A system for capturing and presenting short duration voltage surges on AC power lines

A system for capturing short-duration voltage surges on AC power lines and presenting them for analysis is described. This system records both the surge wave shape and the fundamental wave shape in digital first in, first out (FIFO) buffers. Both signals are continually recorded; recording continues for an interval of time after triggering that is shorter than the depth of the FIFO buffers, yielding detailed pretrigger and posttrigger information. Preliminary field work indicates that some terminology that has previously been used to describe surge parameters, such as duration, may no longer be useful. Initial analysis of the surge waveforms indicates that some surge sources can be identified by their waveforms