Hybrid failure-tolerant energy system with ac-coupled inverters and a bidirectional DC link

Abstract

A failure-tolerant hybrid energy system couples at least one renewable-generation source to at least one energy-storage system (ESS) using independent inverters that provide separate AC paths to a point of interconnection (POI). A bidirectional DC / DC converter establishes a direct DC link between subsystems to transfer energy, recover clipped generation, and time-shift dispatch. During a component outage, power is automatically rerouted through the remaining inverter, ensuring continuous delivery to the grid. A hierarchical controller supervises power routing and enables additional modes such as discharging ESS energy through the generation inverter — based on state of charge and market conditions. Modular configurations, including a "T-Model" with multiple generation branches and pre-integrated skid assemblies, support scalable deployment from distributed to utility scale. The architecture combines advantages of AC and DC coupling to improve round-trip efficiency, operational resilience, and grid responsiveness.

Description

HYBRID FAILURE-TOLERANT ENERGY SYSTEM WITH AC-COUPLED INVERTERSAND A BIDIRECTIONAL DC LINK

[0001] This application also claims the benefit of U.S. Provisional Application Serial No.63 / 676,105, titled “Hybrid coupled Solar-BESS Systems,” filed by Saeed Daneshvardehnavi, filed on July 26, 2024.

[0002] This application incorporates the entire contents of the foregoing application(s) herein by reference.BACKGROUND OF THE INVENTIONFIELD OF THE INVENTION

[0003] The present disclosure relates to power conversion and control architectures for hybrid renewable energy systems. More particularly, it pertains to systems that integrate one or more AC-coupled power sources (e.g., photovoltaic arrays) and a bidirectional DC-coupled energy storage system (ESS), wherein each operates as a distinct subsystem. The architecture maintains operational continuity of either subsystem in the event of a failure or shutdown in the other and includes provisions for direct energy exchange between subsystems via a bidirectional DC / DC converter and coordinated point-of-interconnection (POI) management.DESCRIPTION OF THE RELATED ART

[0004] The present disclosure relates to coupling systems for renewable energy installations. Specifically, it addresses architectures for integrating variable renewable energy sources with colocated energy storage systems.

[0005] As the adoption of renewable energy grows across residential, commercial, and utilityscale sectors, improved strategies are needed to maintain grid stability, maximize energy yield, and ensure operational flexibility. Co-locating energy storage with renewable generation enables time-shifted dispatch and enhanced responsiveness, but the effectiveness of such systems depends heavily on the architecture used to couple the components.

[0006] Accordingly, there is a need in the art for hybrid system architectures that more effectively integrate generation and storage assets across scales, improving system resilience, energy efficiency, and economic performance.SUMMARY

[0007] In one embodiment, a hybrid energy system comprises a renewable power plant, an Energy Storage System (ESS), and a control system. The renewable power plant is electrically coupled to a utility grid via a first AC power conversion assembly including at least a first inverter. The ESS is electrically coupled to the same utility grid via a second, independent AC power conversion assembly including at least a second inverter. A key feature of the disclosed hybrid system is a bidirectional DC / DC converter 3 that establishes a direct DC circuit between a DC side of the renewable power plant and a DC side of the ESS, allowing for direct current transfer between the two subsystems independently of the AC power conversion assemblies. This unique topology provides the resilience of physically separate AC systems while enabling the high efficiency of direct DC energy transfer, a combination not realized by conventional architectures.

[0008] In some embodiments, the system architecture is configured to support multiple operational modes based on its specific structure. For example, the independent first and second AC power conversion assemblies allow for simultaneous power dispatch to the grid from both the renewable power plant and the ESS. Furthermore, the system structure provides for failure tolerance; in the event of a failure of the first inverter, a circuit path is maintained that allows DC power from the renewable power plant to be routed through the bidirectional DC / DC converter to the ESS, and subsequently discharged to the grid via the second inverter. In one embodiment, known as the "T-Model" configuration, the system comprises at least two renewable power generation branches, each including a dedicated inverter. The DC side of each respective branch is electrically coupled via a separate bidirectional DC / DC converter to a common DC bus of a central ESS.

[0009] An embodiment of the system enables operational modes that enhance asset utilization, such as allowing stored battery energy from the ESS to be discharged to the grid through the first (renewable power plant) inverter. This capability increases charging / discharging opportunities and overall system flexibility. The enhanced redundancy and failure-tolerant routing options significantly reduce plant downtime.

