Distributed power unit for data center

Abstract

Techniques are disclosed for providing auxiliary power to a data center, which is typically served by a power utility. The system comprises a controller, a first module and a second module. A common DC bus couples the first module to the second module on the DC side. A common AC bus couples the first module to a second module (e.g., an output of the module) on the AC side. An AC circuit breaker is disposed on the AC bus between the first module and the second module. The controller controls whether the AC circuit breaker is open or closed. The default state of the AC circuit breaker is an off state. The control of the circuit breaker may occur for various reasons, including whether the utility is available or not. Utility may be unavailable due to utility failure or other reasons.

Description

Background Art

[0001] A "data center" is a facility that includes a variety of different computing systems and architectures. Data centers are typically designed to store and share data, applications, or even provide infrastructure to clients. Examples of different systems included in a data center include servers, switches, routers, security systems, and more.

[0002] Maintaining and operating a data center can be a daunting task. For example, customers typically expect their data to be available on demand at any time of day. This means that data centers must be designed to be always operational. As a result, tasks involving providing power to the data center are often considered a high priority.

[0003] Most data centers are powered by the local area's electrical grid, which serves as the primary or main power source. This grid provides a continuous flow of energy to the data center in a reliable manner. Typically, data centers include various transformers and other power components to convert the incoming power into a power signal that can be used by the computing elements in the data center.

[0004] In addition to the power grid, it is common for data centers to be equipped with backup power sources such as generators, uninterruptible power supplies (UPS), battery systems, or capacitor systems for each fleet in the data center, where a "fleet" refers to a group of computing systems that can optionally be powered directly by the backup power system. This secondary power system is designed to provide power to the data center in the event of a power grid failure.

[0005] Solid oxide fuel cell (SOFC) technology is an excellent resource for base load power and can be operated independently or in parallel with a utility (i.e., the grid). Various different fuel cell inverters can be operated at fixed power set points and can be used to generate a fixed amount of power (grid following mode). In grid following mode, the utility can optionally pick up any difference, increment, or shortfall that may exist between the fuel cell power generation and the load demand. In conventional SOFC grid forming applications (e.g., stand-alone) mode, the fuel cell step load capability depends on pre-packaged ultracapacitors for the loads, where the behavior for those loads is predictable or is designed to allow a certain load shedding scheme in microgrid (MG) operation. However, it is worth noting that the load behavior in data centers is generally unpredictable. If SOFC technology is to be used in a data center, then an improved technology is therefore needed to manage how SOFC is used to provide power to the data center.

[0006] The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is merely provided to illustrate one exemplary technology area in which some embodiments described herein may be practiced. Summary of the Invention

[0007] Embodiments disclosed herein relate to systems, devices, and methods for providing auxiliary power to a data center typically served by an electric utility.

[0008] Some embodiments include a controller, a first module, and a second module. Of course, any number of modules can be used, where each module is composed of multiple fuel cell-inverter pairs connected to a step-up transformer. Embodiments also include a common direct current (DC) bus coupling the first module to the second module and a common alternating current (AC) bus coupling the first module to the second module. An AC circuit breaker is placed on the AC bus between the first module and the second module. The controller controls whether the AC circuit breaker is open or closed. The default state of the AC circuit breaker is open.

[0009] Some embodiments enable a group of modules to operate in a grid-following mode, where the modules are coupled together using a common AC bus. For example, some embodiments determine that a utility providing power to a data center is currently available to provide power to the data center. These embodiments maintain a set of circuit breakers on the common AC line open. This set of circuit breakers couples multiple modules on the AC line that can provide supplemental power to the data center. These embodiments enable the modules to operate in grid-following mode while the utility is providing power to the data center.

[0010] Some embodiments enable a group of modules to provide power to a data center, where the modules are coupled together using a common AC bus. For example, some embodiments determine that a utility providing power to the data center is currently unavailable to provide power to the data center. Embodiments determine that the utility is currently unavailable due to a utility failure. These embodiments maintain a group of circuit breakers located on a common AC line open. The group of circuit breakers couples a plurality of modules on the AC line that are capable of providing supplemental power to the data center. Embodiments activate a group of inverters associated with the modules. The modules provide power to the data center.

[0011] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0012] Additional features and advantages will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practicing the teachings herein. The features and advantages of the present invention may be realized and obtained by the means and combinations particularly pointed out in the appended claims. The features of the present invention will become more apparent from the following description and the appended claims, or may be learned by practicing the invention as described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] To illustrate the manner in which the foregoing and other advantages and features may be obtained, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments and are therefore not to be considered limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0014] Figure 1 An example of an electricity providing utility is shown.

[0015] Figure 2 An example of a data center is shown.

[0016] Figure 3 An improved structure capable of providing auxiliary or supplemental power to a data center is shown.

[0017] Figure 4 Various examples of modules are shown.

[0018] Figure 5 An example of a power unit is shown.

[0019] Figure 6 Shown is an architecture designed to facilitate control of certain modules.

[0020] Figure 7 A process flow is shown that details how the modules are controlled.

[0021] Figure 8 An example computer system capable of performing any of the disclosed operations is shown. DETAILED DESCRIPTION

[0022] The disclosed embodiments generally relate to a system for providing auxiliary power to a data center typically served by an electric utility. The embodiments also relate to control of the system.

[0023] Some embodiments include a controller, a first module, and a second module. A common DC bus couples the first module to the second module, and a common AC bus couples the first module to the second module. An AC circuit breaker is disposed on the AC bus between the first module and the second module. The controller controls whether the AC circuit breaker is open or closed. The AC circuit breaker is in an open state by default.

[0024] Some embodiments enable a group of modules to operate in a grid-following mode, wherein the modules are coupled together using a common AC bus. A utility providing power to a data center is currently available to provide power to the data center. A set of circuit breakers on the common AC line is open. This set of circuit breakers couples multiple modules on the AC line that can provide supplemental power to the data center. These embodiments enable the modules to operate in the grid-following mode while the utility is providing power to the data center.

