Gas Insulated Switchgear Patents: Top Companies & Trends 2026
- Filings are concentrated but not locked up. The top five assignees hold 33.5% of all 1,814 records in scope, and the top ten hold 44.1% — leaving well over half the field to a long tail of single- and few-filing entrants.
- Diagnostics dominate the claim space. 73.0% of records carry an electric & magnetic measurement classification, far ahead of the 17.4% sitting in power switchboard & substation hardware — this field is being fought over sensing and analysis, not the enclosure itself.
- Momentum has shifted toward Chinese research institutions. Filings grew 22% from 2021 to 2024 (95 to 116), and recent-year assignee momentum shows a university-linked filer up sharply while several established Japanese and Korean names show no recent activity.
Filing growth compares 2021 (95 records) with 2024 (116) — 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 1,814 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Gas insulated switchgear (GIS) design patenting spans the physical enclosure and spacer hardware, gas density and dielectric monitoring, and — increasingly — the sensor and software layer used to detect partial discharge before it causes failure. The search underlying this page pairs GIS and gas insulated substation terms with the specific technical concerns practitioners actually file around: spacer design, gas density monitoring, assembly cleanliness, seismic qualification and footprint saving. That combination pulls in 1,814 published records dated between 2015 and the current data cut-off.
Because publication lags filing by roughly 18 months, the most recent one to two years in any trend understate real filing activity — 2024 is the last year that can be read as complete, and everything after it is still filling in.
Filing trends and technology composition
Two views of the same 1,814-record dataset: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
Filing trend, 2017–2026
Filings rose from 73 in 2017 to a peak of 126 in 2023, with 2021-to-2024 volume up 22% (95 to 116). 2026 figures (28 so far) are partial and will revise upward as later publications land.
Technology composition by IPC subclass
G01R (electric & magnetic measurement) covers 73.0% of records, well ahead of H02B (power switchboards & substations) at 17.4% and H01H (switches & relays) at 9.9%. G06N (AI-based computing) already reaches 6.7%, signalling that diagnostic modelling is a growing claim surface, not a niche one. Because records can carry multiple classes, these shares sum to more than 100% of the 1,814-record total.
Shares are the percentage of the 1,814 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Gas Insulated Switchgear Design with Eureka
This page is one run against one query. Ask Eureka your own question about gas insulated switchgear design and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited prior art and a representative recent filing
US10191114B2 — System for analysis of partial discharge defects of gas insulated switchgear
The present invention relates to a system for analysis of partial discharge defects of a gas insulated switchgear capable of allowing a user to precisely analyze a defect of a gas insulated switchgear due to a partial discharge, by providing both partial discharge signal information on a partial discharge signal sensed by a detecting sensor, and detection signal information on a detection signal sensed by one or more neighboring sensors adjacent to the detecting sensor, to a monitor.Filed by LSIS CO., LTD., published 2019-01-29 — illustrates the shift from single-sensor discharge detection toward multi-sensor comparative analysis.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | CN102435922A | GIS局部放电的声电联合检测系统和定位方法 | 117 |
| 2 | US5214595A | Abnormality diagnosing system and method for a high voltage power apparatus | 100 |
| 3 | US5107447A | Abnormality diagnosing system and method for a high voltage power apparatus | 96 |
| 4 | EP0342597A2 | Abnormality system for a high voltage power supply apparatus | 80 |
| 5 | US4446420A | Method and device for detecting and locating fault and/or partial discharges in a gas-insulated electrical eq… | 73 |
| 6 | KR101553005B1 | A partial discharge monitoring and diagnosis system for power devices | 63 |
| 7 | KR101574615B1 | A partial discharge monitoring and diagnosis system for power devices by using signal detection based on stat… | 59 |
| 8 | CN102809718A | 一种GIS超高频局部放电信号识别方法 | 59 |
| 9 | US20070221626A1 | Gas insulated switchgear | 55 |
| 10 | US5475312A | Method and device for distinguishing between partial discharge and electrical noise | 54 |
Citation counts reward older filings that have had more time to accumulate citations inside this corpus; treat them as evidence of influence on later work, not of current commercial relevance.
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 patterns stand out once the record set is broken down by class, geography and time.
A leader with real breathing room below it
The top assignee holds 197 records against a fifth-place figure of 61 and a tenth-place figure of 32 — a steep drop-off rather than a plateau. That gap is where a well-targeted filing strategy can still establish a defensible position without displacing the leader.
Filing activity is centred on China
China's receiving office accounts for the largest single share of filings, ahead of Japan, Europe, the US and South Korea combined receiving offices individually. Clearing freedom-to-operate in China first is the practical implication for any new entrant.
