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5110: An Automated Method for Assessment of Harmonics From NonLinear Loads and Distributed Generators

One of the major challenges in enforcing harmonic compliance has to do with quantifying the net harmonic contribution from a given customer system (or distributed generator). The customer or generator is only responsible for the harmonic distortion it produces and should only be penalized for this amount of distortion. The problem is complicated because measurements at a point of common coupling (PCC) between a customer (or generator) and the system can include harmonic distortion that is caus

Aug 1, 2003

Research

5121: Assessing Power Quality Disturbances Using PQ Features of Distribution Network Equipment

This report underlines power quality functionalities available in major distribution equipment controls and relays, and the position of these intelligent devices within a modern and economic Power Quality Monitoring System (PQMS) for distribution systems.Keywords: Distribution Equipment, Power Quality, Controls, Protection Relays, Revenue Meters, Communication

Nov 1, 2005

Research

5136: Survey of Utility Practices in Dealing with Common Power Quality Issues for Large Customers

The primary objective of this project was to gather information on utility practices related to management of PQ complaints from large (> 2 MVA) customers. This report begins by briefly reviewing common sources of disruptive PQ events, both on a generic basis and with particular focus on particular industry sectors based on a review of published literature. An overview of applicable Standards is included. Possible strategic choices available to utilities for managing PQ complaints are present

Feb 1, 2009

Research

5142C: Harmonic Distortion Level Evolution at Residential PCC in North America, Phase III

In 2000 and 2008, harmonic surveys were performed in Canada to measure the harmonics caused by domestic loads. Each survey was performed over a year in single week intervals for each location; together confirming observations made by Professor Alexander Emanuel in 1995 which revealed that the growth rate of harmonics can be up to 0.35% per year.Although harmonic orders 9 and 15 were the only orders identified as being critical in the 2008 survey, the safety margin allowing for additional domesti

Aug 23, 2014 - Apr 1, 2016

Research

5167: Software Application for Calculation of IEC Flicker Indices Using Measured Voltage Quantities

IEC 61000-4-15 provides an algorithm for the computation of flicker perception, based on rms voltages sampled, following the recommendations of IEC 61000-4-30. Many power quality monitors use the algorithm to generate short-term flicker perception (Pst) and long-term flicker perception (Plt). However, many power quality monitors do not compute Pst and Plt. They do, however, provide long-duration recordings of rms voltage. As part of this project, a software application was developed that can be

Jun 30, 2014 - Nov 3, 2015

Research

5143B-05: Transformer Energizing Case Study

ABSTRACT: Energizing saturable devices, such as power transformers, results in inrush currents that are rich in harmonic components. The inrush current interacts with the system impedance vs. frequency characteristics to create a voltage waveform that can have significant harmonic components for the duration that the inrush current is present. Transformer inrush current typically decays over a period on the order of one second. The dynamic overvoltage problem is typically limited to cases of en

Mar 1, 2010

Research

5107: Indices To Assess Voltage Sag Performance

For many years, electricity distribution companies have used sustained interruption indices as indicators of the reliability of service provided on their systems. Today, however, many electricity consumers are adversely affected by more subtle voltage disturbances such as voltage sags and momentary interruptions. Many utilities are aware of these service quality concerns and are responding by implementing extensive monitoring systems that detect such disturbances and assess service quality. Furt

Jul 1, 2002

Research

5112: Case Studies On Utility-Scale Power Quality Mitigation Devices

This report provides information on PQ issues faced by large industrial and commercial customers (e.g. voltage dips, sags and swells, voltage transients, harmonics, flicker, voltage unbalance, stability, short-term interruptions). It describes the remedial options available to the host utility in the form of detailed application case studies of utility-scale PQ mitigation devices. Best Practice utility-side options for the mitigation of various PQ problems are identified in terms of costs, ben

Jul 1, 2002

Research

5143B-03: Induction Motor Starting Case Study

ABSTRACT: Induction motor starting is one of the most common causes of voltage variations. An induction motor will draw several times its full load current during starting. This lagging current creates a voltage drop across the impedances of the system. If the started motor is large enough relative to the system strength (short-circuit capacity), these voltage drops can produce severe voltage sags on the system. The motor starting current magnitude generally decreases relatively slowly dependin

Mar 1, 2010

Research

5138: Practical Guidelines for Evaluating the Impact of Transients on Utility Customers

The objective of this project was to develop an application guide that provides a review of the powersystem transient phenomena that can negatively affect utility and customer systems. The guideincludes relevant standards‐related information and representative waveforms for many of thecommon transients that occur on the electric power system, including capacitor bank switching,feeder and transformer energizing, fuse operation, faults, arrester operation, induction motorstarting, lightning, and f

Oct 1, 2007

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