Assignee
ACTIVE POWER INC
US42 patents
Top patents by PatentIndex Score
US7086231B2Aug 8, 2006
Thermal and compressed air storage system
ACTIVE POWER INC158 citations99
US6192687B1Feb 27, 2001
Uninterruptible power supply utilizing thermal energy source
ACTIVE POWER INC98 citations98
US5767591AJun 16, 1998
Method and apparatus for providing startup power to a genset-backed uninterruptible power supply
ACTIVE POWER INC119 citations98
US6512305B1Jan 28, 2003
Method and apparatus having a turbine working in different modes for providing an uninterruptible supply of electric power to a critical load
ACTIVE POWER INC55 citations96
US6255743B1Jul 3, 2001
Method and apparatus for providing an uninterruptible supply of electric power to a critical load
ACTIVE POWER INC60 citations96
US6166472ADec 26, 2000
Airgap armature coils and electric machines using same
ACTIVE POWER INC73 citations96
US5932935AAug 3, 1999
Energy storage flywheel emergency power source and methods
ACTIVE POWER INC34 citations96
US5905321AMay 18, 1999
Energy storage flywheel apparatus and methods
ACTIVE POWER INC34 citations96
US7127895B2Oct 31, 2006
Systems and methods for providing backup energy to a load
ACTIVE POWER INC61 citations95
US6844706B2Jan 18, 2005
Multiple path variable speed constant frequency device having automatic power path selection capability
ACTIVE POWER INC75 citations95
US7693402B2Apr 6, 2010
Thermal storage unit and methods for using the same to heat a fluid
ACTIVE POWER INC103 citations94
US5994794ANov 30, 1999
Methods and apparatus for providing protection to batteries in an uninterruptible power supply
ACTIVE POWER INC120 citations94
US6657320B1Dec 2, 2003
Integrated flywheel uninterruptible power supply system
ACTIVE POWER INC67 citations93
US6323573B1Nov 27, 2001
High-efficiency inductor-alternator
ACTIVE POWER INC27 citations93
US6236123B1May 22, 2001
Generator providing alternating current which has a selected frequency
ACTIVE POWER INC29 citations93
US6118202ASep 12, 2000
High-efficiency inductor-alternator
ACTIVE POWER INC22 citations93
US6087753AJul 11, 2000
High-efficiency inductor-alternator
ACTIVE POWER INC18 citations93
US5874797AFeb 23, 1999
Permanent magnet generator providing alternating current which has a selected frequency
ACTIVE POWER INC48 citations93
US7750518B1Jul 6, 2010
Transient energy systems and methods for use of the same
ACTIVE POWER INC24 citations92
US7400052B1Jul 15, 2008
Transient energy systems and methods for use of the same
ACTIVE POWER INC43 citations92
US6463738B1Oct 15, 2002
Method and apparatus for providing a continuous supply of electric power
ACTIVE POWER INC82 citations92
US6208056B1Mar 27, 2001
Cartridge armatures for electro-dynamic machines
ACTIVE POWER INC49 citations92
US6029538AFeb 29, 2000
Replaceable bearing cartridge assembly for flywheel energy system
ACTIVE POWER INC34 citations92
US5969457AOct 19, 1999
Energy storage flywheel apparatus and methods
ACTIVE POWER INC22 citations92
US5929548AJul 27, 1999
High inertia inductor-alternator
ACTIVE POWER INC20 citations92
US5920138AJul 6, 1999
Motor/generator and axial magnetic bearing utilizing common magnetic circuit
ACTIVE POWER INC18 citations92
US6914349B2Jul 5, 2005
Universal uninterruptible power supply input circuitry and methods for configuring same
ACTIVE POWER INC26 citations91
US7030593B2Apr 18, 2006
Multiple path variable speed constant frequency device having automatic power path selection capability
ACTIVE POWER INC21 citations90
US7425807B1Sep 16, 2008
Transient energy systems and methods for use of the same
ACTIVE POWER INC20 citations89
US6642682B1Nov 4, 2003
Circuits and methods for preheating a rotor of a motor-generator device
ACTIVE POWER INC41 citations86
US6124702ASep 26, 2000
Step switch cycloconverter utilizing multi-tap armature
ACTIVE POWER INC18 citations84
US7642664B1Jan 5, 2010
Transient energy systems and methods for use of the same
ACTIVE POWER INC13 citations83
US6955050B2Oct 18, 2005
Thermal storage unit and methods for using the same to heat a fluid
ACTIVE POWER INC18 citations83
US5864198AJan 26, 1999
Brushless generator
ACTIVE POWER INC35 citations81
US7753646B1Jul 13, 2010
Systems and methods for cooling bearings
ACTIVE POWER INC8 citations77
US5955816ASep 21, 1999
Energy storage flywheel apparatus and methods
ACTIVE POWER INC9 citations74
US7918091B1Apr 5, 2011
Systems and methods for controlling humidity
ACTIVE POWER INC4 citations62
US7314059B2Jan 1, 2008
Systems and methods for controlling pressure of fluids
ACTIVE POWER INC6 citations60
US6777823B1Aug 17, 2004
Integrated continuous power system assemblies having multiple nozzle block segments
ACTIVE POWER INC3 citations59
US6408627B1Jun 25, 2002
Integrated continuous power system assemblies
ACTIVE POWER INC3 citations54
US9209663B2Dec 8, 2015
Apparatus and methods for passive magnetic reduction of thrust force in rotating machines
ACTIVE POWER INC0 citations30
US9627923B2Apr 18, 2017
Apparatus and methods for backfeed detection in and control of uninterruptible power systems
ACTIVE POWER INC0 citations20