Grid-Forming Inverter Patents: Who Leads, Where the Gaps Are 2026
- Filing peaked in 2022 at 26 families and has not returned to that level since, suggesting the core control-loop claim space filled quickly rather than growing steadily.
- China accounts for 26 of the receiving-office filings versus 20 for the United States and 11 for Europe, and the most-cited fault-current-limiting records are almost all Chinese utility filings.
- Fault ride-through and overcurrent limiting dominate the most-cited records while wind-integration (F03D) and protective-circuit (H02H) claims remain comparatively thin, at 9 and 5 records respectively.
Filing growth compares 2021 (6 records) with 2024 (17) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 74 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Grid-forming inverter control governs how an inverter-based resource — a battery, wind turbine or solar plant — sets its own voltage and frequency reference instead of following the grid, using techniques such as virtual synchronous machine control, droop control and power synchronization control. This matters because as synchronous generation retires, someone has to supply the grid’s inertia and fault behaviour, and the inverter’s control firmware is where that responsibility now sits. The dataset behind this page pulls 74 patent families filed between 2015 and mid-2026 under IPC classes covering grid power systems, power conversion and motor control.
Most records sit in H02J (power supply and grid systems, 71 of 74) and H02M (power conversion, 29), with smaller but present overlap into wind turbines, motor control and protective circuitry — a signature of a control technique that started in grid interconnection and is now being claimed across adjacent hardware.
Filing trend and technology composition
Two views of the same 74 families: when the filings happened, and which IPC subclasses they touch.
Annual filings, 2017–2026
Filings ran near zero through 2017, climbed steadily and peaked at 26 in 2022. The count since has stayed below that peak, and 2026 is still a partial year — so the apparent decline should be read cautiously given the roughly 18-month lag between filing and publication.
IPC subclass distribution
H02J (power supply and grid systems) and H02M (power conversion) carry the bulk of the filings. Wind motors (F03D), motor/generator control (H02P) and protective circuitry (H02H) appear in single digits, marking them as adjacent rather than core claim territory.
Shares are the percentage of the 74 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Grid-Forming Inverter Control System with Eureka
This page is one run against one query. Ask Eureka your own question about grid-forming inverter control system and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records
US20230170704A1 — System and method for constraining grid-induced power deviations from grid-forming inverter-based resources
A method for providing grid-forming control of an inverter-based resource includes receiving, via a controller, a power reference signal. The method also includes determining a dynamic power change limit. Further, the method includes determining, via the controller, an upper power boundary and a lower power boundary for grid-induced power deviations from a desired power operating point based on the power reference signal. Moreover, the method includes determining, via the controller, limits for an inertial power regulator reference based, at least in part, on the upper and lower power boundaries and the dynamic power change limit.Filed by GE Infrastructure Technology LLC, published 2023-06-01.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20230411965A1 | System-level overload ride-through control strategy for grid-forming inverter-based resources | 19 |
| 2 | CN114050561A | 限制对称短路故障下构网型变流器过电流的方法及系统 | 19 |
| 3 | CN116316805A | 电网故障下构网型逆变器动态限流控制方法 | 18 |
| 4 | CN118117651A | 基于并网模式切换的构网型逆变器的低压故障电流限幅方法 | 17 |
| 5 | CN117277414A | 一种基于虚拟电阻的构网型变流器预同步控制方法及系统 | 15 |
| 6 | US20230369865A1 | Virtual impedance current limiting control for grid forming inverter-based resources | 15 |
| 7 | US20230031575A1 | System and method for power control of an inverter-based resource with a grid-forming converter | 7 |
| 8 | CN119891342A | 基于功率匹配的构网型柔直系统限流方法、系统及设备 | 6 |
| 9 | CN119010198A | 一种构网型逆变器并联运行控制方法及系统 | 6 |
| 10 | WO2023117004A1 | Generator power peak limiting in virtual synchronous machine wind turbine | 6 |
Citation counts reflect influence within the searched corpus and skew toward older filings; treat them as a signal of what other filers built on, not a ranking of current importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Three read-throughs from the filing pattern, the citation table and the jurisdiction split.
The core loop was claimed fast, then filing slowed
Filings rose from zero in 2017 to a peak of 26 in 2022, then did not exceed that level in subsequent years. That pattern usually means the foundational control-loop claims — virtual synchronous machine and droop-control basics — were staked out quickly, pushing later filers toward narrower, more specific improvements.
Overcurrent and short-circuit ride-through are the most contested claims
Every one of the most-cited records addresses fault current limiting or overload ride-through during grid disturbances, rather than steady-state droop tuning. That concentration suggests fault-response control is where litigation and licensing risk is most likely to surface first.
