Solid-State Transformer for Utility Grid Patent Landscape
Solid-State Transformer for Utility Grid Patent Landscape in 2026
The solid-state transformer for utility grid space is moderately concentrated, with Huawei Digital Power leading a field still expanding on a multi-year basis, though annual filing volume has eased from its 2023 peak. Power conversion (H02M) and grid-systems (H02J) dominate the technology mix, while EV integration, transformer magnetics, and protective circuits remain comparatively sparse branches.
Huawei Digital Power leads a moderately concentrated field of grid-focused innovators
Huawei Digital Power Technologies Co. Ltd. holds the top position with 56 patent families, followed by Hitachi Energy Ltd. with 40 and Delta Electronics Inc. (CN) with 30, giving the top three a clear lead over the remaining ranked applicants.
The top five filers account for 29% of the hundred largest filers’ combined total, indicating moderate concentration: a dominant Chinese-led tier exists, but meaningful challenger positions remain accessible to well-resourced entrants.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Huawei Digital Power Technologies Co. Ltd. | 56 | |
| 2 | Hitachi Energy Ltd. | 40 | |
| 3 | Delta Electronics Inc. (CN) | 30 | |
| 4 | Delta Electronics (Shanghai) Co. Ltd. | 28 | |
| 5 | State Grid Corporation of China | 24 | |
| 6 | Georgia Tech Research Corporation | 15 | |
| 7 | Global Energy Interconnection Research Institute Co. Ltd. | 14 | |
| 8 | Sungrow Power Supply Co. Ltd. | 13 | |
| 9 | Causam Energy Inc. | 13 | |
| 10 | Guangdong Power Grid Co. Ltd. | 13 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | GE Energy Power Conversion Technology Ltd. | 11 | |
| 12 | Guangdong Power Grid Co. Ltd. Dongguan Power Supply Bureau | 11 | |
| 13 | Southeast University | 11 | |
| 14 | Huawei Technologies Co. Ltd. | 11 | |
| 15 | Resilient Power Systems LLC | 10 | |
| 16 | North Carolina State University | 8 | |
| 17 | Hyosung Heavy Industries Corporation | 8 | |
| 18 | Ohmium International Inc. | 8 | |
| 19 | State Grid Jiangsu Electric Power Co. Ltd. | 8 | |
| 20 | UT-Battelle LLC | 8 |
The leaders’ positions span both commercial manufacturers and state-affiliated grid operators, signalling that the technology is being pushed simultaneously from device-level innovation and system-integration mandates — a dynamic that tends to compress the window for mid-tier differentiation.
Filing counts for 2024 and 2025 are subject to publication lag and likely understate actual activity; the apparent recent dip should not be read as a demand signal. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Annual volume plateaued near its 2023 peak; power-conversion IP dominates the branch mix
Two lenses matter here: the multi-year filing trajectory, which reflects the field’s maturity stage, and the IPC branch distribution, which reveals where inventive effort is concentrated and where it is thin.
Annual filing trend
Filings grew steadily from 25 in 2017 to a peak of 92 in 2023, then eased to 63 in 2024 and 37 in 2025. The 2024–2026 bars are materially under-counted due to publication lag and should not be read as a real decline; the field’s overall 20% recent-window growth confirms continued expansion on a multi-year basis.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H02M (power conversion) and H02J (grid systems) together account for the vast majority of records, reflecting the core converter and grid-interface engineering challenge. All remaining branches — including B60L (EV propulsion), H01F (transformer magnetics), H02H (protective circuits), and digital/AI subclasses — hold single-digit shares, pointing to selective adjacent activity rather than broad-front innovation.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Solid state transformer and converter system
A solid state transformer (1) is specified comprising, – at least two first ports (3) connected in series and configured to be connected to an electrical power grid (13), – at least two second ports (7) configured to be connected to at least two loads (12), and – a single core magnetic link (10) by which the at least two first ports (3) and the at least two… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Power Conversion System | 180 |
| 2 | Modular converter with multilevel submodules | 114 |
| 3 | Power electronic conversion unit and system | 85 |
| 4 | Isolated soft-switch single-stage ac-DC converter | 82 |
| 5 | Four-port power electronic transformer based on hy… | 72 |
| 6 | Wireless power system | 58 |
| 7 | Intelligent photovoltaic interface and system | 58 |
| 8 | Power management utilizing synchronous common coup… | 40 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the structure means for R&D investment and entry strategy
The combination of a maturing lifecycle, moderate concentration, strong state-enterprise collaboration, and. China-dominant filings shapes both the competitive risk and the residual opportunity for new entrants.
