Application of arc-interruption fundamentals to nozzles for puffer interrupters. Final report

Technical Report · Thu Dec 01 04:00:00 EST 1983

OSTI ID:5332528

Noeske, H O; Benenson, D M; Frind, G; Hirasawa, K; Kinsinger, R E; Nagamatsu, H T; Sheer, Jr, R E; Yoshioka, Y

A new concept of an SF/sub 6/ puffer breaker having an insulated dual-flow nozzle with bell-shaped downstream sections and one coaxially located puffer was introduced. When tested as a scaled-down model breaker for thermal (short line fault) interruption, it performed at the higher current and di/dt ratings three times better than an optimized model of a conventional single-flow breaker. As scaling parameters for the model breakers, current densities at the nozzle throat were chosen identical to those of a full size breaker. For the optimization effort, a major number of nozzles were investigated, first on dual-flow dual-pressure apparatus. A method was developed for the computation of the subsonic (upstream) part of the flow field under conditions of compressible, nonviscous cold flow. This method was checked experimentally and then extensively used for the comparison of the flow fields of different nozzles. Interferometric measurements were used to determine the effect of electrode vapor on the arc mantle for an air arc in a single-flow nozzle. High speed movies showed the importance of a short arc section immediately downstream of the vena contracta for interruption speed. Following preliminary optimization in dual-pressure tests, the single- and dual-flow nozzles were used in puffer experiments, where they were exposed to conditions of nozzle blocking and strong nozzle ablation. In these tests the pressure and electrical potential distribution were measured in single-flow nozzles during the arcing period. These results together with measurements of the ablation distribution along the nozzles and the results of a computer program for the flow initiation time gave insight into the blocking and deblocking dynamics of puffer breakers. Complementary work was done also on an asymmetrical dual-flow puffer breaker.

• Research Organization: General Electric Co., Schenectady, NY (USA). Corporate Research and Development Dept.
• OSTI ID: 5332528
• Report Number(s): EPRI-EL-3293; ON: DE84920274
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
CIRCUIT BREAKERS
CURRENT DENSITY
ELECTRICAL EQUIPMENT
EQUIPMENT
EQUIPMENT PROTECTION DEVICES
FLUID FLOW
FLUORIDES
FLUORINE COMPOUNDS
GAS FLOW
HALIDES
HALOGEN COMPOUNDS
NOZZLES
OPTIMIZATION
SCALE MODELS
STRUCTURAL MODELS
SULFUR COMPOUNDS
SULFUR FLUORIDES