Microgrid Automatic Load Sharing Control During Off-Grid Standalone Operation

Abstract

To provide methods and systems for managing electric power demand distribution across electric power generators in a microgrid.SOLUTION: The system may include electric power generator clusters each having electric power generators, electric power output units each electrically connected to at least one of the electric power generator clusters, an energy storage unit electrically connected to an electric power output unit, and a control device. The control device may be configured to determine whether an energy availability of the energy storage unit is less than an energy availability threshold, calculate a sharing multiplication factor for an electric power generator cluster in response to determining that the energy availability of the energy storage unit is less than the energy availability threshold, and calculate a sharing electric power demand for the electric power generator cluster using the sharing multiplication factor.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention is directed generally to power generation systems in general, and specifically to microgrids that manage the distribution of power demand across various generators. [Background technology]

[0002] Electrochemical devices, such as fuel cells, can convert energy stored in fuels into electrical energy with high efficiency. In fuel cell systems, such as solid oxide fuel cell (SOFC) systems, an oxidizing stream passes through the cathode side of the fuel cell, and a fuel inlet stream passes through the anode side of the fuel cell. The oxidizing stream is typically air, and the fuel stream can be a hydrocarbon fuel, such as methane, natural gas, pentane, ethanol, or methanol. Fuel cells can transport negatively charged oxygen ions from the cathode flow stream to the anode flow stream, where the ions combine with either free hydrogen or hydrogen in hydrocarbon molecules to form water vapor and / or with carbon monoxide to form carbon dioxide. Excess electrons from the negatively charged ions are returned to the cathode side of the fuel cell through the completed electrical circuit between the anode and cathode, resulting in current flow in the circuit.

[0003] SOFC systems can be used to power many different loads in many different configurations. The variety of potential applications creates a need for SOFC systems and control methods that can be easily adapted for use with a variety of load types in a variety of usage configurations. Summary of the Invention

[0004] Various embodiments may include a microgrid electrically connectable to a load, the microgrid comprising: two or more generator clusters, each having at least one generator, including a first generator cluster having at least a first generator; two or more power output units, each electrically connected to a respective one of the two or more generator clusters, including a first power output unit electrically connected to the first generator cluster; an energy storage unit electrically connected to the first power output unit; and a controller, the controller configured with controller execution code configured to cause the controller to perform operations including determining whether energy utilization of the energy storage unit is less than an energy utilization threshold; calculating a first sharing multiplication factor for the first generator cluster in response to determining that the energy utilization of the energy storage unit is less than the energy utilization threshold; and calculating a shared power demand of the first generator cluster that is less than a distributed power demand using the first sharing multiplication factor.

[0005] Various embodiments may include a method for managing power demand distribution across a plurality of generators in a microgrid electrically connected to a load, the method including: determining whether energy utilization of an energy storage unit electrically connected to a first power output unit of a plurality of power output units is less than an energy utilization threshold; in response to determining that the energy utilization of the energy storage unit is less than the energy utilization threshold, calculating a first sharing multiplication factor for a first generator cluster including at least a first generator of a plurality of generator clusters electrically connected to the first power output unit; and calculating a shared power demand of the first generator cluster that is less than a distributed power demand using the first sharing multiplication factor.

[0006] Various embodiments may include a microgrid electrically connectable to a load, comprising two or more generator clusters each having at least one fuel cell generator, including a first generator cluster having at least a first fuel cell generator, two or more power output units each including an inverter electrically connected to a respective one of the two or more generator clusters, including a first power output unit electrically connected to the first generator cluster, a battery electrically connected to the first power output unit, and a controller. The controller is configured with controller execution code configured to cause the controller to perform operations including: determining whether energy utilization of the battery is less than an energy utilization threshold; calculating a first sharing multiplication factor for the first generator cluster in response to determining that the energy utilization of the battery is less than the energy utilization threshold; calculating a shared power demand of the first generator cluster that is less than a distributed power demand using the first sharing multiplication factor; configuring the first power output unit to output an amount of power received from the first generator cluster that meets the shared power demand; and configuring the first power output unit to output an amount of power received from the battery that is the difference between the distributed power demand and the shared power demand in response to determining that the energy utilization of the energy storage unit is less than an energy utilization threshold. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a fuel cell system according to various embodiments. [Figure 2] FIG. 2 is a schematic cross-sectional side view of a hot box according to various embodiments. [Figure 3A] FIG. 3A is a block diagram of a microgrid that manages power distribution across generators, according to one embodiment. [Figure 3B] FIG. 3B is a block diagram of a microgrid that manages power distribution across generators, according to one embodiment. [Figure 4] FIG. 4 is a graphical illustration of an example contribution multiplication factor function, according to an embodiment. [Figure 5] FIG. 5 is a graphical illustration of power versus time of an example power output of a microgrid managing power demand distribution across generators, according to an embodiment. [Figure 6] FIG. 6 is a process flow diagram for setting the sharing multiplication factors for each cluster of generators in a microgrid, according to one embodiment. [Figure 7] FIG. 7 is a process flow diagram for managing power demand distribution across generators in a microgrid, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Various embodiments are described in detail with reference to the accompanying figures. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts. References to specific examples and embodiments are for illustrative purposes only and are not intended to limit the scope of the claims.

[0009] As used herein, the terms "electric power generator," "power generator," and "generator" are used interchangeably to refer to a generator capable of producing electrical power from any source, such as, for example, a fuel cell, a combustion generator, a photovoltaic cell, a concentrated solar system, a wind turbine, a geothermal turbine, a hydroelectric turbine, a gas turbine, a nuclear reactor, an alternator, an induction generator, etc. Examples given herein with respect to a fuel cell generator do not limit the scope of the claims and description to such types of generators.

[0010] As used herein, the term "energy storage unit" is used to refer to any form of energy storage that can be converted to electrical power, e.g., electrical storage, mechanical storage, electromechanical storage, electrochemical storage, thermal storage, etc. Examples include batteries, capacitors, supercapacitors, flywheels, liquid reservoirs, gas reservoirs, etc. Examples given herein with respect to batteries do not limit the scope of the claims and description to such types of energy storage units.

[0011] Various embodiments include electrical circuits, electrical components, and methods for managing a microgrid to address power demand distribution across multiple generators with unbalanced generating capabilities (i.e., maximum generating capacities). The unbalanced generators can be configured to supply power to power output units, which can be configured to output balanced, e.g., equal, amounts of power in response to the power demand of each power output unit. The generating capacity can be supplemented with energy stored in respective energy storage units, which can be used to supply power to the power output units when power demand exceeds the generating capacity of a given generator. The microgrid can modify the generator output power based on the energy availability (e.g., state of charge, etc.) of the energy storage units so that power demand does not exceed the capacity of the generator.

[0012] Generators, such as solid oxide fuel cell-based generators, connected in parallel equally share the power demand of the electrical loads, also referred to herein as power demand or load demand. In a distributed generator (e.g., grid-parallel) operating mode, the desired method of microgrid control is to keep the power generation level of each generator stable and constant. However, in a stand-alone generator (e.g., off-grid) operating mode, the power generation level is determined by the nature of the electrical load being powered and cannot be controlled by the generator.

[0013] Existing microgrid systems with parallel-connected generators lack a controller with information about the desired distribution of load across generators or clusters of generators. When generators are unevenly distributed across clusters or have different maximum generating capacities, individual generators or clusters are unevenly loaded. In situations where the load demand for each generator or cluster exceeds the generating capacity of the generator or cluster, conventional microgrids demand equal loads from each generator or cluster. This artificially limits the generating capacity of all other generators or clusters in the microgrid to that of the generator or cluster in the microgrid with the lowest generating capacity.

[0014] The embodiments described herein solve the aforementioned problems by dynamically adjusting the sharing multiplication factor for each generator or cluster of generators based on the amount of energy stored by each energy storage unit of the respective generator or cluster.

[0015] When the power demand for a respective generator or cluster of generators exceeds the generating capacity of the generator or cluster of generators, power can be drawn from the energy storage unit. This can occur when the microgrid operates in an off-grid, stand-alone operating mode, where the loads and the microgrid are not electrically connected to the utility grid. The maximum generating capacity of a generator or cluster of generators can be exceeded by an increase in power demand and / or by a decrease in maximum generating capacity due to various generator health factors.

[0016] When the power demand for a respective generator or cluster of generators exceeds the generating capacity of the generator or cluster of generators, stored energy (i.e., power) is drawn from the respective energy storage unit associated with the respective generator or cluster of generators. The power drawn from the energy storage unit reduces the amount of energy stored in the energy storage unit below a predetermined threshold (e.g., the state of charge of a battery, capacitor, or supercapacitor decreases below 100%). In one embodiment, the reduction in stored energy below the threshold causes a modification (e.g., recalculation) of the sharing multiplication factors of different generators or clusters of generators supplying power to a common load.

[0017] The sharing multiplication factor may be dynamically recalculated as a function of the remaining or consumed stored energy (e.g., state of charge) of the energy storage unit and / or set to a fixed value when the remaining or consumed stored energy (e.g., state of charge) reaches a predetermined cutoff value (e.g., when the state of charge reaches a value in the range of 20-90%). The sharing multiplication factor may be used, for example, to operate the generator or generator cluster with the lowest maximum generating capacity in the microgrid at its maximum generating capacity while operating other generators or clusters at a higher power output to still meet load demand. If possible, the microgrid may operate to recharge the energy storage unit to its full storage capacity (i.e., 100% state of charge) after load demand decreases.