Field is at plateau: multi-year growth positive, annual volume near peak
The lifecycle stage is best described as mature-plateau: annual filings have levelled near the 2023 peak of 92 families, even as the multi-year window still shows positive growth. This signals that foundational converter architectures are largely claimed, and differentiation increasingly requires application-specific or system-integration novelty rather than broad platform patents.
Lifecycle: MaturityModerate top-tier concentration; challenger tier is accessible
The top five filers hold 29% of the hundred largest filers’ combined total. The gap between leader (56 patent families) and the fifth-ranked State Grid Corporation of China (24 patent families) is material but not prohibitive. Focused specialists — particularly those targeting adjacent branches such as protective circuits or magnetics — can still build meaningful positions without competing head-on with the top tier.
Concentration: ModerateCo-filing is dominated by State Grid Corporation and its provincial subsidiaries
The most active co-filing pair is State Grid Corporation of China with Global Energy Interconnection Research Institute Co. Ltd., recorded on 12 joint families. State Grid also co-files frequently with State Grid Jiangsu Electric Power Co. Ltd. (5 families), China Electric Power Research Institute Co. Ltd. (5 families), and State Grid Beijing Electric Power Co. (4 families). This ecosystem is tightly clustered around a single state-owned enterprise hub, leaving the commercial sector — Huawei, Hitachi Energy, Delta — largely operating through independent filings.
Collaboration: State-grid hubChina and the US lead; Europe and PCT provide secondary protection
China accounts for the largest share of records, followed by the United States and Europe (EPO). PCT filings provide a third tier of international reach. India and Australia show emerging activity. The notably thin presence in South Korea and Taiwan — despite significant domestic power-electronics manufacturing in those markets — may represent a protection gap worth monitoring for entrants seeking freedom-to-operate.
Geography: CN/US/EP tierGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| State Grid Corporation of China | Global Energy Interconnection Research Institute Co. Ltd. | 12 |
| Guangdong Power Grid Co. Ltd. | Guangdong Power Grid Co. Ltd. Dongguan Power Supply Bureau | 11 |
| State Grid Corporation of China | State Grid Jiangsu Electric Power Co. Ltd. | 5 |
| State Grid Corporation of China | China Electric Power Research Institute Co. Ltd. | 5 |
| State Grid Corporation of China | State Grid Beijing Electric Power Co. | 4 |
| Global Energy Interconnection Research Institute Co. Ltd. | State Grid Beijing Electric Power Co. | 4 |
| State Grid Corporation of China | XJ Group Corporation | 3 |
| State Grid Corporation of China | XJ Electric Co. Ltd. | 3 |
| State Grid Corporation of China | Northeast Dianli University | 3 |
| Global Energy Interconnection Research Institute Co. Ltd. | Northeast Dianli University | 3 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Huawei Digital Power and Hitachi Energy anchor opposing ends of the top tier
The two largest filers differ in both technology emphasis and trajectory: Huawei Digital Power is accelerating through core converter IP, while Hitachi Energy has entered the ranked corpus recently with a focus bridging conversion and grid-systems integration.
Huawei Digital Power Technologies Co. Ltd.
Holding 56 patent families, Huawei Digital Power concentrates its filings across H02M subgroups covering general power-conversion circuits (H02M1, H02M7, H02M3), reflecting a broad converter-platform strategy. Momentum is strongly positive at +43% in the most recent period, suggesting an active prosecution campaign rather than a mature harvest phase.
families: 56Hitachi Energy Ltd.
Ranked second with 40 patent families, Hitachi Energy’s portfolio spans DC/DC conversion (H02M3), inverter technology (H02M7), and grid interconnection (H02J3) — a mix that positions it squarely at the SST-to-grid interface. Its momentum is flagged as a new entrant in the recent window, indicating that its current ranked volume reflects a concentrated recent build-up rather than a long legacy base.
families: 40| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Huawei Digital Power Technologies Co. Ltd. | 33 | ▲ +43% |
| Hitachi Energy Ltd. | 27 | ▲ new entrant |
| Delta Electronics Inc. | 13 | ▼ -19% |
| Delta Electronics Enterprise Management (Shanghai) Co. Ltd. | 15 | ▲ new entrant |
| State Grid Corporation of China | 3 | ▼ -79% |
| Georgia Tech Research Corporation | 10 | ▲ new entrant |
| Global Energy Interconnection Research Institute Co. Ltd. | 2 | ▲ new entrant |
| Guangdong Power Grid Co. Ltd. | 1 | ▼ -90% |
Under-served adjacent branches worth monitoring
Several IPC branches appear at low share relative to the dominant H02M/H02J core. These observations of relative sparsity become potential entry angles only where technical relevance and a realistic development path can be demonstrated.
