In power quality investigations, triggered waveforms often claim the spotlight, but it is the stripchart that tells the story of the entire recording. Reviewing this data manually is tedious, error-prone,…
Voltage
Defining and Measuring Rapid Voltage Change
Rapid Voltage Change (RVC) represents a specific category of power quality phenomena characterized by a fast transition in the RMS voltage between two steady-state conditions. Unlike a voltage dip or…
Voltage Unbalance and Polyphase Induction Motors
While three-phase AC squirrel-cage motors have been around and reliable since 1889, courtesy of Mikhail Dolivo-Dobrovolsky, one issue that has plagued their operation and lifespan throughout the years has been…
Visualizing Loose Neutrals with RMS Capture Graphs
Loose neutrals represent one of the most hazardous and subtle single-phase service issues encountered by utility power quality (PQ) engineers. The condition arises when the neutral conductor connecting the center…
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…
Voltage Regulation: Standards-based Compliance
Voltage regulation—the ability to maintain steady‑state RMS voltage within acceptable bounds—affects equipment performance, protection, and customer experience. Distributed energy resources (DER) add complexity via bidirectional power flow and daytime voltage…
Voltage Unbalance Within PQ Canvass Compliance Reports
Power Monitors, Inc.'s PQ Canvass is a secure, cloud-based platform built for power-quality (PQ) analysis. PQ Canvass has a beta feature of automated "compliance reports" that transform data uploaded from…
Voltage Sag Analysis: Standards, Testing, and Compliance
Voltage sags, short-duration reductions in supply voltage, pose significant challenges to electrical and electronic equipment, leading to malfunctions, shutdowns, and substantial economic losses across industries. IEEE Std 1668-2017 and SEMI…
Voltage Tug-of-War The Silent VFD Killer
The modern variable-speed drive (VFD) is a sophisticated power electronic system, yet the front end is still a deceptively simple six-pulse diode bridge. That simplicity means the rectifier has little…
High Impedance Faults: Causes, Risks, Detection Techniques
High impedance faults can be a troublesome power quality issue affecting not only utilities, but their customers too. Frequently, these faults can trip arc fault breakers and GFCI outlets and…
Why You Should Transition ProVision to PQ Canvass
Introduction If you own a Power Monitor’s recorder you’re probably quite familiar with ProVision. If you aren’t, it’s Power Monitors’ Windows desktop application that lets you manage your PMI recorders,…
Phasor Decomposition via Symmetrical Components in Three Phase Systems
Introduction When three phase systems are perfectly balanced sinusoidal waveforms, where the B and C phases are exact replicas of the A phase sine wave, but delayed by 120 and…
