초록 ▼

A monitor/analyzer for an alternating current (AC) electrical system responds to power line disturbances by generating a trigger signal when a change in voltage with respect to time electrical parameter is greater than a programmed threshold. The monitor/analyzer includes a sensor for sensing an AC

A monitor/analyzer for an alternating current (AC) electrical system responds to power line disturbances by generating a trigger signal when a change in voltage with respect to time electrical parameter is greater than a programmed threshold. The monitor/analyzer includes a sensor for sensing an AC waveform in the electrical system, an analog-to-digital converter for sampling the AC waveform, and a microcomputer. Firmware of the microcomputer cooperates with the A/D converter and provides a plurality of digital samples of the AC waveform for each of some of its AC cycles. The firmware generates each of plural dV/dt parameters of the AC waveform from a corresponding adjacent pair of the digital samples within one of the waveform's AC cycles. A trigger signal is generated when one of the dV/dt parameters is greater than the programmed threshold. The digital samples of the AC waveform before and after the power line disturbance are captured and output to a display in response to the trigger signal.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for monitoring an electric power system including an alternating current (AC) waveform having a plurality of AC cycles, said apparatus, comprising:sensing means for sensing said AC waveform;sampling means for sampling said AC waveform sensed by said sensing m

[ What is claimed is:] [1.] An apparatus for monitoring an electric power system including an alternating current (AC) waveform having a plurality of AC cycles, said apparatus, comprising:sensing means for sensing said AC waveform;sampling means for sampling said AC waveform sensed by said sensing means;means cooperating with said sampling means for providing a plurality of digital samples of said AC waveform for each of some of the AC cycles of said AC waveform;means for generating a value representing a change in magnitude with respect to time of said AC waveform from a pair of the digital samples of one of the AC cycles,trigger means for generating at least one trigger signal, with said trigger signal being a function of said value representing a change in magnitude with respect to time of said AC waveform and a predetermined threshold;capture means for capturing said digital samples of said AC waveform in response to said trigger signal; andwherein said sensing means includes means for sensing a voltage of said AC waveform; and wherein said means for generating a value includes means for generating a dV/dt value as said value representing a change in magnitude with respect to time of said AC waveform.