Solid-State Transformer Patent Landscape 2026
Solid-State Transformer Patent Landscape in 2026
The solid-state transformer field spans 2,078 patent families and is dominated by Chinese industrial and utility players, with Huawei Digital Power holding the top position. Annual filing volume peaked in 2020 and has eased since, though the most recent data years are subject to publication lag.
Huawei Digital Power leads a concentrated but broadly contested field
China at 106 and 100 patent families respectively, establishing a tight three-way leading cluster.
The top five filers account for 22% of the combined output of the hundred largest filers, indicating moderate-to-high concentration at the top tier without a single dominant monopolist. The gap between the leader and the fifth-ranked Hitachi Energy (74 patent families) is meaningful but not insurmountable.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | Huawei Digital Power Technologies Co Ltd | 136 | |
| 2 | Delta Electronics Inc | 106 | |
| 3 | State Grid Corporation of China | 100 | |
| 4 | Delta Electronics (Shanghai) Co Ltd | 88 | |
| 5 | Hitachi Energy Ltd | 74 | |
| 6 | Georgia Tech Research Corporation | 61 | |
| 7 | ABB (Switzerland) AG | 59 | |
| 8 | Sumitomo Electric Industries Ltd | 56 | |
| 9 | Toyohashi University of Technology | 54 | |
| 10 | Southeast University | 54 |
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 11 | Hitachi Ltd | 48 | |
| 12 | Huawei Technologies Co Ltd | 47 | |
| 13 | Shanghai Jiao Tong University | 45 | |
| 14 | Hunan University | 42 | |
| 15 | State Grid Jiangsu Electric Power Co Ltd | 41 | |
| 16 | Global Energy Interconnection Research Institute Co Ltd | 41 | |
| 17 | North China Electric Power University | 40 | |
| 18 | Xi’an Jiaotong University | 36 | |
| 19 | State Grid Jiangsu Electric Power Co Ltd Research Institute | 36 | |
| 20 | Sungrow Power Supply Co Ltd | 35 |
The presence of both vertically integrated industrial groups (Huawei, Delta, Hitachi) and national grid operators (State Grid) at the top signals that the technology is being developed simultaneously for product commercialization and infrastructure deployment, creating overlapping but distinct IP territories.
Filing counts for 2024–2026 are materially under-represented due to standard patent publication lag of 18–24 months; apparent softness in those years does not indicate a structural retreat. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Activity peaked in 2020; power-conversion IP dominates the technology mix
The annual filing trend and IPC composition together reveal a field that surged through 2020 and has since moderated, while remaining overwhelmingly anchored in core power-conversion and grid-systems engineering.
Annual filing trend
Filings climbed from 130 in 2017 to a peak of 303 in 2020, then settled to the 267–282 range through 2022–2023 before the apparent further decline in 2024–2025 — years that should be treated as under-counted due to publication lag rather than as confirmed contraction.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H02M (power conversion) and H02J (power supply and grid systems) together account for the overwhelming majority of IPC records, confirming that control topologies, converter architectures, and grid-interface schemes are the core battleground. Branches such as B60L (electric vehicle propulsion), H01F (magnetics), and H02H (protection) carry noticeably lower record counts, marking them as adjacent rather than core.
↗ 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.
Power Conversion System
A power conversion system includes a high voltage (HV) switchgear; a solid-state transformer; and a low voltage (LV) switchgear. The HV switchgear connects to and disconnects from a HV or medium voltage (MV) network. The HV switchgear connects to an input of the solid-state transformer. The solid-state transformer comprises a first module and a second… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Power Conversion System | 180 |
| 2 | Solid state regulated power transformer with wavef… | 127 |
| 3 | Reverse phase-controlled dimmer | 126 |
| 4 | Interleaved multi-channel, multi-level, multi-quad… | 114 |
| 5 | Modular converter with multilevel submodules | 114 |
| 6 | Multilevel converter based intelligent universal t… | 107 |
| 7 | Scheme for rapid adjustment of network impedance | 104 |
| 8 | Power conversion system with galvanically isolated… | 95 |
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 patent structure means for R&D investment decisions
Four structural observations — maturity, concentration, collaboration, and geographic spread — define the strategic context for any new entrant or incumbent expanding its position.
