High-voltage bonding unit, power supply for fuel cell system, and manufacturing method thereof

Abstract

The present application relates to a high-voltage connection unit, a power source for a fuel cell system, and a method for manufacturing the same. A power source for a fuel cell system includes: a fuel cell stack configured to cause hydrogen and oxygen in air to react with each other to generate electricity; a high-voltage converter configured to boost the output power of the fuel cell stack; and a high-voltage connection unit configured to transmit the output power of the fuel cell stack to the high-voltage converter and receive high-voltage power from the high-voltage converter. The high-voltage connection unit has a structure configured to simultaneously accommodate the output terminal of the fuel cell stack and the input terminal of the high-voltage converter. Therefore, the assembly structure of the high-voltage connection unit can be simplified, thereby improving productivity. In addition, maintainability can be improved, so that a fuel cell vehicle can be effectively maintained.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10 - 2020 - 0187718, filed with the Korean Intellectual Property Office on December 30, 2020, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present disclosure relates to a high - voltage connection unit of a fuel cell system and a power supply of a fuel cell system including the high - voltage connection unit, and more particularly, to a power supply having an input terminal and an output terminal of a fuel cell stack and a converter provided at the high - voltage connection unit. Background art

[0004] As is well known, in a vehicle equipped with a fuel cell system, reaction gases (e.g., hydrogen used as fuel and air including oxygen used as an oxidant) are supplied to a fuel cell stack to generate electricity, and the electricity is used to operate a drive motor to drive the vehicle.

[0005] For this purpose, the fuel cell system includes: a fuel cell stack configured to generate electrical energy through an electrochemical reaction between reaction gases; a fuel processing system (FPS) configured to supply hydrogen as fuel to the fuel cell stack; an air processing system (APS) configured to supply air necessary for the electrochemical reaction to the fuel cell stack, the air including oxygen as an oxidant; and a thermal management system (TMS) configured to discharge heat, which is a by - product of the electrochemical reaction in the fuel cell stack, to the outside to optimally control the operating temperature of the fuel cell stack and perform a water management function.

[0006] In addition to the fuel cell system, a fuel cell vehicle also includes a drive motor configured to drive the vehicle and an electrical storage device (supercapacitor or battery) as an auxiliary power supply. The electrical storage device stores the electricity generated by the fuel cell. The electricity generated by the fuel cell or stored in the electrical storage device is used to operate the drive motor.

[0007] When equipping a vehicle with a fuel cell stack and its related parts, a drive motor (including a reduction gear), a power distribution unit (PDU), a motor control unit (MCU), etc., there are many things to consider.

[0008] First, the problem of limited space must be solved, the number of simple installation parts must be minimized to achieve weight and cost reduction, and a more favorable layout structure in terms of layout and space utilization must be considered.

[0009] In addition, since a large number of components are installed in a very small space, it is necessary to arrange the components considering assembly efficiency and maintainability; otherwise, problems of inefficiency may occur in terms of vehicle productivity and maintenance.

[0010] For example, each of the output current of the fuel cell stack and the output current of the high-voltage converter is a high current of several hundred amperes. Therefore, in the case of performing power connection between components through wiring, the following problems may occur.

[0011] First, a plurality of connectors and cables must be provided, so that the distance between components can be set longer. That is, connectors must be provided at the power input and output terminals of the components, and the connectors must be connected to each other using cables. At this time, each cable has a minimum curvature, and the cable can be broken at this point. In the case of performing a design with a minimum curvature or a smaller curvature, excessive tension will occur, making assembly difficult. After assembly, the connectors and cables may be mechanically damaged due to the tension applied thereto.

[0012] Second, in the case where the current exceeds the allowable current of the connectors and cables, a plurality of connectors / cables must be provided. Therefore, the power connection structure is complex, resulting in a decrease in assembly efficiency. In addition, due to the increase in the number of components, the weight and volume increase.

[0013] Third, in the case where the voltages used by the electrical loads are different from each other, a plurality of output terminals must be provided at the fuel cell stack serving as a power source, and a plurality of input terminals must also be provided at the high-voltage connection unit, so that the structure is very complex.

[0014] The information included in this background art section is only for enhancing the understanding of the general background of the present disclosure, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0015] The present disclosure is directed to a high-voltage connection unit of a fuel cell system and a power source of a fuel cell system including the high-voltage connection unit, which substantially eliminates one or more problems caused by the limitations and disadvantages of the related art.

[0016] An object of the present disclosure is to provide a power source of a fuel cell system, the assembly structure of which is simplified, thereby improving productivity.

[0017] Another object of the present disclosure is to provide a power source of a fuel cell system, the maintainability of which is improved.

