Simplifying power quality data

Australia’s energy market is transforming. Thanks to technology, businesses across a range of industries are increasingly looking to integrate off-grid solutions.

As organisations begin to steer away from traditional energy sources and towards renewables, monitoring and maintaining power quality will become more crucial than ever. In light of this, understanding power quality levels, and how they can be improved, is an increasingly important issue for personnel charged with maintaining a facility’s electrical system.

Today’s power quality metering devices can capture data on issues ranging from transients and surges to harmonics and power interruptions — but that raw data needs be analysed for real improvement to be made to systems. The good news is new products are addressing this challenge with embedded intelligence to show trends and alerts, with at-a-glance displays designed to meet the needs of many different staff members.

Continuous power quality monitoring is the best way to both maintain current equipment performance and support a facility’s continuous improvement efforts. The new displays make such programs easier in a number of ways. For example, with trend graphs, personnel can obtain a clear indication of many long-term, steady-state power quality disturbances over time. In addition, facility staff can easily see if recommended limits on harmonics, power factor or other potential problem areas have been exceeded.

Figure 1: Trend graphs provide an indication of events or disturbances over time.

Short-term disturbances, such as voltage sags, swells, transients and interruptions, are represented in a more snapshot fashion, using a variety of statistical widgets, charts and counters. Such a presentation can offer a range of views — from a pie-chart-style breakdown of the kinds of power quality events a facility might be experiencing to bar charts comparing the impact of events either upstream or downstream of the measured location.

Figure 2: The dashboard provides a range of views for simple analysis.

Several new-to-market Schneider Electric meters are taking this graphical approach a step further. The systems feature a simplified user interface that uses the green/yellow/red visual metaphor familiar to just about any automobile driver to indicate both short- and long-term power quality issues. In this application, green obviously indicates no critical issues with the characteristic being measured, while yellow and red indicators suggest performance is approaching or exceeding limits outlined in related electrical codes and standards.

                      

Figure 3: GYR is a familiar visual metaphor.

The green/yellow/red approach solves a common problem of those whose job it is to monitor and maintain power systems: the wide diversity of potential power quality problems and their related metrics and applicable standards can be overwhelming. This methodology converts this multitude of taxonomies into meaningful, unified and easy-to-understand indicators for each specific power quality characteristic.

The new systems also are able to calculate an overall power quality index that amalgamates the data on individual measured characteristics into a 0–100% rating — kind of like a report card for a single metered connection or an entire facility.

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