Past-peak annual volume signals a maturing core, not a declining technology
The lifecycle evidence labels this field as in decline relative to its 2020 peak, with annual volume easing back since then. This typically marks the transition from broad exploratory filing to selective, deeper prosecution on commercially viable architectures. New entrants face an increasingly well-occupied core IP space and should expect freedom-to-operate challenges in converter topologies and grid-interface control.
Past-peak · 2020 peakTop-tier is contested among three Chinese-rooted leaders; no single chokepoint owner
With the top five filers holding 22% of the hundred largest filers’ combined output, no single entity can block the field outright. Huawei Digital Power’s 136-family lead is real but narrow relative to Delta Electronics and State Grid. A challenger accumulating 60–80 well-positioned families could credibly enter the top five, provided focus is placed on under-served sub-branches rather than head-on competition in H02M7.
Moderate-high concentrationToyohashi University–Sumitomo Electric is the field’s most active co-filing pair
The strongest co-filing relationship involves Toyohashi University of Technology and Sumitomo Electric Industries, with 64 jointly filed patent families — substantially ahead of all other pairs. State Grid Corporation of China anchors a second dense cluster, co-filing with the Global Energy Interconnection Research Institute (36 families), the China Electric Power Research Institute (19 families), and multiple Jiangsu grid entities (11 families each). These clusters indicate that academic-industrial and utility-research-institute partnerships are the dominant model for innovation in this space.
University–industry pairsChina is the primary filing jurisdiction; US and EPO are meaningful secondary markets
China accounts for the largest share of patent records among all jurisdictions, reflecting both the home-market strategies of leading Chinese filers and the country’s grid-modernization investment. The United States and Europe (EPO) are the next most active jurisdictions, followed by WIPO (PCT) which signals cross-border commercialization ambition. India, Germany, and Japan round out meaningful secondary markets. Coverage in Southeast Asia, the Middle East, and Africa remains sparse, pointing to geographic white space for applicants targeting those emerging grid markets.
China-led · global reachGo 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 |
|---|---|---|
| Toyohashi University of Technology | Sumitomo Electric Industries Ltd | 64 |
| State Grid Corporation of China | Global Energy Interconnection Research Institute Co Ltd | 36 |
| State Grid Corporation of China | China Electric Power Research Institute Co Ltd | 19 |
| State Grid Corporation of China | Jiangsu Electric Power Research Institute Co Ltd | 11 |
| State Grid Corporation of China | State Grid Jiangsu Electric Power Co Ltd Research Institute | 11 |
| State Grid Corporation of China | State Grid Jiangsu Electric Power Co Ltd | 11 |
| Toyohashi University of Technology | Toyohashi University of Technology | 10 |
| Sumitomo Electric Industries Ltd | Toyohashi University of Technology | 10 |
| State Grid Corporation of China | State Grid Beijing Electric Power Co | 8 |
| State Grid Corporation of China | XJ Group Corporation | 7 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Huawei Digital Power and Delta Electronics lead on power-conversion depth; State Grid dominates grid-systems coverage
The top three filers occupy distinct strategic positions despite overlapping in H02M, making their portfolios complementary in some respects and directly competitive in others.
Huawei Digital Power Tech Co Ltd
The field’s leading filer with 136 patent families, concentrating heavily on H02M7 (AC/DC power conversion), H02M1, and H02M3 sub-classes — all core solid-state transformer converter architectures. Recent-period filing trend shows a –14% step down from the prior three-year window, consistent with the broader field moderation rather than a strategic withdrawal. The portfolio depth in power-conversion sub-classes positions this entity as the primary IP reference point for converter topology design.
families: 136Delta Electronics (Shanghai) Co Ltd
Ranked fourth overall with 88 patent families, Delta Electronics (Shanghai) is the fastest-growing major player among the top tier, with recent filings up +92% versus the prior three-year window — the strongest momentum of any top-eight filer. Its focus mirrors the parent entity’s H02M1, H02M3, and H02M7 concentration, suggesting an intentional portfolio build-out in the Shanghai subsidiary that may be designed to support local manufacturing and China-market IP coverage distinct from the Taiwan parent’s filings.
families: 88| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Huawei Digital Power Technologies Co Ltd | 61 | ▼ -14% |
| Delta Electronics Inc | 46 | ▼ -12% |
| State Grid Corporation of China | 13 | ▼ -65% |
| Delta Electronics (Shanghai) Co Ltd | 50 | ▲ +92% |
| Georgia Tech Research Corporation | 26 | ▬ -4% |
| Southeast University | 2 | ▼ -80% |
| Huawei Technologies Co Ltd | 13 | ▼ -66% |
| Shanghai Jiao Tong University | 18 | ▼ -14% |
EV propulsion integration and transformer magnetics are under-served relative to the core
Several IPC branches appear in the corpus at low share, sitting adjacent to the dominant H02M/H02J core. Two of these carry plausible technical relevance and a realistic entry path for focused R&D programs.
