Effects of Reduced Fault Duration Upon Power System Components A Study of the Feasibility of a Greatly Simplified Alternative to the Fault Current Limiter

摘要

This report summarizes the information learned to date and considers in some detail a specific 69KV application of the concept. The present assessment suggests that 160% of rating will meet the needs and is attainable provided that appropriate back-up protection can be devised. This conclusion is based upon (a) the statistical nature of fault characteristics, (b) the practicality of limiting severe faults to a single current loop, and (c) upon characteristics of the substation equipment. It is shown that the likelihood of subjecting circuit breakers to instantaneous currents in excess of close and latch rating is excep-tionally rare. Tests have demonstrated the ability of circuit breakers with multi¬ple finger contact structures to accommodate this duty without any difficulty. Approximate, analytical methods have been devised to assist in the rational identification of systems to which the proposed protection scheme can be applied.