H02H · Protective circuit arrangements
With only 17 records against hundreds in H02M, protection and fault-management circuits for SSTs remain comparatively thin. Solid-state transformers handling grid-level voltages require sophisticated overcurrent, overvoltage, and fault-isolation schemes; the sparse IP here suggests that dedicated protective-circuit innovation — particularly for medium-voltage DC bus architectures — may represent a genuine gap with clear technical necessity and an entry path through targeted filing or licensing partnerships with existing H02M leaders.
Search this in Eureka →H01F · Magnets, inductors & transformers
The H01F branch, covering transformer core design and magnetic component engineering, accounts for only 31 records despite the magnetic core being a critical performance determinant in SSTs. Advances in high-frequency magnetic materials (e.g., amorphous and nanocrystalline cores, wide-bandgap-optimised windings) could differentiate SST performance; the relatively light existing coverage suggests that component-level magnetic innovation has not been fully claimed alongside the surrounding power-electronics patents, offering a potential adjacent filing space for component specialists.
Search this in Eureka →How leaders differ by technology route across the IPC landscape
Strength of each leader across the main technology routes.
| Player | H02J 3 · Power supply & grid systems | H02M 7 · Power conversion (AC/DC etc.) | H02M 3 · Power conversion (AC/DC etc.) | H02M 1 · Power conversion (AC/DC etc.) | H02M 5 · Power conversion (AC/DC etc.) |
|---|---|---|---|---|---|
| Huawei Digital Power Technologies Co. Ltd. | Moderate · 18 | Strong · 33 | Strong · 22 | Strong · 37 | Moderate · 10 |
| Hitachi Energy Ltd. | Strong · 11 | Strong · 14 | Strong · 18 | Strong · 11 | Moderate · 5 |
| Delta Electronics Inc. | Strong · 12 | Strong · 12 | Strong · 13 | Strong · 10 | Moderate · 5 |
| Delta Electronics Enterprise Management (Shanghai) Co. Ltd. | Absent | Strong · 17 | Strong · 13 | Strong · 18 | Absent |
| State Grid Corporation of China | Strong · 18 | Moderate · 7 | Absent | Absent | Moderate · 6 |
| Resilient Power Systems LLC | Absent | Absent | Absent | Strong · 10 | Strong · 9 |
| Georgia Tech Research Corporation | Absent | Strong · 9 | Absent | Strong · 7 | Absent |
Frequently asked questions
The corpus in scope contains 536 patent families, spanning filings from 2017 through 2026 across all major jurisdictions.
Huawei Digital Power Technologies Co. Ltd. leads with 56 patent families, followed by Hitachi Energy Ltd. with 40 and Delta Electronics Inc. (CN) with 30.
On a multi-year basis, growth remains positive at approximately 20% in the recent window. However, annual volume peaked in 2023 at 92 families and has eased since; the 2024 and 2025 figures are additionally under-counted due to publication lag and should not be treated as a confirmed trend.
China leads with 202 records, followed by the United States with 173 and Europe (EPO) with 117. PCT and India follow as secondary markets. South Korea and Taiwan show minimal coverage relative to their manufacturing significance in power electronics.
H02M (power conversion circuits, AC/DC) and H02J (power supply and grid systems) together account for the vast majority of classified records. All other IPC branches, including EV integration, transformer magnetics, and protective circuits, hold single-digit percentage shares.
The dominant co-filing hub is State Grid Corporation of China, which files jointly with Global Energy Interconnection Research Institute Co. Ltd. (12 families), State Grid Jiangsu Electric Power Co. Ltd. (5 families), China Electric Power Research Institute Co. Ltd. (5 families), and State Grid Beijing Electric Power Co. (4 families). Commercial leaders such as Huawei Digital Power and Hitachi Energy appear to operate largely through independent filings, suggesting that cross-sector collaboration between commercial and state-grid entities remains limited.
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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.
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