[0025] Some embodiments provide power to a data center from a group of modules, where the modules are coupled together using a common AC bus. Due to a utility failure, the data center's power supply utility is currently unavailable to provide power to the data center. These embodiments maintain a group of circuit breakers on the common AC line open. The group of circuit breakers couples multiple modules on the AC line that can provide supplemental power to the data center. Embodiments activate a group of inverters associated with the modules. The modules provide power to the data center.

[0026] Examples of technology benefits, improvements, and real-world applications

[0027] The following section summarizes some exemplary improvements and practical applications provided by the disclosed embodiments. However, it should be understood that these are merely examples and the embodiments are not limited to these improvements.

[0028] The disclosed embodiments bring numerous benefits, advantages, and practical applications to the technical field of power system management, particularly for data centers. In particular, the disclosed embodiments advantageously provide modular, flexible data center power control applications. The embodiments also provide for integrating power supplies (e.g., SOFCs or any other similar technology) into a data center fleet, where (as previously mentioned) a "fleet" refers to a group of computing systems that can optionally be powered directly by a SOFC system.

[0029] These embodiments also advantageously provide full DC bus connectivity between all modules, where a "module" refers to a combination of one or more energy sources (e.g., SOFCs) and one or more ultracapacitors connected to a step-up transformer. Embodiments also allow for new connections to be made via normally open circuit breakers present on the AC side of the modules. Yet another benefit relates to the control process used to manage these various configurations.

[0030] By practicing the disclosed principles, these embodiments allow for unlimited expansion of power system plans, such as through a phased process or by including a few modules (also called power units) at a time and adding more as fleets or demand increase. Moreover, the disclosed embodiments can be fully deployed in a short period of time (e.g., a day or less).

[0031] Unlike traditional SOFC configurations that operate with a central unit installed to feed a fixed load, the disclosed new design allows for flexibility and customized, scalable solutions at the fleet level. This includes flexibility in the size of each energy server ("ES") (i.e., a collection of specific energy sources such as SOFCs) and the modules in which these ESs operate (i.e., several energy servers connected to one step-up transformer). Optionally, embodiments allow modules to be of equal or unequal size (e.g., given a data center design, they can be of equal size, but not necessarily).

[0032] The demand for data centers is expected to grow significantly over the next few years. It is often desirable to disconnect data centers from the traditional power grid and control a data center "microgrid" (i.e., a localized power generation system that provides baseload power coverage to the data center). The baseload power for this microgrid comes from local energy sources that can be renewable and / or green.

[0033] When it comes to baseload coverage, there are several options available, and SOFCs have been found to be able to significantly outperform other existing technologies (such as natural gas (NG) or H2 to electricity) in terms of efficiency and emissions. The disclosed embodiments enable the construction of SOFC-based microgrids that provide reliable and scalable on-demand power.

[0034] As mentioned above, the data center industry is experiencing exponential growth in demand, and this demand needs to be met by building data centers in local areas. However, sometimes the regional utility / grid cannot provide the capacity or consistency required to power these data centers. Data center builders must therefore create their own microgrids, which include distributed energy resources. It is generally desirable that these distributed energy resources be (i) designed to reduce emissions, (ii) reliable, (iii) redundant, and (iv) scalable. The disclosed solution can be scaled up or down to fit any design constraints.

[0035] Advantageously, the disclosed embodiments also provide efficiencies greater than 50% and less than 60% for natural gas to electricity conversion, which can be increased by 20-30% when combined with certain heat recovery technologies. It should be noted that SOFCs can also operate with hydrogen instead of natural gas as a fuel if the infrastructure becomes available. Utilizing H2 can also make the entire electricity production a zero-emission process (assuming green hydrogen is used as the fuel). Therefore, the above-mentioned benefits, as well as many others, will now be described in more detail in the remainder of this disclosure.

[0036] Utilities and Data Centers

[0037] Now will focus on Figure 1, which shows an example utility 100 capable of providing power to a grid. Utility 100 can be any type of power generation utility, without limitation. Examples of utilities can include any type of fossil fuel utility, hydroelectric utility, solar utility, wind utility, etc. Figure 1 As shown, utility 100 provides power to remote components via any number of transmission lines.

[0038] Figure 2 Shown from Figure 1 Utility 100 provides transmission lines for power. In this example scenario, these transmission lines connect to data center 200. Data center 200 includes any number of queues, such as queue 205. As described above, a queue is a group of computing elements that can be powered as a group via the utility and via secondary sources (such as the aforementioned SOFCs). A queue can include any number of servers, routers, switches, and the like. Optionally, power isolation can exist between different queues.

[0039] The data center 200 also includes, but is not limited to, any number of cooling or climate control systems, ventilation systems, computing elements, and the like, although these are not labeled. It is highly desirable to provide a consistent, reliable power signal to the data center 200. Typically, this power signal is provided by a utility. However, there are times when the utility may be offline or may experience a power outage or blackout. To account for this eventuality, the data center typically includes or has access to a secondary power source, such as a battery bank, a capacitor bank, an SOFC, or any other power generation element. These elements can operate in parallel with the utility. In the event that the utility is offline, those other power generation elements can then be used to provide power to the grid for at least a period of time. The disclosed embodiments relate to improved configuration and use of this secondary or supplemental power system.

[0040] Supplementary Power Design System

[0041] The disclosed embodiments provide a distributed energy solution to cover the load demands of a data center using energy resources or power cells (e.g., SOFCs). The power cells provide power to the data center either in parallel with the utility (e.g., so-called "grid-following" mode) or as independent voltage sources (e.g., so-called "grid-forming" mode). The power cells operate as current sources when in parallel with the utility and as voltage sources when operating in microgrid or so-called "island" mode.

[0042] For "grid follow" mode, the system is provided with a set point. The system then generates the desired power level (ie, the set point) depending on the voltage and frequency.

[0043] For example, assume the system is instructed to operate at 1 MW. The system will then operate to provide 1 MW of power.

[0044] When the system is in "grid-forming" mode, the system follows the load as the load rises or falls. When the utility becomes available, any shortfall between the power generated by the system and the load demand is picked up by the utility. That is, in grid-forming mode, the system scales with the load. In the event of a utility failure, a seamless transition between grid-forming and grid-following modes can occur. Alternatively, a combination of batteries, ultracapacitors, and solid-state fuel cells can cover the load for extended periods of time.

[0045] Voltage source operation of the power unit with droop functionality allows scalable addition of other distributed energy resources to the same microgrid system, where the second or subsequent distributed energy resources can operate in grid-forming or grid-following modes. The proposed distributed energy resource configuration provides reliable, scalable, redundant, and 24 / 7 power to the data center.

[0046] The disclosed solution and architecture consists of multiple modules, each capable of operating at different voltage levels depending on the DC load block. Module power ratings can be scaled up or down based on the required load and design. Each module consists of one or more energy servers. The size of the power cells / modules within the energy servers and the number of energy servers in a module can be varied, providing 100% flexibility for the disclosed modular solution.

[0047] The system can be black started for the first time (i.e., the process of starting the system for the first time, such as may be after a power outage event) with or without the utility (i.e., the grid). After the black start, the modules in the module are continuously monitored and can be maintained at the same time. The design has a customizable number of ultracapacitors that can provide instantaneous power for rapid load changes. The solution can also optionally utilize natural gas infrastructure or biogas. The fuel cell system does not necessarily rely on batteries as an internal resource, although batteries can be used. It should be noted that natural gas infrastructure is much more reliable than electricity infrastructure, which significantly improves the availability of this solution compared to utility infrastructure.

[0048] Example Architecture

[0049] Now will focus on Figure 3 , which illustrates an example architecture 300 that may be used to provide the disclosed benefits and advantages. The architecture 300 is shown as including or connected to a utility 305 that represents Figure 1 Utilities 100 in . Utilities 305 can be connected to the system in a number of different ways. For example, Figure 3The left path is shown, where the utility 305 is connected to the first transformer 310 and the corresponding circuit breaker (not labeled, but shown as a square below the transformer 310). Additionally, Figure 3 The right path is shown, where the utility 305 is connected to a second transformer 315 and a corresponding circuit breaker (not labeled, but shown as a square below the transformer 315).

[0050] Architecture 300 includes service 300A. As used herein, the term "service" refers to an automated program whose task is to perform different actions based on input. In some cases, service 300A can be a deterministic service that operates completely given a set of inputs and without randomization factors. In other cases, service 300A can be or include a machine learning (ML) or artificial intelligence engine.

[0051] As used herein, references to any type of machine learning or artificial intelligence can include any type of machine learning algorithm or device, convolutional neural network, multi-layer neural network, recursive neural network, deep neural network, decision tree model (e.g., decision tree, random forest and gradient boosting tree), linear regression model, logistic regression model, support vector machine ("SVM"), artificial intelligence device or any other type of intelligent computing system. A machine learning algorithm can be trained using any amount of training data (and potentially later refined) to dynamically perform the disclosed operations.

[0052] In some implementations, service 300A is a cloud service operating in a cloud environment. In some implementations, service 300A is a local service operating on a local device, such as in a data center. In some implementations, service 300A is a hybrid service that includes a cloud component that communicates with a local component. A machine learning engine can optionally be used to adjust thresholds, probability values, delta values, and precision values.

[0053] Service 300A can be used to dynamically control Figure 3 Various modules, switches, circuit breakers, transformers, and other components are shown. Service 300A may enable architecture 300 to operate in either a grid-following mode or a grid-forming mode.

[0054] Transformers 310 and 315 are step-down transformers that step down the high voltage from utility 305 to a medium voltage (e.g., a voltage at or above approximately 1000 V and at or below approximately 69 kV). Transformers 310 and 315 can be considered part of a respective medium voltage distribution system. Another set of transformers, described below, steps down the intermediate voltage to a low voltage usable by the data center.

[0055] The left and right paths are also connected to a series of switches, one of which is labeled switch 320A. These switches can be used by an embodiment to determine which path will be used to feed power to a data center 325, which represents Figure 2 If the left path provides power to the data center, the left portion of each switch is closed and the right portion of each switch is open. If the right path provides power to the data center, the right portion of each switch is closed and the left portion of each switch is open.

[0056] Architecture 300 also shows a plurality of circuit breakers (eg, empty rectangular boxes), one of which is labeled circuit breaker 330. These circuit breakers can be used as disconnect switches to disconnect power to data center 325.

[0057] Additionally, any number of other transformers (eg, transformer 335) may be provided to further modify the voltage level of the power signal sent to the data center 325. For example, the transformer 335 converts the intermediate voltage into a low voltage that is fed to the data center 325.

[0058] In accordance with the disclosed principles, architecture 300 is also constructed to include any number of so-called "modules," such as module 340, module 345, module 350, and module 355. Modules may also be associated with switches, as shown in switch 320B. These modules include the previously mentioned scalable modules (also referred to as power cells). Architecture 300 is designed so that any number of modules can be easily incorporated into architecture 300 to provide secondary or supplemental power to data center 325. In this example scenario, there are four modules, but it should be understood how the number of modules may vary based on the design needs of data center 325. Furthermore, as additional computing elements are added to data center 325 or as the load on an existing data center 325 increases, additional modules may also be added to architecture 300.

[0059] Figure 3 The illustrated solution is constructed from distributed, scalable modules connected to the medium-voltage side of step-down transformers (e.g., transformers 310 and 315), a unique configuration relative to conventional power systems. That is, this particular configuration (i.e., one in which the modules are sized to the fleet requirements with adjustable built-in redundancy and in which the modules are connected at a medium voltage level) is new.

[0060] Another unique aspect of the disclosed embodiments is that the DC connections of the modules can also be connected internally and across modules, so that the DC connection from one module is coupled to the DC connection of a different module. In doing so, the connected DC sides form a large DC energy pool that grows as more modules (i.e., power units) are added.

[0061] Yet another unique aspect of the disclosed embodiment is that the AC connections of the modules can also be connected across the modules. The AC side is connected through various circuit breakers (e.g., circuit breakers 370, 375, 380) that are normally open. As will be discussed in more detail later, when the utility is unavailable (e.g., so-called "island" operation), the circuit breakers (e.g., circuit breakers 370, 375, and 380) are closed during power start and opened when the black start process is complete to limit the fault current on the AC side. Doing so allows each fuel cell module (i.e., power unit) to feed its own load (i.e., string), while those modules can all use a common DC energy pool.

[0062] Normally open AC-side circuit breakers (e.g., circuit breakers 370, 375, and 380) eliminate the need for synchronization between all AC power units, even when the size increases, such as by adding new modules. This design provides the flexibility to customize each module / power unit and add them together to match the size of the data center. This concept provides a unique and novel supplemental power solution that allows for phased construction or full-scale deployment at once.

[0063] As described above, each respective module may be tasked with servicing a particular queue in data center 325. For example, module 340 may service a first queue in data center 325; module 345 may service a second queue in data center 325; module 350 may service a third queue in data center 325; and module 355 may service a fourth queue in data center 325.

[0064] According to the disclosed principles, the architecture 300 can be designed so that the modules have a common direct current (DC) bus, as will be shown below. In addition, the architecture 300 can also be designed so that the modules have a common alternating current (AC) bus, as shown by common AC line 360. Note that common AC line 360 can include logic circuit breakers in the form of normally open circuit breakers, as shown by circuit breakers 370, 375, and 380. Figure 3 Also shown is the module's output 365 and how it connects to the utility line that feeds power to the data center 325 .

[0065] In other words, architecture 300 is constructed to provide various circuit breakers between different modules. For example, circuit breaker 370 is an AC circuit breaker on common AC line 360, and circuit breaker 370 is logically located between module 340 and the other modules. Circuit breakers 375 and 380 are also AC circuit breakers, and they provide further disconnection between different modules. These circuit breakers can be controlled during black start and during the ramp-up process, which will be discussed in more detail later. In some cases, circuit breakers 370, 375, and 380 are "normally open" circuit breakers, and the opening and closing of these circuit breakers can be used to control inrush currents that may occur during black start. When operating in grid forming mode, the demands on the fuel cell / power unit are more severe. However, connecting the fuel cell on the AC side helps to reduce the burden on the fuel cell, especially during startup, in order to regulate inrush currents.

[0066] In some cases, the architecture 300 may include a flywheel 385 to provide power to the data center 325. Further details on this will be provided later. In general, the flywheel 385 can be used as an alternative to ultracapacitors.

[0067] Figure 4 An example of a module 400 is shown, which represents Figure 3 Module 400 is shown as including a first power unit 405 and a second power unit 410. Ellipses 415 indicate how any number of power units may be included in a single module. The power units are connected to each other because they share a common DC bus, as shown by common DC 420. Module 400 is connected to or optionally includes a transformer 425 that is different from Figure 3 Transformer 335.

[0068] Figure 4 A second module 430 is shown. Module 430 includes a first power cell 435 and a second power cell 440. Ellipsis 445 indicates how the module may also include any number of power cells. Optionally, the number of power cells in module 400 may be different from the number of power cells in module 430. The power cells in module 430 also share a common DC bus, as shown by common DC 450. Additionally, module 400 may be connected to module 430 via a common DC bus, as shown by common DC 455. Thus, the power cells in a single module have a common DC bus. Furthermore, the power cells in a first module may be connected to the power cells of a second module using the common DC bus.

[0069] Figure 4 It also shows how modules 400 and 430 share a common AC bus, as shown by common AC 460. Common AC 460 represents Figure 3The public AC line 360. A circuit breaker 465 is also shown. The circuit breaker 465 represents Figure 3 Any of circuit breakers 370, 375, or 380 in FIG. Circuit breaker 465 can be considered a "normally open" circuit breaker. When circuit breaker 465 (or circuit breakers 370, 375, or 380) is open, each module serves only its own queue, and no synchronization is performed or required between different modules. When the circuit breaker is open, each module operates independently and feeds its own load on the AC side. A major advantage of circuit breakers 465, 370, 375, and 380 occurs when a black start is required and when the utility is unavailable.

[0070] Figure 5 Provide information about Figure 4 Further details of the power units 405, 410, 435 and 440. In particular, Figure 5 A unit 500 is shown, which represents any of the power units just mentioned.

[0071] The illustrated unit 500 includes an energy server 505 that includes a first SOFC 510 and a second SOFC 515. Ellipses 520 indicate that any number of SOFCs may be included in the energy server 505. Although Figure 5 Examples involving the use of SOFCs are shown, but a person skilled in the art will realize how any other type of energy source may be used as well or alternatively instead of a SOFC.

[0072] SOFCs output DC power, and the output is typically (though not always) between about 50 KW and about 75 KW. Energy servers can output between about 300 KW and about 325 KW.

[0073] Figure 5 Also shown is how unit 500 includes an ultracapacitor, shown as capacitor 525. Capacitor 525 is provided to facilitate ramp-up events, in which unit 500 is brought online to provide power quickly. Capacitor 525 can be operated to discharge substantially immediately when the SOFC is ramping up. Once the SOFC is operating, it can also be used to charge capacitor 525. Optionally, capacitor 525 can be a 100KJ or 1500KJ type capacitor. Of course, other sizes can also be used. An alternative to capacitor 525 could be the flywheel mentioned above.

[0074] The capacitor 525 and the energy server 505 are shown to share a common DC bus, as shown by common DC 530. The common DC 530 represents Figure 4of common DC 420. As a result of this common DC bus, if any particular data center load is high, any number of capacitors and / or power cells can be used to help service that load.

[0075] Providing a common DC 530 allows all modules to access a common DC energy pool, which includes the stored power of capacitors. It is worth noting that any number of capacitors can be included in this architecture.

