One of the major problems observed in distribution
systems in recent days is Power Quality. Today most of the industries,
commercial customers and residents are using the sophisticated electrical
equipment based on semiconductor device, these equipment pollute the power
most significant problems in the distribution system are the very high voltage
drop, especially at residential usage. This exaggerated voltage drop affects
the performance of electric stoves and heaters that the customers are forced to
wait for a long time to make stew, to toast bread, and to boil water. Moreover,
the working life of light bulbs, in addition to giving less-bright lights, is
getting shortened life due to under voltages. It is also a lot of times that
light bulbs and electronic appliances get burned due to over voltages, which is
a symptom of weak voltage regulation of the distribution system power system.
Negligence of the effects of voltage and current distortions from both the
utility side and end-user side is another motivating factor. Even though
utilization of semiconductor based equipments are greatly increasing from day
to day, without giving emphasis to the issue of harmonic distortions. The loss
of electric power at moderate to heavy rain, and following lightning strokes;
the increasing number of distribution transformers with high oil leakage;
hanging overhead lines and resulting short circuits are also some of the major
observations that lead to questionable electric power quality of the utility.
industrial companies are installing capacitor bank, but it will not functional because
of the improper rating and fuse failure due to disturbances in the system.
solve this problem, custom power devices are used. One of those devices
UPQC, which is
the most efficient and effective modern custom power device used in power
distribution networks, because the main purpose of
UPQC is to compensate for the supply voltage PQ issues such as voltage sags,
swells, unbalance, flicker, harmonics, and load current PQ problems such as
harmonics, unbalance, reactive current, power factor to unity and neutral
investigation of power quality issues and enhancement of power quality issues
using UPQC in distribution system provides alternative method of mitigating
power quality phenomena where power quality is a core issue. The study
therefore sought to address the following questions:
What design parameters that must be considered in the system
with respect to the size and type of filters, DC link capacitors, etc?
What simulation techniques to utilize in order to effectively
model the UPQC?
What control algorithms are suit for the UPQC?
What evaluation method to be used to measure the
effectiveness of the system?