Waveform capture is one of the most important data types available for PQ analysis. The sample-level data provides detailed information for voltage disturbances such as oscillatory transients, notches, sub-cycle overvoltages etc.
The high time resolution also provides cycle-by-cycle RMS information via the RMS Capture graph, generated from the waveform data. This high resolution is very useful for motor start studies, and both sample and RMS data are important for generator or dual-supply switching studies, etc.
Unfortunately, waveform capture data requires high speed memory, and consumes it very quickly. Without a mechanism such as PMI’s PQ Canvass and cloud data storage, or ProVision scheduled downloads through cell modems to provide essentially unlimited memory, the PQ recorder’s local waveform memory must be managed through the waveform capture settings to make optimal use of it.
A key parameter is the waveform capture sample rate. Reducing this increases the total number of waveform cycles that can be stored, but also involves trade-offs in data resolution.
Guidelines for this parameter are presented here...
This White Paper Includes: