Untitled - Journal of Lighting Engineering

evealed that losses due to drivers represent
on average 15% of all the power.
The final part of the first chapter
presents the software for analyzing the
lighting equipments available on the
market. The program aims to assist the
lighting designer in the stage of
preselecting lighting equipments. The
Visual Basic programming environment
was used to develop the software which
relies on a database containing data on over
1000 lamps, ballasts and luminaires. The
program consists of several windows that
perform key functions as: presenting the
main electrical, photometrical and general
characteristics of the lighting equipments,
allowing the comparison between the same
type of equipments, providing the user with
the possibility to obtain a complete lighting
solutions so it could be implemented in a
new lighting network, allowing the
possibility to update the database so it can
display new products available on the
market. Based on these features the user can
compare the existing equipments and
determine the best solutions available.
Chapter 2 Power quality in public
lighting installations synthesizes the
aspects regarding electromagnetic
disturbances (unbalances and harmonic
distortions) that determine the growth of
power losses in lighting networks and
provides the results obtained due to the
analysis of three study cases. It also presents
the methodology for calculating the power
losses in power lines and the results obtained
due to the power losses calculation in
lighting networks working in asymmetrical
sinusoidal, symmetrical sinusoidal,
asymmetrical sinusoidal and asymmetrical
non-sinusoidal operating regimes.
60
Theses and Dissertations
The connection of the same number of
identical lamps on every phase of the supply
system very often does not assure the
balance of the distribution network. The
advantage of using the U distribution, which
assures the same voltage losses, is
highlighted. The methods used to calculate
the supplementary neutral current do to the
use of discharge lamps that represent singlephase
non-linear loads are also presented.
The measurements of the electrical
characteristics of three lamp-ballast
assemblies (equipped with high pressure
and metal halide lamps and electronic or
electromagnetic ballast) are presented. The
measurements were conducted for different
supply voltages in order to observe the
variation of the main electric quantities
(active and reactive power, power factor,
input current) and harmonic pollution
indicators (THD, current harmonics level).
In order to determine the neutral current
based on the measurement results, three
study cases were defined that implied a
lighting network (consisting of 30 luminaires
equipped with the above mentioned
assemblies) operating in balanced or
unbalanced regimes. The results show a
decrease in value for the neutral current as
the supply voltage is reduced for the
assemblies equipped with electromagnetic
ballast and just the opposite in the case of
the one equipped with an electronic ballast.
Based on the methodology of
determining power losses in power lines a
study was conducted. The study implied the
calculation of power losses in active and
neutral conductors for a lighting network,
equipped with the assemblies described
before, operating in theoretical and real
working regimes. The study revealed that in
Ingineria Iluminatului 2012; 14, 2: 59-62