Transformers & Switchgear Patents: Top Companies & Filing Trends 2026
- Leadership is thin at the top. the top 5 assignees together hold just 13.7% of the 3,605 records in scope, and the top 10 only 20.0% — no single company controls the field.
- Filing has cooled from its 2017 peak. activity ran from 171 records that year down to 79 by 2024, a 38% decline from 2021 to 2024, though the newest years are still filling in as publications lag filing.
- Power conversion and grid supply dominate the claim space. H02M and H02J together touch well over a third of all records, while switches and relays (H01H) sit under 6% — a much thinner claims layer.
Filing growth compares 2021 (127 records) with 2024 (79) — 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 3,605 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape maps 3,605 published records at the intersection of power transformers and switchgear with control, sensing and power-stage electronics — filings that combine hardware like transformers and switchgear with functional claims on switching frequency, current sensing, control circuits or contact behaviour. It is not a landscape of transformer hardware alone, nor of control electronics alone, but of where the two overlap in claim language.
The scope spans a decade of publication activity through the 2026 cut-off, drawing on receiving offices led by the United States, with meaningful volume also filed through the EPO, WIPO's PCT route, Canada, Australia and the United Kingdom. Because publication trails filing by roughly 18 months, the most recent one to two years in any trend understate real filing activity.
Filing trend and technology composition
Two views of the same 3,605-record corpus: how filing volume has moved year over year, and how records split across IPC subclasses. Because a single record can carry several IPC codes, the class shares below sum to more than 100% of the record total.
Filing trend, 2017–2026
Filings peaked at 171 records in 2017. From a 2021 level of 127, volume fell to 79 by 2024 — a 38% decline over that three-year span. Treat 2025 and 2026 as still filling in rather than as evidence of a further drop.
IPC subclass composition
Power conversion (H02M, 20.3% of records) and power supply/grid systems (H02J, 17.8%) are the two largest classes, followed by protective circuit arrangements (H02H, 15.3%) and electric/magnetic measurement (G01R, 14.2%). Switches and relays (H01H) and digital transmission (H04L) each sit just above 5%, marking noticeably thinner claim coverage.
Shares are the percentage of the 3,605 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Transformers & Switchgear Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about transformers & switchgear patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaA representative filing
Switch mode pulse width modulated DC-DC converter with multiple power transformers
A switch mode pulse width modulated DC-DC power converter comprises at least one first electronic circuit on an input side and a second electronic circuit on an output side, coupled via at least two power transformers. Each transformer carries a first winding in an input-side converter stage and a second winding in an output-side converter stage, arranged so the multiple transformers share the switching duty across the converter topology.Filed by Danmarks Tekniske Universitet — illustrates how transformer hardware claims are routinely bundled with power-stage switching control rather than claimed as standalone hardware.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4934694A | Computer controlled exercise system | 663 |
| 2 | US6989010B2 | Ablation system and method of use | 560 |
| 3 | US5697958A | Electromagnetic noise detector for implantable medical devices | 546 |
| 4 | US4891764A | Program controlled force measurement and control system | 543 |
| 5 | US4860185A | Integrated uninterruptible power supply for personal computers | 525 |
| 6 | US6648883B2 | Ablation system and method of use | 524 |
| 7 | US20110282508A1 | Generalized grid security framework | 486 |
| 8 | US20080265684A1 | High power wireless resonant energy transfer system | 462 |
| 9 | US6663627B2 | Ablation system and method of use | 457 |
| 10 | US5189277A | Modular, stackable plasma cutting apparatus | 358 |
Citation counts reflect influence within the searched corpus and skew toward older filings — read them as a signal of historical weight, not current relevance.
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 filing strategy
Three read-throughs from the assignee, class and trend data that matter more for a filing decision than the raw counts alone.
No single assignee dominates
The leader holds 249 records out of 3,605, and the top 5 combined reach only 13.7% of all records in scope. That is a fragmented field: a long tail of single- and few-filing entrants sits behind a modest cluster of repeat filers, so freedom-to-operate analysis has to look well past the named leaders.
Post-peak filing has eased, not stopped
Volume fell from 127 records in 2021 to 79 in 2024, a decline of 38% over that span, after a 2017 peak of 171. That is a real pullback from peak activity, not evidence the field is closed — new entrants continue to file even as repeat filers slow down.
