Fuel cell system

Abstract

The present disclosure relates to fuel cell systems. A fuel cell system includes a plurality of fuel cell units, each fuel cell unit configured to generate lower voltage DC power. The fuel cell system includes a plurality of DC-DC converters, each DC-DC converter electrically connected to each fuel cell unit and configured to convert the lower voltage DC power to higher voltage DC power. The fuel cell system includes a main load power conversion unit, the main load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a main load. The fuel cell system includes an auxiliary load power conversion unit, the auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load.

Description

TECHNICAL FIELD

[0001] Embodiments disclosed herein relate to fuel cell systems, and more particularly, to fuel cell systems for powering external units and one or more auxiliary systems of a fuel cell system. BACKGROUND

[0002] A fuel cell system can power one or more systems external to the fuel cell system. For example, a fuel cell system can be used to power a vehicle, a building, or a data center. SUMMARY

[0003] This section provides a general summary of the disclosure and explains neither fully the scope nor all the features of the present disclosure.

[0004] In one aspect, a fuel cell system includes a plurality of fuel cell units configured to generate lower voltage DC power. The fuel cell system includes a plurality of DC-DC converters electrically connected to the fuel cell units and configured to convert the lower voltage DC power to higher voltage DC power. The fuel cell system includes a main load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a main load. The fuel cell system includes an auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load.

[0005] In another aspect, a fuel cell system includes a fuel cell container configured to house a plurality of fuel cell units configured to generate lower voltage DC power. The fuel cell container is further configured to house a plurality of DC-DC converters electrically connected to the fuel cell units and configured to convert the lower voltage DC power to higher voltage DC power. The fuel cell system further includes a power electronics container configured to house a main load power conversion unit. The main load power conversion unit is electrically connected to the plurality of DC-DC converters and configured to output a main load. The power electronics container is further configured to house an auxiliary load power conversion unit. The auxiliary load power conversion unit is electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load.

[0006] In yet another aspect, a fuel cell system includes a plurality of fuel cell units configured to generate lower voltage DC power. The fuel cell system includes a plurality of DC-DC converters electrically connected to the fuel cell units and configured to convert the lower voltage DC power to higher voltage DC power. The fuel cell system includes a main load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a main load. The fuel cell system includes an auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load. The fuel cell system further includes a programmable logic controller configured to operate the fuel cell system according to a power request.

[0007] These and other aspects will be described in greater detail below. BRIEF DESCRIPTION OF DRAWINGS

[0008] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various systems, methods, and other embodiments of the technology. It should be understood that the element boundaries (e.g., boxes, groups of boxes, or other shapes) shown in the figures represent one embodiment of boundaries. In some embodiments, one element can be designed as multiple elements or multiple elements can be designed as one element. In some embodiments, an element shown as an internal component of another element can be implemented as an external component, and vice versa. Additionally, elements can not be drawn to scale.

[0009] Figure 1 An example of a fuel cell system is shown.

[0010] Figure 2 An example of a fuel cell unit of a fuel cell system is shown.

[0011] Figure 3 An example of a communication interface for a fuel cell system is shown. DETAILED DESCRIPTION

[0012] A fuel cell system for powering external units and one or more auxiliary systems of the fuel cell system is described. The fuel cell system includes a container for housing the fuel cell system and a communication interface for operating the fuel cell system.

[0013] Turning to Figure 1FIG. 1 shows one example of a fuel cell system 10. The fuel cell system 10 can be used to supply power to an external unit 12. The external unit 12 can be a building, such as a residential or commercial building. However, it should be understood that the external unit 12 can be any type of power demand structure, system, etc. The external unit 12 can be configured to request power (e.g., issue a power request or demand) from the fuel cell system 10 to receive power from the fuel cell system 10, or the external unit 12 can draw a load from the fuel cell system 10, which can measure the power draw and generate power accordingly.