[0018] The embodiments described herein can individually control the power output of generators or clusters thereof in a microgrid. By relying on the availability of stored energy in each energy storage unit, the embodiments described herein can dynamically respond to changes in the health state of the generators or clusters thereof, or any other changing generating capacity conditions, without requiring knowledge of the actual health state of the generators or clusters thereof. Furthermore, individually controlling the power output of clusters of generators can increase utilization of the generating capacity of a generator microgrid system by avoiding artificial limitations on the generating capacity of all generators or clusters thereof in a microgrid based on the maximum generating capacity of the generator or cluster of generators with the lowest maximum generating capacity in the microgrid.

[0019] 1 shows an example of a generator including a modular fuel cell system, more fully described in U.S. Patent No. 8,440,362, which is incorporated herein by reference for its description of modular fuel cell systems. The modular system may include modules and components described in the aforementioned patents as well as U.S. Patent No. 9,190,693, which is incorporated herein by reference for its description of modular fuel cell systems. The modular design of the fuel cell system containment enclosure 10 provides for flexible system installation and operation.

[0020] The modular fuel cell system enclosure 10 includes multiple power module housings 12 (containing fuel cell power module components), one or more fuel input (i.e., fuel processing) module housings 16, and one or more power conditioning (i.e., electrical output) module housings 18. For example, the system enclosure can include any desired number of modules, such as 2 to 30 power modules, e.g., 6 to 12 power modules. FIG. 1 shows a system enclosure 10 including six power modules (six modules stacked horizontally), one fuel processing module, and one power conditioning module on a common base 20. Each module can have its own cabinet or housing. Alternatively, the power conditioning and fuel processing modules can be combined into a single input / output module located in a single cabinet or housing 14. For simplicity, each housing 12, 14, 16, 18 will hereinafter be referred to as a "module."

[0021] Although one row of power modules 12 is shown, the system may include more than one row of power modules 12. For example, the system may include two rows of power modules stacked back to back.

[0022] Each power module 12 is configured to house one or more hot boxes 13. Each hot box contains one or more stacks or columns of fuel cells (not shown for clarity), such as, for example, one or more stacks or columns of solid oxide fuel cells having a ceramic oxide electrolyte separated by conductive interconnect plates. Other types of fuel cells, such as PEM, molten carbonate, phosphoric acid, etc., can also be used.

[0023] The modular fuel cell system containment enclosure 10 also includes one or more input or fuel processing modules 16. The modules 16 include cabinets containing components used for fuel pretreatment, such as desulfurization beds. The fuel processing modules 16 can be designed to process different types of fuels. For example, a diesel fuel processing module, a natural gas fuel processing module, and an ethanol fuel processing module can be provided in the same or separate cabinets. Each module can have a different bed composition tailored to a specific fuel. The processing modules 16 can process at least one fuel selected from pipeline natural gas, compressed natural gas, methane, propane, liquid petroleum gas, gasoline, diesel, home heating oil, kerosene, JP-5, JP-8, aviation fuel, hydrogen, ammonia, ethanol, methanol, syngas, biogas, biodiesel, and other suitable hydrocarbon- or hydrogen-containing fuels. If desired, a reformer 17 can be located in the fuel processing module 16. Alternatively, if it is desired to thermally integrate the reformer 17 with the fuel cell stack, a separate reformer 17 can be located in each hot box 13 within each power module 12. Furthermore, if an internal reforming fuel cell is used, the external reformer 17 can be omitted entirely.

[0024] The modular fuel cell system containment enclosure 10 also includes one or more power conditioning modules 18. The power conditioning modules 18 include a cabinet containing components for converting DC power generated by the fuel cell stacks to AC power, electrical connectors for the AC power output to the grid, circuitry for managing electrical transients, and a system controller (e.g., a computer or dedicated control logic device or circuitry). The power conditioning modules 18 can be designed to convert DC power from the fuel cell modules to a variety of AC voltages and frequencies, including 208V, 60Hz; 480V, 60Hz; 415V, 50Hz, and other common voltages and frequencies.

[0025] The fuel processing module 16 and the power conditioning module 18 may be housed in a single input / output cabinet 14. If a single input / output cabinet 14 is provided, the modules 16, 18 may be arranged vertically (e.g., power processing module 16 desulfurization canister / floor above power conditioning module 18 components) or side-by-side within the cabinet 14.

[0026] 1, one input / output cabinet 14 is provided for one row of six power modules 12 arranged side-by-side in a straight line on one side of the input / output module 14. The row of modules may be positioned, for example, adjacent to the building to which the system will power (e.g., with the backs of the module cabinets facing the wall of the building). Although one row of power modules 12 is shown, the system may include two or more rows of modules 12. For example, as described above, the system may include two rows of power modules stacked back-to-back.

[0027] Each of the power modules 12 and input / output modules 14 includes a door 30 (e.g., a hatch, access panel, etc.) to allow access to the module's internal components (e.g., for maintenance, repair, replacement, etc.). According to one embodiment, the modules 12, 14 are arranged in a linear array with doors 30 on only one side of each cabinet, allowing successive rows of systems to be installed end-to-end adjacent to each other. In this manner, the size and capacity of the fuel cell containment enclosure 10 can be adjusted with additional modules 12 or 14 and base 20 with minimal rearrangement of existing modules 12, 14 and base 20. If desired, the doors 30 to the modules 14 can be located on the side of the cabinet rather than the front.

[0028] FIG. 2 shows a plan view of a fuel cell system hot box 13 including a fuel cell stack or column 40. It is understood that the hot box 13 includes a fuel cell stack or column 40. However, the hot box 13 may include more than one stack or column 40. The stack or column 40 may include fuel cells 45 stacked and electrically connected together with interconnects 50 disposed between the fuel cells 45. The first and last fuel cells 45 of the stack or column are disposed between respective end plates 60 and interconnects 50. The end plates 60 are electrically connected to the electrical outputs of the fuel cell stack or column 40. The hot box 13 may include other components, such as fuel conduits, air conduits, seals, electrical contacts, etc., and may be incorporated into a fuel cell system including balance-of-plant components. The fuel cells 45 may be solid oxide fuel cells including a ceramic electrolyte, such as yttria-stabilized zirconia (YSZ) or scandia-stabilized zirconia (SSZ), an anode electrode, such as nickel-YSZ, Ni-SSZ, or nickel-samaria-doped ceria (SDC) cermet, and a cathode electrode, such as lanthanum strontium manganite (LSM). The interconnects 50 and / or end plates 60 may comprise any suitable gas-impermeable, electrically conductive material, such as a chromium-iron alloy, e.g., 4-6 wt% iron, the remainder chromium. The interconnects 50 electrically connect adjacent fuel cells 45 and provide channels for fuel and air to reach the fuel cells 45.

[0029] A fuel cell system, such as the modular fuel cell system containment enclosure 10, may include and / or be enhanced by various support equipment. The support equipment may include various auxiliary equipment and systems to support the operation of the fuel cell system. The support equipment may vary based on the constraints and / or characteristics of the site where the fuel cell system is installed. By way of non-limiting example, the support equipment may include fuel support equipment, air support equipment, and / or ventilation support equipment. One type of fuel support equipment may include equipment configured to control supply and / or exhaust fuel pressure within the fuel cell system, such as a fuel blower or pump for supplying fuel to the fuel cell system, recirculating fuel / exhaust gas through the fuel cell system, and / or exhausting fuel from the fuel cell system. Another type of fuel support equipment may be configured to process fuel for the fuel cell system, such as a fuel preheater, exhaust scrubber, etc. Other types of fuel support equipment may also be used. One type of air support equipment may be air supply equipment configured to supply air to and / or exhaust air from the fuel cell system, such as a blower or fan for providing air to and / or exhausting air from the fuel cell cathode, anode tail gas oxidizer (ATO), air heat exchanger, CPOx reactor, etc. Other types of air support equipment may also be used. One type of ventilation support equipment may include equipment configured to ventilate and / or circulate air through a portion of the housing external to the hot box (e.g., a portion inside the modular fuel cell system containment enclosure 10 but outside the hot box 13 itself), such as a ventilation fan for blowing air from the interior of the containment enclosure 10 to the exterior of the containment enclosure 10 to maintain an acceptable containment enclosure 10 pressure. Other types of ventilation support equipment may also be used.

[0030] 3A and 3B illustrate different embodiments of a microgrid configured to manage power demand distribution across different generators or clusters thereof. The microgrid may include various components, including any number and combination of generator clusters 300, generators 302, power output units 304, energy storage units 306, a power generator bus 310, an energy storage unit bus 312, and an electrical load bus 316.

[0031] Each generator cluster 300 may include one or more generators 302. The generators 302 may include a fuel cell module or system, a combustion generator, a photovoltaic cell, a concentrated solar system, a wind turbine, a geothermal turbine, a hydroelectric turbine, a gas turbine, a nuclear reactor, an alternator, or an induction generator. In one embodiment, the generator 302 may comprise one fuel cell power module 12 described above with respect to FIG. 1 . In this embodiment, the generator cluster 300 includes all fuel cell generator modules 12 in one system enclosure 10. All generator modules 12 in one system enclosure 10 are electrically connected to the same power output unit 304, including the inverter, using a DC bus 310. In another embodiment, the generator 302 may include all power modules 12 in one system enclosure 10. In this embodiment, the generator cluster 300 includes two or more system enclosures 10, electrically connected to the same power output unit 304, including the inverter, using a DC bus 310.

