AUTO SELECTION OF ANY AVAILABLE PHASE, IN 3 PHASE SUPPLY SYSTEM

Abstract

Power failure is a common problem. It hampers the production of industry, construction work of new plants and building.
It can be overcome by using a backup power supply such as a generator. But it is cost effective and also time consuming as a certain
time is required to switch on the generator manually. It is often noticed that power interruption in distribution system is about 70
percent for single phase faults while other two phases are in normal condition. Thus, in any commercial or domestic power supply
system where three phases is available, an automatic phase selector system is required for uninterrupted power to critical loads in the
event of power failure in any phase. This project presents a system which is a power based auto select technology which automatically
selects an alternating current (A.C) phase out of three phases instead of the usual manual changing of cut out fuses which is tedious
and prone to human error. The purpose of this project is to use the system of automation to carry out the selection of an Alternating
current (A.C) power phases using a combination of power, microcontroller and relay (switch) circuit thereby eliminating every form of
human involvement in the process. This project also includes a current sensing circuit which is fed back to the microcontroller for
balancing of the three phases. The goal of A.C phase automatic selection was achieved using fewer components, lesser consumption of
energy as well and at a lesser cost compared to the usual, conventional way (manual switching) of phase selection.