[0076] This common connection on the DC side also addresses sudden load changes that may occur in each queue or temporary uneven loads on the AC side. That is, if one queue is overloaded, it can draw more energy from the DC side as long as that energy is available without causing a voltage drop on that DC bus, acting like the heartbeat of the entire system.

[0077] Including more modules / power units results in a higher step load capability that can be provided to each train. Additionally, sharing a large DC energy bus is advantageous because SOFC technology is designed for base load coverage, and the ultracapacitors provide the short period of step load energy before the SOFCs can ramp up their power to take over the load from the ultracapacitor(s).

[0078] The same power sharing characteristics apply to overload situations on one or more trains. This is also true when the load on the AC side of the inverter drops suddenly on one train, because the additional energy on the DC side can be picked up by the other (multiple) medium voltage trains that may be experiencing a load increase. Therefore, by connecting all the DC buses, the design provides a group of energy whose energy-time graph is flatter than the energy-time graphs of the individual DC buses (if they were not connected together). Because it is difficult to predict the maximum load change on a train (for example, because it must deal with customer demand rather than data center train characteristics), the disclosed embodiments are very advantageous because they provide a high level of flexibility in handling unpredictable loads.

[0079] The capacitor 525 and the energy server 505 are also shown coupled or connected to a power inverter 535. The inverter 535 converts the DC power to AC power. Optionally, a circuit breaker 540 may be provided downstream of the inverter 535. The inverter 535 is then connected to a transformer, such as Figure 4 of transformer 425. Typically, the power inverter 535 is a 355KVA inverter, although other sizes can be used.

[0080] Inverter 535 can be considered a master or central inverter serving multiple SOFCs. However, in some embodiments, each respective SOFC can be provided or associated with its own corresponding inverter. Thus, in some cases, the number of inverters in the system can match the number of power cells or SOFCs. In other cases, a single inverter can be provided for each power cell, which can include multiple different SOFCs.

[0081] In island operation, by closing the normally open circuit breaker (e.g. Figure 3 With the first module black (circuit breaker 370), the other modules and the entire system are started. Once the system is started and the voltage and frequency stabilize, the other breakers (e.g., circuit breakers 375 and 380) can be opened to prevent large fault currents on the AC side and isolate the modules / power units, thereby minimizing the risk of various interference. This is beneficial because once the outputs of the power units are connected, they can push power into the other side and cause inverter problems.

[0082] If the utility is available, these circuit breakers (e.g., circuit breakers 370, 375, and 380) can be used as normally open. In the presence of utility, a black start can be performed by the utility. If the utility fails and the power unit (e.g., SOFC) takes over the load after the interruption, there is no need to close these circuit breakers when the power unit (e.g., the fuel cell in those units) enters standby, and they will be reopened once the system is completely isolated from the grid. This time interval (i.e., the time it takes for the inverter to enter standby and return) is also used for the inverter to switch from current source or "grid following" mode to voltage source or "grid forming" mode.

[0083] In other words, during grid operation, the SOFC can operate in parallel with the grid. If a utility failure occurs, the system has a period of time (e.g., 2 seconds or whatever time is set based on regional code) to isolate itself from the grid. The SOFC can enter standby mode or seamlessly switch to grid-forming mode. This process can be done in stages (e.g., perhaps 10 MW, 20 MW, etc.) or all at once.

[0084] A control mechanism, service, or controller is used to control normally open circuit breakers (e.g., circuit breakers 370, 375, and 380) according to an operating scenario. For example, Figure 3 The service 300A may operate as the control mechanism.

[0085] The controller uses a control algorithm that considers the utility voltage and frequency, as well as the status of each circuit breaker. This algorithm is unique due to the novel configuration disclosed herein. Typically, the control mechanism commands the circuit breakers to open or close, depending on whether the system is operating with or without the utility. These circuit breakers can also be used to feed any combination of modules / power units into any combination of fleets. This feature is particularly advantageous when a downstream transformer or data center circuit breaker fails. Using these circuit breakers, two adjacent modules / power units can be connected, and power can be diverted away from the failed utility component.

[0086] In this regard, embodiments utilize a central controller (eg, service 300A) that coordinates the activities of all modules. Each module may also optionally have its own controller that can communicate with the central controller.

[0087] The state of the utility (e.g., available / unavailable) affects the state of the normally open circuit breaker. If the utility is available, the controller will keep the circuit breaker open unless a combination module is needed. If the utility is unavailable, the circuit breaker is closed only during startup. Upon a complete and successful startup, the circuit breaker can be opened. Even if the utility fails and a power unit (e.g., SOFC) takes over the load, the circuit breaker remains open once the system starts the utility. This is because, in the event of a power failure, the inverter enters a standby state and waits for a "source isolation" signal to return to voltage source (grid forming) mode before taking over the load.

[0088] Control process

[0089] At a high level, the disclosed embodiments relate to a distributed, reliable, potentially zero-emission, redundant, scalable, and 24 / 7 available fuel cell solution, with operational and black start details described herein. The disclosed solution can black start a system with or without utility support. The design, block connectivity, integration into data center infrastructure, and control logic are unique compared to traditional architectures and approaches.

[0090] Typically, if a black start is being performed by the utility, the normally open circuit breakers remain open during the startup. Otherwise, they are closed, allowing the first module to start the remaining modules. Normally open circuit breakers can also be closed to combine modules / power units when some downstream equipment in a module fails, allowing power to flow through that path.

[0091] All DC buses on the module can be connected to provide a DC energy pool, including ultracapacitors, to each train. Inverter-based technologies have low fault currents, so flywheel-based technologies can also be applied to the system. Additionally or alternatively, a rotary UPS, motor, or generator set can be used instead of a flywheel or capacitor. The use of a flywheel can further improve stability, fault current, and rapid injection / absorption of power. These embodiments can also use zone selective interlocking (ZSI) or voltage control (limiting) protection for detecting low fault currents.

