PMSM Design Patents: Who Leads, Where the Gaps Are 2026
- Filing peaked in 2019 at 108 records and has since flattened toward the high-70s by the midpoint year, suggesting the core claim space around rotor topology and flux weakening is largely staked out rather than still expanding.
- China dominates the filing venue with 522 of 849 receiving-office records, more than triple the United States (136) and over five times the EPO (87) — a strong signal of where enforcement and freedom-to-operate risk concentrates.
- Control-side claims now outnumber machine-side claims H02P (motor control) appears in 462 records against H02K (motor construction) at 432, showing algorithmic control — not rotor geometry alone — is where recent competitive activity has shifted.
What this landscape covers
Permanent magnet synchronous motor design spans two overlapping claim territories: the physical construction of the rotor and stator (H02K) and the control algorithms that drive them (H02P), including field-oriented control, flux weakening and torque-ripple suppression. This dataset pulls 849 patent families published between 2015 and mid-2026 that combine PMSM or interior permanent magnet motor terminology with claims touching torque ripple, demagnetization, flux weakening, rotor topology or efficiency mapping.
Because publication lags filing by roughly 18 months, the most recent year in the trend line is necessarily undercounted; treat the drop-off after the midpoint year as a floor, not a hard ceiling. The filing venue split — heavily weighted to China with meaningful but smaller pools in the US, Europe, India, PCT and Korea — matters more for where competitors will actually enforce than for where the underlying research originates.
Filing trend and technology composition
Two views of the same 849-family dataset: the year-by-year filing count, and the IPC subclasses that carry the claims.
A flat-to-declining trend after a 2019 peak
Filings rose to a peak of 108 in 2019, then eased toward 78 by the midpoint year of 2022. That pattern is more consistent with a maturing, well-claimed field than with an emerging one — new entrants face denser prior art than the raw family count alone suggests.
Control claims edge out construction claims
H02P (motor and generator control) and H02K (motor and generator construction) are near-evenly split at 462 and 432 records respectively, with smaller adjacent pools in digital processing, power conversion, lifts, measurement, EV propulsion and appliances — evidence that PMSM design claims increasingly cross into control software and system integration rather than staying confined to magnet and lamination geometry.
Shares are the percentage of the 849 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Permanent Magnet Synchronous Motor Design with Eureka
This page is one run against one query. Ask Eureka your own question about permanent magnet synchronous motor design and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this space
Load adaptive flux weakening of PMSM operating in voltage control mode
This filing describes a field-oriented control method where a current controller measures direct-axis and quadrature-axis motor currents and generates a direct-axis error value from the difference between a flux weakening reference current and the measured direct-axis current, then regulates the direct-axis motor voltage from that error. The approach targets adaptive flux weakening in voltage control mode rather than a fixed weakening schedule.Filed by Infineon Technologies Austria, published 2023 — illustrates how flux-weakening claims have moved toward adaptive, load-responsive control loops rather than static current tables.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20080224558A1 | Interior permanent magnet motor including rotor with flux barriers | 271 |
| 2 | US20100026128A1 | Interior permanent magnet motor including rotor with unequal poles | 145 |
| 3 | US7932658B2 | Interior permanent magnet motor including rotor with flux barriers | 100 |
| 4 | US6285104B1 | Motor with reduced torque ripple | 100 |
| 5 | CN103684196A | 一种可切换绕组的永磁同步电机驱动系统 | 91 |
| 6 | CN102904520A | 一种永磁同步电机电流预测控制方法 | 83 |
| 7 | JP1999299297A | Controller for permanent magnet synchronous motor | 78 |
| 8 | US20020047432A1 | Interior permanent magnet synchronous motor | 67 |
| 9 | US6717314B2 | Interior permanent magnet motor for use in washing machines | 60 |
| 10 | US20040017123A1 | Interior permanent magnet synchronous motor | 59 |
Citation counts accumulate over time, so older records such as the 2008 and 2010 interior permanent magnet motor filings lead the table by volume of citations rather than by current filing relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. 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 filing strategy
Three patterns stand out once the raw counts are read against publication lag and venue concentration.
The core claim space is largely staked out
A single peak year followed by a flattening trend is the signature of a field where the obvious rotor-topology and flux-weakening variants have already been claimed. New filings now need to differentiate on narrower control-loop or measurement details rather than broad geometry claims.
Enforcement risk is not evenly distributed
China's receiving-office share is more than triple the United States and over five times the EPO. Freedom-to-operate work that only screens US and European filings will miss the majority of the documented claim space.
Control algorithms now rival machine geometry
The near-even split between motor control (H02P) and motor construction (H02K) IPC codes shows that torque-ripple suppression and flux-weakening strategies implemented in software are as heavily claimed as the physical rotor and stator designs they run on.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to permanent magnet synchronous motor design, with the prior art for and against each one.
