الفهرس 
Power Quality ProblemsOnly 14 pages are availabe for public view
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Abstract
Power qual ity is an issue that has generated much
interest to both electric utilities and customers today. With the
increased use of complex and sensitive electronic circuitry, any
slight variation in magnitude, frequency or purity of the
WaVef01TI1can often affect and lead to expensive failures of
equipment. The performance and operation of this equipment
may unavoidably cost customers in lost time and revenue.
Efficient simulation tools are important to investigate the
causes and effects of these power quality problems, possibly
saving large amount of time and money especially in today’s
challenging and competitive environment. In addition, through
the development of technologies and instruments, highly
developed power quality monitoring tools are available to meet
local and international standards.
The present thesis is concerned with the power quality
problem especially when induction motors are concerned.
It comprises a background review of induction motors
and the type of induction motor modeled. Parameters are
extracted from the selected induction motor by means of
experimental methods while some are synthetic parameter
values.
In order to understand more on the effects of the power
quality problems, we will make use of simulation methods.
MATLAB is currently used by the industry intensively for simulation and is widely recognized [0 be reliable. The
simulation in MATLAB comprises a high-performance
language for technical computing that includes functions for
numeric computation, data analysis, system simulation, and
application.
By using Sirnulink in MA TLAB, the power quality
problems response in a controlled environment can be
observed. In the process of simulation, the control settings can
be changed and the power quality problems response are
displayed in the graphical format with variable loading to
ensure better understanding of the outcome.
Power quality disturbances such as capacitor switching
and voltage sags events with emphasis on system faults and
induction motor starting are of particular interest. Computer
simulation results indicate that the software can be utilized as
an effective tool for simulating power quality problems.
Identifying problems in an electrical network before any
extensive damage occurs is advisable for any power system.
Not only does monitoring of power quality necessary for
maintaining accurate operation of sensitive equipment, it also
ensures that unnecessary energy losses in a power system are
kept at a minimum which leads to more profits. This thesis
seeks to identify the effect of power quality problems m a
small power system mainly containing induction motors.
For the problems identified recommendations are
suggested to improve the power quality. The lifetime shorting of the induction motor caused by the voltage sags and
momentary interruption is investigated with measured data
from the motor and simulated using MATLAB to observe the
extent of the sag throughout the system. The extent of sags
from faults is also simulated