Digital Substation Process Bus Patents: Who Leads, Trends 2026
Digital Substation Process Bus Patents: Filing Trends and Who Holds the Ground
29.8% concentration at the top. The five most active filers combine for 397 of 1,332 records in scope — under a third of the field, leaving a long tail of single- and few-filing entrants. Filings rose from 72 in 2017 to a peak of 79 in 2021, then eased to 58 by 2024 — a 27% decline over that three-year span. That is a cooling from peak activity, not a collapse; 2024's 58 filings still sit well above the 2017 baseline. Years after 2024 are not yet comparable because of publication lag and should not be read as a continued slide.
- 1HITACHI ENERGY LTD108
- 2MITSUBISHI ELECTRIC CORP81
- 3SCHWEITZER ENGINEERING LABORATORIES INC71
- 4ABB (SCHWEIZ) AG71
- 5ABB RES LTD66
See the full digital substation process bus analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions about digital substation process bus patents
Who holds the most patents on digital substation process bus technology?
The ranking is led by a single assignee with 108 records, well ahead of the fifth-placed filer at 66 and the tenth at 42. The top five assignees combined account for 397 of the 1,332 records in scope, or 29.8% — meaningful concentration but not a lockout, since the remaining 70% spreads across a ranked list of 100 companies plus a long tail beyond it. Established grid-equipment vendors and protection-relay specialists dominate the upper ranks, reflecting the fact that process-bus deployment requires both switchyard hardware and communications expertise.
Is process bus patent filing activity growing or slowing down?
Filing peaked at 79 records in 2021 and had eased to 58 by 2024, a 27% decline over that three-year span — a real cooling from peak activity rather than a collapse, since 2024 still sits above the 2017 level of 72. Figures for 2025 and 2026 are not yet comparable because publication typically lags filing by around 18 months, so recent years will keep filling in. Read the 2021-to-2024 window as the most reliable recent signal.
What patent classes cover digital substation process bus inventions?
The densest classes are H04L (digital information transmission, 29.3% of the 1,332 records), H02H (protective circuit arrangements, 22.5%) and G01R (electric and magnetic measurement, 21.8%), with H02J (power grid systems) close behind at 20.1%. Smaller but active classes include G06F for data processing, G05B for control systems, and H04B and H04W for general and wireless transmission. Because a single record can carry several IPC classes, these shares each compare against the full record base and add up to more than 100%.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Digital Substation Process Bus covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.