Who is filing, and where activity has cooled
Co-assignee activity is thin — only seven pairs across the entire dataset — and the strongest link is a single automotive pairing, not a research consortium. Recent-year momentum figures point downward across the assignees tracked here, which is consistent with the flattening filing trend rather than a sign that any one player has withdrawn.
Collaboration is rare and mostly corporate
The strongest co-assignee link pairs two automotive manufacturers filing jointly seven times; the next strongest pairs are university-institute or corporate-subsidiary links at two filings each. Cross-organisation R&D partnerships are the exception in this dataset, not the norm.
Every tracked assignee is filing less, not more
Across the assignees with visible recent-year activity, year-over-year filing counts are flat or negative, including one assignee down to zero filings in the latest year after previously filing. This mirrors the post-2019 plateau in the aggregate trend rather than signalling a company-specific retreat.
A broad base of small filers around a few repeat names
The ranking mixes automotive OEMs, a specialist power semiconductor firm, appliance and compressor manufacturers, and multiple Chinese universities. No single assignee's recent-year count is large enough to suggest one company is currently outpacing the field.
| Assignee | Recent year | YoY |
|---|---|---|
| Jiangsu University | 2 | -33% |
| Harbin Institute of Technology | 1 | -50% |
| Mitsubishi Electric Corporation | 0 | — |
| Infineon Technologies Austria AG | 0 | — |
| Steering Solutions IP Holding Corporation | 0 | — |
| Gree Electric Appliances, Inc. of Zhuhai | 0 | -100% |
| Samsung Electronics Co., Ltd. (Korea) | 0 | — |
| Hyundai Motor Company | 0 | — |
Where to take this research
The aggregate numbers point to specific next steps depending on whether the goal is freedom-to-operate, white-space filing, or competitor tracking.
Run a full-text FTO screen weighted to China
With 522 of 849 receiving-office records filed in China, an FTO search limited to US and EPO databases will systematically undercount the active claim space around rotor topology and flux weakening.
Explore China filings in EurekaProbe the control-side white space
The near-even H02P/H02K split suggests remaining differentiation lies in adaptive control loops, sensorless estimation and system-integration claims rather than magnet or lamination geometry alone.
Search control-claim white space in EurekaTrack momentum quarter by quarter, not year by year
Because the latest filing year is structurally undercounted by publication lag, single-year momentum figures should be checked against a rolling multi-quarter view before concluding an assignee has exited the field.
Set up assignee tracking in EurekaCommon questions about PMSM design patents
This dataset identifies 849 patent families published between 2015 and mid-2026 that combine PMSM or interior permanent magnet motor terminology with claims on torque ripple, demagnetization, flux weakening, rotor topology or efficiency mapping. The true figure is somewhat higher because the most recent year is undercounted due to the roughly 18-month lag between filing and publication. Family counts, rather than raw document counts, are the more reliable measure since they neutralise duplicate filings across jurisdictions for the same invention.
China leads by a wide margin with 522 of the 849 tracked records filed through its receiving office, more than three times the United States (136) and over five times the European Patent Office (87). India, the PCT route and South Korea make up smaller secondary pools. Any competitive or freedom-to-operate analysis that skips Chinese filings will miss the majority of the documented claim activity in this field.
Filing activity peaked in 2019 at 108 records and had eased to 78 by the 2022 midpoint, a pattern consistent with a maturing rather than emerging field. Recent-year momentum figures for individual assignees are flat to sharply negative, though the most recent one to two years are always undercounted because of publication lag. The overall shape suggests the broad rotor-topology and flux-weakening claim space is largely occupied, pushing new filers toward narrower control-loop and sensorless-estimation claims.
H02K covers the physical construction of electric motors and generators, including rotor and stator geometry, magnet placement and lamination design. H02P covers the control of motors and generators, including field-oriented control, flux weakening and torque-ripple suppression algorithms. In this dataset the two are nearly evenly split at 432 and 462 records respectively, showing that control-side software claims now carry as much weight as machine-side geometry claims in PMSM design filings.
The IPC composition shows only thin coverage in areas adjacent to the dense H02K/H02P core, including sensorless flux-weakening estimation, demagnetization-tolerant lamination stacking for high-temperature operation, torque-ripple compensation tuned for compressor-integrated motors, and PMSM control specific to lift and escalator drive systems. These branches show up in the data as small counts within adjacent IPC subclasses like G01R, B66B and D06F rather than as dedicated dense clusters. A prior-art search focused on these narrower intersections is more likely to surface open claim territory than a broad rotor-topology search.
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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.