[0032] The energy storage unit 306 may include at least one battery, capacitor, supercapacitor, flywheel, liquid reservoir, or gas reservoir. In one embodiment, the energy storage unit 306 includes a battery bank, a capacitor bank, or a supercapacitor bank. Each power output unit 304 is electrically connected to a respective cluster 300 and at least one respective energy storage unit 306. Each respective energy storage unit 306 may be physically located within or outside of a respective cluster 300, as long as the energy storage unit 306 and each cluster 300 are electrically connected to the same power output unit 304. In the case of the fuel cell generator 302 shown in FIG. 1 , the energy storage unit 306 may be located within the same system enclosure 10 as the power modules 12, or may be located outside the system enclosure 10.

[0033] The power output unit 304 may be configured as and / or include a DC / AC inverter, an AC / DC rectifier, a DC / DC converter, and / or an AC / AC transformer. For example, the power output unit 304 may be an uninterruptible power module configured as and / or including a DC / AC inverter and configured to invert DC power received from the generator cluster 300 and / or the energy storage unit 306 into AC power. The power output unit 304 may be unidirectional and configured to receive DC power from the generator cluster 300 at an input end and provide AC power to the load 308 at an output end. The power output unit 304 may be electrically connected to each generator cluster 300 and each energy storage unit 306 via a respective generator bus 310 and may be electrically connectable to the electrical load 308 via an electrical load bus 316.

[0034] Each generator bus 310 may be configured as a common conduit for one or more generator clusters 300 and power output units 304. The generator bus 310 may be a DC bus configured to transfer DC power between the generator clusters 300 and the power output units 304.

[0035] Each energy storage unit bus 312 may be a DC bus configured to transfer DC power between the energy storage units 306 and the generator bus 310. Alternatively, the energy storage unit bus 312 may be connected directly to the power output units 304 rather than to the generator bus 310.

[0036] The electrical load bus 316 may be configured as a common electrical conduit for the power output units 304. The electrical load bus 316 may be an AC bus configured to transfer power between the power output units 304 and the electrical loads 308. The electrical load bus 316 may electrically connect each output end of the power output units 304 to the electrical loads 308.

[0037] The loads 308 may include any suitable electrical loads, such as, for example, one or more buildings, one or more factories, one or more data centers, one or more pieces of electrical equipment, etc. The maximum generating capacity of all the generators 302 in a single generator cluster 300 may be insufficient to generate enough electrical power to meet at least the normal electrical demands of the electrical loads 308. However, the number of generators 302 deployed in two or more generator clusters 300 of the microgrid must be sufficient to generate enough electrical power to meet at least the normal electrical demands of the electrical loads 308.

[0038] At any point in time, the loads 308 generate a total power demand at all power output units 304 of the microgrid, which is distributed among the power output units 304 of the microgrid that are electrically connected to the electrical loads 308. As used herein, "distributed power demand" may be an equal distribution (i.e., portion) of the power required to meet the power demand of the power loads 308 to each power output unit 304 and its associated (i.e., electrically connected) generator cluster 300 and / or energy storage unit 306. In some embodiments, such as during normal operation of the generator clusters 300 described further herein, the distributed power demand may be the power demand of the power loads 308 divided by the number of power output units 304 and / or associated clusters 300. For example, if there are two power output units 304 and associated clusters 300 in a microgrid, the distributed power demand of each output unit 304 is half of the total power demand of the loads 308. In some embodiments, the distributed power demand may be greater than the power demand of the power load 308 to make up for a shortfall in providing power from at least one power output unit 304 and / or associated cluster 300, such as during abnormal operation of the generator cluster 300 as described further herein.

[0039] The controller 314 then determines the shared power demand using the allocated power demand and the sharing multiplication factor. Specifically, the shared power demand may be the product of the allocated power demand and the sharing multiplication factor, as discussed in more detail below. Each cluster 300 receives its shared power demand and, in response, outputs an amount of power (e.g., current) that meets its shared power demand. In one embodiment, if no power is drawn from the energy storage unit 306, the sum of all shared power demands (and thus the total output power of all clusters 300 of the microgrid) equals the total power demand of the loads 308.

[0040] In various embodiments, the number of generators 302 can include any number of redundant generators 302 such that in the event of reduced or no electrical output from at least one generator 302, the redundant generators 302 can be used to continue supplying the electrical needs of the electrical loads 308. In some embodiments, the microgrid can include any number and combination of generator clusters 300, generators 302, and / or energy storage units 306. The electrical power output units 304 can be electrically connected at the input end to the respective clusters 300 and energy storage units 306 via a generator bus 310 and / or an energy storage unit bus 312.

[0041] For example, a microgrid may include any number “M” of generator clusters 300, where M is a positive integer greater than 1, such as between 2 and 20, e.g., between 2 and 6. Each generator cluster 300 may include any number of generators 302. In some embodiments, at least one of the generator clusters 300 may include any number “N” of generators 302, and at least another of the generator clusters 300 may include any number “Q” of generators 302, where N and Q are positive integers between 1 and 12, e.g., between 5 and 8. In one embodiment, N and Q are unequal. In another embodiment, N and Q are equal, but the N generators 302 in one cluster 300 have a different maximum generating capacity than the Q generators in the other cluster 300. Thus, the number of generators 302 in each generator cluster 300 and / or their maximum generating capacities may vary among the various generator clusters 300.

[0042] A microgrid may include any number “R” of power output units 304, each electrically connected between a respective cluster 300 and an electrical load 308. In some embodiments, a microgrid may include a one-to-one ratio of generator clusters 300 to power output units 304, such that R=M.

[0043] A microgrid can include any number “V” of energy storage units 306, where V is a positive integer between 2 and 20, e.g., between 3 and 6. In some embodiments, a microgrid can include at least one energy storage unit 306 per generator cluster 300 and / or power output unit 304, such that V is greater than or equal to M.

[0044] The microgrid may include any number of control devices (also referred to herein as controllers) 314 configured to receive data signals from and send control signals to any number and combination of microgrid components via any number “T” of wired and / or wireless connections A1 through AT. The control devices 314 may be any form of programmable computing device or system, such as a server or system controller, and may be configured to perform the operations of various embodiments, including the operations of methods 600 and 700 described herein with reference to FIGS. 6 and 7. The microgrid may be electrically connectable to electrical loads 308 configured to operate using power provided by the microgrid. Each power output unit 304 may be configured to supply the same amount of power to the electrical loads 308 via an electrical load bus 316.

[0045] In some embodiments, the controller 314 may be a central controller 314 configured to communicatively connect to any number and combination of microgrid components. In some embodiments, the controller 314 may be a plurality of distributed controllers 314 configured to communicatively connect to any number and combination of microgrid components. In some embodiments, the controller 314 may be a stand-alone controller for the microgrid. In some embodiments, the controller 314 may be an integrated controller for any number and combination of microgrid components. Any number and combination of the above configurations of controller 314 may be implemented in a microgrid.

[0046] The controller 314 can directly measure and / or read the received signals as the energy utilization of the energy storage unit 306. For example, the controller 314 can directly measure and / or read the received signals from the energy storage unit 306, the generator bus 310, the energy storage unit bus 312, and / or the power output unit 304. The controller 314 can determine the energy utilization of the energy storage unit 306 from the measurement and / or reading of the received signals. The energy utilization can be determined based on one or more parameters, such as, for example, the state of charge or impedance (e.g., in the case of a battery, capacitor, or supercapacitor), frequency, speed (e.g., in the case of a flywheel), or temperature, volume, or pressure (e.g., in the case of a gas or liquid storage device) of the energy storage unit 306. The term energy utilization includes the amount of stored energy remaining in the energy storage unit 306. The state of charge can be a measure of the remaining charge or the amount of charge drawn (i.e., 100% minus the percent charge remaining).

[0047] The controller 314 may further determine whether the energy utilization of the energy storage unit 306 is below an energy utilization threshold. In some embodiments, the energy utilization threshold may be 100% and / or near 100% of the energy storage capacity of the energy storage unit 306. The controller 314 may compare the energy utilization of the energy storage unit 306 to the energy utilization threshold to determine whether the energy utilization is below the energy utilization threshold. For example, if the energy utilization is below 100% of the energy storage capacity of the energy storage unit 306, the controller determines that power is being drawn from the energy storage unit 306 and the energy utilization is below the energy utilization threshold. Alternatively, the energy utilization threshold may be less than 100% of the energy storage capacity of the energy storage unit 306, such as between 20% and 90%, such as between 50% and 80%, etc.

[0048] In response to determining that the energy utilization of the energy storage units 306 does not reach the energy utilization threshold, the controller 314 may signal and / or control each power output unit 304 to modify its allocated power demand by changing and applying a sharing multiplication factor to reduce the shared power demand for the generator cluster 300 of the power output units 304 that had to resort to drawing power from their associated energy storage units 306.

[0049] In some embodiments, in response to determining that the energy utilization of the energy storage units 306 does not reach the energy utilization threshold, the controller 314 may further signal and / or control each power output unit 304 to modify its distributed power demand by increasing its distributed power to make up for the shortfall in supplying power from the generator cluster 300 of the power output unit 304 that had to resort to drawing power from its associated energy storage unit 306.

