Active neutral point clamped (ANPC) converters are a specific three-level topology that uses active switches, rather than diodes alone, to clamp the neutral point, which lets designers actively balance conduction losses across devices. Multilevel converter topology is the broader category that also includes modular multilevel converters and other multi-level architectures. In this dataset, every record classifies under the general H02M power-conversion group, but only a subset specifically claim ANPC-style neutral-point clamping versus other multilevel arrangements like the modular multi-port DC power flow control family. When drafting or searching, treat ANPC as a subset of multilevel converter claims, not a synonym for it.

The ranking for this dataset covers only 5 companies, spanning a mix of universities and power-equipment manufacturers, with the leading assignee holding 4 of the ranked records and the fifth-ranked holding 1. This is a short, complete ranking rather than a top-50 cut, so it should be read as showing the field is not dominated by a single large filer. Recent-year filing activity has also shifted toward a newer academic entrant, while assignees with more historical records show no filings in the latest year. Anyone tracking this space competitively should watch for new entrants rather than assuming the historical leader remains most active.

One family — the internal-paralleled ANPC converter with logic-based flying capacitor voltage balancing, published as US20190363644A1 and extended through CA3005583A1 and US10924031B2 — is cited far more than any other record in this dataset, with 64 citations on the lead publication alone. That level of citation concentration means later filings on ANPC balancing logic are almost certainly differentiating against this family's specific approach. It is a useful anchor point for freedom-to-operate work in ANPC balancing, though citation counts inside a searched corpus do skew toward older, more-cited records rather than necessarily the most commercially active ones today.

Based on this dataset, filing activity peaked in 2019 at 3 records and has not returned to that level since, with the 2022 midpoint sitting at 2 records. That reads as flat to declining rather than an accelerating technology area, though the most recent one to two years are understated because publication typically lags filing by around 18 months. Readers should treat the very latest year's low count as incomplete rather than as evidence of an actual drop-off. The overall pattern still suggests this is a maturing claim space rather than one in an early growth phase.

The densest citation weight in this dataset sits on ANPC flying-capacitor balancing and on modular multilevel DC power flow control, so claims adjacent to those — such as fault-tolerant switch redundancy logic, common-mode voltage reduction modulation schemes, and device-count reduction circuit topologies — carry less documented prior art in this search. That does not guarantee an easy grant, but it indicates these branches are not where the current citation and filing concentration sits. A prospective filer should still run a fresh, broader prior-art search on any specific claim language before relying on this as a filing strategy, since this dataset is scoped to a specific IPC and keyword combination rather than the full universe of converter topology art.