Matches 1 - 29 out of 29


Match Document Document Title
8154836 Line current differential protection upon loss of an external time reference  
A line current differential protection system that uses an external time reference continues providing protection to a power apparatus upon the loss of the external time reference. An external time...
7864533 Semiconductor device  
A semiconductor device includes: a first output unit configured to output a first phase; a second output unit configured to output a second phase different from the first phase, the second output...
7846027 Handheld electronic devices  
A handheld electronic device, the device comprising a housing and a retractable handle, the device being arranged to allow the handle to be retracted into the housing along a sliding axis to...
7570470 Self-powered communications link for smart circuit breakers  
A circuit breaker communication system is provided including a circuit breaker, an electronic module to record and store data associated with the operation of the circuit breaker, and a portable...
7558038 Field upgradeable circuit breaker firmware and programmer therefor  
A system (10) is provided for communicating with a residential electronic circuit breaker (18, 20, 22, 24). The system (10) comprises a residential electrical wiring system (16) including a power...
7558033 Arc fault circuit interrupter and method of parallel and series arc fault detection  
An arc fault circuit interrupter includes separable contacts, a neutral conductor, an operating mechanism structured to open and close the separable contacts, at least one current sensor structured...
7154722 Loop control for distribution systems  
The invention contemplates a technique for providing loop control on a faulted overhead or underground loop system, while preventing restored current from being fed or back fed into the fault. In...
6678182 Electrical bus with associated porous metal heat sink and method of manufacturing same  
A module is formed in which semiconductor components are soldered to an electrically conductive heat sink. The electrically conductive heat sink is formed so that it will serve as an electrical bus...
6529394 Inverter for an electric motor  
An oil-cooled inverter for an electric traction motor that uses six IGBT switches to generate 3-phase AC electrical current as its output. The switches are mounted on heat sinks that use hot motor...
6469629 Distributed logic in multiple protective relays  
A protective relay, system, and relay operation method which allows logic functions to be distributed amongst multiple protective relays associated with a power distribution system. The protective...
6373670 Fault protection apparatus  
A fault protection apparatus is disclosed for use in a time graded fault protection scheme. The apparatus comprises a circuit breaker having a normally closed trip contact provided in a line,...
5838525 High speed single-pole trip logic for use in protective relaying  
A protective relaying system includes a local protective relay operatively coupled to a protected line segment at a first location, and a remote protective relay operatively coupled to the...
5592354 Audio bandwidth interface apparatus for pilot wire relays  
An apparatus for enabling pilot wire relays to communicate across voice-grade, non-metallic communication channels converts sinusoid signals representative of phase currents at a location in an...
5574611 Service interruption minimizing system for power distribution line  
Upon the occurrence of a fault on the first distribution line, a faulty section on the distribution line is pinpointed, then a tie point switchgear at the tie point between the first distribution...
4675774 Direct transfer trip apparatus for use with an active pilot wire communications channel  
Direct transfer trip apparatus for sharing a common active communication channel utilized for signal transfer between at least two electromechanical units which form a current differential...
4675775 Active pilot wire apparatus for electromechanical current differential relays  
Active pilot wire apparatus for replacing a passive continuous metallic wire pair coupling between the electromechanical units of a conventional electromechanical pilot wire protective relay is...
4674002 Directional comparison blocking system  
An echo-keyed directional comparison blocking system for protecting an electrical power transmission path in a power system network against internal faults is disclosed. The system includes a...
4464697 Protective relay system  
Protective relaying apparatus of the pilot type, incorporating a direct transfer trip function (DTT) which reliably and securely utilizes the same communication channel utilized by the pilot...
4317151 Apparatus for fault direction-comparison protection  
With heretofore known directional comparison protection systems working with fault direction detectors at both ends of a line section which is to be protected and data transmission between both end...
4295175 Pilot wire relay protection system for electrical distribution networks  
A pilot wire relay protection system for detecting and responding to phase-to-phase, three-phase, phase-to-phase to ground, and ground current faults including relatively low level ground current...
4173774 Parallel AC electrical system with differential protection immune to high current through faults  
In systems, such as aircraft electric power generation systems, three phase AC generators are often operated in parallel when supplying power to load busses and differential protection networks are...
4164773 Transfer trip circuit with pilot wire monitoring  
A transfer trip circuit has a first station which contains a circuit breaker and a source of control current in which the control current is increased from a first value to a second value in...
3912979 Pilot wire protective relaying apparatus  
The disclosed apparatus comprises a conventional pilot wire exclusively used for the operating force and a separate pilot wire exclusively used for the restraining force. At each of terminals of a...
3796920 ARRANGEMENT FOR A REPEATERED POWER LINE CARRIER SYSTEM THAT PROVIDES PROTECTIVE RELAYING  
In power line carrier systems, repeaters are provided at station or switchyard locations between line sections to transmit signals in both directions around the location. In some systems tones are...
3497772 PILOT WIRE PROTECTIVE ARRANGEMENT FOR ALTERNATING CURRENT SYSTEM WHEREIN RELAY OPERATING AND RESTRAINT SIGNALS ARE DERIVED DURING HALF CYCLES OF OPPOSITE POLARITIES  
3588824 SPARE CHANNEL SYSTEM FOR SECTIONALIZING A COMMUNICATION LINE CIRCUIT  
3296495 Polyphase protective relay circuits  
2974257 Protective apparatus for power systems  
2849660 Protective circuit for high tension lines with series condensers  
Matches 1 - 29 out of 29