[0050] The shared power demand may be a portion (i.e., a fraction) of the distributed power demand or may be equal to the distributed power demand. In response to determining that the energy utilization of the energy storage unit 306 is not below the energy utilization threshold, the controller 314 may signal and / or control the respective power output unit 304 to provide the distributed power demand to the associated generator cluster 300. Alternatively, under abnormal operation of the generator cluster 300, the energy utilization of the energy storage unit 306 may not reach the energy utilization threshold because the energy storage unit 306 may output power to make up for the amount of power needed to meet the distributed power demand that the generator cluster 300 may not be able to supply. The controller 314 may signal and / or control the power output unit 304 to provide the distributed power demand to the associated generator cluster 300, while the energy utilization of the associated energy storage unit 306 remains below the energy utilization threshold. The controller 314 can determine and dynamically adjust the sharing multiplication factor over time based on the energy utilization of the energy storage unit 306 .

[0051] Controlling the power output units 304 may enable the power output units 304 to provide enough power to meet the shared power demand, which may be part or all of the same distributed power demand for each power output unit 304 of the microgrid. This control may enable full utilization, or at least higher utilization, of the generating capacity of all generator clusters 300 of the microgrid. Full or higher utilization may be provided by avoiding artificially limiting the higher generating capacity of one generator cluster 300 of the microgrid by another generator cluster 300 in the same microgrid that has a lower generating capacity.

[0052] The embodiments shown in Figures 3A and 3B are described for illustrative purposes and are not meant to limit the scope and disclosure of the claims made herein. These embodiments are herein referred to as a system including two generator clusters 300 (a first generator cluster 300, e.g., generator cluster 1 in Figures 3A and 3B, and a second generator cluster 300, e.g., generator cluster M in Figures 3A and 3B) and their respective generator buses 310 (a first generator bus 310 and a second generator bus 310), two associated energy storage units 306 (a first energy storage unit 306, e.g., energy storage unit 1 in Figures 3A and 3B, and a second energy storage unit 306, e.g., energy storage unit M in Figures 3A and 3B). 3A and 3B) and their respective energy storage unit buses 312 (first energy storage unit bus 312 and second energy storage unit bus 312), and two power output units 304 (first power output unit 304, e.g., power output unit 1 of FIGS. 3A and 3B electrically connected to cluster 1 via first DC bus 310, and second power output unit 304, e.g., power output unit R of FIGS. 3A and 3B electrically connected to cluster M via second DC bus 310). However, it is contemplated that the embodiments shown and described herein are applicable to any number of generator clusters 300 and their respective generator buses 310, energy storage units 306 and their respective energy storage unit buses 312, and / or power output units 304 greater than two.

[0053] The microgrid may include at least a first power output unit 304 and at least a second power output unit 304, each electrically connectable at an output end to a load 308 via an electrical load bus (e.g., AC bus) 316. The first power output unit 304 may be electrically connected at an input end to at least a first generator cluster 300 via at least a first generator bus (e.g., DC bus) 310 and to at least a first energy storage unit 306 via at least a first energy storage unit bus 312. The second power output unit 304 may be electrically connected at an input end to at least a second generator cluster 300 via at least a second generator bus (e.g., DC bus) 310 and to at least a second energy storage unit 306 via at least a second energy storage unit bus 312. The first generator cluster 300 may include a first number of generators 302, represented as "N" in Figures 3A and 3B, and the second generator cluster 300 may include a second number of generators 302, represented as "Q" in Figures 3A and 3B. For purposes of illustration and explanation, N may be less than Q. However, in alternative embodiments, N may be equal to Q and the maximum power capacity of the N generators may be different from the maximum power capacity of the Q generators.

[0054] 3A and 3B, the electrical loads 308 may have a total power demand, represented as "X." The X power demand may indicate to one or more controllers 314 of the microgrid the total amount of power that the electrical loads 308 require from the microgrid.

[0055] The controller 314 may use the X power demand to determine the distributed power demand, represented as "Y" in Figures 3A and 3B, for the generators 302 of each power output unit 304. For example, the Y distributed power demand may be determined by dividing the X power demand by the number of power output units 304, represented as "R" in Figures 3A and 3B. Under normal operation of the generator cluster 300, the power output units 304 may be configured such that the power output of each power output unit 304, represented as "PO" in Figures 3A and 3B, is equal to one another and is the Y distributed power demand.

[0056] Each of the generators 302 may have a generator output, represented by "PG" in Figures 3A and 3B, and an equal or approximately equal maximum power generation capacity, represented as "PG Max" in Figures 3A and 3B. As noted above, in alternative embodiments, the PG Max of the generators may not be equal. Each of the energy storage units 306 may have an energy availability, represented by "A" in Figures 3A and 3B, and an energy storage unit output, represented by "ES" in Figures 3A and 3B.

[0057] Using the A energy availability of the energy storage unit 306, the controller 314 can determine a sharing multiplication factor, represented as "S" in Figures 3A and 3B, for each power output unit 304. Thus, the controller 314 can use the A energy availability of the first energy storage unit 306 to determine the S sharing multiplication factor for the first power output unit 304. The controller 314 can use the A energy availability of the second energy storage unit 306 to determine the S sharing multiplication factor for the second power output unit 304.

[0058] The controller 314 may determine the shared power demand of the generator cluster 300 of each power output unit 304 by multiplying the S sharing multiplication factor by the Y distributed power demand using the S sharing multiplication factor. The S sharing multiplication factor may be such that under normal operation of the generator cluster 300, the shared power demand is equal to the Y distributed power demand when the A energy availability is greater than or equal to the energy availability threshold. Alternatively, the S sharing multiplication factor may be such that under abnormal operation of at least one generator cluster 300, the shared power demand is less than the Y distributed power demand when the A energy availability is less than the energy availability threshold. In such a case, the P0 power output of each power output unit 304 may be the shared power demand combined with the E1 energy storage unit output of each energy storage unit 306 without limiting the power output of other clusters 300 electrically connected to the other electrical output units 304 in the microgrid.

[0059] For generator clusters 300 when at least one cluster 300 is under abnormal operation, the controller 314 can continuously and / or repeatedly calculate the Y distributed power demand, which may change over time. The controller 314 can continuously and / or repeatedly increase the Y distributed power demand of each generator cluster 300 under abnormal operation and decrease the S sharing multiplication factor until the cluster 300 can support the X power demand without the support of the energy storage unit 306. For example, if under abnormal operation the generator cluster 300 supports the cluster's 300 shared power demand without the support of the associated energy storage unit 306, and under normal operation the generator cluster 300 supports the Y distributed power demand, the cluster 300 can support the X power demand without the support of the energy storage unit 306. The shared power demand and the Y distributed power demand can be combined to support the X power demand. At such a point, the A energy utilization of the energy storage unit 306 can become uniform.

[0060] 3A illustrates an example of a microgrid managing power demand distribution across generators 302 under normal operation of generator clusters 300. The power output units 304 may be controlled and / or signaled by a controller 314 to provide a P0 power output equal to their respective shared power demands. The controller 314 may determine the shared power demand of the generators 302 of each generator cluster 300 to be equal to the Y-distributed power demand and equal to the other shared power demands of all generator clusters 300 under normal operation.

[0061] As described herein, under normal operation of the generator clusters 300, the generators 302 of the generator clusters 300 can provide sufficient PG generator output to meet the Y distributed power demand. Thus, the PG MAX maximum power generation capacity of any generator 302 may be equal to or greater than the Y distributed power demand divided by the number of generators 302 in the generator cluster 300. The PG generator output of any generator 302 may be controlled and / or signaled by the controller 314 to be equal to the Y distributed power demand divided by the number of generators 302 in the respective generator cluster 300. The PG generator output of the generators 302 of the first generator cluster 300 may be equal to the Y distributed power demand divided by the N generators 302. The PG generator output of any generator 302 of the second generator cluster 300 may be equal to the Y distributed power demand divided by the Q generators 302.

[0062] As a result of the generator cluster 300 satisfying the Y distributed power demand, the energy storage unit 306 may have no ES energy storage unit output and / or negligible ES energy storage unit output and may maintain an A energy utilization level that is equal to or greater than the energy utilization threshold. The first energy storage unit 306 and the second energy storage unit 306 may have no ES energy storage unit output and / or negligible ES energy storage unit output. The controller 314 may measure and / or read the received A energy utilization signals of the first energy storage unit 306 and the second energy storage unit 306, compare the A energy utilization level to the energy utilization threshold, and determine that the first energy storage unit 306 and the second energy storage unit 306 maintain an A energy utilization level that is equal to or greater than the energy utilization threshold.

[0063] Using the A energy availability of each of the energy storage units 306, the controller 314 can determine, control, and / or signal the shared power demand of the generators 302 of each generator cluster 300 to be the same for all clusters 300 and equal to the Y distributed power demand. The controller 314 can use the respective A energy availability to determine the S sharing multiplication factor of each power output unit 304. Under normal operation of the generator clusters 300, the S sharing multiplication factor, when used to generate the shared power demand, can be such that the resulting shared power demand can be equal to the Y distributed power demand. The shared power demand of the generators 302 of the first generator cluster 300 and the second generator cluster 300 can be determined, controlled, and / or signaled to be the same and equal to the Y distributed power demand.

[0064] The power output units 304 may be controlled and / or signaled by the controller 314 to provide a P O power output equal to the Y distributed power demand. The first power output unit 304 and the second power output unit 304 may be controlled and / or signaled to provide a P O power output equal to their respective shared power demand, which may be equal to the Y distributed power demand. Under normal operation of the generator cluster 300, the P O power output of the power output units 304 may be a combination of the P G generator output of each generator 302 and no and / or little E S energy storage unit output of each energy storage unit 306, equal to the shared power demand.

