Superconducting Cable Patents: Who Leads, Where Filings Stall 2026
- Filing has cooled since its 2019 peak. 29 families published that year against a single family so far in the most recent (partial) year — publication lag understates the last 12-18 months, but the multi-year decline from the 2019 high is real.
- Cable and magnet classes dominate the claim map. H01B (cables, conductors & insulators) covers 538 of 672 records, more than three times the next largest class, meaning most claim territory is already staked on conductor and insulation architecture rather than protection circuitry.
- One filing pair anchors the field. Sumitomo Electric Industries and Tokyo Electric Power Company (TEPCO) co-file at a scale — 47 shared records — that dwarfs every other collaboration pair in the dataset, and neither shows activity in the latest year.
Filing growth compares 2021 (9 records) with 2024 (4) — 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 672 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This dataset tracks 672 patent families filed against superconducting power cables and superconducting fault current limiters (SFCL), captured through claims and abstracts referencing cryogenic cooling, AC loss, quench recovery, current density and termination hardware, and classified under H01B12, H02H9 and H01F6. The scope spans conductor and insulation design, cryostat and refrigeration integration, and the protective-circuit logic that lets a superconducting element absorb and clear a fault without permanent damage.
Coverage runs from 2015 through the 2026-07-31 cut-off. Because publication typically lags filing by around 18 months, the last one to two years of the trend will fill in further as pending applications publish — treat the most recent year as a floor, not a peak.
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Filing trend and technology composition
Two views of the same 672 families: how filing activity moved year over year, and which IPC subclasses carry the claim density.
A 2019 peak followed by a multi-year decline
Filings rose from 6 in 2017 to a peak of 29 in 2019, then eased back toward 11 at the 2022 midpoint and lower still since. That shape is consistent with an early wave of foundational cable and SFCL claims being staked out, followed by consolidation rather than a fresh wave of entrants — though the final two years will revise upward as later filings publish.
Claim density concentrated in cabling and magnet classes
H01B (cables, conductors & insulators) accounts for 538 of 672 records, making it the dominant subclass by a wide margin. H10N (other electric solid-state devices) and H01F (magnets, inductors & transformers) follow at 179 and 140, with H02H (protective circuit arrangements) — the core SFCL protection logic — at 100. The gap between H01B and everything else suggests conductor and insulation architecture is where the claim space is most occupied, while protective-circuit and grid-integration claims (H02J, 17 records) remain comparatively open.
Shares are the percentage of the 672 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Superconducting Power Cables and FCL with Eureka
This page is one run against one query. Ask Eureka your own question about superconducting power cables and fcl and every answer comes back with the patent numbers behind it.
Try EurekaThe records other filings cite most
US20120257313A1 — Superconducting Fault Current Limiter
A superconducting fault current limiter (SCFCL) includes a cryogenic tank defining an interior volume, a superconductor disposed in the interior volume, and a refrigeration system configured to adjust a temperature of the superconductor in response to a condition during a steady state operation of the SCFCL. A method of operating a SCFCL includes cooling a superconductor disposed within an interior volume of a cryogenic tank to a temperature less than a critical temperature of the superconductor, and adjusting the temperature of the superconductor in response to a condition during a steady state operation of the SCFCL.Filed by Varian Semiconductor Equipment Associates; published 2012-10-11.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6921042B1 | Concentric tilted double-helix dipoles and higher-order multipole magnets | 166 |
| 2 | US5932523A | Superconducting cable conductor | 103 |
| 3 | US7558030B2 | Resistive superconducting fault current limiter | 72 |
| 4 | US10186858B2 | Device for a current limiter and a current limiter comprising said device | 68 |
| 5 | US5617280A | Superconducting fault current limiter | 64 |
| 6 | US6271474B1 | Methods of manufacturing oxide superconducting stranded wire and oxide superconducting cable conductor, and c… | 62 |
| 7 | US6596945B1 | Superconducting cable | 61 |
| 8 | US20050173149A1 | Triaxial superconducting cable and termination therefor | 59 |
| 9 | US20140221213A1 | Superconducting cable, superconducting cable line, method of installing superconducting cable, and method of … | 58 |
| 10 | US6275365B1 | Resistive fault current limiter | 57 |
Citation counts reflect influence within this searched corpus and skew toward older filings; a high count signals a foundational reference, not current filing activity.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three read-throughs from the trend, the IPC split and the citation table.
The wave has crested, on current data
Filings peaked at 29 in 2019 and have declined through the 2022 midpoint of 11 down to a single record in the latest partial year. Publication lag means the last year or two will revise upward, but the multi-year downward trend from 2019 predates that lag window.
Cabling claims dominate the IPC map
H01B outnumbers the next subclass (H10N, 179) by roughly three to one. New entrants targeting conductor geometry or insulation should expect dense prior art; the comparatively thin H02J footprint (17 records) around grid-integration and power-supply claims is a different story.
Older SFCL and magnet patents still anchor the field
The most-cited records date back to the 1990s and 2000s and cover foundational conductor and resistive-limiter designs. High citation counts here reflect age and centrality within the corpus rather than present-day relevance — useful for prior-art searches, less so for gauging where activity is headed.
