While the Power Quality Standard EN 50160 defines a 10-minute measuring interval (all 10 ms values are averaged and reported each 10 minutes), customers often want to record data at faster intervals.
Our February newsletter highlighted the A.Eberle PQ-Box 150 and PQ-Box 200’s ability to record data to their memory at 200 ms and 3-second intervals (in addition to the 1s-30min user-defined intervals). Capturing data at such speeds does quickly consume device memory – even with 32 GB memory on board.
PQI-DA Smart, supplied 'ready' for dutch utility logging application
HV Power also supplies 'installed' PQ monitoring devices, allowing data to be automatically streamed back from a substation (and other locations) to one central SQL database. Again, while most standards are based on 10-minute data, one customer considering a system asked about the bandwidth required to bring back ‘faster’ data. To see for ourselves we ran a test where close to 1,000 measured voltage, current and harmonic values were selected and recorded for 200 ms, 3 seconds and 10 minute intervals and transferred across a 100 Mbps Ethernet network to a SQL server (using WinPQ software). While gathering about 60 MB of data per hour, bandwidth wasn’t actually a significant issue.
With the ability on these installed devices (e.g: PQI-DA Smart) to select just the measurement points required for each of the available data classes, it is surprising what is actually possible with existing network infrastructure and modern technology.
Contact Warwick Beech (04 3877 339) for more information.