[0014] The fuel cell system 10 can be housed in one or more containers. For example, the fuel cell system 10 can be housed in a single container 14. In another example, the fuel cell system 10 can be housed in two containers, such as a fuel cell container 16 and a power electronics container 18. The fuel cell container 16 can house one or more components of the fuel cell system 10, and the power electronics container 18 can house one or more power electronics components of the fuel cell system 10, as will be described in further detail below.

[0015] The fuel cell system 10 includes a plurality of fuel cell units 22A-22F. Each of the fuel cell units 22A-22F can include four individual fuel cells connected in parallel. As shown in Figure 2 FIG. 2, a single fuel cell unit 22 is shown, which can be similar to any one of the fuel cell units 22A-22F of Figure 1 Here, the fuel cell unit 22 includes four fuel cells 24A-24D connected in parallel with each other. Each of the fuel cells 24A-24D can be an electrochemical cell that converts chemical energy of a fuel (oxidizer) into electrical energy. In one example, the fuel can be hydrogen, but any type of fuel suitable for different types of fuel cells can be utilized. The fuel cells 24A-24D can be configured to output direct current (DC) power. For example, each fuel cell unit 22 can output 240 kw of DC power, but the power can vary depending on the size and number of fuel cells included in the fuel cell unit.

[0016] Referring back to Figure 1The fuel cell system 10 also includes a plurality of DC-DC converters 26A-26F. The DC-DC converters 26A-26F can be housed in the fuel cell container 16. The DC-DC converters 26A-26F can be electrically connected to the fuel cell units 22A-22F, respectively. The DC-DC converters 26A-26F are configured to regulate the output voltage of the fuel cell units 22A-22F, respectively. For example, the DC-DC converters 26A-26F can regulate the output voltage of the fuel cell units 22A-22F to 650 V. The DC-DC converters 26A-26F can also convert the output power of the fuel cell units 22A-22F to a higher voltage, respectively. For example, the DC-DC converters 26A-26F can convert 650 V DC power output from the fuel cell units 22A-22F to 1000 V DC power. The DC-DC converters 26A-26F can also be electrically connected to one or more components of the power electronics container 18. The DC-DC converters 26A-26F can be any suitable DC-DC converter. For example, one or more of the DC-DC converters 26A-26F can be a Dynapower DPS-500 bidirectional DC-DC converter sold by Dynapower Company, LLC of South Burlington, Vermont. However, any similar DC-DC converter can be used.

[0017] The fuel cell system 10 also includes one or more switchgear assemblies 28. The switchgear assemblies 28 can be housed in the power electronics container 18. The switchgear assemblies 28 can be DC switchgear assemblies and can include one or more switches, circuit breakers, and / or fuses configured to connect components of the fuel cell container 16 to components of the power electronics container 18. For example, the switchgear assemblies 28 can be electrically connected to the DC-DC converters 26A-26F, the main load power conversion unit 30, the auxiliary load power conversion unit 32, and the battery unit 34. The switchgear assemblies 28 can also be configured to provide DC power output by the fuel cell units 22 to the external unit 12.

[0018] The main load power conversion unit 30 can be housed in the power electronics container 18. The main load power conversion unit 30 can be configured to provide a main load (e.g., electrical power) to the external unit 12. The main load power conversion unit 30 can be electrically connected to the switchgear assembly 28 and can be configured to convert DC power output by the DC-DC converter 26 to AC power. For example, the main load power conversion unit 30 can convert 1000V DC power output by the DC-DC converter 26 to 480V AC power, which can be provided to the external unit 12. The main load power conversion unit 30 can be any suitable power conversion unit, such as an inverter. For example, the main load power conversion unit 30 can be a Dynapwer CPS-1500 1500kW Utility-Scale Energy Storage Inverter sold by Dynapower Company, LLC of South Burlington, Vermont. The auxiliary load power conversion unit 32 can be housed in the power electronics container 18. The auxiliary load power conversion unit 32 can be configured to provide an auxiliary load (e.g., electrical power) to one or more auxiliary systems 52 (e.g., parasitic systems) of the fuel cell system 10 (see Figure 3 ). The auxiliary systems 52 can include one or more systems and / or components of the fuel cell system 10 necessary to keep the fuel cell system 10 operational. For example, the auxiliary load power conversion unit 32 can be configured to provide an auxiliary load to one or more of the power panels 36A-36E, the transformer 38, the uninterruptible power supply 40, a control system, a lighting system, a valve, a sensor, etc. of the fuel cell system 10. Some of these components will be described in further detail below.

