552 patents currently held
Held is read from USPTO's recorded assignments; a transfer never recorded there does not appear.
The next term ends in Dec 2026. from the record
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
55
Ending by 2030
Dec 2026
Next term end
482
Patent families
When these terms end
Held patents by the year their term ends
notable patents
fee due within 90 days
all others
Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
Notable: the highest-ranked patents in this portfolio by citations and family size. Fee due within 90 days: a maintenance fee is due within 90 days of when this page was computed and not yet paid.
Notable patents
Ranked by citations and family size, against patents of the same kind granted the same year. How we rank
Notable
Ends Sep 2034 · High confidence
Also notable
Ends Sep 2035 · High confidence
Also notable
Ends Sep 2035 · High confidence
Power Line Parameter Adjustment and Fault Location Using Traveling Waves
US 8,990,036
Cited by 47 later US patents, top 10% of utility patents granted in 2015 in our data, and renewed at 3 of 3 maintenance windows. Protection runs to 2034.
Fault Detection in Electric Power Delivery Systems Using Underreach, Directional, and Traveling Wave Elements
US 9,594,112
Cited by 29 later US patents, top 25% of utility patents granted in 2017 in our data, and renewed at every maintenance window due so far. Protection runs to 2035.
Fault Detection in Electric Power Delivery Systems Using Underreach, Directional, and Traveling Wave Elements
US 9,627,881
Cited by 26 later US patents, top 25% of utility patents granted in 2017 in our data, and renewed at every maintenance window due so far. Protection runs to 2035.
Fee deadlines
Maintenance fees fall due 3.5, 7.5 and 11.5 years after grant. A missed fee ends a patent at the end of the six month grace period that follows, not on the due date.
- 14 fees due Nov 14 to 30, 2026 · next Nov 14
- 15 fees due Dec 2 to 27, 2026 · next Dec 2
- 7 fees due Jan 2 to 30, 2027 · next Jan 2
- 14 fees due Feb 6 to 22, 2027 · next Feb 6
- 12 fees due Mar 3 to 24, 2027 · next Mar 3
- 3 fees due Apr 3 to 30, 2027 · next Apr 3
- 5 fees due May 7 to 28, 2027 · next May 7
- 9 fees due Jun 3 to 30, 2027 · next Jun 3
- 3 fees due Jul 2 to 23, 2027 · next Jul 2
- 7 fees due Aug 6 to 20, 2027 · next Aug 6
- 8 fees due Sep 3 to 30, 2027 · next Sep 3
- 9 fees due Oct 2 to 30, 2027 · next Oct 2
- 3 fees due Nov 5 to 12, 2027 · next Nov 5
Recent changes
- 5 of the patents on this record were granted since Aug 16, 2026
- 6 terms have ended since Aug 16, 2026
What they patent
The 5 largest of its 482 families, grouped by real patent family and labeled by the earliest filing in each. No technology classification is inferred from titles.
| Time-Based Network Operation Profiles in a Software-Defined Network | 4 in force | to Jun 2038 |
| Time-Domain Differential Line Protection of Electric Power Delivery Systems | 4 in force | to May 2037 |
| Power Line Sag Monitoring Device | 3 in force | to Nov 2039 |
| Systems, Methods and Apparatuses for Wet Stack Residue Mitigation | 3 in force | to Oct 2039 |
| Microgrid Power Flow Monitoring and Control | 3 in force | to Jun 2038 |
Patents held now
Soonest term end first.
| Patent | Title | Status | Expires | Confidence |
|---|---|---|---|---|
| US 7,480,580 | Apparatus and Method for Estimating Synchronized Phasors at Predetermined Times Referenced to an Absolute Time Standard in an Electrical System In force · High confidence | In force | High confidence | |
| US 7,425,778 | Apparatus and Method for Compensating Secondary Currents Used in Differential Protection to Correct for a Phase Shift Introduced Between High Voltage and Low Voltage Transformer Windings In force · High confidence | In force | High confidence | |
| US 7,504,806 | Apparatus and Methods for Controlling Operation of a Single-Phase Voltage Regulator in a Three-Phase Power System In force · High confidence | In force | High confidence | |
| US 7,457,088 | Systems and Methods for Protection of Electrical Networks In force · High confidence | In force | High confidence | |
| US 7,804,303 | Apparatus and Method for Detecting a Brush Liftoff in a Synchronous Generator Rotor Circuit In force · Low confidence | In force | Low confidence | |
| US 7,460,590 | Handheld Communication Tester and Method for Testing Direct Serial Communication Capability of an Intelligent Electronic Device in a Power System In force · High confidence | In force | High confidence | |
| US 7,692,538 | User Interface for Monitoring a Plurality of Faulted Circuit Indicators In force · High confidence | In force | High confidence | |
| US 7,502,696 | System and Method for Detecting Power System Conditions In force · High confidence | In force | High confidence | |
| US 7,570,469 | Dynamically Configurable Relay Element and Related Methods In force · High confidence | In force | High confidence | |
| US 7,630,863 | Apparatus, Method, and System for Wide-Area Protection and Control Using Power System Data Having a Time Component Associated Therewith In force · High confidence | In force | High confidence |
Also on record, not counted in the 552: 170 patents ended · 40 applications pending · 63 applications abandoned. List them
Sources and methods
Compiled from USPTO application file histories, grants and recorded assignments, with the company's own names reviewed by hand. How this record was built
Portfolio grouped automatically from ownership conveyances to the names matched to this company, usually every name that begins with its own, so it counts patents an affiliate holds; each list row names the holder of record. Security interests are excluded and ambiguous records are not reviewed by hand.
Fee due within 90 days marks a patent with a maintenance fee due within 90 days of the date this page was computed and not yet recorded paid, so it can end earlier than the bar shows. A fee left unpaid ends the patent at the close of the six month grace period that follows its due date, not on the due date itself. It is not a prediction that the fee will be missed.
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.