HVDC Transmission Protection Patents: Leaders & Trends 2026
- Filing has cooled since 2020. Filings peaked at 16 in 2020 and had fallen to 10 by the 2022 midpoint, with no recovery visible in the data since — a maturing rather than an expanding claim space.
- Protection circuitry dominates the IPC mix. H02H protective-circuit filings (179) and H02J grid-system filings (167) together anchor the corpus, dwarfing the 7 pulse-technique and 5 telephonic-communication filings at the periphery.
- Europe leads filing venues. EPO receives more filings (67) than the US (48), China (33) or India (13), pointing to where DC fault-protection claims are being contested first.
What this patent landscape covers
This landscape tracks 262 patent families filed against HVDC transmission systems where the claims specifically address DC fault protection, DC circuit breakers, protection relaying or fault detection. The search combines HVDC-transmission terminology with protection-specific claim language and restricts the IPC to H02H7/26, H02H3 and H02J3/36, so the set is narrower than general HVDC patenting — it isolates the protection and relaying layer rather than converter topology or cable design.
Publication data runs from 2015 through the 2026-07-31 cut-off. Because publication typically lags filing by around 18 months, the most recent one to two years in any trend line understate actual filing activity and should be read as provisional rather than a genuine drop-off.
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Filing trend and technology composition
Two views of the same 262-family corpus: how filing activity has moved year over year, and how those filings distribute across IPC subclasses.
Filing trend, 2017–2026
Filings opened at 13 in 2017, rose to a peak of 16 in 2020, and had eased to 10 by the 2022 midpoint with no subsequent recovery in the recorded data — consistent with a technology area where the core protection-circuit claims are largely staked out rather than one still attracting a wave of new entrants.
IPC subclass composition
H02H (protective circuit arrangements, 179 records) and H02J (power supply and grid systems, 167) carry the bulk of the corpus, with G01R measurement claims (51) and H01H switch/relay hardware (36) forming a second tier. H02M power conversion (34) sits adjacent rather than central, and H03K logic circuits (7), H04M communication (5) and H01R connectors (4) mark the thin outer edge of the field.
Shares are the percentage of the 262 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on HVDC Transmission Protection and Relaying with Eureka
This page is one run against one query. Ask Eureka your own question about hvdc transmission protection and relaying and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this corpus
Fault protection of HVDC transmission lines (US20130088802A1)
A protection system for high voltage direct current, HVDC, transmission lines is provided. The protection system includes a direct current, DC, bus, a device configured to connect an HVDC transmission line to the bus, at least one DC circuit breaker arranged for disconnecting the transmission line from the bus upon reception of a trip signal, current and voltage sensors, an inductor arranged such that the current through the transmission line passes the inductor, and a fault detection unit. The fault detection unit is arranged for assessing, on the basis of current and/or voltage measurements, whether a fault exists on the transmission line, and sending, if a fault is detected on the transmission line, a trip signal.Filed by Hitachi Energy Ltd, published 2013-04-11 — one of the corpus's most-cited records at 39 citations.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4300181A | Commutation circuit for an HVDC circuit breaker | 50 |
| 2 | US20140347897A1 | High voltage direct current transmission and distribution system | 44 |
| 3 | US20120092904A1 | Coordinated control of multi-terminal HVDC systems | 44 |
| 4 | US20150015066A1 | Method and system for control and protection of direct current subsea power systems | 39 |
| 5 | US20130088802A1 | Fault protection of HVDC transmission lines | 39 |
| 6 | WO2013127463A1 | High voltage DC circuit breaker apparatus | 38 |
| 7 | WO2011157305A1 | Fault protection of HVDC transmission lines | 38 |
| 8 | WO2013127462A1 | Composite high voltage DC circuit breaker | 34 |
| 9 | WO2012044369A1 | Coordinated control of multi-terminal HVDC systems | 32 |
| 10 | US20140313628A1 | HVDC hybrid circuit breaker with snubber circuit | 31 |
Citation counts are drawn from within this searched corpus and favour older filings that have had more time to accumulate citations — treat them as a measure of influence on subsequent filers, not of current commercial 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 a filing decision
Three read-outs from the trend, IPC and venue data that matter more than the raw counts on their own.
The wave has passed its peak
Filings crested at 16 in 2020 and had dropped to 10 by 2022, with the trend line showing no rebound through the end of the recorded data. That pattern is typical of a sub-field where the foundational circuit-breaker and fault-detection architectures are already claimed, and new filings increasingly have to work around, rather than alongside, existing coverage.
Protection circuitry and grid integration are the crowded lanes
H02H and H02J together account for the large majority of the 262 families, meaning the core protective-circuit and grid-integration claim space is dense. G01R measurement and H01H switch/relay hardware form a smaller second tier, while H03K, H04M and H01R together total only 16 records — the thin edges of the field.
