Ferroresonance is a nonlinear electrical phenomenon that can damage transformers, surge arresters, cable insulation, and switchgear — and create dangerous backfeed voltages on conductors that should be de-energized. Although relatively…
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Meet Merlin™: How AI is Transforming PQ Analysis
As grid and load complexity increases and distributed generation proliferates, utilities face a torrent of sensor data that outpaces human capacity to interpret it. This paper introduces Merlin™, an analyst-grade…
Introduction to Temporary Overvoltage
Temporary overvoltage is a common, but often overlooked stress condition on modern electric distribution systems. Although it receives less attention than lightning and fast transients, it can damage equipment, overheat…
Loose Neutrals and Grounding
A loose neutral is a common but dangerous single-phase problem. The situation often presents as a power quality problem but in reality it's a safety issue that demands immediate attention.…
Residential Interharmonics
Interharmonics are produced when loads draw current asynchronously to the utility voltage. Traditional loads include arc furnaces, welders, and AC-DC converter systems where the loads are fed from DC supplies.…
Distributed Generation Power Quality Standards
The dramatic proliferation of Distributed Generation (DG) deployments began before power quality (PQ) standards were in place to ensure compatibility in the grid. IEEE 519-2014, a recommended practice for limiting…
Interharmonic Analysis with Python
Traditional harmonic analysis in electrical systems has revolved around looking at the spectral content on, well, the magnitudes of harmonic frequency components. The IEEE 519 specification provides guidelines for measuring…
Automatic IEEE 519 Report Generation
The IEEE 519-2014 standard specifies measurements, analysis methods and limits for harmonic voltage and current. The 2014 version is very rigorous with multiple sets of limits, time intervals, statistical groupings,…
Power Quality in Traffic Signal Cabinets
The first electric traffic signals were installed over 100 years ago but now are a ubiquitous aspect of modern life. Today's intersections are far more complex, with a cabinet of…
An Overview of Harmonics and Power Quality
Harmonic distortion is a broad, complex power quality issue with significant economic impacts for electric utilities and end users. Distorted current waveforms from end-user loads create excessive heating for utility…
Power Factor vs Displacement Power Factor: What’s the Difference?
True power factor (PF) and displacement power factor (DPF) are commonly available on power analyzers and loggers. At first glance (and in some situations), they appear to measure the same…
PMI PQ Ruler
PMI's PQ Ruler is packed with power quality formulas, industry standard limits, tolerance curves, and engineering reference material in the form of a handy 6" ruler. Here the information is…