AC waveform monitoring system.

摘要

An AC waveform monitoring system (10) includes detecting circuitry (16) for providing a sensed analog signal. Oscillator circuitry (20) is coupled to the detecting circuitry for providing a zero crossing signal (20A). The oscillator circuitry (20) is synchronized with a frequency of the sensed analog signal. Signal processing circuitry (12) is coupled to both the detecting circuitry and the oscillator circuitry for identifying a peak voltage signal at the output of a peak detector (22) and an integral volt-seconds signal of the sensed analog signal at the output of an integrator (24), responsive to the zero crossing signal (20A). Digital processing circuitry (14) is coupled to the signal processing circuitry and the oscillator circuitry. The digital processing circuitry (14) includes memory (24, 26) for storing a plurality of predetermined signal voltage boundary values and a program (36, FIG. 2) utilizing the identified peak voltage signal, the integral volt-seconds signal and the stored predetermined signal values to identify an abnormal voltage event.