[0018] Still another object of the present disclosure is to provide a power source of a fuel cell system, the maintenance of which is effectively performed.

[0019] The object of the present disclosure designed to solve these problems is not limited to the foregoing object, and other unmentioned objects will be clearly understood by those skilled in the art based on the following detailed description of the present disclosure.

[0020] The high-voltage connection unit of the fuel cell system according to the present disclosure is characterized in that the input terminals and output terminals of the stack and the converter are integrally provided at the high-voltage connection unit, and the cover is frequently attached to and detached from the high-voltage connection unit to maintain and replace internal parts.

[0021] To achieve these objects and other advantages, and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, the high-voltage connection unit of the fuel cell system includes: a fuel cell output terminal receiving groove on a first surface such that the output terminal of the fuel cell stack extends into the fuel cell output terminal receiving groove; a high-voltage converter input terminal receiving groove located on a second surface perpendicular to the first surface and thus adjacent to the fuel cell output terminal receiving groove such that the input terminal of the high-voltage converter extends into the high-voltage converter input terminal receiving groove; and a high-voltage converter output terminal receiving groove on the second surface and thus spaced a predetermined distance from the high-voltage converter input terminal receiving groove such that the output terminal of the high-voltage converter extends into the high-voltage converter output terminal receiving groove.

[0022] The high-voltage connection unit may include a first circuit portion configured to use the output power of the fuel cell stack and a second circuit portion configured to use the output power of the high-voltage converter.

[0023] The input terminal of the high-voltage converter may be directly connected to the output terminal of the fuel cell stack in the fuel cell output terminal receiving groove.

[0024] The fuel cell output terminal receiving groove may further receive the input terminal of a first load connected to the first circuit portion.

[0025] The first load may include a stack-end cell heater.

[0026] The input terminal of the stack-end cell heater may be directly connected to the output terminal of the fuel cell stack in the fuel cell output terminal receiving groove.

[0027] The second circuit portion may supply the power required for driving the motor, the blower power control unit, the coolant supply pump, and the air compressor.

[0028] In another aspect of the present disclosure, a fuel cell system power supply includes: a fuel cell stack configured to react hydrogen and oxygen in air with each other to generate electricity; a high-voltage converter configured to boost the output power of the fuel cell stack; and a high-voltage connection unit configured to transmit the output power of the fuel cell stack to the high-voltage converter and receive high-voltage power from the high-voltage converter, wherein the high-voltage connection unit has a structure configured to simultaneously receive the output terminal of the fuel cell stack and the input terminal of the high-voltage converter.

[0029] The output terminal of the fuel cell stack and the input terminal of the high-voltage converter can be inserted into the high-voltage connection unit in the vertical direction and can be directly connected to each other.

[0030] It should be understood that the above summary and the following detailed description of the present disclosure are both exemplary and explanatory and are intended to provide further explanation of the claimed present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the invention.

[0032] Figure 1 is an explanatory diagram schematically showing the power network topology of a fuel cell system according to the present disclosure;

[0033] Figure 2 is a perspective view schematically showing a high-voltage converter of a fuel cell system power supply according to the present disclosure;

[0034] Figure 3 is a perspective view schematically showing a high-voltage connection unit of a fuel cell system power supply according to the present disclosure;

[0035] Figure 4 is a perspective view schematically showing a fuel cell stack of a fuel cell system power supply according to the present disclosure;

[0036] Figure 5 is a flowchart showing the manufacturing process of a fuel cell system power supply according to the present disclosure;

[0037] Figure 6 is a perspective view showing the coupling relationship between a high-voltage converter and a high-voltage connection unit of a fuel cell system power supply according to the present disclosure;

[0038] Figure 7 is showing Figure 6 a plan view of the coupling relationship between the shown high-voltage converter and the high-voltage connection unit;

[0039] Figure 8is a perspective view showing a state in which a high-voltage converter and a high-voltage bonding unit are coupled to a fuel cell stack in a state where they are coupled to each other in a fuel cell system power supply according to the present disclosure;

[0040] Figure 9 is a perspective view showing an appearance of a fuel cell system power supply according to the present disclosure after coupling is completed; and

[0041] Figure 10 is showing in Figure 9 a perspective view of a state where assembly is completed by coupling a cover to a high-voltage bonding unit in a state of Detailed Description

[0042] Giving a specific structural or functional description of the embodiments of the present disclosure disclosed in this specification is only for explaining the embodiments of the present disclosure. The embodiments of the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments of the present disclosure disclosed in this specification.