[0010] Embodiments of the system may be deployed in a pre-integrated, modular assembly. Such an assembly includes a common, rigid support frame, referred to herein as a "skid" 20. The essential power conversion components, including the first inverter 8, the second inverter 13, andthe bidirectional DC / DC converter 3, are mounted directly upon this common support frame 20 to create a factory-assembled, integrated power block designed for rapid field deployment.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure is further described in detail below with reference to the accompanying figures, in which:

[0012] FIG. l is a one-line schematic illustrating a conventional AC-coupled renewable energy system.

[0013] FIG. 2 is a one-line schematic illustrating a conventional DC-coupled renewable energy system.

[0014] FIG. 3 is a block diagram illustrating an embodiment of the hybrid AC / DC-coupled system housed within a modular skid.

[0015] FIG. 4 is a block diagram illustrating a "T-Model" embodiment having two independent PV generation branches interconnected with a central energy storage branch.

[0016] FIG. 5 is a block diagram illustrating a scalable, multi -assembly power plant deployment feeding a central substation.

[0017] FIG. 6A is a graph illustrating the recovery of clipped energy.

[0018] FIG. 6B is a graph illustrating energy recovery during transient low-irradiance conditions.

[0019] FIG. 6C is a graph illustrating the capture of low-irradiance energy during early-morning ramp-up.

[0020] FIG. 6D is a graph illustrating time-shifted energy dispatch to align PV generation with a net-load curve.

[0021] FIG. 7 is an isometric view illustrating a modular skid assembly with separate enclosures for PV and BESS equipment.

[0022] FIG. 8A is a schematic illustrating a failure-tolerant power rerouting method upon a PV inverter failure.

[0023] FIG. 8B is a schematic illustrating a failure-tolerant power rerouting method upon a BESS inverter failure.

[0024] FIG. 8C is a schematic illustrating a failure-tolerant power rerouting method upon a DC / DC converter failure.

[0025] FIG. 9 is a flowchart illustrating a processor-executed method for failure detection and system resilience.

[0026] FIG. 10 is a block diagram illustrating the primary power flow paths and control parameters of the disclosed system.

[0027] FIG. 11 is a flowchart illustrating a hierarchical economic dispatch method for the system.

[0028] FIG. 12 is a flowchart illustrating a control method for determining a PV inverter power setpoint.DETAILED DESCRIPTION

[0029] FIG. 1 illustrates a conventional AC-coupled renewable energy system 100, comprising separate photovoltaic (PV) generation and battery energy storage system (BESS) components. A PV array 2 is electrically connected via terminals 2a and 2b to a terminal block 6, which routes direct current (DC) power to a first inverter 8. The DC input port of inverter 8 receives the power and converts it into alternating current (AC), which is then routed through a circuit breaker 9, a transformer 10, and AC switchgear 11. The resulting AC power is delivered via feeder line 12 to a common point of interconnection (POI) 30.

[0030] Similarly, a BESS 4 is electrically connected via terminals 4a and 4b to a terminal block 7, which routes DC power to a second inverter 13. The second inverter 13 is configured for bidirectional power conversion to support both charging and discharging of the BESS. The AC output of inverter 13 passes through circuit breaker 14, transformer 15, and AC switchgear 16, before being delivered via feeder line 17 to the same POI 30.

[0031] In this prior art AC-coupled topology, the PV array and the BESS are independently interfaced to the AC grid via separate inverters and parallel AC feeder lines. The first inverter 8 (PV inverter) provides grid-tied solar energy delivery, while the second inverter 13 (BESS inverter) enables bidirectional energy exchange between the grid and the energy storage system.

[0032] This architecture suffers from several technical limitations, including: (i) efficiency losses due to multiple DC-AC-DC conversion steps; (ii) energy clipping during periods when PVgeneration exceeds the rated power of the PV inverter 8; and (iii) inability to capture energy during low irradiance conditions when PV voltage is insufficient to activate the inverter, such as during early morning, late evening, or under transient cloud cover.

