. 3 is a side view of the electrical connection structure 10 shown in FIG. 2, FIG. 4 is a plan view of the electrical connection structure 10 shown in FIG. It is a figure which shows the braided flexible bus bar 16 and the waterproof boot (cover member) 18 contained.

  The electrical connection structure 10 is provided between the fuel cell stack 12 and the first DC / DC converter 76 that are disposed to face each other in the lateral direction or in the horizontal direction. As shown in FIG. 3, the fuel cell stack 12 is mounted and supported on a frame 3 that forms part of the vehicle body or chassis, and the first DC / DC converter 76 is another frame that forms part of the vehicle body or chassis. 2 is mounted and supported.

  However, the electrical connection structure 10 is naturally applicable even when the fuel cell stack 12 and the first DC / DC converter 76 are supported on the same frame. FIG. 3 shows a state in which the bottom surfaces of the fuel cell stack 12 and the first DC / DC converter 76 are fixed at the same height. However, the present invention is not limited to this and is fixed at different heights in the vertical direction. May be.

  As shown in FIG. 2, the electrical connection structure 10 electrically connects the output side terminal 13 provided in the fuel cell stack 12, the input side terminal 77 provided in the first DC / DC converter 76, and both terminals 13, 77. A braided flexible bus bar 16 to be connected and a waterproof boot 18 that covers both terminals 13 and 77 and the braided flexible bus bar 16 in a connected state.

  The output side terminal 13 of the fuel cell stack 12 is a metal terminal for outputting a DC voltage generated inside the stack to the outside of the stack, and is composed of two terminals for positive and negative electrodes. The output side terminal 13 is formed to extend from the side end face 12 a facing the first DC / DC converter 76 of the fuel cell stack 12 to the first DC / DC converter 76 side. A screw insertion hole is formed through the tip of the output terminal 13.

  On the other hand, the input side terminal 77 of the first DC / DC converter 76 is a terminal for receiving the output voltage of the fuel cell stack 12, and, like the output side terminal 13, is constituted by two terminals for positive electrode and negative electrode. Has been. The input side terminal 77 is formed to extend from the side end face 76 a of the first DC / DC converter 76 facing the fuel cell stack 12 to the fuel cell stack 12 side. That is, the extending direction of the input side terminal 77 and the extending direction of the output side terminal 13 are opposite directions. Further, a screw insertion hole is formed through the tip of the input side terminal 77.

  In the present embodiment, the output side terminal 13 is located below and the input side terminal 77 is located above, but the opposite positional relationship, that is, the output side terminal 13 is located above and the input side terminal 77 is located below. It may be. Further, the screw insertion holes formed in the output side terminal 13 and the input side terminal 77 may be formed as a screw hole in which a female screw is formed on the inner peripheral surface instead of a simple through hole. This eliminates the need for bolt fastening nuts in the electrical connection operation described below.

  As shown in FIG. 3, the output side terminal 13 of the fuel cell stack 12 and the input side terminal 77 of the first DC / DC converter 76 are spaced apart from each other in the vertical direction, but the direction in which the terminals extend (that is, in FIG. 3). The left and right directions are arranged in a positional relationship where overlapping portions exist. By arranging the output-side terminal 13 and the input-side terminal 77 in such a positional relationship, the fuel cell stack 12 and the first DC / DC converter 76 are installed close to each other without hindering each of the terminals 13 and 77. It becomes possible.

  Although FIG. 4 shows an example in which the output side terminal 13 and the input side terminal 77 are arranged along the vertical direction, the present invention is not limited to this. For example, as long as the above positional relationship is satisfied, the output side terminal 13 and the input side terminal 77 may be arranged so as to be shifted in the horizontal direction or the horizontal direction.

  The output side terminal 13 and the input side terminal 77 are connected to each other by two braided flexible bus bars 16 for positive electrode and negative electrode. As shown in FIG. 5, the braided flexible bus bar 16 includes a braided wire 20 made of, for example, a conductive strip having flexibility and stretchability formed by flat knitting a tin-plated conductive wire, and caulking at both ends of the braided wire 20. For example, the connecting portions 22 and 24 are formed of conductive metal cylinders that are connected by such a method. A screw insertion hole 25 is formed at a substantially central position of each connection portion 22, 24.