[0043] Since various modifications can be made to the embodiments of the present disclosure and various forms can be adopted, specific embodiments will be shown in the drawings and will be described in detail in this specification. However, the embodiments according to the concept of the present disclosure are not limited to such specific embodiments, and it should be understood that the present disclosure includes all changes, equivalents, and alternatives falling within the spirit and technical scope of the present disclosure.

[0044] It should be understood that although terms such as "first", "second", etc. may be used herein to describe various elements, the corresponding elements should not be understood as being limited by these terms, and these terms are only used to distinguish one element from another. For example, within the scope defined by the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0045] It should be understood that when a component is referred to as being "connected to" or "coupled to" another component, it may be directly connected to or coupled to the other component, or there may be an intermediate component. In contrast, when a component is referred to as being "directly connected to" or "directly coupled to" another component, there is no intermediate component. Other terms describing the relationship between components must be interpreted in the same way, such as "between" and "directly between" or "adjacent to" and "directly adjacent to".

[0046] The terms used in this specification are provided only to explain specific embodiments and are not intended to limit the present disclosure. The singular forms may include the plural forms unless they indicate an absolutely different meaning from the context. It should be understood that when used in this specification, the terms "comprising", "having", etc. specify the presence of the stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0047] Unless otherwise defined, all terms used in this specification, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0048] In the case of differently implementing a certain embodiment, the functions or operations specified in specific blocks may be executed in an order different from that specified in the flowchart. For example, depending on the relevant functions or operations, two consecutive blocks may be executed substantially simultaneously, or these blocks may be executed in the reverse order.

[0049] Figure 1 is an explanatory diagram schematically showing the power network topology of a fuel cell system according to the present disclosure. As shown, the power supply 10 of the fuel cell system according to the present disclosure includes a fuel cell stack 100, a high-voltage converter 200, and a high-voltage connection unit 300.

[0050] The fuel cell stack 100 causes hydrogen and oxygen in the air to react with each other to generate electricity having a voltage of about 348 to 640V. The high-voltage converter 200 boosts the output of the fuel cell stack 100. The high-voltage connection unit 300 transmits the output power of the fuel cell stack 100 to the high-voltage converter 200 and receives high-voltage power from the high-voltage converter 200.

[0051] The power from the fuel cell stack 100 is output through the fuel cell output lines L11 and L12 and input to the converter 200 through the converter input lines L21 and L22. In addition, the power from the fuel cell stack 100 is transmitted to the stack end cell heater 140 through the input lines L31 and L32 to be used as the power required to operate the stack end cell heater 140.

[0052] The first high-voltage power input to the converter 200 through the converter input lines L21 and L22 has a voltage of approximately 600V. The high-voltage converter 200 converts the first high-voltage power of approximately 600V into a second high-voltage power of 800V through a DC-DC boost method and outputs the second high-voltage power through the output lines L41 and L42.

[0053] The second high-voltage power boosted by the high-voltage converter 200 is transmitted to the high-voltage connection unit 300 and is supplied to the first load and the second load through the first load lines L51 and L52 and the second load lines L61 and L62, respectively.

[0054] The second high-voltage power is transmitted to the first load device that requires a large amount of power, such as a drive motor, through the first load lines L51 and L52. The second high-voltage power is transmitted to the first load devices that require a relatively low amount of power, such as the blower power control unit 410 and the coolant supply pump 420, through the second load lines L61 and L62.

[0055] Figure 2 is a perspective view schematically showing the high-voltage converter 200 of the power supply of the fuel cell system according to the present disclosure. As shown, the converter input terminal portion 231 and the converter output terminal portion 232 are formed on the first surface S21 of the main body 210 of the high-voltage converter 200. A cover 240 configured to protect the internal circuit is provided on the upper surface of the high-voltage converter 200.

[0056] A plurality of first connection portions 211 are provided on the second surface S22 (which is connected to the first surface S21) of the high-voltage converter 200. Each first connection portion 211 has a connection groove 211a configured to connect the main body 210 of the high-voltage converter 200 to the fuel cell stack 100. A second connection portion 212 for connecting to the high-voltage connection unit 300 is provided at the corner between the first surface S21 and the second surface S22.

[0057] Figure 3 is a perspective view schematically showing the high-voltage connection unit of the power supply of the fuel cell system according to the present disclosure. As shown, a first circuit portion 330 and a second circuit portion 320 are provided in the main body 310 of the high-voltage connection unit 300. The first circuit portion 330 has a circuit configured to use the output power of the fuel cell stack 100 therein.

[0058] The second circuit portion 320 has a circuit configured to use the output power of the high-voltage converter therein. The second circuit portion 320 includes the circuit portions required for driving the drive motor of the fuel cell vehicle, the blower power control unit, the coolant supply pump, and the air compressor.