[0033] FIG. 2 illustrates a conventional DC-coupled renewable energy system 200, in which both a photovoltaic (PV) array 2 and a battery energy storage system (BESS) 4 are electrically interconnected on the DC side. The PV array 2 is connected via terminals 2a and 2b to a first DC bus 6, while the BESS 4 is connected via terminals 4a and 4b to a second DC bus 7. A bidirectional DC / DC converter 3 electrically couples the two DC buses 6 and 7, enabling energy transfer between the PV system and the BESS. The first DC bus 6 also serves as the primary input to a single inverter 8, which converts DC power into alternating current (AC) and delivers it through circuit breaker 9, transformer 10, and AC switchgear 11 to a point of interconnection (POI) 30.

[0034] While this DC-coupled configuration improves round-trip efficiency by enabling direct DC-to-DC charging between the PV array and the BESS, it introduces critical limitations. First, the use of a single inverter 8 creates a single point of failure for both PV generation and BESS discharge. Second, the inverter’s rated power constraint imposes a hard cap on total export capacity, limiting simultaneous delivery from both PV and BESS during high-output periods. Third, this architecture complicates retrofitting of existing AC -coupled systems due to its centralized inverter requirement and lack of modular feeder isolation.

[0035] FIG. 3 illustrates an embodiment of a hybrid AC / DC-coupled renewable energy system 300, which integrates photovoltaic (PV) generation and battery energy storage system (BESS) components. The PV array 2 subsystem and the BESS 4 subsystem are coupled to a common point of interconnection via independent AC pathways and are also directly interconnected on their DC sides via a dedicated DC pathway. Key power conversion components — including PV inverter 8, BESS inverter 13, transformers 10 and 15, AC circuit breakers 9 and 14, and a bidirectional DC / DC converter 3 — are housed within a modular, prefabricated skid 20. The system provides independent AC export paths to the grid via terminals 8a and 8b, while also enabling direct DC coupling between the subsystems through the DC / DC converter 3. It is this combination of independent AC export paths and a direct, bidirectional DC coupling path that constitutes a core aspect of the disclosed system, overcoming the limitations of the prior art systems shown in FIGs. 1 and 2.

[0036] The system further includes a control system housed within the skid 20. The control system comprises at least one processor and at least one non-transitory computer-readable medium (e.g., memory) communicatively coupled to the processor. The memory stores instructions that, when executed by the processor, cause the control system to perform the operational and failure-handling methods described herein, including the steps illustrated in FIG. 9. The processor may be implemented as a microprocessor, a programmable logic controller (PLC), a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC).

[0037] The PV array 2 is connected via terminals 2a and 2b to a DC terminal block 6 within the skid. The terminal block 6 routes DC power to the DC input port of the PV inverter 8. The AC output of inverter 8 is routed through AC-side circuit breaker 9, transformer 10, and switchgear 11, and exits the skid via terminal 8a to deliver AC power to a grid point of interconnection (POI) 30.

[0038] The BESS 4 is connected via terminals 4a and 4b to a separate DC terminal block 7, which routes DC power to the BESS inverter 13. The inverter 13 supports bidirectional operation to enable both charging from and discharging to the grid. Its AC output is routed through circuit breaker 14, transformer 15, and switchgear 16, and is delivered to POI 30 via terminal 8b.

[0039] A bidirectional DC / DC converter 3 establishes a direct DC link between the PV-side terminal block 6 and the BESS-side terminal block 7. This enables multiple operational modes: (i) surplus PV energy that would otherwise be clipped at inverter 8 can be diverted to charge the BESS 4 via the DC / DC converter; (ii) energy from the BESS can be discharged to the grid via inverter 13 or, optionally, via inverter 8 if configured to support bidirectional operation; and (iii) low-voltage PV energy during low-irradiance conditions can be harvested and stored in the BESS. This architecture enables curtailed energy recovery, time-shifted dispatch, and dual-path grid support while maintaining operational redundancy.

[0040] FIG. 4 illustrates a "T-Model" embodiment of the advanced-coupled renewable energy system 400. This configuration features multiple renewable generation branches and a central energy storage branch, all interconnected on the DC side to enable flexible energy management. The power conversion components may be housed within a single, integrated modular skid 20.

[0041] In some embodiments, the system includes at least two independent PV generation branches. A first PV generation branch includes a PV array 2 connected to a first DC bus 6,which routes power to a first PV inverter 8. The AC output of inverter 8 passes through circuit breaker 9, transformer 10, and switchgear 11 to an AC terminal 8a. A second, independent PV branch includes another PV array 2 connected to a second DC bus 60, which feeds a second PV inverter 18. The AC output of inverter 18 passes through circuit breaker 19, transformer 21, and switchgear 22 to a separate AC terminal 8a.