[0092] It should be noted that any comparable fuel cell technology can be used in this design. Depending on the design and load requirements, this ranges from seamless current-to-voltage transfer and vice versa, or break-before-make operations. Even so-called "green" hydrogen can be used as a fuel. This solution breaks down any barriers that data centers have established in areas with limited to no power capacity. Data center power generation can become zero-emission, a significant milestone to meet. The solution's reliability and redundancy can meet any design, as both the number of fuel cells in the energy server and the number of energy servers in the module are adjustable. Furthermore, for fixed loads, redundancy increases with the number of fuel cells.

[0093] Now see Figure 6 and 7 . Figure 6 Shown are methods that can facilitate the operations disclosed herein (including Figure 7 In other words, the process shown in the flowchart of FIG. Figure 6 The architecture 600 is used to facilitate the process in the flowchart. Figure 6 and 7 Frequent references between.

[0094] Figure 6 The architecture 600 includes a controller 605, which is Figure 3 Controller 605 is an example of the central controller mentioned above. As mentioned above, controller 605 can be a service type.

[0095] In some cases, the controller 605 can be implemented in a cloud environment, such that the controller is a cloud-based service. In some cases, the controller 605 can be implemented locally on the device. In some cases, the controller 605 can be a hybrid service that includes cloud-based components and local components.

[0096] Controller 605 can control or manage any number of local, module-based controllers, such as module controller 610 and module controller 615. For example, module controller 610 can control Figure 3 Similarly, the module controller 615 can control the operation of the module 340 from Figure 3 The controller 605 controls the operation of the module 345. Such operations include, but are not limited to, controlling various circuit breakers, inverters, capacitors (e.g., discharging, charging, etc.), and the module's power cells (e.g., SOFCs). The controller 605 may also control various other resources 620 (e.g., BESS or PV).

[0097] The controller 605 can facilitate Figure 7 The operations shown in the process flow 700. Figure 7 The present invention provides a discussion of various methods and method actions that may be performed. Although method actions may be discussed in a particular order or shown in flowcharts as occurring in a particular order, no particular order is required unless otherwise stated or because an action is dependent on another action being completed before the action is performed.

[0098] Example Method

[0099] The following discussion now relates to a number of methods / processes and method actions that can be performed. Although method actions may be discussed in a particular order or shown in a flowchart as occurring in a particular order, no particular order is required unless otherwise stated or because an action depends on another action being completed before the action is performed. The process flow 700 can be performed by Figure 3 The service 300A is realized. Figure 6 The controller 605 of FIG. 7 is an example implementation of the service 300A, and thus the process flow 700 may also be implemented by the controller 605 .

[0100] Process flow 700 can be performed at Figure 3 The system is implemented within the architecture 300 of FIG. For example, the architecture is designed to provide auxiliary power to a data center, which is typically served by an electric utility. The structure or system may include a controller, a first module, and a second module. The system / architecture may also include a common DC bus coupling the first module to the second module. The system also includes a common AC bus coupling the first module to the second module. Further, the system may include an AC circuit breaker disposed on the AC bus between the first module and the second module. The controller controls whether the AC circuit breaker is open or closed. In addition, the default state of the AC circuit breaker is an open state.

[0101] Process flow 700 (i.e., method) initially includes an act 705 of determining whether a utility is available. For example, controller 605 may have a voltage or current sensing mechanism for a line connected to the utility. If a signal is observed on the line, controller 605 may determine that the utility is currently providing power to the data center. If no signal is observed, controller 605 may determine that the utility is not currently providing power to the data center.

[0102] If the utility is available (ie, the "yes" branch), the controller 605 may facilitate action 705A, which includes keeping the normally open circuit breakers open. For example, keeping the circuit breakers 370, 375, and 380 open on the common AC line 360 (or Figure 4 The circuit breaker 465 may remain open. It is possible that the circuit breaker includes a wireless fidelity (Wi-Fi) connection, a Bluetooth connection, or some other wireless or wired connection. The controller 605 is able to communicate with these various circuit breakers to control their status. In some cases, the circuit breakers can be treated as Internet of Things (IoT) devices and can optionally be controlled from the cloud.

[0103] Action 705B then includes black starting the system. This black start can be performed using a utility or power unit. A black start typically involves energizing the entire system, which means first starting all resources, then connecting the loads and monitoring the system for a period of time until everything is fully stable.

[0104] Action 705C includes causing the power unit and the utility to operate in parallel with each other. Here, the power unit is caused to operate in a grid-following mode.

[0105] Action 705D includes determining whether a grid fault has occurred, for example, by analyzing voltage and frequency characteristics. If a grid fault has occurred, the controller 605 isolates the data center from the grid (e.g., using a power supply from a source) for a threshold number of seconds (e.g., perhaps two seconds). Figure 3 320A or upstream circuit breakers near transformers 310 and 315). Action 705E then includes placing the power unit into standby mode. The power unit may return after confirming grid isolation. Alternatively, the power unit may seamlessly transition to grid forming mode.

[0106] On the other hand, if the utility is unavailable (i.e., the "No" branch), action 710 is performed. As described above, the controller can determine that the utility is unavailable by attempting to observe a power signal on the line from the utility. If no signal is observable, the utility may be offline or at least not providing power to the data center.

[0107] Action 710 includes determining whether the unavailability of the utility is the result of a utility failure. If the unavailability is due to a utility failure, action 710A is performed. Any type of utility failure may occur. As various examples, a utility failure may include a power line outage. A utility failure may also include a situation where the power source for the utility is currently offline. Indeed, any type of failure may occur. Controller 605 is capable of communicating with the utility to determine whether the utility is offline. In some cases, controller 605 may trigger a query or alert to be sent to an administrator at the utility to determine whether a utility failure has occurred.

[0108] Action 710A includes keeping the normally open circuit breakers open. For example, keeping circuit breakers 370, 375, and 380 open (or Figure 4 Circuit breaker 465 in).

[0109] Action 710B then includes isolating the data center from the utility. Action 710C then includes isolating the inverter (e.g., Figure 5 The inverter 535 in the power supply 100 is switched from the standby mode to the active mode. Action 710D then includes causing the power unit to provide power in a reliable, redundant, and continuous manner.