[0059] A fuel cell output terminal receiving groove 311 is formed in the bottom surface S31 of the main body 310 of the high-voltage connection unit 300, which is configured to receive the output terminals of the fuel cell stack. A high-voltage converter input terminal receiving groove 312 is formed in the second surface S32 perpendicular to the first surface S31. The high-voltage converter input terminal receiving groove 312 is formed adjacent to the fuel cell output terminal receiving groove 311 and is configured to receive the converter input terminal portion 231 of the high-voltage converter 200.

[0060] A high-voltage converter output terminal receiving groove 312 is formed in the second surface S32 of the high-voltage connection unit 300. The high-voltage converter output terminal receiving groove 312 is arranged at a predetermined distance from the high-voltage converter input terminal receiving groove 312 and is configured to receive the converter output terminal portion 232.

[0061] A plurality of third connection portions 315 are provided on one side of the third surface S32 perpendicular to the second surface S21. Each third connection portion 211 has a connection groove 315a, which is configured to connect the main body 310 of the high-voltage connection unit 300 to the fuel cell stack 100. A fourth connection portion 314 for connecting to the high-voltage converter 200 is provided at the corner between the second surface S32 and the third surface S33. Although not shown, the high-voltage connection unit 300 naturally has a cover configured to protect the internal circuit.

[0062] Figure 4 is a perspective view schematically showing a fuel cell stack of a fuel cell system power supply according to the present disclosure. As shown, the fuel cell stack 100 includes a main body 110 and an end plate 120. A plurality of coupling recesses 111a and 112a for coupling with the high-voltage converter 200 and the high-voltage connection unit 300 are formed in the upper surface of the main body 110 of the fuel cell stack 100. A terminal portion 130 is provided on the upper surface of the main body 110 of the fuel cell stack 100. The terminal portion 130 is formed by the protrusions of the output terminals 131 of the fuel cell stack 100 and the input terminals 132 of the stack end cell heaters.

[0063] Figure 5 is a flowchart showing the manufacturing process of a fuel cell system power supply according to the present disclosure. Figure 6 is a perspective view showing the coupling relationship between the high-voltage converter and the high-voltage connection unit of a fuel cell system power supply according to the present disclosure, and Figure 7 is showing Figure 6 is a plan view showing the coupling relationship between the high-voltage converter and the high-voltage connection unit shown. First, the bolts fastened to the upper part of the cover 340 of the high-voltage connection unit 300 are removed to separate the cover from the main body 310 of the high-voltage connection unit 300 (S501).

[0064] As Figure 6 and Figure 7As shown, the first surface S21 of the high-voltage converter and the second surface S32 of the high-voltage bonding unit 300 are coupled to each other in the horizontal direction. At this time, the converter input terminal portion 231 formed on the first surface S31 of the high-voltage converter 200 is inserted into the high-voltage converter input terminal receiving groove 312 formed in the second surface S32 of the high-voltage bonding unit 300. The converter output terminal portion 232 formed on the first surface S21 of the high-voltage converter 200 is inserted into the high-voltage converter output terminal receiving groove 313 formed in the second surface S32 of the high-voltage bonding unit 300. At this time, the second connection portion 212 formed at the corner of the high-voltage converter 200 is coupled to the fourth connection portion 314 of the high-voltage bonding unit 300 formed at the corresponding position. Various coupling methods can be used. The high-voltage converter 200 and the high-voltage bonding unit 300 can be coupled to each other by bolt connection (S502).

[0065] Figure 8 is a perspective view showing a state in which a high-voltage converter and a high-voltage bonding unit are coupled to a fuel cell stack in a coupled state in a power supply of a fuel cell system according to the present disclosure. As shown, the assembled high-voltage converter 200 and high-voltage bonding unit 300 are disposed on the upper part of the fuel cell stack 100 (S503). The high-voltage converter 200 and the high-voltage bonding unit 300 are vertically coupled to the fuel cell stack 100. At this time, a plurality of coupling grooves 111a and 112a formed in the upper surface of the main body 110 of the fuel cell stack 100, connection grooves 211a of a plurality of first connection portions 211 formed on the second surface S22 of the high-voltage converter 200 and its opposite side (not shown), and connection grooves 315a of a plurality of third connection portions 315 formed on the third surface S33 of the high-voltage bonding unit 300 are coupled to each other in a vertically aligned state.

[0066] The terminal portion 130 protruding from the upper surface of the main body 110 of the fuel cell stack 100 can be inserted into the fuel cell output terminal receiving groove 311 formed in the bottom surface S31 of the high-voltage bonding unit 300.

