The ranked assignee list covers 100 companies, and the leading assignee holds 103 records against 27 for the fifth-placed company and 17 for the tenth-placed company — a steep drop after the top position rather than a gradual taper. The top five combined hold 20.8% of all 1,349 records in scope, and the top ten hold 28.4%, which means the majority of filings sit outside the leading group. This is a field with a clear leader but no single dominant monopoly over the whole claim space.

Filing rose from 91 records in 2017 to a peak of 143 in 2024, including a documented +68% increase between 2021 (85 filings) and 2024 (143 filings). The apparent dip in 2025 and 2026 in the raw trend chart is a publication-lag artefact, not a real slowdown — patent publication typically trails filing by around 18 months, so the last two years in any chart understate true activity. 2024 is the most recent year that should be treated as a complete data point.

The dominant IPC class is H02J (power supply and grid systems), appearing on 74.2% of the 1,349 records in scope, followed by H02M power conversion at 21.5%. Control-specific classes are filed less often: G05B control and regulating systems appears on 11.6% of records and G05F electric variable control on 9.3%. These shares sum to more than 100% because a single patent record can carry several IPC classes, reflecting how grid-interface hardware claims and control-logic claims often appear together in the same filing.