[0019] The auxiliary load power conversion unit 32 can be electrically connected to the switchgear assembly 28 and can be configured to convert the DC power output by the DC-DC converters 26A-26F to AC power. For example, the auxiliary load power conversion unit 32 can convert the 1000V DC power output by the DC-DC converters 26A-26F to 480V AC power, which can be provided to the auxiliary systems 52 of the fuel cell system 10. The auxiliary load power conversion unit 32 can be any suitable power conversion unit, such as an inverter. For example, the auxiliary load power conversion unit 32 can be a Dynapower MPS-125EHV Inverter for Behind-the-Meter Energy Storage sold by Dynapower Company, LLC of South Burlington, Vermont. The battery unit 34 can be housed in the power electronics container 18 and can be configured to provide initial start-up power to the fuel cell system 10. The battery unit 34 can also be configured to adjust the input voltage of the DC-DC converters 26A-26F when the power requirements of the external unit 12 change. In addition, the battery unit 34 can also be configured to provide additional power to the external unit 12 as needed and cover the power gap between the fuel cell power and the load in the event of a failure of one or more of the fuel cell units 22A-22F. The battery unit 34 can be any suitable battery unit. For example, the battery unit 34 can be a 1000V lithium-titanium-oxide (LTO) battery.

[0020] As previously mentioned, the auxiliary systems 52 and / or assemblies of the fuel cell system 10 can include one or more power panels 36A-36E. The power panel(s) 36A and 36B can be housed in the power electronics container 18 and can be configured to connect the auxiliary load power conversion unit 32 to various other assemblies of the fuel cell container 16 and / or the power electronics container 18 via the power panels 36C-36E. The power panel(s) 36A-36E can include one or more circuit breakers and can be configured to protect the assemblies of the fuel cell system 10 from power surges or voltage drops. The power panel(s) 36A-36E can also be configured to convert the 480V AC power output by the auxiliary load power conversion unit 32 to 120V AC power or 220V AC power depending on the voltage requirements of the external unit 12.

[0021] Fuel cell system 10 can also include an uninterruptible power supply (UPS) 40. UPS 40 can be electrically connected to one or more power panels 36 and can be configured to provide emergency power to fuel cell system 10 and / or any auxiliary systems of the fuel cell system in the event of a failure of battery units 34. UPS 40 can also be connected to a utility feed 42. Fuel cell system 10 also includes a transformer 38 electrically connected to at least one of power panels 36A and / or 36B. Transformer 38 can be configured to reduce the input and / or output voltage of power panel(s) 36A-36B and / or UPS 40.

[0022] Turning now to Figure 3 Fuel cell system 10 can include a communication interface 44. Communication interface 44 includes various communication components configured to distribute and / or transmit commands and / or information between external unit 12 and fuel cell system 10. For example, fuel cell system 10 can be configured to receive a power request from external unit 12 through communication interface 44 and operate the fuel cell system in accordance with the power request. Accordingly, external unit 12 can include an external unit interface 46. External unit interface 46 can be configured to transmit a power request to fuel cell system 10.

[0023] Communication interface 44 can include a programmable logic controller (PLC) 50. PLC 50 can include a processor coupled with memory, power supply, input interface, and output interface, among other components of a typical PLC. PLC 50 can be configured to operate different components of fuel cell system 10 in accordance with a power request from external unit 12. PLC 50 is also configured to receive requests from one or more auxiliary systems 52 and / or one or more power electronics components 54 of fuel cell system 10 and / or output requests to one or more auxiliary systems 52 and / or one or more power electronics components 54 of fuel cell system 10.