Filing strategy diverges by region
China leads on raw receiving-office count, with the most-cited Chinese filings concentrated on dynamic fault-current limiting methods. The United States follows closely, with its most-cited record addressing system-level overload ride-through — a difference in framing that likely reflects different grid-code priorities.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to grid-forming inverter control system, with the prior art for and against each one.
Who is filing, and what is still open
Filing activity clusters around a small set of grid operators, OEMs and research institutes, with several co-filing relationships between them; recent-year momentum has flattened across the named assignees.
State Grid entities file jointly, not solo
State Grid Corporation of China, its Fujian electric power research institute, and the State Grid Smart Grid Research Institute appear as co-assignees on multiple families — a pattern consistent with centralized R&D filed under regional and national entities together rather than one dominant filer.
Turbine and inverter OEMs anchor the fault-response claims
GE's US filings on overload ride-through and power-deviation constraints sit among the most-cited records, indicating the OEM side of this field is concentrated on protecting inverter-based resources during grid events rather than steady-state control tuning.
Named leaders show no latest-year filings
Every assignee tracked for recent momentum — including GE, Vestas, Battelle, Huazhong University of Science and Technology, and State Grid Corporation — shows zero filings in the latest year, with Huazhong down 100% year-on-year. Given publication lag, this likely understates true recent activity rather than confirming a real pullback.
| Assignee | Recent year | YoY |
|---|---|---|
| General Electric Company | 0 | — |
| General Electric Renewable Energy Spain, S.L. | 0 | — |
| Battelle Memorial Institute | 0 | — |
| Huazhong University of Science and Technology | 0 | -100% |
| Vestas Wind Systems A/S | 0 | — |
| State Grid Corporation of China | 0 | — |
| SIEMENS CORP | 0 | — |
| Hitachi Energy Ltd. | 0 | — |
Where to take this next
The dataset points to fault-response control as the contested ground and to several adjacent branches that remain thinly claimed.
Map the fault-current-limiting claims in detail
Because the most-cited records cluster on overcurrent and ride-through control, a claim-by-claim comparison of the top Chinese and US filings would show exactly how much room remains for a differentiated method.
Explore fault-response claims in EurekaTrack State Grid's co-filing pattern
The linked co-assignee pairs suggest centralized filing strategy; watching which regional institute takes lead inventor credit next can signal where State Grid's internal priorities are shifting.
Follow assignee activity in EurekaAssess the wind-integration overlap
With only 9 F03D records against 71 in H02J, grid-forming control specific to wind turbine retrofits is comparatively open — worth a closer prior-art check before committing claim language.
Run a white-space search in EurekaCommon questions about grid-forming inverter control patents
It is a control method or apparatus that lets an inverter-based resource set its own voltage and frequency reference rather than following an existing grid signal, typically implemented through virtual synchronous machine control, droop control or power synchronization control. Patent claims in this space usually cover the control algorithm and its parameters — power references, boundary limits, current-limiting logic — rather than the inverter hardware itself. That is why the dataset spans IPC classes for grid systems (H02J), power conversion (H02M) and motor control (H02P) simultaneously.
Based on citation counts within this dataset, the most-referenced records are a mix of a US filing on system-level overload ride-through from GE and several Chinese filings on dynamic fault-current limiting during grid faults, including methods based on virtual resistance pre-synchronization. Citation counts favour older filings within a searched corpus, so this reflects influence built up over time rather than current filing volume. State Grid-affiliated entities also appear frequently as co-assignees rather than as solo filers.
The filing trend in this dataset rises from zero in 2017 to a peak of 26 families in 2022, then does not exceed that level in later years. This pattern is typical of a field where the foundational control-loop techniques get claimed quickly by early movers, after which later filers must either narrow their claims or target adjacent applications. It is also worth noting that publication lags filing by roughly 18 months, so the most recent one to two years in any such dataset will look artificially quiet.
Relative to the dense H02J and H02M filing activity, wind-turbine-integrated grid-forming retrofits (F03D, 9 records), protective circuit arrangements (H02H, 5 records) and multi-inverter interaction effects such as parasitic oscillation damping appear thinly claimed. A first claim in one of these branches would likely combine a grid-forming control method with a specific hardware context — for example, a wind turbine converter — rather than restating the core droop or virtual synchronous machine loop. These branches are worth a focused prior-art search before drafting.
China leads this dataset with 26 receiving-office filings, followed by the United States at 20 and Europe (EPO) at 11, with India, WIPO/PCT and Spain trailing behind. The most-cited Chinese filings concentrate on fault-current limiting methods, while the most-cited US filing addresses system-level overload ride-through — a difference that likely tracks different grid-code emphasis in each region. Filers targeting global protection should expect to navigate both the Chinese utility-heavy claim set and the US OEM-heavy one.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.