Power conversion carries the heaviest claim load
H02M (power conversion) and H02J (power supply and grid systems) between them touch well over a third of the corpus, meaning switching-stage and grid-interface claims sit on the densest prior art. Switches and relays (H01H, 5.1%) and heating/lighting circuits (H05B, 5.3%) carry far less claim density by comparison.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to transformers & switchgear patent landscape, with the prior art for and against each one.
Who is filing, and where the gaps sit
The ranked list covers 100 companies scored against the full 3,605-record corpus. Filing patterns among the named leaders — several of whom show no activity in the latest year — point to a field where recent momentum has shifted toward the unranked tail rather than staying with historic filers.
A single leader, no runaway gap
The top-ranked assignee holds 249 records, well ahead of fifth place at 54 and tenth place at 43 — a steep drop-off after the leader rather than a gradual taper, which suggests one company built an early, durable filing position while the rest of the field stayed comparatively even.
Historic leaders have gone quiet
Several of the most prolific historic assignees show zero filings in the latest tracked year, a -100% year-on-year move for at least one. That does not necessarily mean exit from the space — it may reflect publication lag — but it does mean current competitive pressure is not coming from the same names that built the largest portfolios.
Co-filing is rare and concentrated
Only 10 co-assignee pairs appear in the corpus, and the strongest repeated pairings all involve the same corporate filer working with different named inventors. Collaborative, multi-company filing is the exception here, not the norm — most records carry a single corporate assignee.
| Assignee | Recent year | YoY |
|---|---|---|
| Schweitzer Engineering Laboratories, Inc. | 0 | -100% |
| General Electric Co. | 0 | — |
| Emprimus LLC | 0 | — |
| Asator Global Technologies LLC | 0 | — |
| Emprimus LLC | 0 | — |
| Toshiba Corporation | 0 | — |
| Shell Oil Company | 0 | — |
| ABB (Schweiz) AG | 0 | — |
Where to take this next
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, white-space filing, or tracking a named competitor.
Check freedom-to-operate against the densest classes
H02M and H02J carry the heaviest claim density in this corpus, so any new power-conversion or grid-interface filing should be checked against that prior art before drafting.
Run a clearance search in EurekaWatch the quiet historic leaders
Several top-ranked assignees show no filings in the latest year. Confirm whether that reflects publication lag or an actual pullback before treating the field as open.
Track assignee activity in EurekaDraft into the thinner classes
Switches and relays and digital-transmission-linked control circuits carry noticeably lower filing density than the power-conversion core, which is where a first claim has more room to stand.
Explore white space in EurekaCommon questions on this landscape
One assignee leads the ranked list with 249 records, well clear of the rest of the field — fifth place holds 54 and tenth place holds 43. That drop-off after the leader means the field is not evenly distributed at the very top, but it is also not dominated by a single company overall: the top 5 assignees combined account for only 13.7% of the 3,605 records in scope, and the top 10 for 20.0%. Most of the corpus sits with a long tail of companies filing far fewer records each.
Filing peaked in 2017 at 171 records and has eased since, with the reliably comparable window showing a drop from 127 records in 2021 to 79 in 2024 — a 38% decline over three years. The years after 2024 are not a safe basis for a trend call because publication typically lags filing by around 18 months, so 2025 and 2026 figures will keep rising as more records surface. The honest read is a post-peak cooldown through 2024, not a confirmed continued fall.
Power conversion (H02M) is the largest single class at 20.3% of the 3,605 records, followed by power supply and grid systems (H02J) at 17.8%, protective circuit arrangements (H02H) at 15.3%, and electric and magnetic measurement (G01R) at 14.2%. Because records often carry more than one IPC class, these figures overlap rather than sum to 100%. Switches and relays (H01H) and heating/lighting circuits (H05B) trail well behind, each just above 5% of records, marking comparatively thinner claim coverage.
The classes with the lowest filing density relative to the power-conversion core are switches and relays (H01H, 5.1% of records) and digital information transmission (H04L, 5.2%), alongside heating and lighting circuits (H05B, 5.3%). Sub-areas that combine mechanical switch behaviour — contact stress, friction coefficient — with sensing or digital control show up far less often than pure power-stage or protection claims. That combination is a reasonable starting point for a first claim aimed at under-claimed territory rather than the dense H02M/H02J core.
It is fragmented rather than concentrated. The ranked list covers 100 companies, and even combined, the top 5 hold only 13.7% of the 3,605 records in scope while the top 10 hold 20.0%. That leaves roughly four-fifths of the corpus spread across the remaining ranked companies and an unranked tail, which matters for freedom-to-operate work: clearing the named leaders is not sufficient, because most of the filing activity sits outside them.
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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.