[0042] A central energy storage branch includes a BESS 4 connected to a central DC bus 7, which is coupled to a BESS inverter 13. The AC output of inverter 13 is delivered to the grid via AC terminal 8b. The “T-Model” structure is defined by the DC-side interconnections. A first bidirectional DC / DC converter 3 establishes a direct DC link between the first PV branch bus 6 and the central ESS bus 7. A second bidirectional DC / DC converter 3 establishes a DC link between the second PV branch bus 60 and the same ESS bus 7.

[0043] This configuration enables highly flexible operational modes. The BESS 4 can be dynamically charged using surplus energy from either PV array. Stored energy from the BESS can be dispatched to the grid through its dedicated inverter 13, or optionally through either PV inverter 8 or 18, depending on system configuration. This topology provides operational redundancy, load-following capability, and enhanced energy utilization during curtailment or ramp-constrained events.

[0044] FIG. 5 illustrates a scalable, multi -unit power plant deployment 500 comprising a plurality of assemblies 29. Each assembly 29 includes at least one modular skid 20, as previously described in FIGs. 3 and 4. Each skid houses PV and BESS subsystems with independent AC and DC connectivity, as well as shared DC / DC coupling.

[0045] Unlike conventional hybrid systems that rely on a single shared inverter or restrict energy flow to unidirectional export, the disclosed architecture enables reverse energy flow from the grid into the battery energy storage system. The second inverter, which is independently connected to the grid, may receive power from the utility and convert it to DC to charge the BESS. This feature provides grid service flexibility and ensures system operability even in the absence of available renewable generation. The architecture supports grid-charging modes, pricebased optimization, and demand-response integration.

[0046] Within each assembly 29, the AC outputs from the PV inverters (via terminals 8a) are aggregated onto a common first feeder line 27a. Simultaneously, the AC outputs from the BESS inverters (via terminals 8b) are aggregated onto a separate second feeder line 27b. Each assemblythereby maintains physical and electrical separation of PV-gen erated and storage-dispatched power.

[0047] The first and second feeder lines (27a, 27b) from each assembly 29 are routed to a central substation 30. The substation includes a first common feeder bus 32a for all incoming PV lines and a second common feeder bus 32b for all ESS lines. This architecture preserves system-level separation of generation and storage paths up to the substation level. The aggregated power is then delivered to the utility grid via a main point of interconnection (POI) 39.

[0048] FIG. 6A illustrates a power profile 600 highlighting the inverter clipping problem. Curve 24 shows the available DC power from the PV array, while line 51 represents the AC power limit of a conventional inverter. The shaded region 50 represents clipped energy typically lost in prior art systems. The hybrid AC / DC-coupled system (e.g., FIG. 3 or FIG. 4) enables recovery of this energy by routing excess DC power to the BESS through a bidirectional DC / DC converter.

[0049] FIG. 6B shows an example 610 of energy recovery during low-irradiance conditions.Curve 85 represents typical PV power generation, which may be reduced due to events like cloud cover. Shaded areas 84, 86, and 87 illustrate energy harvested during early morning, cloud cover, and evening ramp-down, respectively. The DC / DC converter, configured to operate at lower power thresholds than the main inverter, enables recovery of this otherwise unutilized energy.

[0050] FIG. 6C illustrates an early-morning recovery mode 620. Curve 80 shows available PV power during early irradiance, while curve 85 marks the conventional inverter threshold. The shaded region 82 indicates the additional energy recovered by the DC / DC converter and routed to the ESS before the inverter would have otherwise activated.

[0051] FIG. 6D illustrates time-shifted dispatch 630 enabled by integrated DC-coupled energy storage. The PV generation curve peaks at midday, while the net load curve peaks later in the evening. The system stores excess midday PV energy in the BESS, then discharges it during peak demand periods, aligning delivery with high-value pricing. This arbitrage strategy enhances overall economic performance and grid responsiveness.

[0052] FIG. 7 depicts an alternative modular skid design (700) comprising two inverter enclosures, one dedicated to the photovoltaic (PV) system and the other to the battery energy storage system (BESS). Each inverter connects to the grid via its respective three-phase AC terminal — (8a) for PV and (8b) for BESS — where each AC terminal includes LI, L2, and L3 phases. A bidirectional DC / DC converter (3) interlinks the two systems on the DC side, enablingcontrolled energy exchange between PV and BESS. The entire configuration is housed within a shared skid (20) that consolidates power electronics, simplifies field wiring, and facilitates DC- side optimization for energy transfer and recovery.