[0067] The high-voltage bonding unit 300 according to the present disclosure has a structure configured to simultaneously receive and interconnect the input terminal of the high-voltage converter 200 and the output terminal of the fuel cell stack 100. Therefore, assembly and disassembly can be easily performed, thereby improving maintainability.

[0068] Figure 9is a perspective view showing the appearance of a power supply of a fuel cell system according to the present disclosure. As shown, the converter input terminal portion 231 is inserted into the input terminal receiving groove 312 formed in the second surface S32 of the high-voltage bonding unit 300 and is coupled to the output terminal 131 of the fuel cell stack 100, which is an element of the terminal portion 130 constituting the fuel cell stack 100, and is inserted into the fuel cell output terminal receiving groove 311 formed in the bottom surface S31 of the high-voltage bonding unit 300. The stack end cell heater input terminal 132 of the fuel cell stack 100 can be directly connected to the output terminal 131 of the fuel cell stack 100 in the fuel cell output terminal receiving groove (S504). The converter output terminal portion 232 inserted into the output terminal receiving groove 313 formed in the second surface S32 of the high-voltage bonding unit 300 is coupled to the high-voltage bus bar 321 of the second circuit portion 320 (S505).

[0069] In this state, the cover 340 of the high-voltage bonding unit 300 can be fastened, as Figure 10 shown, whereby the assembly of the power supply can be completed.

[0070] As described above, the output terminal of the high-voltage converter, the output terminal of the fuel cell stack, and the stack end cell heater input terminal can be simultaneously connected thereto in the fuel cell output terminal receiving groove. Therefore, the assembly structure of the high-voltage bonding unit can be simplified, thereby improving productivity. In addition, maintainability can be improved, thereby effectively maintaining the fuel cell vehicle.

[0071] It is obvious from the above description that in the high-voltage bonding unit of the fuel cell system according to the present disclosure and the power supply of the fuel cell system including the high-voltage bonding unit, its assembly structure can be simplified, thereby improving productivity. In addition, maintainability can be improved, thereby effectively maintaining the fuel cell vehicle.

[0072] Although the exemplary embodiments of the present disclosure have been described above with reference to the drawings, those skilled in the art will understand that the present disclosure can be implemented in various other embodiments without changing its technical idea or features.

Claims

1. A fuel cell system power supply, comprising: A fuel cell stack configured to react hydrogen and oxygen in air with each other to generate electricity; A high-voltage converter configured to boost the output power of the fuel cell stack by converting a lower voltage potential to a higher voltage potential; And A high-voltage connection unit configured to transmit the output power of the fuel cell stack to the high-voltage converter and receive high-voltage power from the high-voltage converter, wherein the high-voltage connection unit has a structure into which the output terminal of the fuel cell stack and the input terminal of the high-voltage converter extend; Wherein, the input terminal of the stack-end cell heater of the fuel cell stack is connected to the output terminal of the fuel cell stack in the high-voltage connection unit.

2. The power supply of the fuel cell system according to claim 1, wherein, The output terminal of the fuel cell stack and the input terminal of the high-voltage converter are in contact with each other and extend into the high-voltage connection unit in the vertical direction.

3. The power supply of the fuel cell system according to claim 1, wherein, The high-voltage connection unit includes: A first circuit portion configured to receive the output power of the fuel cell stack; and A second circuit portion configured to receive the output power of the high-voltage converter.

4. The fuel cell system power supply according to claim 3, wherein, The high-voltage connection unit is further configured to accommodate the input terminal of the stack-end cell heater connected to the first circuit portion.

5. The fuel cell system power supply according to claim 3, wherein, The second circuit portion supplies power required for driving a motor, a blower power control unit, a coolant supply pump, and an air compressor.

6. A method of manufacturing a fuel cell system power supply, the method comprising: Separating a cover from the high-voltage connection unit; Assembling the high-voltage converter and the high-voltage connection unit; Placing the assembled high-voltage converter and high-voltage connection unit on the fuel cell stack; Fastening the output terminal of the fuel cell stack and the input terminal of the high-voltage converter to each other; Fastening the output terminal of the high-voltage converter to the bus bar of the high-voltage connection unit; Connecting the input terminal of the stack-end cell heater of the fuel cell stack to the output power usage end of the fuel cell stack; and Assembling the cover to the high-voltage connection unit.

7. The method according to claim 6, wherein Assembling the high-voltage converter and the high-voltage connection unit includes inserting the high-voltage input terminal and the high-voltage output terminal of the high-voltage converter into the input terminal receiving groove and the output terminal receiving groove on one side in the horizontal direction of the high-voltage connection unit, respectively.

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