[0024] Communication interface 44 can also include a plurality of gateway electronic control units (ECUs) 56A and 56B. Gateway ECUs 56A and 56B can be electrically connected to PLC 50 as well as fuel cell units 22A and 22B. It should be understood that only two fuel cell units 22A and 22B are shown for simplicity of illustration. In one example, gateway ECU 56A can control one subset of fuel cell units while gateway ECU 56B will control another subset of fuel cell units.

[0025] Gateway ECUs 56A and 56B can be configured to operate fuel cell units 22A and 22B, respectively, based on a power request from external unit 12. Gateway ECUs 56A and 56B can also be configured to communicate with and / or operate one or more fuel cell ECUs 58 of the fuel cells within each fuel cell unit 22. For example, as previously mentioned, fuel cell unit 22A can have four individual fuel cells connected in series, such as Figure 2 Each of the four individual fuel cells has an ECU that can control operation of the fuel cell. In this example, fuel cell unit 22A has fuel cell ECUs 58A-58D for its four fuel cells, while fuel cell unit 22B has fuel cell ECUs 58E-58H for its four fuel cells. If gateway ECUs 56A and 56B receive an “ON” command from external unit 12, gateway ECUs 56A and 56B can transmit the request to fuel cell units 22A and 22B and turn on each fuel cell unit 22A and 22B so that operation of any fuel cells contained in fuel cell units 22A and 22B begins to generate electricity. Gateway ECUs 56A and 56B can allocate the power request equally or unequally between fuel cell units 22A and 22B.

[0026] It should be appreciated that any of the systems described in this specification can be configured with individual integrated circuits and / or chips in various arrangements. These circuits are connected via connection paths to provide communication signals between the individual circuits. Of course, while individual integrated circuits are discussed, in various embodiments, these circuits can be integrated into a common integrated circuit board. Moreover, the integrated circuits can be combined into fewer integrated circuits or divided into more integrated circuits.

[0027] In another embodiment, the described methods and / or equivalents thereof can be implemented in computer-executable instructions. Thus, in one embodiment, a non-transitory computer-readable medium is configured with stored computer-executable instructions that, when executed by a machine (e.g., a processor, a computer, etc.), cause the machine (and / or related components) to perform the methods.

[0028] For simplicity of explanation, the methods illustrated in the figures are shown and described in a series of blocks. It is to be understood that the methods are not limited by the order of the blocks as some blocks can occur in different orders and / or concurrently with other blocks from that shown and described. Moreover, not all illustrated blocks can be required to implement the example methods. Blocks can be combined or separated into constituent sub- blocks. In addition, additional and / or alternative methods can be employed.

[0029] Detailed embodiments are disclosed herein. It should be understood, however, that the disclosed embodiments are merely examples. It is, therefore, expressly intended that specific

[0030] The flow diagrams and the block diagrams in the drawings are presented to illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments. In this regard, each block in the flow diagrams or block diagrams can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. These and other alternatives are within the scope of the claims.

[0031] The systems, components, and / or processes described above can be implemented in hardware or a combination of hardware and software, and can be implemented in a centralized fashion in one processing system or in a distributed fashion where different elements are distributed across several interconnected processing systems. Any kind of processing system or other apparatus adapted for carrying out the methods described herein is suited. A combination of hardware and software can be a processing system with computer-usable program code which, when being loaded and executed, controls the processing system such that it carries out the methods described herein. The system, component and / or process can also be embedded in a computer-readable storage medium such as a computer program product or other data program storage device, machine-readable, tangibly embodying a program of instructions executable by the machine to perform the methods and processes described herein. The elements can also be embedded in an application product including all the features enabling the methods described herein and, when being loaded in a processing system, can perform these methods.

