Design And Construction Of A Microcontroller Based Automatic Phase Failure Controller For 3-Phase Power Supply

This project work is on the design and construction of automatic phase failure controller for 3-phase power supply. It provides a means of switching from one phase of AC mains to another in the case of failure in the existing phase using PIC16F88 as the heart of the project; This project has been improved on the existing types of electromechanical device that has being in use over the years.

Hence this has been achieved by the use of operational amplifier, timing circuit and high current relay switches and it is powered by 12V dc power supply.
The aim of this work is to design and construct an automatic phase failure controller introduces an automatic solution to overcome power fluctuation/phase interruption by selecting next most healthy available phase from three phase supply to feed the equipment without any notice of power outage.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• AIM/OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• STATEMENT OF PROBLEMS
• LIMITATION OF THE PROJECT
• PURPOSE OF THE PROJECT
• APPLICATION OF THE PROJECT
• METHODOLOGY
• PROJECT ORGANISATION

CHAPTER TWO

2.0     LITERATURE REVIEW
2.1     REVIEW OF ELECTRICAL PHASES
2.2     REVIEW OF THREE-PHASE ELECTRIC POWER
2.3     REVIEW OF THREE PHASE GENERATION AND DISTRIBUTION
2.4   REVIEW OF THREE-PHASE LOADS

2.5     OVERVIEW OF RELEVANT TECHNOLOGY

2.6     REVIEW OF RELATED WORKS EXISTING SYSTEM

2.7     SUMMARY OF REVIEWED WORKS

CHAPTER THREE

3.0      METHODOLOGY

3.1     BLOCK DIAGRAM OF THE SYSTEM

3.2     DESCRIPTION OF THE SYSTEM BLOCK

3.3     SYSTEM CIRCUIT DIAGRAM

3.4     CIRCUIT OPERATION

3.5     CALCULATION OF POWER SUPPLY

3.6     DESCRIPTION OF COMPONENTS USED

CHAPTER FOUR

RESULT ANALYSIS

4.0     CONSTRUCTION PROCEDURE AND TESTING

4.1     CASING AND PACKAGING

4.2     ASSEMBLING OF SECTIONS

4.3     TESTING OF SYSTEM OPERATION

4.4     COST ANALYSIS

CHAPTER FIVE

5.0     CONCLUSION

5.1     RECOMMENDATION

5.2     REFERENCES

CHAPTER ONE

1.0                                             INTRODUCTION

1.1                                       BACKGROUND OF THE STUDY

In Nigeria today the problems of power outage across phases is so rampant thus leading to some sensitive equipment and appliances being redundant, this could sometimes be the cause of one phase going out with respect to the other according to [William D, 2009] .

It may surprise one to note that in an attempt to solve this problems, so many unskilled electricity consumers has in recent past resorted to some crude means of swapping between phases to obtain power. So many souls have been lost in this act. This is an undesirable condition to consumers and the need now arises to design a device that can automatically select among the phases and make power supply available at the consumers terminal [William D, 2009].

However, this can only be possible if one have a three phase met or and there is supply from any of the service line or the entire line, this project known as a three phase automatic phase selector has been constructed with a view of solving the problems stated above. The design and construction was based on the principle of Electro magneto-Dynamism and alignment as demonstrated in the contactor arrangement [Theo. Audel and Co, 1998].

Among other components are the timers miniature-circuit breakers the contactors and indicator bulbs, the ease with which the device is operated is well elaborated to ensure simplicity effort were made to present a stop by step operation of the project. As much as there is no project without limitation and applications, we have as well dedicated a section of this paper to look into it [William D, 2009].

In order to ease the effort of technicians in restoring the devices should there be any malfunction associated.

Faults and how they are cleared is presented, however, there are no user serviceable parts in the device therefore all maintenance should be referred to a qualified electrical personnel [Cotton H, 2011].

1.2                                   PROBLEM STATEMENT

Power failure in a country, state or city is highly detrimental to development in public and private industries. The insecurity associated with these problems brings about limitation to power consistent investments, thus hampering the development of industries and multinational ventures. Processes like carrying out surgical operations in hospitals, laboratories which require constant power supply for research, money transactions between banks and more require constant use of uninterrupted power. In other to solve this problem, an automatic changeover switch was invented. This research covers the design and construction of a single phase digital automatic power changeover. It has the capacity to automatically switch power from  national grid to generator and vice versa, once there is power failure in any of the two power supplies and at the same time has the capacity of shutting down a generator set once the mains grid is been restored according to Theo. Audel and Co, 1998.

1.3                                          OBJECTIVE OF THE PROJECT

The objective of this work is to design a device that will overcome power phase interruption by selecting next most healthy available phase to feed the equipment.

1.4                                      SIGNIFICANCE OF THE PROJECT

Industries require three phases power to run their machinery. Some of them require continuous \ uninterrupted power to maintain their data. Auto phase failure controller unit for equipment whose supply is single phase. The single phase supply is selected automatically from three phases supply.

Auto Phase failure controller introduces an automatic solution to overcome power phase interruption by selecting next most healthy available phase to feed the equipment [ Fowler, Nick 2011].

1.5                         LIMITATION OF THE PROJECT

In every home, office or industries, automatic phase selector plays a vital role, that is, It provides a means of switching from one phase of AC mains to another in the case of failure in the existing phase; This project has been improved on the existing types of electromechanical device that has being in use over the years.

In the course of designing this project, different kinds of problem was notice such as:

• Difficulty in troubleshooting with circuit without the circuit diagram
• Difficulty in connecting the output without the three phases short-circuiting, until a multiplexing circuit was gotten.
• Difficult in wiring because of the strong wiring the project required [ Fowler, Nick 2011].

1.6                               SCOPE OF THE PROJECT

This work covers only a three phase automatic phase failure controller which can only be used for providing a means of switching from one phase of AC mains to another in the case of failure in the existing phase.

1.7                           APPLICATION OF THE PROJECT

Here are some application where the controller is been used, like various large processing plants, pharmaceutical industry and also in thermal power station etc.

Here are also some example where huge application been controlled like infrastructure airport and railways. Automatic phase selector is also been used in commercial and service sector .This also reduces the manpower on field

1.8                                         METHODOLOGY

To achieve the aim and objectives of this work, the following are the steps involved:

1. Study of the previous work on the project so as to improve it efficiency.
2. Draw a block diagram.

• Test for continuity of components and devices,

1. Design and calculation for the device was carried out.
2. Studying of various component used in circuit.
3. Construction of the device is carried out

• Finally, the whole device was cased and final test was carried out.

1.8                                             DEFINITION OF TERMS

POWER OUTAGE / POWER FAILURE: A power outage is the loss of the electrical power network supply to an end user.

AUTOMATIC CHANGEOVER is device that automatically transfers power from generator supply to PHCN supply when available and stops the generator without without human intervention

1.8                             PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.