Fault protection for high-current distribution

Journal Article · Thu Jul 01 04:00:00 EDT 1982 · EPRI J.; (United States)

OSTI ID:5914745

Hopkinson, J

Describes a circuit protector that can carry high normal current up to 2000 A yet still limit the magnitude and duration of fault current to less than 15,000 A and well within the first ac cycle. The CLP, a compact 28 x 7-in cylinder of fiberglass that contains a copper bar conductor in parallel with a conventional silver sand current-limiting fuse, is based on a new concept combining the high-current-carrying capabilities of the circuit breaker and the extra-protective characteristics of the current-limiting fuse. Being relatively lightweight, the CLP can be positioned on a pole, a wall, or almost any convenient structure on a line. It has low power losses (waste heat), comparable to a 20-30-W light bulb, so it is more economical than a common alternative, the currentlimiting feeder reactor, which has losses between 3000 and 4000 W. In the event of a fault current, a sensor-and-trigger mechanism fires a series of chemical charges, which cut special, thin sections of the copper conductor in several places. The pressure of the gases given off by the charges bends these severed sections upward, creating gaps and diverting current into the parallel fuse. The fuse then melts rapidly, generating an opposing voltage higher than the circuit voltage, which forces the current to zero even before the normal peak of fault current can be reached. Phoenix Electric is working on a project with DOE to develop fault current protection of large auxiliary power transformers connected directly to generator buses.

• OSTI ID: 5914745
• Journal Information: EPRI J.; (United States), Journal Name: EPRI J.; (United States) Vol. 7:6; ISSN EPRJD
• Country of Publication: United States
• Language: English

Related Subjects

200300* -- Electric Power Engineering-- Power Transmission & Distribution-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
42 ENGINEERING
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
AC SYSTEMS
CIRCUIT BREAKERS
CONDUCTOR DEVICES
CURRENT LIMITERS
ELECTRIC FUSES
ELECTRICAL EQUIPMENT
ELECTRICAL FAULTS
ENERGY LOSSES
ENERGY SYSTEMS
EQUIPMENT
EQUIPMENT PROTECTION DEVICES
FIBERGLASS
HVAC SYSTEMS
LOSSES
POWER LOSSES
POWER SYSTEMS
TRANSFORMERS