One utility-supplier pairing dwarfs the rest
Sumitomo Electric Industries and Tokyo Electric Power Company co-file together at a scale no other pair in the dataset approaches; the next strongest pairs sit at 7 shared records each. Neither anchor party shows filings in the latest year, consistent with the broader slowdown.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to superconducting power cables and fcl, with the prior art for and against each one.
Who holds the claim territory
Filing activity concentrates around a small group of cable manufacturers, utilities and national research bodies, with a long tail of single- or few-filing entrants behind them.
Filing is collaborative at the top
The strongest collaborations pair a cable or wire manufacturer with a utility or national lab — Sumitomo Electric with TEPCO, Furukawa Electric with Japan's national research institute, LS Cable & System with its own affiliated entity. This pattern points to cable-plus-grid-operator development programmes rather than pure vendor R&D.
The named leaders have gone quiet recently
Every one of the highest-volume assignees in the recent-momentum data — Sumitomo Electric, TEPCO, Southwire, Prysmian, Furukawa, Varian Semiconductor Equipment — shows zero filings in the latest year. That is consistent with the broader post-2019 decline rather than any single company exiting the field.
US, Europe and PCT carry most of the volume
The United States leads receiving offices at 199 records, ahead of the EPO at 141 and WIPO/PCT at 65. Japan, Australia and Canada each hold smaller but non-trivial shares, suggesting protection strategies that prioritise the US and European markets first before regional filings elsewhere.
| Assignee | Recent year | YoY |
|---|---|---|
| Sumitomo Electric Industries, Ltd. | 0 | — |
| Tokyo Electric Power Company Holdings, Inc. (TEPCO) | 0 | — |
| Southwire Company, LLC | 0 | — |
| Pirelli Cavi e Sistemi S.p.A. | 0 | — |
| Furukawa Electric Co., Ltd. | 0 | — |
| Varian Semiconductor Equipment Associates, Inc. | 0 | — |
| American Superconductor Corporation | 0 | — |
| ASEA Brown Boveri (ABB) | 0 | — |
Where to take this analysis
The landscape points to where claim space is dense and where it is thin. The next step is testing a specific claim or design-around against the full record set.
Check freedom-to-operate on a specific conductor or termination design
With 538 of 672 records sitting in H01B, a new cabling or insulation claim needs a close read against the densest part of this corpus before drafting proceeds.
Run a freedom-to-operate check in EurekaTrack the quiet leaders for renewed activity
Sumitomo Electric, TEPCO and the other named leaders all show zero filings in the latest year — worth monitoring for whether that is a genuine pause or a publication-lag artefact.
Set up assignee alerts in EurekaExplore the thinner protective-circuit and grid-integration branches
H02J and quench-recovery-specific claims sit well below the cabling classes in volume, which may leave room for a first-mover claim structured around grid-side integration.
Explore white space in EurekaCommon questions about this landscape
The dataset shows Sumitomo Electric Industries and Tokyo Electric Power Company as the most tightly linked pair, co-filing 47 shared records together, which is far ahead of any other collaboration in the corpus. Other recurring names include Furukawa Electric, Southwire, Prysmian Cable Systems, LS Cable & System and American Superconductor. None of these leading assignees show filings in the latest year of the dataset, which is consistent with the broader slowdown after the 2019 peak rather than a single company's exit.
Filing peaked at 29 families in 2019, fell to 11 by the 2022 midpoint, and sits near a single record in the latest partial year. Because publication lags filing by roughly 18 months, the most recent one to two years will revise upward as pending applications publish. Even accounting for that lag, the multi-year decline from the 2019 peak reflects a genuine slowdown rather than a lag artefact alone.
H01B, covering cables, conductors and insulators, accounts for 538 of the 672 records in this dataset — more than three times the next largest class, H10N, at 179. Protective-circuit claims under H02H sit at 100, and grid-integration claims under H02J are the thinnest category at just 17. This tells a filer that conductor and insulation architecture is heavily claimed territory, while grid-side integration and some protective-circuit sub-areas carry comparatively less prior art.
A superconducting fault current limiter (SFCL) uses a superconducting element that normally carries current with near-zero resistance but transitions to a resistive state when a fault current exceeds a threshold, limiting the surge before it damages grid equipment. That transition, called a quench, and the subsequent quench recovery process are technically distinct from ordinary circuit-breaker behaviour, which is why SFCL claims are classified separately (H02H9) from general cable claims (H01B12). Patent claims in this space typically cover the cryostat and refrigeration design, the current-limiting element's material and geometry, and the control logic that manages quench and recovery.
The IPC composition points toward grid-integration and power-supply logic (H02J, only 17 records) and quench-recovery-specific control circuitry as comparatively under-claimed relative to the dense cabling classes. Connector and termination hardware, and AC loss reduction specifically at cryostat interfaces, also show less concentrated filing than core conductor design. A first claim in these areas would likely need to tie a specific control or interface mechanism to a defined operating condition rather than claim the broader cable or limiter structure, which is already heavily occupied.
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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.