[0053] Referring to FIG. 8 A, scenario 800 illustrates a failure of the PV inverter 8. Upon detection of this failure, the system controller executes its embedded recovery algorithm to reconfigure power flow: DC power from PV array 2 is directed through the bidirectional DC / DC converter 3 into the DC bus of the BESS inverter 13. The BESS inverter 13, operating in discharge mode, converts that DC energy to AC and delivers it to the grid 30 via terminal 8b. Dashed arrows in FIG. 8A denote this redirected energy path, ensuring uninterrupted delivery despite the PV inverter outage.

[0054] Referring to FIG. 8B, scenario 810 illustrates a failure of the BESS inverter 13. Upon failure detection, the controller places the DC / DC converter 3 into a PV-only configuration, preventing power exchange with the BESS. PV array 2 continues to feed inverter 8, which supplies AC power to the grid via terminal 8a. The “X” on inverter 13 in FIG. 8B denotes the disabled BESS path, while the PV path remains fully operational.

[0055] Referring to FIG. 8C, scenario 820 addresses a failure of the bidirectional DC / DC converter 3. When this converter failure occurs, the controller reverts both PV inverter 8 and BESS inverter 13 to independent, AC-coupled operation. PV inverter 8 delivers PV array 2 output directly to the grid via terminal 8a, and BESS inverter 13 independently discharges stored energy via terminal 8b. This fallback maintains both generation and storage dispatch capabilities in the absence of DC-side coupling.

[0056] Referring to FIG. 9, a flowchart illustrates a processor-executed method 900 for failure handling and operational resilience in a hybrid AC / DC-coupled energy system. The method enables real-time response to inverter and converter failures, maintaining power flow continuity under multiple failure scenarios.

[0057] The method begins at step 137 and proceeds to step 138, where the processor initiates real-time monitoring of key system components, including a PV inverter, a BESS inverter, and a DC / DC converter. The method then enters a continuous diagnostic loop.

[0058] At step 139, the PV inverter is evaluated. If it is determined at step 140 that the PV inverter is not operational (140: NO), the system executes a recovery sequence. This sequence begins at step 141, where a PV inverter failure handling procedure (handle PV Inverter failure)is activated. The method then proceeds to step 142, where the controller redirects DC power from the PV array through the bidirectional DC / DC converter to the BESS inverter, which delivers AC power to the grid. This event is logged in system records at step 143.

[0059] If the PV inverter is determined to be operational (140: YES), the method continues to step 144 to assess the BESS inverter. If at step 145 it is determined that the BESS inverter is inoperative (145: NO), the system executes an alternative recovery procedure. This procedure begins at step 146, where a BESS inverter failure-handling routine(handle BESS Inverter failure) is activated, indicating a general recovery action taken through the PV inverter pathway. The controller then, at step 147, disables DC power exchange with the BESS and continues grid export solely through the PV inverter. The BESS failure is logged at step 148.

[0060] If both the PV inverter and the BESS inverter are determined to be functional (145: YES), the method advances to step 149 to check the DC / DC converter, and then to step 150 to assess if the DC / DC converter is operational. If the DC / DC converter is found to be non- operational (150: NO), the method proceeds to step 151, where a DC / DC converter failure handling procedure (handle DC DC Converter failure) is activated. Subsequently, at step 152, a fallback operation is initiated where the PV and BESS subsystems operate independently using AC-coupled paths; for example, the BESS inverter may receive charge via its grid-tied AC input while the PV inverter exports directly to the grid. The DC / DC converter failure is recorded at step 153.

[0061] If all system components (PV inverter, BESS inverter, and DC / DC converter) are determined to be functional (from 150: YES, leading to a confirmation at 154: YES), the system proceeds to step 155 to maintain coordinated operation. This coordinated operation includes direct DC energy transfers via the DC / DC converter when appropriate. The system continuously monitors its state at step 156, records operational data and generates reports at step 157, configures alerts for failures at step 158, issues maintenance notifications at step 159, and provides real-time updates to the user interface at step 160. This continuous loop for normal operation and monitoring persists until the method is terminated at step 161. In scenarios where not all components are functional after a check (154: NO), the method includes a return path 162 back to respective failure handling procedures to re-evaluate and address outstanding issues.