[0032] Furthermore, the arrangements described herein can take the form of a computer program product embodied in one or more computer readable medium having stored thereon computer readable program code. Any combination of one or more computer readable medium can be utilized. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The phrase "computer readable storage medium" means a non-transitory storage medium. The computer readable medium can take the form of various forms including, but not limited to, non-volatile media and volatile media. Non-volatile media can include, for example, optical, magnetic disks, and the like. Volatile media can include, for example, semiconductor memories, dynamic memory, and the like. Examples of such computer readable media can include, but are not limited to, a floppy disk, a flexible disk, a hard disk, a magnetic tape, other magnetic media, an ASIC, a graphical processing unit (GPU), a CD-ROM, other optical media, a RAM, a ROM, a memory chip or card, a memory stick, and other media from which a computer, processor or other electronic device can read. In the context of this document, a computer readable storage medium can be any tangible medium that can contain or store a program for use by an instruction execution system, apparatus or device.

[0033] The following includes definitions of selected terms employed herein. The definitions include various examples and / or forms of components that fall within the scope of a term and that can be used for various implementations. Not all of the components are required, but each of the components can be utilized. One or more of the components can be utilized singly or in combination with others.

[0034] References to "one embodiment", "an embodiment", "one example", "an example", and the like, indicate that the embodiment(s) or example(s) can include a particular feature, structure, characteristic, property, element, or limitation, but every embodiment or example can not include the particular feature, structure, characteristic, property, element, or limitation. Moreover, the repeated use of the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it can.

[0035] As used herein, a "module" includes a computer or electrical hardware component(s), firmware, a non-transitory computer-readable medium storing instructions, and / or combinations of these components, configured to perform a function or action(s), and / or cause a function or action(s) from another logic, method, and / or system. A module can include a microprocessor controlled by an algorithm, discrete logic (e.g., an ASIC), analog circuitry, digital circuitry, a programmable logic device, a memory device including instructions that, when executed, perform an algorithm, and the like. In one or more embodiments, a module can include one or more CMOS gates, combinations of gates, or other circuit components. Where multiple modules are described, one or more embodiments can include consolidating the multiple modules into one physical module component. Similarly, where a single module is described, one or more embodiments distribute the single module among multiple physical components.

[0036] Further, as used herein, a module includes routines, programs, objects, components, data structures, etc. that perform tasks or implement data types. In other aspects, memory generally stores the modules. Memory associated with a module can be a buffer or cache embedded in a processor, RAM, ROM, flash, or other suitable electronic storage medium. In other aspects, modules contemplated by the present disclosure are implemented as hardware components of an application specific integrated circuit (ASIC), a system on a chip (SoC), a programmable logic array (PLA), a graphics processing unit (GPU), or another suitable hardware component that has a defined set of configurations (e.g., instructions) for performing the disclosed functions embedded.

[0037] In one or more arrangements, one or more modules described herein can include artificial or computational intelligence elements, such as neural networks, fuzzy logic, or other machine learning algorithms. Further, in one or more arrangements, one or more modules can be distributed among multiple modules described herein.

[0038] Program code embodied on a computer readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber, cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present disclosure can be written in any combination of one or more programming languages, including an object oriented programming language such as Java TMSmalltalk, C++, ladder logic, any other PLC text-based programming language, and conventional programing languages such as the "C" programming language or similar programming languages. Program code can be completely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or completely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0039] The terms "a" and "an," as used herein, are defined as one or more than one. The term "plurality," as used herein, is defined as two or more than two. The term "another," as used herein, is defined as at least a second or more. The terms "including" and / or "having," as used herein, are defined as comprising (i.e., open language). The phrase at least one of... and... as used herein indicates any and all possible combinations of one or more of the associated listed items. For example, the phrase at least one of A, B, and C includes only A, only B, only C, or any combination thereof (e.g., AB, AC, BC, or ABC).

