PROCESSING BY LOGIC PROGRAMMING OF CIRCUIT-BREAKER AND PROTECTIVE-RELAYING INFORMATION

This paper develops in a general fashion a logical procedure that analyzes circuit-breaker and protective-relaying operations in a power system. The purpose of the analysis, referred to as Automatic System Trouble Analysis (ASTA), is to derive an up-to-date picture of the power-system network and to obtain a realistic diagnosis of a case of system trouble. The ASTA procedure is characterized by a flexibility in its approach to accommodate design or operating changes with minimum logic modification. The logic statements are simple, requiring a minimum of relaying information inputs. Although the ASTA procedure is intended for future implementation by a process computer at a system control center, it may be programmed for a time-sharing computer for earlier use by the system dispatcher. In fact, the ASTA logic may be applied without the aid of a computer. ASTA is an improvement over conventional supervisory indications of breaker positions in that all de-energized circuits are also identified. More important, it is an improvement over existing procedures in which the human operator is expected to process and interpret a large collection of relay targetry reported from various system locations. Relaying functions rather than relay targets are used as the information inputs, and the ASTA interpretation is based on the prevailing protective-relaying philosophy. Copyright © 1969 by The Institute of Electrical and Electronics Engineers, Inc.