[0062] Referring to FIG. 10, a system block diagram 1000 illustrates the primary power flow paths and measurement points of the disclosed system, including a PV array 2, a BESS 4, a PV power block 8, a BESS power block 13, and a bidirectional DC / DC converter 3. DC power from the PV array 2 flows along path 90. DC power from the BESS 4 flows along path 91. The bidirectional DC / DC converter 3 manages the transfer of DC power between the PV and BESS subsystems along path 92. The PV power block 8 converts DC power to AC power for export to the grid 30 along AC path 93, and the BESS power block 13 likewise exports AC power along AC path 94.

[0063] The system is managed by a control algorithm that utilizes several defined parameters. The Locational Marginal Price (LMP) is monitored for making economic dispatch decisions. Power flows are represented by: P PV DC (path 90), representing DC output from the PV array; P BESS DC (path 91), representing DC output from the BESS; P DCDC Link (path 92), representing power flowing through the DC / DC converter; P_PV_AC (path 93), representing the AC output from the PV power block; and P BESS AC (path 94), representing the AC output from the BESS power block. The battery's energy level is represented by its State of Charge (SOC). A logic module referred to as the BESS Optimizer executes decisions related to charging, discharging, and curtailment based on these and other inputs, such as curtailment flags, commitment flags, and economic thresholds.

[0064] Referring to FIG. 11, a flowchart illustrates an exemplary hierarchical optimizer method 1100 for controlling the hybrid AC / DC-coupled system. After start at step 165 and system monitoring initialization at steps 166-169, the logic reaches decision block 170 to determine whether the system is operating in a commitment mode or an economic dispatch mode.

[0065] If the system is in the commitment mode (170: YES), the method advances to step 171 to determine whether any PV-generated power has been clipped at the PV inverter. When clipped power exists (171 : YES), the method proceeds to step 172 to check whether the BESS has available storage capacity. If capacity is available (172: YES), the method may adjust the SOC limits based on current operating data (step 173), then routes the clipped PV power through the DC / DC converter to charge the BESS (step 174).

[0066] If, at step 172, the BESS is full (172: NO) despite clipped PV power, the method sends a clipped-energy notification to the BESS Optimizer module at step 175. At step 176, theBESS Optimizer determines whether to accept the clipped energy for storage (step 177) or to curtail the excess power (step 178).

[0067] If the system cannot satisfy its power delivery commitments (170: NO) or if the clippedenergy check (171) fails, the method sets the DC / DC link transfer to zero and notifies the BESS Optimizer at step 182. The method then skips all further dispatch logic (step 183) to prevent erroneous BESS operation.

[0068] If the system is in economic dispatch mode (170: NO), the method evaluates the locational marginal price (LMP) at step 184. When the LMP exceeds a predefined threshold (184: YES), the SOC is examined at step 185. If the SOC is above its minimum threshold (185: YES), the method routes clipped PV power to the BESS via the DC / DC converter (step 186); otherwise (185: NO), the method curtails the clipped power (step 187). If the LMP does not exceed the threshold (184: NO), the method also curtails clipped power (step 188). Finally, the method collects performance data at step 189 and loops back to step 165 for continuous operation (step 190).

[0069] Referring to FIG. 12, a flowchart illustrates an exemplary control method 1200 for determining a power setpoint for a photovoltaic (PV) inverter (P PV INV Set). The method is embodied as a set of instructions executed by a controller (e.g., a microprocessor or digital signal processor, which may be housed within the skid 20) to manage the PV system's output.

[0070] The method is initiated at a start step (194) and proceeds to initialize system monitoring (195), execute error handling routines (196), and perform redundancy checks (197). At step (198), the controller reads a set of current parameters, including a locational marginal price (LMP), a PV curtailment flag (P PV Curtailment Flag), and a PV commitment flag (P PV Commitment Flag).

[0071] At a first decision block (199), the controller determines if the current LMP exceeds a predefined price limit, LMP PV Lim, wherein LMP PV Lim is a configurable threshold stored in a memory accessible by the controller. If the controller determines that the LMP exceeds the price limit (199: YES), it proceeds to a second decision block (205).

