A floating-window algorithm for detecting certain power line faults that disrupt sensitive electronic loads

AC power is generally distributed in a voltage waveform that closely approximates a sinusoidal function with respect to time. Sensitive electronic loads, including computers and medical equipment, may be disrupted by substantial deviations from this sine wave approximation. A floating-window algorithm that uses a triggering function to detect changes in the voltage waveform that may disrupt sensitive electronic loads is described. This triggering function can be used to capture digitally sampled power line disturbances so that their cause can be identified and corrective measures taken. The algorithm can be applied in other situations where deviation from a repetitive waveform must be detected, such as electrocardiograms.>