Coordination of Load Conservation with Turbine-Generator Underfrequency Protection

A system disturbance or operating abnormality may leave a power system with a generation deficiency, which, if uncorrected, can result in an extensive power outage. The possibility of such disturbances has led to increased interest in the application of automatic underfrequency protection schemes to restore load/generation balance and to prevent equipment damage. This paper presents a comprehensive underfrequency protection program recently developed for the Southern electric system in which digital computer simulations were used to optimize a system- wide load shed program and to verify its coordination with a steam turbine-generator underfrequency protection scheme.