[0065] For example, if the total load 308 demand X is 180 kW during a normal mode of microgrid operation, then the Y distributed power demand for each of two clusters 300 (e.g., cluster 1 and cluster M of a two-cluster 300 microgrid) is 90 kW (i.e., 180 / 2). If the PG Max of each generator 302 in both clusters 1 and M is 45 kW, and there are two generators in cluster 1 (i.e., N=2) and three generators in cluster M (i.e., Q=3), then the shared power demand for the first cluster 300 (e.g., cluster 1) and its associated power output unit 304 (e.g., unit 1) is 90 kW. Each generator 302 in the first cluster 1 outputs its PG Max of 45 kW of power (i.e., 45 kW x 2 = 90 kW) to meet its shared power demand. Thus, the shared power demand of the first cluster 1 is equal to the Y distributed power demand. The S sharing multiplication factor of the first cluster 1 and the first power output unit 1 is 100% (i.e., equal to 1). For the first energy storage unit 1 associated with the first cluster 1 and the first power output unit 1, the value of A is 100% and the value of ES=0.

[0066] Similarly, the shared power demand for a second cluster 300 (e.g., cluster M) and its associated power output unit 304 (e.g., unit R) is also 90 kW. Each generator 302 in the second cluster M outputs 30 kW of power (i.e., 30 kW x 3 = 90 kW) to meet the 90 kW shared power demand. Therefore, each generator 302 in the second cluster M outputs a PG that is 2 / 3 of its PG Max of 45 kW. The shared power demand of the second cluster M is also equal to the Y distributed power demand. The S sharing multiplication factor of the second cluster M and the second power output unit R is also 100% (i.e., equal to 1). For the second energy storage unit V associated with the second cluster M and the second power output unit R, the value of A is 100% and the value of ES=0.

[0067] 3B illustrates an example of a microgrid that manages power demand distribution across generators 302 under a mixture of normal and abnormal operation of the generator clusters 300. The power output units 304 may be controlled to provide a P0 power output equal to their respective shared power demands. The controller 314 may determine the shared power demand of the generators 302 of each generator cluster 300 under normal operation to be equal to the Y shared power demand and equal to the other shared power demands of all generator clusters 300. The controller 314 may determine the shared power demand of the generators 302 of each generator cluster 300 under abnormal operation to be a fraction of the Y shared power demand.

[0068] The second generator cluster 300 may operate under normal operation and may be as described herein with reference to FIG. 3A . The first generator cluster 300 may operate under abnormal operation. Under abnormal operation of one or more generator clusters 300, the generators 302 of the generator cluster 300 may provide insufficient PG generator output to meet the Y-distributed power demand. Therefore, the PG MAX maximum power generation capacity of any generator 302 may be less than the Y-distributed power demand divided by the number of generators 302 in the generator cluster 300. The PG generator output of any generator 302 may be controlled and / or signaled by the controller 314 to be the PG MAX maximum power generation capacity of each respective generator 302. The PG generator output of any generator 302 of the first generator cluster 300 may be the PG MAX maximum power generation capacity of each respective generator 302.

[0069] As a result of the Y distributed power demand not being met by the first generator cluster 300 of the microgrid, the first energy storage unit 306 may have an ES energy storage unit output and may have an A energy availability that is less than the energy availability threshold. The controller 314 may measure and / or read the received A energy availability signal of the first energy storage unit 306 and compare the A energy availability to the energy availability threshold to determine that the first energy storage unit 306 may have an A energy availability that is less than the energy availability threshold.

[0070] Using the A energy availability of each of the energy storage units 306, the controller 314 can determine, control, and / or signal the shared power demand of the generators 302 of each generator cluster 300. The controller 314 can use the respective A energy availability to determine the S sharing multiplication factor of each power output unit 304. Under abnormal operation of one or more generator clusters 300, the sharing multiplication factor may be such that, when used to generate the shared power demand, the resulting shared power demand may be less than the Y distributed power demand. Thus, in certain embodiments, the shared power demand of the generators 302 of the first generator cluster 300 may be determined, controlled, and / or signaled to be less than the Y distributed power demand.

[0071] The power output units 304 may be controlled and / or signaled by the controller 314 to provide a P O power output equal to the Y distributed power demand. The first power output unit 304 may be controlled and / or signaled to provide a P O power output equal to its respective shared power demand, which may be less than the Y distributed power demand. Under abnormal operation of the generator cluster 300, the P O power output of the power output unit 304 may be a combination of the P G generator output of each generator 302 and the E S energy storage unit output of each power storage device 306 that is equal to its shared power demand. The first power output unit 304 may output a combination of the P G generator output of the generator 302 of the first power output unit 304 and the E S energy storage unit output of the first energy storage unit 306 that is equal to its shared power demand.

[0072] The shared power demand of the power output units 304 under abnormal operation may be adjusted continuously and / or repeatedly until the A energy utilization of the associated energy storage units 306 is equalized. The shared power demand of the power output units 304 under normal operation may also be adjusted continuously and / or repeatedly until the A energy utilization of the energy storage units 306 associated with the power output units 304 under abnormal operation is equalized. The shared power demand may be adjusted by changing the Y distributed power demand of all power output units 304 and the S sharing multiplication factor of the power output unit 304 under abnormal operation.

[0073] For example, the shared power demand of a first power output unit 304 (e.g., power output unit 1) and a second power output unit 304 (e.g., power output unit R) may be adjusted until the A energy availability of the first energy storage unit 306 (e.g., energy storage unit 1) associated with the first power output unit 1 is equalized. More specifically, if the total load 308 demand X is 215 kW during an abnormal mode of microgrid operation, the Y distributed power demand in each of the two clusters 300 (e.g., cluster 1 and cluster M in a two-cluster 300 microgrid) is 107.5 kW (i.e., 215 / 2). The PG Max of each generator 302 in both clusters 1 and M is 45 kW, and cluster 1 has two generators (i.e., N=2) and cluster M has three generators (i.e., Q=3).

[0074] The sum of the PG Max of all generators 302 in first cluster 1 is 90 kW, which is less than the Y-distributed power demand of 107.5 kW. This causes power to be drawn from first energy storage unit 1, which causes the output of ES energy storage unit 1 to be greater than zero and the A energy utilization to be less than 100%. This drawing of power from first energy storage unit 1 triggers controller 314 to recalculate the S-sharing multiplication factor for first output unit 1 and its associated first cluster 1 to be less than 1. The drawing of power from first energy storage unit 1 triggers controller 314 to recalculate the Y-distributed power demand, increasing the Y-distributed power demand to make up for the shortfall of first cluster 1 in supplying the previous Y-distributed power demand.

[0075] The sum of PG Max of all generators 302 in the second cluster M is 135 kW, which is greater than the Y distributed power demand of 107.5 kW. There is no need to draw power from the second energy storage unit V. Therefore, for the second energy storage unit V, the ES energy storage unit output is zero or slightly above zero, and A may be 100% or approximately 100%. The S sharing multiplication factor for the second cluster M may be 100%. The controller 314 does not trigger further recalculation of the Y distributed power demand and S sharing multiplication factor for the second cluster M based on these ES energy storage unit outputs, and the A energy availability value persists for the second energy storage unit V.

[0076] Once the Y allocated power demands of both the first cluster 1 and the second cluster M and the S sharing multiplication factor of the first cluster 1 have been recalculated, the controller may repeatedly or continually determine whether the first cluster 1 and the second cluster M match their respective shared power demands. Recalculating the Y allocated power demands and / or the S sharing multiplication factor may continue until the A energy utilization of the first energy storage unit 1 equalizes. At which point the A energy utilization of the first energy storage unit 1 equalizes, the first cluster 1 and the second cluster M can meet their respective shared power demands and no power drawing from the first energy storage unit 1 is required.

[0077] Continuing with the example, recalculating the Y allocated power demand may ultimately set the Y allocated power demand to 125 kW. Recalculating the S shared power multiplication factor may ultimately set the S shared power multiplication factor to 72% (i.e., 0.72) for the first output unit 1 and its associated first cluster 1, resulting in a shared power output equal to PG Max (i.e., 90 kW). In other words, multiplying the Y allocated power demand (i.e., 125 kW) by the S shared power multiplication factor (i.e., 0.72) results in a shared power output of 90 kW, which is equal to PG Max for the first cluster 1 and its associated power output unit 1. However, in alternative embodiments, the calculation of S may be configured such that the shared power output is set to a fixed, predetermined value that is less than PG Max.

[0078] In contrast, the Y distributed power demand (i.e., 125 kW) is less than the sum of the PG Max of all generators in the second cluster M (i.e., 45 + 45 + 45 = 135 kW). Therefore, the second cluster M and its associated power output units R continue to operate in normal mode because no power is drawn from the associated energy storage units V and the energy utilization of A is at or near 100%. The shared power demand of the second cluster M and its associated power output units R is also 125 kW. Each generator 302 in the second cluster M outputs 41.6 kW of power (i.e., 41.6 kW x 3 = 125 kW), satisfying both its shared power demand and its Y distributed power demand of 125 kW. Therefore, each generator 302 in the second cluster M outputs a PG generator output that is 92.4% of the PG Max generator output of 45 kW. The shared power demand for the second cluster M is equal to the distributed power demand. The S sharing multiplication factor of the second cluster M and the second power output unit R is also 100% (i.e., equal to 1). For the second energy storage unit V associated with the second cluster M and the second power output unit R, the value of A energy utilization is 100% and the value of ES energy storage unit output=0.

