Tag Archives: Power Quality

Electric Power Quality and Lighting (part 2)

Posted May 29 2012 by Sufi Shah Hamid Jalali in Energy Efficiency, Lighting on Electrical Engineering Portal

Original Source: Wolsey, Robert, Power Quality, Volume 2, Number 2, February 1995 (Lighting Research Center (LRC) and Power Quality),

What is power factor?

Power factor is a measure of how effectively a device converts input current and voltage into useful electric power. Mathematically it is defined as follows:power-factor-triangle-explained

Power factor triangle

power-factor-formula

 

 

Where P is active power and S is the apparent power.

It is often confused with: Continue reading

Electric Power Quality and Lighting (part 1)

Posted May 26 2012 by Sufi Shah Hamid Jalali in Energy Efficiency, Lighting with 2 Comments
on Electrical Engineering Portal
Original Source: Wolsey, Robert, Power Quality, Volume 2, Number 2, February 1995 (Lighting Research Center (LRC) and Power Quality)

Introduction

Concerns about the effects of lighting products on power distribution systems have focused attention on power quality. Poor power quality can waste energy and the capacity of an electrical system; it can harm both the electrical distribution system and devices operating on the system.

There are many elements in a power system that affects two major parameters; power factor and harmonics. Electric motors, some lighting fixtures, transformers and other inductive and capacitive appliances introduce reactive power to the system, and thus involved in damaging the power factor. These components need reactive power to work.

Nonlinear loads like UPS, computer systems, fluorescent fixtures, CFLs, digital electronics, etc. are distorting current waveforms and introducing harmonics to the power system.

This technical article will help lighting specifiers and consumers better understand power quality, so that they can more confidently select energy-efficient lighting products. Continue reading

Harmonic Mitigation Techniques Applied to Power Distribution Networks

Source: Advances in Power Electronics
Volume 2013 (2013), Article ID 591680, 10 pages
http://dx.doi.org/10.1155/2013/591680

Faculty of Engineering, Sohar University, P.O. Box 44, 311 Sohar, Oman

Academic Editor: Hadi Y. Kanaan

Abstract

A growing number of harmonic mitigation techniques are now available including active and passive methods, and the selection of the best-suited technique for a particular case can be a complicated decision-making process. The performance of some of these techniques is largely dependent on system conditions, while others require extensive system analysis to prevent resonance problems and capacitor failure. A classification of the various available harmonic mitigation techniques is presented in this paper aimed at presenting a review of harmonic mitigation methods to researchers, designers, and engineers dealing with power distribution systems. Continue reading