Thesis Abstract

Abstract
This research project focuses on the design and implementation of an automatic 3-phase changeover system with generator set switching. The purpose of this system is to provide seamless and reliable power transfer between the main utility supply and a backup generator in the event of power outages or fluctuations. The automatic changeover system is designed to monitor the status of the utility supply and automatically switch to the generator set when needed, ensuring continuous power supply to critical loads. The system consists of sensors to detect the presence and quality of the utility supply, as well as the status of the generator set. These sensors provide real-time information to a microcontroller unit, which controls the switching mechanism. The microcontroller unit is programmed with logic to determine when to initiate the switch between the utility supply and the generator set based on predefined criteria such as voltage levels, frequency deviations, and duration of power interruptions. The implementation of the automatic changeover system involves integrating the sensors, microcontroller unit, and switching mechanism into a cohesive system that can operate autonomously. The system is designed to be robust and fault-tolerant, with built-in safeguards to prevent improper switching and ensure the safety of connected equipment. The benefits of this automatic changeover system include improved reliability of power supply, reduced downtime during power outages, and increased convenience for users who do not have to manually intervene to switch between power sources. The system is particularly useful for critical applications such as data centers, hospitals, and industrial facilities where uninterrupted power supply is essential. Overall, the design and implementation of this automatic 3-phase changeover system with generator set switching provide a practical solution for ensuring continuous power supply in situations where reliability and stability are paramount. By automating the process of switching between power sources, the system enhances the resilience of electrical systems and contributes to improved efficiency and performance in various applications.

Thesis Overview

INTRODUCTION

The evolutionary trend in industrial electronics and automation has engulfed all parts of the world and proved more challenging to as third world like Nigeria. Regarding the milestone, it was decided to make the choice of project research on the design and implementation of an automatic 3 – phase change – over with Generator switching which will eliminate the stress and lapses involved in the manual process. This electronics system is realized using 3 – phase regulated Dc power supply unit whose output is compared and fed to a 3 – input AND gate that encodes control logic to the driver stage realized using NPN Bipolar junction transistors which energize three electromagnetic relays. These relays in turn energize single coil three contacts contactors that switch the phases. (Manaha, 2008) A control/switching circuit is also integrated that takes care of the Gen set switching whenever at least one phase from mains is low/faulty.
1.1. GENERAL DESCRIPTION OF THE PROJECT
The project design and implementation of automatic 3 – phase change – over with Gen set switching is built in several functional blocks all combined to form one functional unit. The first is made up of regulated Dc voltage power supply unit whose output is compared and fed into 74 LS11 that generates the control logic. This logic is used to bias the driver stage which energizes electromagnetic relay. These relays serve as auxiliary to a single coil 3 – contact contactor of suitable rating. The Gen set switching module incorporates delay timer and solid state relay that takes care of the process.
The project, so constructed is packaged in a plastic casing for compatibility. On the surface of the package, there are three 100k vol/pot which are used to demonstrate low voltage in a given phase. Three amber LEDs represents the mains while the three blue LEDs are for the Gen set. And these make up of the panel indicator.
1.2. OBJECTIVES OF THE PROJECT
One of the objectives of this project is to design and construct an automatic 3 – phase change – over with Gen set switching facility which will automatically switch ON/OFF Gen set and change over between PHCN and Gen set. It is also aimed at exposing the graduating student to electronics system designing using random logic – especially in designing in industries and power electronic. Another objective of this study is to ground the graduating students in Engineering, scientific and technical writing which is indispensable in their professional practice.
1.3. SIGNIFICANCE OF THE PROJECT
This project work signifies a lot in industrial automation and power electronics. It is very useful in wood processing industries, oil rig equipments and other manufacturing industries that used 3 – phase machines. A project of this nature can be modified to function as automatic phase selector which can be used anywhere.
1.4. SCOPE OF THE PROJECT
This project work covers the following; transistor drivers, electromagnetic relay, contractors, 3 – input AND gate encoder, shunt regulation and comparator using Zener diode, delay/un-delay timer and other system components. It x-rays the design calculations of the basic circuit parameters and areas of application of the system.
1.5. PROJECT REPORT ORGANIZATION
This project report is presented in six chapters to appropriately illustrate the steps involved in its implementation.
Chapter one introduces the project overview objectives and its significance. Chapter in basically the literature review and some theories relevant to the design chapter three x –rays the methodology and analysis while chapter four covers the system design and description. Chapter five elaborates on the implementation, testing and result. Finally, chapter six is about the summary of the entire theories and recommendation.