[0079] FIG. 4 illustrates an example sharing multiplication factor function, according to some embodiments. Graph 400 illustrates the relationship between the energy utilization of the energy storage unit 306 ("Energy Storage Available" along the horizontal axis of graph 400 in FIG. 4) and the sharing multiplication factor ("Sharing Multiplication Factor" along the vertical axis of graph 400 in FIG. 4) determined by the controller 314. Plot 402 may represent the sharing multiplication factor function plotted on graph 400. In some embodiments, plot 402 may represent the sharing multiplication factor function of the generators 302 of the generator cluster 300 associated with the energy storage unit 306 and the power output unit 304. In some embodiments, the sharing multiplication factor function may be implemented by the controller 314.

[0080] In this example, the function of the sharing multiplication factor may plot a point 404 where the energy utilization of the energy storage unit 306 may be equal to or greater than an energy utilization threshold, such as and / or approximately the energy storage capacity of the energy storage unit 306. In some embodiments, the energy utilization threshold may be 100% and / or approximately 100% of the energy storage capacity of the energy storage unit 306. In alternative embodiments, this threshold may be less than 100%, such as 20-90%. Further, at point 404, the sharing multiplication factor may be configured to generate a shared power demand equal to the allocated power demand of the generator 302. For example, the sharing multiplication factor may be 100%, and the shared power demand calculated using the allocated power demand and the sharing multiplication factor may be equal to the allocated power demand.

[0081] The remainder of the plot 402 may represent energy utilization values ​​for the energy storage units 306 that are below the energy utilization threshold, which may indicate to the controller 314 that the generators 302 in a given cluster 300 may not be able to support the distributed power demand. Thus, the controller 314 may determine a shared power demand for the generators 302 that is less than the distributed power demand.

[0082] The function of the sharing multiplication factor may include a line 406 in which a decreasing energy utilization of the energy storage unit 306 below an energy utilization threshold may correlate with a decreasing sharing multiplication factor. Similarly, for line 406, an increasing energy utilization of the energy storage unit 306 below an energy utilization threshold may correlate with an increasing sharing multiplication factor. When the energy utilization of the energy storage unit 306 remains below the energy utilization threshold, the sharing multiplication factor may be configured to generate a shared power demand that is less than the allocated power demand of the generator 302. When the energy utilization of the energy storage unit 306 decreases and / or the allocated power demand of the generator 302 increases, the sharing multiplication factor decreases. The shared power demand calculated using the allocated power demand and the sharing multiplication factor may be less than the allocated power demand. For example, the energy utilization of the energy storage unit 306 may be less than 100% and greater than 85%, while the sharing multiplication factor may be less than 100% and greater than 25%. 3B, if the controller determines that the energy utilization of the first energy storage unit 306 is, for example, 89.2%, then the sharing multiplication factor for the first cluster 300 will be 72% based on the slope of line 406. Thus, the S sharing multiplication factor can dynamically change for a range of energy utilization values ​​based on the slope of line 406.

[0083] The function of the sharing multiplication factor may include a point 408 at which the energy utilization of the energy storage units 306 may be equalized. The energy utilization of the energy storage units 306 may be equalized when the generators 302 of the cluster 300 can meet their respective shared power demands without having to draw power from the energy storage units 306. For example, the point 408 at which the energy utilization of the energy storage units 306 may be equalized may be 85% and / or approximately 85% of the energy storage capacity of the energy storage units 306. In some embodiments, at point 408, the sharing multiplication factor may be a fixed value configured to generate a shared power demand that is less than the allocated power demand of the generators 302. For example, the sharing multiplication factor may be 25% and / or approximately 25%, and the shared power demand calculated using the allocated power demand and the sharing multiplication factor may be less than the allocated power demand.

[0084] 4 is for illustrative and descriptive purposes and does not limit the scope of the claims and specification to the values ​​of this example. The function of the sharing multiplication factor may be any function configured to relate the energy utilization of the energy storage unit 306 below the energy utilization threshold to the sharing multiplication factor such that the shared power demand calculated using the allocated power demand and the sharing multiplication factor may be less than the allocated power demand. Furthermore, it is contemplated that the energy utilization threshold, the leveling point of the energy utilization of the energy storage unit 306, and / or the fixed sharing multiplication factor may be any value and may depend on variations in application and implementation.

[0085] FIG. 5 illustrates a plot of power versus time for a microgrid managing power demand distribution across generators 302, according to some embodiments. Graph 500 illustrates the power output of various generators 302, the power availability of various energy storage units 306, and the power demand of electrical loads 308 ("power" along the vertical axis of graph 500 in FIG. 5) over time ("time" along the horizontal axis of graph 500 in FIG. 5). Graph 500 illustrates an example of the relationship between the power demand and output of generators 302 and the power availability of associated energy storage units 306 to meet the power demand of the electrical loads 308. Plot 502 represents the total power demand of the electrical loads 308. Plots 504a, 504b, and 506 represent the shared power demand and corresponding power output of a first cluster 300 (e.g., cluster 1). Plots 504a, 504b, and 508 represent the shared power demand and corresponding power output of a second cluster 300 (e.g., cluster M). Plots 510a, 510b, and 512 represent the power utilization of a first energy storage unit 306 (e.g., unit 1). Plots 510a, 510b, and 514 represent the power utilization of a second energy storage unit 306 (e.g., unit V). In some embodiments, power demand 502, shared power demand and power output 504a, 504b, 506, 508, and / or power utilization 510a, 510b, 512, 514 may be measured, read, and / or determined by controller 314.

[0086] In the example of FIG. 5 , the load 308 may be a building that has a higher total power demand during the day than in the morning, evening, or night. A first time 516 corresponds to the beginning of the day (e.g., 7:30 AM), and a second time 518 corresponds to the end of the day (e.g., 4:30 PM). Prior to the first time 516 (i.e., during the night and morning), the power utilization 510a of the first energy storage unit 1 and the second energy storage unit V may be at or above an energy utilization threshold. In some embodiments, the energy utilization threshold may be the energy storage capacity of an individual energy storage unit 306 and / or may be approximately the energy storage capacity (e.g., when no power is drawn from the energy storage unit 306 and the generator 302 alone can meet the total power demand of the load 308). In the example shown in FIG. 5 , the power utilization 510a of the first energy storage unit 306 and the second energy storage unit 306 may be the same and / or approximately the same.

[0087] A first cluster 300 of generators 302 (e.g., cluster 1) and a second cluster 300 of generators 302 (e.g., cluster M) may each have a respective shared power demand represented by curve 504a and equal power output (i.e., P0). The shared power demand 504a of the first cluster of generators 302 and the second cluster of generators 302 may be equal to the distributed power demand, which may be an equal portion of the total load power demand 502. The shared power demand 504a may represent the shared power demand of the first cluster of generators 302 and the second cluster of generators 302 under normal operation. The power demand 504a may be determined by the controller 314 to be the distributed power demand without using a sharing multiplication factor. If a sharing multiplication factor is used to determine the power demand 504a, the controller 314 may use a sharing multiplication factor equal to 1 to generate a shared power demand equal to the distributed power demand.

[0088] Between the first time 516 and the second time 518 (e.g., during the day), the first cluster 300 of generators 302 may operate under abnormal operation when its share of power demand 502 equal to the distributed power demand may exceed the power output capacity of the first cluster 300 of generators 302. When the controller 314 responds to the total power demand 502 of the loads and the shortfall of the first cluster 300 of generators 302 to meet the distributed power demand, the first cluster 300 of generators 302 may be unable to meet the distributed power demand (which may be the same as power demand 508). A first energy storage unit 306 (e.g., unit 1) associated with the first cluster 300 of generators 302 (e.g., cluster 1) may output power to make up the shortfall between the distributed power demand and the power output capacity of the first cluster 300 of generators 302. As a result of outputting power, the power utilization 512 of the first energy storage unit 306 may be reduced below an energy utilization threshold. The controller 314 may determine a new sharing multiplication factor less than one for the first cluster 300 of generators 302 such that the shared power demand is less than the distributed power demand 508 .

[0089] During the same period (e.g., daytime) between the first time 516 and the second time 518, the second cluster 300 of generators 302 (e.g., cluster M) may operate under normal operation and continue to supply power to meet the power demand 508, which may equal the distributed power demand. As the distributed power demand continues to be met, the power availability 514 of the second energy storage unit 306 (e.g., unit V) associated with the second cluster of generators 302 may remain above the energy availability threshold. The power demand and output 508 may be determined by the controller 314 such that the clusters 300 can meet the total power demand 502 with and / or without the aid of the energy storage units 306 using unequal shared power demands for the at least two clusters 300.

[0090] After a second time 518 (e.g., in the evening and night), the first cluster 300 of generators 302 may return to operating under normal operation when its share of power demand 502 equal to the distributed power demand may no longer exceed the power output capability of the first cluster 300 of generators 302 (i.e., the sum of PG Max). The power availability 510b of the first energy storage unit 306 may again be above the energy availability threshold. The power availability 510b of the second energy storage unit 306 may remain above the energy availability threshold.

[0091] The power demand and output 504b of the first cluster 300 of generators 302 may return to equal the distributed power demand, and the power demand and output 504b of the second cluster 300 of generators 302 may remain equal to the distributed power demand. The power demand 504b may represent the power demand of the first cluster 300 of generators 302 and the second cluster 302 of generators 302 under normal operation. The power demand 504b may be determined by the controller 314 in a manner similar to the power demand 504a.

