Inventor · Baraboo, WI, US

Douglas C. Folts

26Patents
10h-index
31Co-inventors
75Inventor score

Filing activity: May 17, 1991 → Dec 4, 2018

Most-cited inventions

PatentTitleAreaCited byStatus
US5315533A Back-up uninterruptible power system Electricity 182 Expired
US5302858A Method and apparatus for providing battery charging in a backup power system Electricity 78 Expired
US6987331B2 Voltage recovery device for use with a utility power network Emerging Cross-Sectional Technologies 60 Expired
US7091703B2 Dynamic reactive compensation system and method Emerging Cross-Sectional Technologies 51 Expired
US6266260A Inverter having center switch and uninterruptible power supply implementing same Electricity 34 Expired
US6577108B2 Voltage regulation of a utility power network Emerging Cross-Sectional Technologies 31 Expired
US6906434B1 Electric utility system with superconducting magnetic energy storage Emerging Cross-Sectional Technologies 26 Expired
US8120932B2 Low voltage ride through Emerging Cross-Sectional Technologies 15 Active
US7567160B2 Supplementary transformer cooling in a reactive power compensation system Electricity 13 Active
US6900619B2 Reactive power compensation to minimize step voltage changes and transients Emerging Cross-Sectional Technologies 12 Expired
US7989983B2 Power conversion systems Emerging Cross-Sectional Technologies 10 Active
USRE41170E1 Voltage regulation of a utility power network General 8 Active
US7265521B2 Reactive power compensation to minimize step voltage changes and transients Emerging Cross-Sectional Technologies 7 Expired
US8189324B2 Power electronic assembly with slotted heatsink Electricity 6 Active
US7674751B2 Fabrication of sealed high temperature superconductor wires Emerging Cross-Sectional Technologies 6 Active
US6414853B2 Method and apparatus for controlling a phase angle of AC power to keep DC voltage from an energy source constant Electricity 5 Expired
US6445555B1 Method and apparatus for discharging a superconducting magnet Emerging Cross-Sectional Technologies 5 Expired
US7724482B2 Parallel HTS transformer device Emerging Cross-Sectional Technologies 5 Active
US7902461B2 Fault current limiting HTS cable and method of configuring same Emerging Cross-Sectional Technologies 3 Active
US8886267B2 Fault current limiting HTS cable and method of configuring same Emerging Cross-Sectional Technologies 3 Active
US6600973B1 Method and apparatus for providing power to a utility network Emerging Cross-Sectional Technologies 2 Expired
US10669001B2 Hybrid electrical and mechanical propulsion and energy system for a ship Emerging Cross-Sectional Technologies 1 Active
US10193340B2 Multi-level cascaded H-bridge STATCOM circulating cooling fluid within enclosure Emerging Cross-Sectional Technologies 1 Active
US8532725B2 Parallel connected HTS utility device and method of using same Emerging Cross-Sectional Technologies 1 Active
US9172312B2 Reducing photovoltaic array voltage during inverter re-enablement Emerging Cross-Sectional Technologies 1 Active

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.