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…
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185 results in Power Quality — Clear
Power Quality
Feeder Resonance
Substation circuit loads are mostly inductive, dominated by distribution transformers and large motors. Canceling a portion of this inductance with Power Factor Correction capacitors (PFCs) improves power factor by reducing…
Linear vs Non-Linear Loads
In this white paper I define linear and non-linear loads, describe what characteristics cause a load to be linear or nonlinear, and show how these load types can affect the…
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…
TDD and IEEE 519:2014
IEEE standard 519 was first released in 1982 and was then updated in 1992 and 2014. It defines limits on Total Harmonic Distortion (THD) as well as Total Demand Distortion…
Understanding Crest Factor
Crest factor is an often neglected power compatibility measurement, but can be very important in certain applications. This white paper presents the definition of crest factor and the method for…
Tips on Transformer K-factor
Transformer loading is ultimately limited by internal heating caused by load current flow. Some heating is caused by resistive losses in the transformer winding. Another important heating source is eddy…
RMS Measurements and Harmonic Analysis
The RMS value is used to quantify the overall "size" of a waveform with a single number. By extension, harmonic amplitudes can be used to describe a complex waveform with…
Measuring and Analyzing Voltage Regulation
Voltage Regulation Basics Utilities are generally required to ensure the delivered steady-state voltage is within the limits specified in ANSI C84.1. Persistent under- or over-voltage can result in customer complaints…
Transferring ProVision Recordings to PQCanvass
We've added a major enhancement to ProVision - the ability to sync recordings with PQ Canvass, PMI's cloud-based PQ data analysis system. The implications of this are profound because you…
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…