[0110] On the other hand, if the unavailability is not due to a utility failure (i.e., the "No" branch), then action 715A is performed. The unavailability may be due to maintenance. For example, a technician may be currently managing or maintaining a line to the utility or perhaps the utility itself. When the system is started in grid forming mode, the circuit breakers are here to solve the black start problem. Action 715A includes closing the normally open circuit breakers. For example, closing circuit breakers 370, 375, and 380 (or Figure 4 The circuit breaker 465) is closed.

[0111] Action 715B then involves performing a black start of the power units on the system.Those power units are also caused to operate in a grid forming mode.

[0112] Alternatively, the modules can be operated in a ramp-up manner over a defined time period. For example, the first module can be ramped up over a selected number of seconds. Then, one, some, or all of the other modules can be started immediately after sensing the stable voltage generated by the first module. In this case, the normally open circuit breakers (e.g., circuit breakers 370, 375, and 380) are closed to allow for a rapid startup of the system. Doing so allows for a rapid startup of the system regardless of the number of modules.

[0113] Action 715C then includes calculating how many power units may be needed. This calculation can optionally be based on the design and / or desired reliability and redundancy expectations. Action 715D then includes enabling the system to provide power to the data center in a reliable, redundant, and continuous manner.

[0114] Advantageously, the disclosed principles can be key to filling the power capacity gap before a utility can deliver the required power to a new data center (e.g., a standalone microgrid), or it can provide a permanently scalable local power resource solution to a data center. The solution can work with other distributed energy resources in the system in grid forming or grid following mode. Flywheel-based technology can also be added to address the low fault current of the fuel cell inverter. The proposed solution can form a microgrid on its own or it can be part of a microgrid system where the SOFC is the baseload resource and other resources can be added to the microgrid and can work with the SOFC.

[0115] The disclosed principles can be used to address phased expansion or full-scale buildout of a data center. The principles can also be used to address unpredictable load variations in data center loads. Traditionally, supplemental power systems are designed for baseload coverage, not for unpredictable coverage. The principles can also enable rapid startup of SOFC units in standalone mode (without utility) by connecting all modules on the AC side via certain circuit breakers (e.g., circuit breakers 370, 375, and 380) (such that the first module is initially ramped up and then the remaining modules are started immediately).

[0116] A key benefit and difference of the disclosed embodiments compared to traditional technologies involves introducing a distributed and scalable approach to a technology designed for baseload needs, where the approach can be infinitely expanded to cover baseload, load steps, and the creation of microgrids with or without other distributed energy resources. This solution can be implemented by any cloud service provider looking to source local power generation resources for their data centers and reduce or eliminate carbon emissions from their power generation plans.

[0117] Thus, some disclosed embodiments generally and advantageously relate to a unique arrangement of fuel cell DC and AC bus connections and the integration of these connections with the power infrastructure, operating logic, and black start procedures of a data center. The embodiments are capable of filling the power capacity gap before the utility is able to deliver the required power to a new data center (e.g., a standalone microgrid). The embodiments may also provide a permanent scalable local power resource solution for a data center. The solution may work in grid forming or grid following mode with other distributed energy resources in the system. Flywheel based technology may also be added to address the low fault current of the fuel cell inverter.

[0118] Example Computer / Computer System

[0119] Now will focus on Figure 8 , which illustrates an example computer system 800 that may include and / or be used to perform any of the operations described herein. For example, the computer system 800 may implement Figure 6 Controller 605 or Figure 3 service 300A or any other controller or service mentioned in this disclosure.

[0120] The computer system 800 can take a variety of different forms. For example, the computer system 800 can be implemented as a tablet computer, a desktop computer, a laptop computer, a mobile device, or a standalone device, such as those described throughout this disclosure. The computer system 800 can also be a distributed system including one or more connected computing components / devices that communicate with the computer system 800.

[0121] In its most basic configuration, computer system 800 includes a variety of different components. Figure 8 Computer system 800 is shown including one or more processors 805 (also referred to as “hardware processing units”) and storage 810 .

[0122] With respect to the processor(s) 805, it should be appreciated that the functionality described herein may be performed, at least in part, by one or more hardware logic components (e.g., the processor(s) 805). For example, and without limitation, illustrative types of hardware logic components / processors that may be used include field programmable gate arrays (“FPGAs”), application-specific or application-specific integrated circuits (“ASICs”), application-specific standard products (“ASSPs”), system-on-a-chip (“SOCs”), complex programmable logic devices (“CPLDs”), central processing units (“CPUs”), graphics processing units (“GPUs”), or any other type of programmable hardware.

[0123] As used herein, the terms “executable module,” “executable component,” “component,” “module,” “controller,” “service,” or “engine” may refer to a hardware processing unit or a software object, routine, or method that may be executed on the computer system 800. The different components, modules, engines, and services described herein may be implemented as objects or processors executing on the computer system 800 (e.g., as separate threads).

[0124] Storage device 810 may be physical system memory, which may be volatile, non-volatile, or some combination of the two. The term "memory" may also be used herein to refer to non-volatile mass storage devices, such as physical storage media. If computer system 800 is distributed, processing, memory, and / or storage capabilities may also be distributed.

[0125] Memory 810 is shown as including executable instructions 815. Executable instructions 815 represent instructions executable by the processor(s) 805 of the computer system 800 to perform the disclosed operations, such as those described in the various methods.

[0126] The disclosed embodiments may include or utilize a special-purpose or general-purpose computer including computer hardware, such as one or more processors (e.g., processor(s) 805) and system memory (e.g., storage device 810), as discussed in more detail below. Embodiments also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media can be any available media that can be accessed by a general-purpose or special-purpose computer system. Computer-readable media that store computer-executable instructions in the form of data are "physical computer storage media" or "hardware storage devices." Furthermore, computer-readable storage media, including physical computer storage media and hardware storage devices, exclude signals, carrier waves, and propagating signals. On the other hand, computer-readable media that carry computer-executable instructions are "transmission media" and include signals, carrier waves, and propagating signals. Thus, by way of example and not limitation, the present embodiments may include at least two distinct types of computer-readable media: computer storage media and transmission media.