[0040] Aspects herein can be embodied in other forms without departing from the spirit or essential attributes thereof. Thus, the scope of the disclosure should be determined, not with reference to the above description, but should be instead determined with reference to the appended claims, along with their full scope of equivalents.

Claims

1. A fuel cell system, the fuel cell system comprising: a plurality of fuel cell units housed in a fuel cell vessel and each configured to generate lower voltage DC power; a plurality of DC-DC converters housed in the fuel cell vessel and each electrically connected to each of the plurality of fuel cell units and configured to convert the lower voltage DC power to higher voltage DC power; a main load power conversion unit housed in a power electronics vessel and electrically connected to the plurality of DC-DC converters and configured to output a main load to an external unit located outside the fuel cell system; an auxiliary load power conversion unit housed in the power electronics vessel and electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load to one or more auxiliary systems of the fuel cell system necessary to keep the fuel cell system operational; an uninterruptible power supply to supply emergency power to the fuel cell system and the one or more auxiliary systems of the fuel cell system; and one or more switchgear assemblies housed in the power electronics vessel and configured to electrically connect the plurality of DC-DC converters to the main load power conversion unit and the auxiliary load power conversion unit and configured to supply the lower voltage DC power to the external unit.

2. The fuel cell system of claim 1, wherein the main load power conversion unit is configured to convert the higher voltage DC power to AC power and wherein the main load is AC power.

3. The fuel cell system of claim 2, wherein the main load is supplied to the external unit to power the external unit.

4. The fuel cell system of claim 3, wherein the external unit is a residential or commercial building.

5. The fuel cell system of claim 1, wherein the auxiliary load power conversion unit is configured to convert the higher voltage DC power to AC power and wherein the auxiliary load is AC power.

6. The fuel cell system of claim 5, wherein the auxiliary load is supplied to the one or more auxiliary systems of the fuel cell system to power the one or more auxiliary systems.

7. The fuel cell system of claim 1, further comprising a battery unit housed in the power electronics vessel and electrically connected to the one or more switchgear assemblies and configured to provide start-up power to the fuel cell system.

8. The fuel cell system of claim 7, further comprising an uninterruptible power supply housed in the power electronics vessel and configured to supply power to the fuel cell system in the event of a failure of the battery unit.

9. A fuel cell system, the fuel cell system comprising: ​ a fuel cell container housing a plurality of fuel cell units, each fuel cell unit configured to generate lower voltage DC power, and the fuel cell container housing a plurality of DC-DC converters, each DC-DC converter electrically connected to each fuel cell unit of the plurality of fuel cell units and configured to convert the lower voltage DC power to higher voltage DC power; and a power electronics container housing a main load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output a main load to an external unit located outside of the fuel cell system, and the power electronics container housing an auxiliary load power conversion unit electrically connected to the plurality of DC-DC converters and configured to output an auxiliary load to one or more auxiliary systems of the fuel cell system, the one or more auxiliary systems necessary to maintain operation of the fuel cell system, and the power electronics container housing an uninterruptible power supply supplying emergency power to the fuel cell system and the one or more auxiliary systems of the fuel cell system, wherein the main load power conversion unit and the auxiliary load power conversion unit are configured to convert the higher voltage DC power to AC power, and wherein the main load and the auxiliary load are AC power, wherein the power electronics container further houses one or more switchgear assemblies configured to electrically connect the plurality of DC-DC converters to the main load power conversion unit and the auxiliary load power conversion unit, and configured to supply lower voltage DC power to the external unit.

10. The fuel cell system of claim 9, wherein the main load is supplied to the external unit to power the external unit.

11. The fuel cell system of claim 10, wherein the external unit is a residential or commercial building.

12. The fuel cell system of claim 9, wherein the auxiliary load is supplied to the one or more auxiliary systems of the fuel cell system to power the one or more auxiliary systems located within the fuel cell container.

Images