[0072] At decision block (205), the controller evaluates the P PV Curtailment Flag. If the flag is active (205: YES), the controller proceeds to step (207) and sets the inverter power setpoint, P_PV_INV_Set, to a curtailment value (P_PV_INV_Set = P_PV_Curtailment). If the flag is inactive (205: NO), the controller proceeds to step (206) and sets P_PV_INV_Set to a maximumpower point value corresponding to the inverter's full rated size (P PV INV Set = PV INV Size (Max MPP)).

[0073] If, at decision block (199), the controller determines that the LMP does not exceed the price limit (199: NO), it proceeds to a third decision block (200) to evaluate the P PV Commitment Flag.

[0074] If the controller determines the commitment flag is inactive (200: NO), it proceeds to step (201) and sets P_PV_INV_Set to zero (P_PV_INV_Set = 0 MW).

[0075] If the controller determines the commitment flag is active (200: YES), it proceeds to a fourth decision block (203) to again evaluate the P PV Curtailment Flag. If the flag is active (203: YES), the controller proceeds to step (204) and sets P_PV_INV_Set to the curtailment value (P_PV_INV_Set = P_PV_Curtailment). If the flag is inactive (203: NO), the controller proceeds to step (202) and sets P_PV_INV_Set to a commitment value (P_PV_INV_Set = P PV Commitment).

[0076] Following any of the setpoint assignment steps, the method concludes at step (208), wherein the controller directs the PV inverter to maintain the assigned P_PV_INV_Set until the next control cycle.

Claims

CLAIMS1. A hybrid, failure-tolerant energy system, comprising:(a) at least one renewable-energy generation source configured to deliver direct- current (DC) power to a DC collection bus, the power being supplied either (i) directly as DC or (ii) as alternating current (AC) that is rectified to DC before reaching the DC collection bus.(b) at least one DC energy-storage subsystem having a DC power port electrically coupled to a DC input of at least one storage-side inverter having an AC output.(c) at least one generation-side inverter having a DC input connected to the DC collection bus and an AC output; and(d) at least one bidirectional DC / DC converter electrically disposed between the DC collection bus and the DC power port of the DC energy -storage subsystem, the DC / DC converter configured for bidirectional power transfer; wherein the AC outputs of the at least one generation-side inverter and the at least one storage-side inverter are independently connectable to one or more AC grid-connection points.

2. The system of claim 1, wherein the at least one renewable-energy generation source comprises at least one photovoltaic (PV) array connected directly to the DC collection bus; and further comprising a hydrogen electrolyzer and a fuel-cell loop electrically coupled to the DC collection bus.

3. The system of claim 1, wherein the system comprises a plurality of generation-side inverters connected in parallel to the DC collection bus and a plurality of storage-side inverters connected in parallel to the DC power port of the at least one DC energystorage subsystem; and wherein at least one additional generation-side inverter is connected downstream of the at least one bidirectional DC / DC converter, thereby forming a dual-inverter “T-Model” topology.

4. The system of claim 1, the generation-side and storage-side inverters are each connected through respective transformers and circuit breakers to independent feeder lines that terminate at a shared substation; and wherein the shared substationcomprises a plurality of feeder ports, each port configured to receive at least two of the independent feeder lines and route power to a grid-connection bus.

5. The system of claim 1, wherein the at least one DC energy-storage subsystem is further configurable for charging from an AC grid by operation of the at least one storage-side inverter in a reverse direction.

6. The system of claim 1, further comprising a resilience-management module configured to: (a) detect a fault in the at least one generation- si de inverter, the at least one storage-side inverter, or the at least one bidirectional DC / DC converter; and (b) in response to the detected fault, command a rerouting of power through an alternate pathway to maintain power export to the one or more AC grid-connection points.

7. The system of claim 1, wherein the at least one bidirectional DC / DC converter, the at least one generation-side inverter, and the at least one storage-side inverter are mounted on a common, transportable skid.

8. A method for controlling a hybrid failure-tolerant energy system, the system including a generation source coupled to a generation-side inverter, an energy storage subsystem coupled to a storage-side inverter, and a bidirectional DC / DC converter coupling a DC side of the generation source to a DC side of the energy storage subsystem, the method comprising:(a) monitoring, in real time, (i) generation output, (ii) state-of-charge of the energystorage subsystem, (iii) available capacity at a point of interconnection (POI), (iv) locational marginal price, curtailment signals, and (v) inverter availability.(b) dispatching energy from the generation source to one or more of:(i) the grid through a generation-side inverter,(ii) the energy-storage subsystem through the DC / DC converter, or(iii) the grid through the DC / DC converter and a storage-side inverter, based on POI headroom and economic optimization.(c) selectively discharging the energy-storage subsystem through one or more available inverters to maximize export within POI constraints; and(d) automatically rerouting energy through alternate inverter paths upon detection of a component fault, thereby reducing downtime.

