Power Factor (PF) is a measure of the efficiency of electric power delivery to a load. Traditionally the phase shift from inductive loads was the major cause of poor PF…
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IEEE 519 Harmonics in Residential Locations
IEEE 519 specifies the measurement technique and limits for harmonics in a wide variety of locations, from transmission through distribution. For the first time, the 2014 edition also provides separate…
Voltage Sag Source: Upstream or Downstream?
The first step in voltage sag mitigation is finding the source of the sag. In a power quality recording, spotting the voltage sag itself is often easy, but determining whether…
Computing IEEE 519-2014 Short Time Harmonic Values
IEEE 519-2014 specifies two time periods for analyzing harmonic data: "very short time", or 3 seconds, and "short time" or 10 minutes. For achieving the best resolution, the 3 second…
Hardware for Power Quality and Distribution Monitoring
PMI offers an array of monitoring devices for just about any utility distribution monitoring need. Data needs, location, and communications requirements are all factors involved in selecting the right monitor…
Adjusting Waveform Capture Sampling Rates
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…
Seven Common Utility Distribution Challenges: How the Boomerang and Canvass Can Help
Here's our quick list of 7 common utility distribution challenges. These shouldn't come as a surprise to anyone in the industry as utility companies are experiencing more challenges than ever.…
Steady State vs. Transient Harmonics
A harmonic analysis is a powerful method for analyzing waveform distortion, given the periodic nature of most nonlinear loads. Steady-state harmonic tools are sometimes extended for use with waveform events…
Four-Wire Delta Voltage Unbalance
Voltage unbalance in a four-wire or "high leg" delta can be tricky to measure. A 4-wire delta often involves unbalanced impedances, and phase shifts in the hot leg are common.…
Capturing Oscillatory Transients
Oscillatory transients are caused by switching operations, nearby lightning strikes, or other impulsive noise exciting electrical resonances present on the network. The most common in the distribution system is defined…
Per-Unit Analysis with ProVision
A per-unit scaling system simplifies many AC power analysis tasks. Eliminating transformer ratios, normalizing power values to equipment ratings, and allowing for like-to-like comparisons of differing nominals are just three…
Estimating THD with Power Factor Histograms
In the previous whitepaper Estimating THD with PF and DPF, a technique for estimating THD was shown given power factor and displacement power factor stripchart data. In many case, there's…