  Moreover, it is preferable to attach the waterproof boot 18 to the braided flexible bus bar 16 in a state where the braided wire 20 is shrunk around the braided wire 20 before the connection work. If it does in this way, after connecting the connection parts 22 and 24 of the braided flexible bus-bar 16 to each terminal 13 and 77, the waterproof boot 18 can be rapidly extended and it can be set as the state which expand | deployed.

  The waterproof boot 18 is preferably composed of a cylindrical body having insulating properties, waterproof properties and flexibility, such as a rubber tube or a plastic tube. By covering the terminals 13 and 77 and the braided flexible bus bar 16 that are electrically connected by the waterproof boot 18, the electrical connection portion between the fuel cell stack 12 and the first DC / DC converter 76 is insulated. Waterproofness can be ensured.

  Further, as shown in FIG. 6, a conductive layer 19 may be formed on the inner surface of the waterproof boot 18 by a method such as attaching a flexible conductive sheet. In this way, when the waterproof boot 18 covers the electrical connection between the fuel cell stack 12 and the first DC / DC converter 76, an electromagnetic shielding function can be achieved.

  Insulation and waterproofing regarding the electrical connection between the fuel cell stack 12 and the first DC / DC converter 76 are, for example, a fuel cell case (not shown) that houses a part of the fuel cell stack 12 and the power system 70. The waterproof boot is not an essential component in the electrical connection structure of the present invention.

Subsequently, an assembly procedure of the electrical connection structure 10 will be described.
As shown in FIG. 3, after the fuel cell stack 12 and the first DC / DC converter 76 are attached on the frames 2 and 3, the braided flexible bus bar 16 constituting the electrical connection structure 10 is attached. As shown in FIGS. 5 and 6, waterproof boots 18 are attached to the braided flexible bus bar 16 in advance.

  First, the connection portion 22 at one end of the braided flexible bus bar 16 is connected to the input side terminal 77 of the first DC / DC converter 76 located above using a bolt 26 and a nut 28. Thereafter, the connecting portion 24 at the other end of the braided flexible bus bar 16 is connected to the output side terminal 13 of the fuel cell stack 12 located below using a bolt 26 and a nut 28.

  In this way, after the output side terminal 13 of the fuel cell stack 12 and the input side terminal 77 of the first DC / DC converter 76 are electrically connected by the braided flexible bus bar 16, the waterproof boot 18 is extended to both sides to output the output side terminal. 13. The entire braided flexible bus bar 16 and the input side terminal 77 are covered. Both ends of the waterproof boot 18 may be fixed so as not to be displaced by appropriate fixing means (for example, an adhesive or the like), or may be adhered to the terminal by its own elastic force so as not to be displaced. Good.

  When connecting the braided flexible bus bar 16 as described above, the output side input 13 of the fuel cell stack 12 is caused by manufacturing errors of the fuel cell stack 12 and the first DC / DC converter 76, bending of the frames 2 and 3, and the like. Position error may occur between the first DC / DC converter 76 and the input-side terminal 77 of the first DC / DC converter 76, but the braided flexible bus bar 16 has excellent flexibility with respect to bending and twisting, and also has elasticity. The position error as described above can be easily absorbed, and the electrical connection work between the terminals 13 and 77 can be easily performed.

  In the fuel cell system 1 to which the electrical connection structure 10 of the present embodiment is applied, the output side terminal 13 of the fuel cell stack 12 and the input side terminal 77 of the first DC / DC converter 76 are aligned in the vertical direction or the vertical direction. However, the braided flexible bus bar 16 is described and illustrated as being connected in a substantially straight state, but is not limited thereto.

  For example, as shown in FIG. 7, the positions, shapes, orientations, and the like of the output side terminal 13 and the input side terminal 77 may be designed so that the braided flexible bus bar 16 is connected in a state of being bent by about 90 degrees, for example. Alternatively, as shown in FIG. 8, the positions, shapes, orientations, etc. of the output side terminal 13 and the input side terminal 77 are designed so that the braided flexible bus bar 16 is bent by about 90, for example, and connected in a twisted state. May be. Thus, the electrical connection using the braided flexible bus bar 16 has an advantage that the degree of freedom in designing the output side terminal 13 of the fuel cell stack 12 and the input side terminal 77 of the first DC / DC converter 76 is increased. .