9. The method of claim 8, wherein the monitored parameters are processed by a control algorithm that evaluates a weighted score based on real-time locational marginal price, curtailment penalties, and storage state-of-charge to determine an optimal dispatch path; and wherein the system selects a discharge path for the energy-storage subsystem based on a comparison of real-time POI export capacity available through each inverter.

10. The method of claim 8, wherein, when generation exceeds a rated capacity of a generation-side inverter or during grid-curtailment events, the system directs at least a portion of excess power to the energy -storage subsystem via the bidirectional DC / DC converter, and optionally exports remaining power to the grid through the storageside inverter.

11. The method of claim 8, further comprising charging the energy-storage subsystem from the AC grid during time periods associated with low electricity pricing by operating the storage-side inverter in reverse.

12. The method of claim 8, wherein upon detection of a fault in any inverter or the bidirectional DC / DC converter, the system automatically reroutes power and redistributes set-points among remaining operational components within less than one second to maintain export continuity.

13. A modular renewable-energy system assembly comprising:(a) at least one generation-side inverter with a DC input port and an AC output port, configured to receive DC power from a renewable-generation source.(b) at least one storage-side inverter with a DC input port and an AC output port, configured to exchange power with a DC energy-storage subsystem.(c) one or more bidirectional DC / DC converters electrically coupled between the DC input of the generation-side inverter and the DC input of the storage-side inverter, configured for bidirectional power transfer.(d) one or more transformers and circuit breakers coupled to the AC output ports of each inverter.(e) internal DC busbars electrically configured to aggregate power from one or more generation units and / or energy-storage subsystems.(f) pre-wired AC and DC connection terminals within the assembly, configured for external feeder lines and energy sources; and(g) a system controller housed within the assembly, configured to monitor inverter states, coordinate dispatch between inverters and DC / DC converters, and enforce protection and operational constraint. wherein the system assembly is (i) pre-integrated within a transportable skid for deployment as a single unit, or (ii) assembled on-site from interoperable components sourced from multiple manufacturers, and wherein all constituent components are commercially available and not limited to any particular energy -generation or storage chemistry.

14. The system of claim 13, wherein the assembly includes a central control unit configured to manage power flow, protection coordination, inverter dispatch, and DC / DC-converter routing based on real-time operating conditions, and wherein the integrated components are further configured to comply with applicable interconnection and protection standards including voltage ride-through, antiislanding, and grid-code requirements.

15. The system of claim 13, wherein the skid includes modular bays for inverter units, transformers, DC / DC converters, and control electronics, allowing flexible system sizing and future component replacement.

16. The system of claim 13, wherein the assembly is factory-assembled and tested within a transportable skid including pre-wired AC and DC terminals, internal control systems, and structural mounting for all components, or field-assembled using interoperable components sourced from multiple original-equipment manufacturers, and wherein the assembly can be configured for residential, commercial, or utilityscale use, with component ratings and grid-interface hardware adapted accordingly.

17. The system of claim 13, wherein any environmental enclosures provide temperature control, dust filtration, and weather resistance suitable for outdoor installation.

18. A control system for a renewable-energy plant comprising:(a) a skid-level controller and a plant-level supervisory controller, each configured to receive real-time data streams comprising generation output, energy-storage state-of- charge, POI limits, price signals, and component-status flags; and(b) non-transitory memory storing instructions that, when executed, implement:(i) a redundancy -check algorithm that, upon detection of a component fault, commands power rerouting through alternative pathways with minimal latency.(ii) an economic-dispatch algorithm that jointly optimizes inverter set-points and DC / DC-converter power direction based on price, curtailment risk, and storage constraints; and(iii) a learning engine that refines dispatch policies using historical operating data.

19. The control system of claim 18, wherein the learning engine employs machinelearning techniques to forecast short-term generation, curtailment probability, and price volatility.

20. The control system of claim 18, wherein the redundancy-check algorithm isolates a faulty component and restores export capability without manual intervention.

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