Sensing and measurement, not hardware, is the crowded zone
Nearly three-quarters of records touch electric and magnetic measurement classifications, compared with under a fifth touching switchboard and substation hardware directly. New enclosure or spacer geometry claims face a thinner prior art field than new discharge-detection claims do.
Growth is real but unevenly distributed
Aggregate filing volume grew 22% across the last fully-observable three-year window, yet assignee-level momentum diverges sharply — one university-linked filer is up 200% year over year while several long-established filers show no activity in the latest year.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to gas insulated switchgear design, with the prior art for and against each one.
Who is filing, and where the field is still open
Filing leadership sits with grid operators, diversified electronics majors and power-focused research institutes, but co-filing patterns and recent momentum tell a more granular story than the headline ranking alone.
Grid operator plus national research institute is the dominant collaboration
The strongest co-assignee pair in this dataset links a state grid operator with a national electric power research institute, and a second strong pair links the same grid operator with a university. This pattern suggests joint filings are a common route to combine field deployment access with lab-side diagnostic development.
Japanese equipment makers pair with utility partners
A leading Japanese electronics major and a major Japanese utility form the second-strongest co-filing pair in the dataset, consistent with equipment vendors developing diagnostic hardware in tandem with the operators who will deploy it.
Academic filers are the fastest-moving group right now
While several established corporate filers show flat or declining activity in the latest year, one university-linked filer's output tripled year over year, a signal that some of the newest diagnostic and AI-assisted detection work is originating outside the traditional equipment vendors.
| Assignee | Recent year | YoY |
|---|---|---|
| Xi'an Jiaotong University | 3 | +200% |
| State Grid Corporation of China | 2 | -75% |
| Toshiba Corporation | 1 | — |
| Mitsubishi Electric Corporation | 0 | -100% |
| Prysmian S.p.A. | 0 | — |
| Korea Electric Power Corporation | 0 | — |
| Hitachi, Ltd. | 0 | — |
| China Electric Power Research Institute Co., Ltd. | 0 | -100% |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, whitespace filing, or competitive tracking.
Map claim scope on the top assignees' families
With 33.5% of records held by five assignees, a claim-by-claim review of their granted families is the fastest way to identify where new filings would actually collide with existing scope versus where they would sit clear of it.
Explore assignee families in EurekaTest draft claims against the under-claimed sub-areas
Seismic qualification, assembly cleanliness and gas density sensor fusion show thinner claim density than core measurement classes — running a draft claim through prior-art search in these areas can confirm whether the white space is real or simply under-indexed.
Run a claim check in EurekaCommon questions about GIS design patents
The leading assignee in this dataset holds 197 of the 1,814 records in scope, with a steep drop to 61 records at fifth place and 32 at tenth place. State-owned grid operators, diversified electronics majors and national power research institutes make up most of the top of the ranking. The gap between first place and the rest of the ranked leaders is large enough that no single company controls the field outright, which leaves room for new entrants to build a defensible position rather than simply licensing around an incumbent.
Measurement and diagnostic classifications dominate: 73.0% of the 1,814 records carry an electric & magnetic measurement (G01R) classification, compared with 17.4% for power switchboard & substation hardware (H02B) and 9.9% for switches & relays (H01H). Because a single record can carry several IPC codes, these figures add up to more than 100% of the record total. In practical terms, the sensing and diagnostic layer around GIS equipment is a far more actively claimed space than the enclosure or switching hardware itself.
Yes, on the most recent complete data: filings rose 22% from 95 in 2021 to 116 in 2024, with a peak year of 126 filings in 2023. Figures for 2025 and 2026 appear lower, but that reflects publication lag of roughly 18 months rather than a genuine slowdown — those years will revise upward as more filings publish. Anyone reading the trend line should treat the last one to two years as incomplete rather than declining.
China's receiving office accounts for 833 of the filings tracked in this dataset, well ahead of Japan at 220, the European Patent Office at 163, the United States at 136, South Korea at 129, and the WIPO/PCT route at 61. This concentration reflects both the scale of grid infrastructure build-out in China and the presence of major state-owned grid operators and research institutes among the top filers. Companies planning freedom-to-operate clearance should prioritise Chinese prior art first given this volume.
US10191114B2, assigned to LSIS CO., LTD. and published in January 2019, covers a system that combines partial discharge signal information from a detecting sensor with detection signal information from one or more neighbouring sensors, presenting both to a monitor for defect analysis. It does not claim single-sensor discharge detection generally, nor does it claim the underlying discharge sensing hardware — its scope centres on the comparative multi-sensor presentation and analysis step. Designs that rely on single-sensor detection, or that fuse sensor data before presentation rather than presenting parallel signal information, sit outside its literal claim language, though a full freedom-to-operate opinion would need to check the granted claim set directly.
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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.