An oscillation detector used in the BPA power system disturbance monitor

In 1987, an oscillation trigger was developed for the power system disturbance monitor that the Bonneville Power Administration (BPA) operates at the Dittmer control center. The trigger logic resembles that for extracting information from an amplitude-modulated carrier wave. Operating experience shows the trigger to be sensitive, reliable, and versatile. The trigger is described, and its basic principles are detailed. Filter response curves and Fortran source code are provided.>