[0092] 6 illustrates a method 600 for setting an S-sharing multiplication factor for each cluster 300 of generators 302 in a microgrid, according to various embodiments. Method 600 may be implemented using one or more controllers 314 configured to receive signals from and / or send control signals to any number and combination of generators 302, generator clusters 300, energy storage units 306, power output units 304, generator bus 310, energy storage unit bus 312, and electrical load bus 316. To encompass alternative configurations possible in various embodiments, hardware implementing method 600 is referred to herein as a “controller.”

[0093] In block 602, the controller may monitor the energy utilization of the energy storage unit 306. In some embodiments, the controller may determine the state of charge of the battery, capacitor, or ultracapacitor energy storage unit 306 using any known state of charge determination method, such as, for example, open circuit voltage measurement, coulomb counting, electrochemical impedance spectroscopy, etc. In some embodiments, the controller may directly measure and / or read the received signal as the voltage and / or current available at the energy storage unit 306. In some embodiments, the received signal may include the power output by the energy storage unit 306. For example, the controller may directly measure and / or read the signal received at and / or from the energy storage unit 306, the energy storage unit bus 312, and / or the DC bus 310, and / or the power output unit 304.

[0094] At decision block 604, the controller may determine whether the energy utilization of the energy storage unit 306 is below an energy utilization threshold. In some embodiments, the controller may determine whether the energy utilization of the energy storage unit 306 is below an energy utilization threshold based on the state of charge and / or power output of the energy storage unit 306. In some embodiments, the controller may measure and / or read the energy utilization of the energy storage unit 306 and compare it to an energy utilization threshold, as discussed further herein with reference to block 606. From the comparison, the controller may determine whether the energy utilization of the energy storage unit 306 is below an energy utilization threshold. In some embodiments, the energy utilization threshold may be 100% and / or nearly 100% of the energy storage capacity of the energy storage unit 306.

[0095] In response to determining that the energy utilization of the energy storage units 306 is less than the energy utilization threshold (i.e., decision block 604="Yes"), the controller may determine, at decision block 606, whether the energy utilization of the energy storage units 306 is equalized. In some embodiments, the controller may determine that the energy utilization of the energy storage units 306 is equalized when the generators 302 of the clusters 300 output enough power to meet their respective shared power demands without drawing power from the energy storage units 306. For example, the shared power demand may be some or all of the allocated power demand calculated by applying a share multiplication factor to the allocated power demand. The controller may compare the maximum generating capacity and / or measured power output of the clusters 300 to their respective shared power demands. The energy utilization of the energy storage units 306 may be equalized when the maximum generating capacity and / or measured power output of the clusters 300 meet and / or exceed their respective shared power demands. In some embodiments, the controller may determine that the energy utilization of the energy storage unit 306 is equalized when the energy utilization reaches a predetermined value.

[0096] In response to determining that the energy utilization of the energy storage unit 306 is equalized (i.e., decision block 606="Yes"), the controller may monitor the energy utilization of the energy storage unit 306 in block 602.

[0097] In response to determining that the energy utilization of the energy storage unit 306 is not equalized (i.e., decision block 606="No"), the controller may determine the amount of energy utilization of the energy storage unit 306 in block 608. The controller may directly measure and / or interpret the received signals as voltage and / or current available at the energy storage unit 306. For example, the controller may determine the energy utilization of the energy storage unit 306 through an electrochemical impedance spectroscopy (EIS) response of a battery, capacitor, supercapacitor, etc., an open circuit voltage state of charge determination method, coulomb counting, etc. As another example, the controller may determine the energy utilization of the energy storage unit 306 as the speed of a flywheel. As another example, the controller may determine the energy utilization of the energy storage unit 306 as the fill volume and / or pressure of a liquid reservoir, gas reservoir, etc. In some embodiments, the function of block 608 may also be performed by the controller at other points in method 600, such as before and / or as part of decision block 604.

[0098] At block 610, the controller may calculate a distributed power demand. As discussed herein, the distributed power demand may be an equal distribution (i.e., a portion) of the power required to meet the power demand of the electrical loads 308 for each power output unit 304 and its associated generator cluster 300 and / or energy storage unit 306. In some embodiments, the distributed power demand may be the power demand of the electrical loads 308 divided by the number of power output units 304 and / or associated clusters 300, such as during normal operation of the generator clusters 300. In some embodiments, the distributed power demand may be greater than the power demand of the electrical loads 308 to compensate for a shortfall in the supply of power from at least one power output unit 304 and / or associated cluster 300, such as during abnormal operation of the generator cluster 300. The controller may modify the previous distributed power demand value by increasing the distributed power to compensate for the shortfall in the supply of power from the generator cluster 300.

[0099] At block 612, the controller may calculate a sharing multiplication factor for the generator 302 of the cluster 300 associated with the energy storage unit 306. The controller may execute a sharing multiplication factor function that may calculate the sharing multiplication factor using the energy availability of the energy storage unit 306. The sharing multiplication factor function may be any function configured to associate energy availability of the energy storage unit 306 that is below an energy availability threshold with a sharing multiplication factor such that the shared power demand of the generator 302, calculated using the product of the allocated power demand and the sharing multiplication factor, is less than the allocated power demand.

[0100] At block 614, the controller may set the sharing multiplication factors for the generators 302 in the cluster 300. The controller may set the sharing multiplication factors using the sharing multiplication factors calculated at block 612. In some embodiments, the controller may set the sharing multiplication factors for the generators 302 at each power output unit 304. In some embodiments, the controller may set the sharing multiplication factors by storing values ​​representing the sharing multiplication values ​​in a memory, such as a cache, buffer, register, etc.

[0101] In response to determining that the energy utilization of the energy storage unit 306 is greater than or equal to the energy utilization threshold (i.e., decision block 604="NO"), the controller may set the sharing multiplication factors for the generators 302 of the cluster at block 616. In some embodiments, the controller may use a default sharing multiplication factor equal to 1 so that the shared power demand of the generators 302 calculated using the product of the allocated power demand and the sharing multiplication factor equals the allocated power demand. In some embodiments, the controller may set the sharing multiplication factors for the generators 302 at each power output unit 304. In some embodiments, the controller may set the sharing multiplication factors by storing values ​​representing the sharing multiplication values ​​in a memory, such as a cache, buffer, register, flag bit, etc.

[0102] 7 illustrates a method 700 for managing power demand and power dispatching across generators in a microgrid, according to various embodiments. Method 700 may be implemented using one or more controllers 314 configured to receive signals from and / or send control signals to any number and combination of generators 302, generator clusters 300, energy storage units 306, power output units 304, generator bus 310, energy storage unit bus 312, and electrical load bus 316. To encompass alternative configurations possible in various embodiments, hardware implementing method 700 is referred to herein as a “controller.”

[0103] In block 702, the controller may monitor the power demand of the electrical loads 308. In some embodiments, the controller may directly measure and / or interpret the received signal as a voltage and / or current of the power demand of the electrical loads 308. In some embodiments, the received signal may include a reference signal on the electrical load bus 316 that electrically connects the microgrid to the electrical loads 308.

[0104] At block 704, the controller may set a distributed power demand. As discussed herein, the distributed power demand may be an equal distribution (i.e., a portion) of the power required to meet the power demand of the electrical loads 308 for each power output unit 304 and its associated generator cluster 300 and / or energy storage unit 306. In some embodiments, the distributed power demand may be the power demand of the electrical loads 308 divided by the number of power output units 304 and / or associated clusters 300, such as during normal operation of the generator clusters 300. In some embodiments, the distributed power demand may be greater than the power demand of the electrical loads 308 to compensate for a shortfall in the supply of power from at least one power output unit 304 and / or associated cluster 300, such as during abnormal operation of the generator cluster 300. The controller may modify the previous distributed power demand value by increasing the distributed power to compensate for the shortfall in the supply of power from the generator cluster 300. In some embodiments, the distributed power demand may be the distributed power demand calculated in block 610 of the method 600 described herein with reference to Figure 6. In some embodiments, the controller may set the distributed power demand for each generator cluster 300 at the respective power output unit 304. In some embodiments, the controller may set the distributed power demand by storing a value representing the distributed power demand in a memory, such as a cache, buffer, register, or the like.

[0105] In block 706, the controller may calculate the shared power demand using the distributed power demand and the sharing multiplication factor. In some embodiments, the distributed power demand may be the distributed power demand set in block 704. In some embodiments, the sharing multiplication factor may be the shared multiplication factor set in block 612 and / or block 614 of method 600 described herein with reference to FIG. 6 . The controller may calculate the shared power demand using the shared multiplication factor and the distributed power demand in a shared power demand function. The shared power demand function may calculate the shared power demand from the shared multiplication factor and the distributed power demand using any number and combination of mathematical and / or logical operations. Under normal operation of the generator 302, the shared power demand may be the distributed power demand. Under abnormal operation of the generator 302, the shared power demand may be less than the distributed power demand.

[0106] At block 708, the controller may set the shared power demand of the generators 302 in the cluster 300. The controller may set the shared power demand of the generators 302 using the calculated shared power demand calculated at block 706. In some embodiments, the controller may set the shared power demand of the generators 302 at each power output unit 304. In some embodiments, the controller may set the shared power demand by storing a value representing the shared power demand in a memory, such as a cache, buffer, register, or the like.

[0107] At block 710, each power output unit 304 may output its share of the power output from the generator 302 to meet its shared power demand. The generator 302 may generate sufficient power to meet its shared power demand. Each power output unit 304 may receive the power generated by the generator 302. Each power output unit 304 may output the power received from the generator 302 to meet its shared power demand.