Europe is the primary contested venue
The EPO received more filings (67) than the United States (48) or China (33), with WIPO/PCT filings (34) indicating a meaningful share of applicants are still keeping jurisdictional options open. Germany's 15 filings and India's 13 suggest secondary but active regional interest rather than a two-country contest.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to hvdc transmission protection and relaying, with the prior art for and against each one.
Who is active, and where the momentum has stalled
The recent-year momentum data shows an unusual pattern for this corpus: the assignees tracked all show zero filings in the latest recorded year, which is more consistent with the 18-month publication lag masking recent activity than with the field going genuinely quiet.
A tight inventor cluster around multi-terminal control
The strongest co-assignee pairing in the dataset — Nuqui Reynaldo with Wang Jianping — appears together on 9 filings, with two further pairings (Nuqui Reynaldo with Srivastava Kailash, and with Pan Juiping) each at 6. Only 10 co-assignee pairs exist across the whole corpus, so most filings here are single-assignee work rather than joint development.
Recent-year momentum looks flat — read it with the lag in mind
Every assignee in the recent-momentum table shows zero filings in the most recent year, including established players in the space. Given the roughly 18-month gap between filing and publication, this almost certainly reflects filings still working through the pipeline rather than a genuine stop in R&D activity.
Older commutation-circuit art still sets the reference point
The most-cited record in the corpus, a commutation circuit for an HVDC circuit breaker, predates the rest of the dataset by decades and still draws the highest citation count. New filers in circuit-breaker commutation should expect examiners to cite it as foundational prior art.
| Assignee | Recent year | YoY |
|---|---|---|
| ABB Technology Ltd | 0 | — |
| General Electric Company | 0 | — |
| Siemens AG | 0 | — |
| General Electric Technology GmbH | 0 | — |
| ABB Research Ltd | 0 | — |
| ASEA Brown Boveri (ABB) | 0 | — |
| Scottish Hydro Electric Transmission Ltd | 0 | — |
| NUQUI REYNALDO | 0 | — |
Where to take this analysis
The trend and IPC data point to specific next questions for a freedom-to-operate or whitespace review.
Map the circuit-breaker commutation cluster
US4300181A anchors a citation cluster around commutation-circuit design for HVDC breakers. A targeted search on that cluster's citing families would clarify how much of the breaker-commutation claim space is genuinely occupied versus assumed occupied.
Explore citation clusters in EurekaCheck the under-claimed branches against your own architecture
The gate chips above — hybrid AC/DC discrimination, sub-sea protection, multi-terminal coordinated relaying — are thin in filing count relative to the H02H/H02J core. Any of them could be a viable first-claim position depending on the specific fault-detection method involved.
Run a whitespace search in EurekaRe-check momentum once the lag clears
Because every tracked assignee shows zero filings in the latest year, this dataset's most recent 12–18 months should be revisited once later publications land, rather than read as a genuine slowdown in R&D.
Set up a monitoring alert in EurekaCommon questions about HVDC protection and relaying patents
The corpus includes established grid-equipment manufacturers alongside a cluster of individually named inventors, notably Nuqui Reynaldo, who co-appears on the strongest co-assignee pairings in the dataset with 9 shared filings with Wang Jianping. Rather than a single dominant filer, the picture is one of several established manufacturers holding foundational circuit-breaker and fault-detection art alongside more recent, more narrowly scoped filings. Anyone assessing freedom to operate should look at both the corporate assignees and the named-inventor clusters, since patent rights can sit with either depending on jurisdiction and filing date.
No — filings peaked at 16 in 2020 and had fallen to 10 by the 2022 midpoint, with the trend showing no recovery through the most recent recorded years. That said, publication typically lags filing by around 18 months, so the last one to two years of any dataset like this will always look thinner than actual filing activity turns out to be. The honest read is that the field has moved past its most active filing period rather than that it has stopped entirely.
H02H (protective circuit arrangements) and H02J (power supply and grid systems) dominate, together covering the large majority of the 262 families tracked here. G01R (electric and magnetic measurement) and H01H (switches and relays) form a meaningful second tier tied to sensing and switching hardware. Filers should expect examiners searching this space to draw heavily from H02H and H02J prior art regardless of which specific fault-detection method is being claimed.
The European Patent Office receives the most filings in this dataset (67), ahead of the United States (48), WIPO/PCT applications (34) and China (33), with Germany (15) and India (13) as smaller but active venues. That ordering suggests Europe is currently the primary venue where DC fault-protection and circuit-breaker claims are being contested and examined. A company planning a filing strategy in this space should weight European prosecution risk accordingly, rather than defaulting to a US-first approach.
US20130088802A1, assigned to Hitachi Energy Ltd, claims a protection system for HVDC transmission lines built around a DC bus, a DC circuit breaker, current and voltage sensors, an inductor in the transmission-line current path, and a fault detection unit that issues a trip signal based on the sensor readings. It is one of the most-cited records in this corpus, with 39 citations, indicating it has been treated as relevant prior art by a substantial number of later filers. Anyone designing a DC fault-detection-and-trip architecture around similarly placed sensors and an inductor-based current path should review its claims closely before finalising a design.
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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.