Automation and utility system security

An electric utility system is predicated to be in one of four possible states: normal, alert, emergency, or restorative. Examination of these states and the structure of the system's operating problems has led to a multilevel, multicomputer approach involving computers at various action centers interconnected by data links. Within the hierarchical computer arrangement, a four-step approach of monitor and display, contingency evaluation, corrective strategy, and automatic control is suggested. Major attention is directed toward minimizing the probability of leaving the normal state as well as the time required to return to this state. The computer functions to be undertaken at each level are described.