B60L · Electric vehicle propulsion
This branch records 126 patent records — only 3% of the corpus by share — despite solid-state transformers being a natural enabling technology for bidirectional EV charging and traction power. The sparsity likely reflects that EV charging IP is filed primarily under dedicated charging and power-electronics classes rather than SST-specific classifications. An entrant with existing EV powertrain expertise could build differentiated IP by explicitly claiming SST-based on-board or off-board charging architectures, targeting a gap between the EV and grid-power filing communities.
Search this in Eureka →H01F · Magnets, inductors & transformers
H01F covers the magnetic component design — high-frequency transformer cores, winding geometries, and insulation — that is physically central to every solid-state transformer but accounts for only 118 patent records (3% share). Core converter-circuit patents dominate because applicants typically claim at the system or control level rather than the magnetic component level. This creates an opening for materials or magnetics specialists to establish IP in high-frequency core design, integrated winding structures, and thermal management of SST transformers, areas where the corpus is observably thin.
Search this in Eureka →How leading filers differ across power-conversion sub-routes and grid-systems coverage
Strength of each leader across the main technology routes.
| Player | H02M 3 · Power conversion (AC/DC etc.) | H02M 7 · Power conversion (AC/DC etc.) | H02M 1 · Power conversion (AC/DC etc.) | H02J 3 · Power supply & grid systems | H02M 5 · Power conversion (AC/DC etc.) |
|---|---|---|---|---|---|
| Huawei Digital Power Technologies Co Ltd | Strong · 51 | Strong · 83 | Strong · 75 | Moderate · 38 | Moderate · 33 |
| Delta Electronics Inc | Strong · 42 | Strong · 58 | Strong · 50 | Absent | Moderate · 15 |
| Delta Electronics (Shanghai) Co Ltd | Strong · 41 | Strong · 40 | Strong · 54 | Moderate · 21 | Absent |
| State Grid Corporation of China | Moderate · 25 | Strong · 27 | Moderate · 24 | Strong · 52 | Moderate · 23 |
| Huawei Technologies Co Ltd | Strong · 32 | Strong · 26 | Strong · 23 | Absent | Absent |
| Shanghai Jiao Tong University | Strong · 21 | Strong · 26 | Absent | Strong · 33 | Absent |
| Georgia Tech Research Corporation | Absent | Strong · 43 | Strong · 30 | Absent | Absent |
Frequently asked questions
The corpus contains 2,078 patent families in scope, representing the global patent activity mapped for this technology area.
Huawei Digital Power Tech Co Ltd holds the top position with 136 patent families, ahead of Delta Electronics Inc (106 families) and State Grid Corporation of China (100 families).
Annual filings peaked in 2020 at 303, then moderated to the 267–282 range in 2021–2023. Figures for 2024 and 2025 are materially under-counted due to the standard 18–24 month patent publication lag and should not be read as confirmed decline.
China is the leading filing jurisdiction by a wide margin, followed by the United States, Europe (EPO), and WIPO (PCT). India, Germany, and Japan are the next most active secondary markets.
Toyohashi University of Technology and Sumitomo Electric Industries Ltd jointly filed 64 patent families, making them the most active co-filing pair. State Grid Corporation of China anchors the next densest cluster, with multiple co-filing relationships with grid research institutes and provincial grid entities.
B60L (electric vehicle propulsion) and H01F (magnets, inductors and transformers) each account for approximately 3% of corpus records, despite strong technical adjacency to solid-state transformer applications. H02H (protective circuit arrangements) and H05K (printed circuits and assemblies) are also observably sparse at roughly 2% and 1% respectively.
Generate your own solid-state transformer landscape in minutes
Join 18,000+ innovators using PatSnap Eureka to map any technology landscape: search 2B+ patents and papers, surface key assignees, and generate a report like this in minutes.
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.