CHAPTER ONE
INTRODUCTION
As the growing
population of human race widens the gulf between energy supply and energy
demand, the imbalance in energy availability sent researchers into excavating
for a way of settling this age long squabble. A lasting solution is vested on
alternative use of the renewable energy source, a project that is yet to be
widely applied. Hence, the continuation of the unsettled yearns for sufficient
power. Consequently, the power lines are frequently over loaded resulting to a
trip of power by the action of switch gears or by the load shading process
undertaken by the distribution authorities.
Since it is
crystal clear that some institutions such as health related institutions and
some other delicate systems should not be allowed to suffer equally with their
counterparts, Automatic Phase Selector is used to sustain energy consumption in
the time of phase trip. The design of this circuit involves the use of
automatic switches but the details of design varies from place to place, time
to time and also depends on the type of load involved.
This project
involves the use of transistor driven relays to affect the change of phase
whenever the voltage condition becomes intolerable in the previous phase
connected.
1.1 BACKGROUND
The intelligent phase selector is a system
that is capable of comparing three phases and switching automatically to any of
the three phases. The system consists of three main parts namely; the
transformer, comparators (which is the brain of the system) and electrical
switching device (relay).
The transformer
used here is the step down type of transformer (it step down 240v to 12v) and
these transformer is feed in with different phase voltage, rectified and
smooth. Then fed in to a voltage regulator that has positive output. The
regulator outputs were connected to comparators. Here the comparators are three
in number. We call the comparators the brain of the system because these
comparators are connected in a way that each of them will give out an output.
The relay in the system is where the output voltage is connected. In this
project we even went as far as using pictures for illustration of some
components.
1.2 AIMS/OBJECTIVES OF THE PROJECT
The analysis of this project cannot
go without enumerating the goals meant to be achieved in the pursuit of the
work. These objectives include:-
i.
To develop a simple low cost device aimed at
easing the prevalent burden faced by delicate offices, parastatals and
institutions who need very low but constant power supply. Since supply is
always on along the distribution lines that supply such sites, what pesters on
the progress of work thereof is always the unwarranted trip of phases due to
power usage from neighboring consumers. The automatic phase selector therefore,
erases this setback form the face of progress of work in such offices.
ii.
To stimulate the interest of upcoming students
to take up research not only in their field of study “Electrical/Electronic
Engineering” but also to extend their arms to other disciplines, thus enhancing
the versatility of Electrical/Electronic Engineering.
iii. To
create awareness that will stimulate the interest of fellow students who intend
to take up research topic on automatic switch of any type.
1.3
RELEVANCE OF
THE PROJECT
The issue of
selecting or switching over manually is now a thing of the past. Nowadays we
know that homes and offices enjoy steady power supply once the three phases are
available (i.e. red yellow and blue
phases). Is just a question of making a quick and automatic three phase
selector?
1.4
SCOPE OF THE
PROJECT
The scope of the project covers
aspects like the features of automatic three phase selector, its applications,
and its operations. Its advantages and its components.
Finally, it covers the importance on the need of automatic
three phase selector and contributions toward a greater sharing load balance
and a better three phase power distribution and monitoring for domestics
consumers.
1.5
LIMITATIONS
Owning to the
nature of this project, the research centers and the resources were not easy to
come by within the immediate environment. Some of the limitation encountered on
the course of this project include financial and time constrains which did not
really take much room for additional capacity beyond what is at hand.
1.6
TARGET
BENEFICIARIES
This project
will provide lasting solutions to the heavy losses incurred by commercial
institution, industries, hospitals, airport etc caused by poor manual selector
means and efficient switching facilities. It will also be of use in our
household because poor selector of phase manually causes damage to our
household equipment example electronics like television,radio,videoplayer
etc and electrical appliances like refrigerator, air condition, fans just to
mention but a few. Finally another target is to eliminate the loss of human
life due to manual selection of the three phases.
1.7
SIGNIFICANCE
OF STUDY
The
significance of this project work cannot be overemphasized. This is because the
number of lives that has being lost to the hand of interruption of power in
health institutions and the like is not negligible. Delicate appliances have
become the main victim of this artificial circumstance. The applicability of
the outcome of this research work in several facets of human endeavor makes
this work of real importance to humanity.
The use of the
device produced from this research work would help to reduce human labor and
hazard, going by the fact that many have been handicapped by electric shock
because of the attempt they made to select another phase, and that the
handicapped are helpless and cannot change phase.
1.8
ACHIEVEMENT
OF THE CONSTRUCTION OF THE PROJECT
As long as electrical generation
and construction is must in everyday activities, electrical power consumption
is expected to be reliable and constant supply.
Therefore, what we tend to achieve from this project is;
1.
To have constant power supply.
2.
To have quick operation i.e. phase selection
3.
Reliable power supply
4.
Easy operation
Avoidance
of risk in doing manual changeover or switch