[0127] Computer storage media (also called "hardware storage devices") are computer-readable hardware storage devices such as RAM, ROM, EEPROM, CD-ROM, RAM-based solid-state drives ("SSD"), flash memory, phase-change memory ("PCM") or other types of memory, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code means in the form of computer-executable instructions, data or data structures and that can be accessed by a general purpose or special purpose computer.

[0128] The computer system 800 may also be connected (via wired or wireless connections) to external sensors (e.g., one or more remote cameras) or devices via the network 820. For example, the computer system 800 may communicate with any number of devices or cloud services to obtain or process data. In some cases, the network 820 itself may be a cloud network. Furthermore, the computer system 800 may also be connected to (multiple) remote / separate computer systems configured to perform any of the processing described with respect to the computer system 800 via one or more wired or wireless networks.

[0129] A "network" similar to network 820 is defined as one or more data links and / or data switches capable of transmitting electronic data between computer systems, modules and / or other electronic devices. When information is transmitted or provided to a computer via a network (hardwired, wireless, or a combination of hardwired and wireless), the computer appropriately considers the connection as a transmission medium. The computer system 800 will include one or more communication channels for communicating with the network 820. Transmission media include networks that can be used to carry data or desired program code devices in the form of computer executable instructions or in the form of data structures. In addition, these computer executable instructions can be accessed by general or special-purpose computers. The above combinations should also be included in the scope of computer-readable media.

[0130] Upon reaching various computer system components, program code means in the form of computer-executable instructions or data structures can be automatically transferred from transmission media to computer storage media (and vice versa). For example, computer-executable instructions or data structures received over a network or data link can be cached in RAM within a network interface module (e.g., a network interface card or "NIC") and then ultimately transferred to computer system RAM and / or less volatile computer storage media at the computer system. Thus, it should be understood that computer storage media can be included in computer system components that also (or even primarily) utilize transmission media.

[0131] Computer executable (or computer interpretable) instructions include, for example, instructions that cause a general-purpose computer, a special-purpose computer, or a dedicated processing device to perform a specific function or group of functions. Computer executable instructions can be, for example, binary code, intermediate format instructions such as assembly language, or even source code. Although the subject matter has been described in a language dedicated to structural features and / or method actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the above-mentioned features or actions. On the contrary, the described features and actions are disclosed as example forms of implementing the claims.

[0132] Those skilled in the art will appreciate that embodiments can be practiced in network computing environments having many types of computer system configurations, including personal computers, desktop computers, laptop computers, message processors, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile phones, PDAs, pagers, routers, switches, etc. Embodiments can also be practiced in distributed system environments where local and remote computer systems linked by a network (by hardwired data links, wireless data links, or by a combination of hardwired and wireless data links) each perform tasks (e.g., cloud computing, cloud services, etc.). In a distributed system environment, program modules may be located in both local and remote memory storage devices.

[0133] The present invention may be implemented in other specific forms without departing from the characteristics of the present invention. The described embodiments are to be considered in all respects as illustrative and not restrictive. Therefore, the scope of the present invention is indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalents of the claims are intended to be included within their scope.

Claims

1. A system for providing auxiliary power to a data center, the data center typically being served by an electric utility, the system comprising: Controller; First module; Second module; a common direct current (DC) bus coupling the first module to the second module; a common alternating current (AC) bus coupling the first module to the second module; as well as An AC circuit breaker is arranged on the AC busbar between the first module and the second module, wherein the controller controls whether the AC circuit breaker is opened or closed, and wherein a default state of the AC circuit breaker is an open state.

2. The system of claim 1, wherein the first module comprises one or more energy sources.

3. The system of claim 2, wherein the one or more energy sources comprise a solid oxide fuel cell (SOFC).

4. The system of claim 1, wherein the second module comprises one or more energy sources.

5. The system of claim 4, wherein the one or more energy sources comprise a solid oxide fuel cell (SOFC).

6. The system of claim 4, wherein the one or more energy sources comprise ultracapacitors.

7. The system of claim 6, wherein the ultracapacitor is connected to a step-up transformer.

8. The system of claim 1, wherein a size of the first module is equal to a size of the second module.

9. The system of claim 1, wherein a size of the first module is different from a size of the second module.

10. The system of claim 1, wherein the first module provides power to the data center in parallel with a utility.

11. A method for operating a group of modules in a grid-following mode, wherein the modules are coupled together using a common alternating current (AC) bus, the method comprising: determining that a power supply utility for a data center is currently available to provide power to the data center; maintaining open a set of circuit breakers on a common AC line coupled to a plurality of modules capable of providing supplemental power to the data center; as well as The plurality of modules are operated in a grid-following mode when the utility is providing power to the data center.

12. The method of claim 11, wherein the plurality of modules provide power to the data center in parallel with the power providing utility. The method of claim 11 , wherein the plurality of modules operate as current sources. The method of claim 11 , wherein the plurality of modules are configurable to operate at different voltage levels. 15 . The method of claim 11 , wherein a first module included in the plurality of modules is connected to a medium voltage side of a step-down transformer.

16. The method of claim 11, wherein direct current (DC) connections of the plurality of modules are interconnected.

17. A method for enabling a group of modules to provide power to a data center, wherein the modules are coupled together using a common alternating current (AC) bus, the method comprising: determining that a power supply utility for a data center is currently unavailable to provide power to the data center; determining that the utility is currently unavailable due to a utility failure; maintaining open a set of circuit breakers on a common AC line coupled to a plurality of modules capable of providing supplemental power to the data center; activating a group of inverters associated with the plurality of modules; as well as The plurality of modules are enabled to provide the power to the data center.

18. The method of claim 17, wherein direct current (DC) connections of the plurality of modules are interconnected. The method of claim 18 , wherein the DC connections of the plurality of modules are connected across the plurality of modules.

20. The method of claim 19, wherein the plurality of modules operate as a pool of scalable DC energy.

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