  In the above-described embodiment, the fuel cell stack 12 and the first DC / DC converter 76 are described as being disposed close to each other in the lateral direction. However, the electrical connection structure according to the present invention is as shown in FIG. The fuel cell stack 12 is supported by another frame 4 at a position close to the top of the first DC / DC converter 76 fixed on the frame 2, and the fuel cell stack 12 and the first DC / DC converter 76 are the same. The present invention is also applicable to the case where the output side terminal 13 and the input side terminal 77 are formed to extend in the same direction from the side end faces 12a and 76a in the direction.

  In the above embodiment, the electrical connection structure 10 has been described as being used for connection between the fuel cell stack 12 and the first DC / DC converter 76. However, in a fuel cell system that does not use a boost converter, The electrical connection structure of the present invention may be applied to electrical connection between the connected inverters.

  Further, although the fuel cell system 1 has been described as being mounted on a fuel cell vehicle in the above embodiment, the fuel cell system to which the present invention is applied is not limited to this application, for example, other than a fuel cell vehicle May be mounted as a power source for mobile bodies (robots, ships, aircraft, etc.) and industrial machines (construction machines, agricultural machinery, etc.), or used as power generation equipment (stationary power generation systems) for houses, buildings, etc. May be.

  DESCRIPTION OF SYMBOLS 1 Fuel cell system, 2, 3, 4 frame, 10 Electrical connection structure, 12 Fuel cell stack, 12a End surface, 13 Output side terminal, 16 Braided flexible bus bar, 18 Waterproof boot, 19 Conductive layer, 20 Braided wire, 22, 24 connection part, 40 air supply system, 50 hydrogen supply system, 70 power system, 76 first DC / DC converter, 76a side end face, 77 input side terminal, 78 battery, 84 second DC / DC converter, 90 inverter, 92 motor, 100 Control device.

Claims (7)

An electrical connection structure of a fuel cell system comprising a fuel cell that generates power upon receiving supply of a reaction gas, and a voltage converter that converts an output voltage of the fuel cell,
An output side terminal extending from the fuel cell, an input side terminal extending from the voltage converter, and a braided flexible bus bar electrically connecting the output side terminal and the input side terminal,
The electrical connection of the fuel cell system, wherein the output side terminal of the fuel cell and the input side terminal of the voltage converter are arranged in a positional relationship where they are separated from each other but overlap when viewed only in the terminal extending direction Construction. The fuel cell system electrical connection structure according to claim 1,
The fuel cell and the voltage converter are arranged close to each other in the lateral direction, an output side terminal projecting on the side end face facing the voltage converter of the fuel cell, and a side of the voltage converter facing the fuel cell An electrical connection structure of a fuel cell system, characterized in that an input side terminal projecting from an end face is formed to extend in a facing direction. The fuel cell system electrical connection structure according to claim 1,
The fuel cell and the voltage conversion device are arranged close to each other in the vertical direction, and are arranged on the output side terminal projecting from the side end surface of the fuel cell and the side end surface of the voltage conversion device in the same direction as the side end surface of the fuel cell. An electrical connection structure of a fuel cell system, characterized in that the projecting input terminal is formed to extend in the same direction. The fuel cell system electrical connection structure according to claim 1,
An electrical connection structure of a fuel cell system, wherein an output side terminal of a fuel cell, an input side terminal of a voltage converter, and a braided flexible bus bar are covered with an insulating and waterproof cover member. The electrical connection structure of the fuel cell system according to claim 4,
An electric connection structure of a fuel cell system, wherein a conductive layer is formed on an inner surface of the cover member. The fuel cell system electrical connection structure according to claim 1,
The voltage converter is a DC / DC converter capable of boosting a DC voltage output from a fuel cell, or an inverter capable of converting a DC voltage output from a fuel cell into an AC voltage. System electrical connection structure. A fuel cell and an electrical converter connected by the electrical connection structure of the fuel cell system according to any one of claims 1 to 6,
A load connected to the electrical converter and supplied with power;
A power storage device connected in parallel to the fuel cell so as to be chargeable / dischargeable with respect to the load;
A fuel cell system comprising:

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