[0108] In optional block 712, each power output unit 304 may output the difference between its allocated power demand and its shared power demand from its respective energy storage unit 306 to meet the distributed power demand of the generator 302. Each energy storage unit 306 may output sufficient power to meet the difference between its allocated power demand and its shared power demand. Each power output unit 304 may receive the power output by its respective energy storage unit 306. Each power output unit 304 may output the power received from its respective energy storage unit 306 along with its shared power output from the generator 302 to meet the distributed power demand. In some embodiments, optional block 712 may be executed for a generator 302 of a cluster 300 under abnormal operation where the maximum power generating capacity is less than the distributed power demand.

[0109] In some embodiments, methods 600, 700 may be performed serially and / or in parallel. Methods 600, 700 may be performed periodically, repeatedly, and / or continuously.

[0110] The foregoing method descriptions and illustrations are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be understood by one of ordinary skill in the art, the order of steps in the foregoing embodiments may be performed in any order. Furthermore, terms such as "then," "then," and "next" are not intended to limit the order of steps; rather, these terms are used merely to guide the reader through the method descriptions.

[0111] One or more diagrams have been used to describe exemplary embodiments. The use of a diagram does not imply a limitation with respect to the order of operations performed. The foregoing description of exemplary embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to be limiting with respect to the precise form disclosed, but modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed embodiments. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

[0112] The control elements, including the control device 314 and associated controllers described herein, can be implemented using a computing device (e.g., a computer) that includes a programmable processor, memory, and other components programmed with instructions to perform specific functions, or can be implemented with a processor designed to perform a specified function. The processor may be any programmable microprocessor, microcomputer, or multiprocessor chip or chip that can be configured with software instructions (applications) to perform various functions, including the functions of the various embodiments described herein. In some computing devices, multiple processors may be provided. Typically, software applications may be stored in internal memory before being accessed and loaded into the processor. In some computing devices, the processor may include sufficient internal memory to store application software instructions.

[0113] The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, and such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0114] The hardware used to implement the various example logic, logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using controllers that may be or include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Alternatively, some blocks or methods may be performed by circuitry that is specific to a given function.

[0115] The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the described embodiments. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles set forth herein may be applied to other embodiments without departing from the scope of the present disclosure. Thus, the scope of the claims is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the claims and the principles and novel features disclosed herein.

Claims

1. 1. A microgrid electrically connectable to a load, comprising: two or more generator clusters each having at least one generator, including a first generator cluster having at least a first generator; two or more power output units, each electrically connected to a respective one of the two or more generator clusters, including a first power output unit electrically connected to the first generator cluster; an energy storage unit electrically connected to the first power output unit; Control device and Equipped with The control device determining whether an amount of energy available from the energy storage unit is less than an energy amount threshold; responsive to determining that the amount of energy available from the energy storage unit is less than the energy amount threshold, calculating a first sharing multiplication factor for the first generator cluster using the amount of energy available from the energy storage unit; calculating a shared power demand of the first generator cluster using the first share multiplication factor, the shared power demand being less a distributed power demand, which is a power demand of a load divided by the total number of power output units; and setting the distributed power demand of the first generator cluster such that, in response to determining that the amount of energy available from the energy storage unit is less than the energy amount threshold, the first power output unit outputs the power received from the first generator cluster and an amount of power received from the energy storage unit sufficient to satisfy a difference between the distributed power demand and the shared power demand, and, in response to determining that the amount of energy available from the energy storage unit is equal to or greater than the energy amount threshold, the first power output unit outputs an amount of power received from the first generator cluster sufficient to satisfy the distributed power demand; a controller executing code configured to cause the controller to perform operations including:

2. The control device setting the shared power demand of the first generator cluster such that the first power output unit outputs power received from the first generator cluster that satisfies the shared power demand; The microgrid of claim 1 , configured with a controller executing code configured to cause the controller to perform operations further comprising:

3. The control device 2. The microgrid of claim 1, further comprising: controller execution code configured to cause the controller to perform operations in which setting the distributed power demand of the first generator cluster includes setting the distributed power demand to an amount equal to the number of power output units.

4. The control device calculating the first sharing multiplication factor for the first generator cluster; Determining the amount of energy available from the energy storage unit. The microgrid of claim 1 , configured with a controller executing code configured to cause the controller to perform operations including:

5. The control device a controller executing code configured to cause the controller to perform operations further including determining whether an amount of energy available from the energy storage unit is maintained constant; 2. The microgrid of claim 1, wherein calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the energy storage unit is less than the energy amount threshold further comprises calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the energy storage unit is not maintained constant.

6. The microgrid of claim 1 , wherein the energy storage unit comprises at least one of an electrical energy storage unit, a mechanical energy storage unit, an electromechanical energy storage unit, an electrochemical energy storage unit, or a thermal energy storage unit.

7. the first generator comprises a fuel cell generator; each of the at least two power output units includes an inverter; the energy storage unit includes at least one of a battery, a capacitor, or a supercapacitor; and 7. The microgrid of claim 6, wherein the controller is configured with controller executable code configured to cause the controller to perform operations where determining the amount of energy available from the energy storage unit includes determining a state of charge of at least one of the battery, capacitor, or supercapacitor.

8. 10. The microgrid of claim 1, wherein the first generator comprises at least one of a fuel cell generator, a combustion generator, a photovoltaic, a concentrated solar power, a wind turbine, a geothermal turbine, a hydroelectric turbine, a gas turbine, a nuclear reactor, an alternator, or an induction generator.

9. 1. A method for managing power demand distribution across a plurality of generators in a microgrid electrically connected to a load, comprising: The method comprises: determining whether an amount of energy available from an energy storage unit electrically connected to a first power output unit of the plurality of power output units is less than a threshold amount of energy; in response to determining that the amount of energy available from the energy storage unit is less than the threshold amount of energy, calculating a first sharing multiplication factor for a first generator cluster including at least a first generator electrically connected to the first power output unit among a plurality of generator clusters using the amount of energy available from the energy storage unit; calculating a shared power demand of the first generator cluster using the first share multiplication factor, the shared power demand being less a distributed power demand, which is a power demand of a load divided by the total number of power output units; and setting the distributed power demand of the first generator cluster such that, in response to determining that the amount of energy available from the energy storage unit is less than the energy amount threshold, the first power output unit outputs the power received from the first generator cluster and an amount of power received from the energy storage unit sufficient to satisfy a difference between the distributed power demand and the shared power demand; and, in response to determining that the amount of energy available from the energy storage unit is equal to or greater than the energy amount threshold, the first power output unit outputs an amount of power received from the first generator cluster sufficient to satisfy the distributed power demand; A method comprising:

10. 10. The method of claim 9, further comprising: setting the shared power demand of the first generator cluster such that the first power output unit outputs a sufficient amount of power received from the first generator cluster to satisfy the shared power demand.

11. 10. The method of claim 9, wherein setting the distributed power demand of the first generator comprises setting the distributed power demand equally divided by the number of power output units.

12. Calculating a first sharing multiplication factor for the first generator cluster includes: Determining the amount of energy available from the energy storage unit.

10. The method of claim 9, comprising:

13. the generator comprises a fuel cell generator; the energy storage unit includes at least one of a battery, a capacitor, or a supercapacitor; and The method of claim 12 , wherein determining the amount of energy available from the energy storage unit includes determining a state of charge of at least one of the battery, capacitor, or supercapacitor.

14. determining whether the amount of energy available from the energy storage unit remains constant; 10. The method of claim 9, wherein calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the energy storage unit is less than the energy amount threshold further comprises: calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the energy storage unit is not maintained constant.

15. 1. A microgrid electrically connectable to a load, comprising: two or more generator clusters each having at least one fuel cell generator, including a first generator cluster having at least a first fuel cell generator; two or more power output units, each including an inverter electrically connected to a respective one of the two or more generator clusters, including a first power output unit electrically connected to the first generator cluster; a battery electrically connected to the first power output unit; Control device and Equipped with The control device determining whether an amount of energy available from the battery is less than an energy amount threshold; responsive to determining that the amount of energy available from the battery is less than the threshold amount of energy, calculating a first sharing multiplication factor for the first generator cluster using the amount of energy available from the battery; using the first share multiplication factor to calculate a shared power demand of the first generator cluster that is less than a distributed power demand, which is a power demand of a load divided by the total number of power output units; configuring the first power output unit to output an amount of power received from the first generator cluster that satisfies the shared power demand; In response to determining that the amount of energy available from the battery is less than the threshold amount of energy, configuring the first power output unit to output an amount of power received from the battery sufficient to satisfy a difference between the distributed power demand and the shared power demand; configuring the first power output unit to output an amount of power received from the first generator cluster sufficient to meet the distributed power demand in response to determining that the amount of energy available from the battery is equal to or greater than a threshold amount of energy; a controller executing code configured to cause the controller to perform operations including:

16. The control device 16. The microgrid of claim 15, wherein configuring the first power output unit to output the power received from the first generator cluster in an amount sufficient to meet the shared power demand comprises comprising a controller executing code configured to cause the controller to perform operations including setting the shared power demand of the first generator cluster.

17. The control device calculating the first sharing multiplication factor for the first generator cluster; determining the amount of energy available from the battery; 16. The microgrid of claim 15, configured with a controller executing code configured to cause the controller to perform operations including:

18. The control device a controller executing code configured to cause the controller to perform operations further including determining whether an amount of energy available from the battery is maintained constant; 18. The microgrid of claim 17, wherein calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the battery is less than the threshold amount of energy further comprises calculating the first sharing multiplication factor for the first generator cluster in response to determining that the amount of energy available from the battery is not remaining constant.

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