The leading assignee in this dataset holds 124 of the 1,210 records in scope, well ahead of the fifth-ranked company at 44 and the tenth-ranked company at 29. That gap between first place and the rest of the top ten suggests one applicant has built a substantially broader portfolio than any single competitor, though the field as a whole is not tightly concentrated: the top five combined hold only 26.6% of all records, and the top ten hold 42.1%. The remaining ranked companies each contribute comparatively few filings, forming a long tail rather than a second tight cluster.

Filings rose from 24 in 2017 to a peak of 56 in 2023, then pulled back to 25 by 2024 — a -52% move when comparing the two complete years 2021 (52 filings) and 2024 (25 filings). That is a real decline over that window, not a data artefact. However, because patent publication typically lags actual filing by around 18 months, the 2025 and 2026 figures in this dataset are still incomplete and should not yet be read as confirmation that the decline is continuing.

Three IPC subclasses dominate: H02M (power conversion, including AC/DC conversion) at 30.7% of the 1,210 records, H02J (power supply and grid systems) at 29.8%, and H02P (control of motors and generators) at 28.8%. Because a single record can carry multiple IPC classes, these percentages overlap rather than sum to 100%, meaning most DC microgrid filings claim across conversion, supply and control together. Protection-specific class H02H is comparatively thin at 4.5%, despite protection schemes being a named element of the search topic itself.