The Construction Of A 2KVA Automatic Voltage Regulator (AVR)

Project and Seminar Material For Electrical Electronics Engineering EEE

Abstract

The AVR is automatic voltage regulator and it is a device which is used to regulate or stabilize electrical power supply for electrical or electronic appliances.

In this project therefore, we are interested in the construction of this all important device. Furthermore we shall discuses the techniques, processes, switching stages and then the working principle of the automatic voltage regulator

Chapter one of this project dwells on the introduction of the project topic. It also talks about the objectives of the project, bringing to mind what we intend to achieve at the end

Chapter two of the project reviews the research works that has been carried out by some other people in this study area. It also discusses on some of the components used in this project

Chapter three gives a detailed account of the basic construction and the operation of the AVR. It also highlights on some other components used, discussing their working principles using both the circuit and block diagrams

Chapter four of this project, draws the conclusion an consequently gives the recommendation on how to better the operation of the AVR. It also includes the references and articles consulted in the course of this project.

Certification page
Abstract
Acknowledgement
Dedication
Table of content

Chapter One

1.1 Introduction to automatic voltage regulator
1.2 Objectives of the project

Chapter Two

2.0 Literature review
2.1 Some of the components used
2.2 Resistors
2.3 Capacitors
2.4 Transistors
2.5 Relays

Chapter Three

3.0 Basic construction and operation of the AVR
3.1 Components
3.2 Transformers
Circuit diagram of the AVR
3.3 The working principle
3.4 The main function of the AVR
3.5 The need for voltage regulation/stabilization

Chapter Four

4.0 Conclusion and recommendation
4.1 Conclusion
4.2 Recommendation
Reference

Chapter One

1.0 Introduction To Automatic Voltage Regulators.

Automatic voltage regulators (AVR) in power supply unit is a device which is used to regulate or stabilize electrical power supply for electrical or electronic appliances. This device helps automatically to keep the voltage level from the public power supply system constant. In other words, the minimum and maximum ranges of voltage are maintained in order to achieve a constant output of 220V.

This devices also serve as a protective device for appliances connected directly to it, while the AVR is connected directly to the public supply. The protective system in AVR either regulate or stabilize it to 220V output for the safety of our appliances or the fuse in the AVR will rupture by excess current of the surge and thereby cut-off the incoming power supply.

The stabilization and regulation is achieved through the control circuit which include relays and other components of various voltages from the secondary winding of the auto-transformer used in this project work.

This control circuitry, does the work of cut and boost in the case of higher and lower voltage respectively. If the supply voltage drops below 220V down to 180V,the primary control does the work of the boost which brings the output to normal , while when the voltage increases beyond 220V up to 260V ( which is not ideal), it does the work of cut. The coils of the relay are triggered by the 11.5V D.C from the last stage of the operational Amplification.

By this arrangement, an improved automatic voltage regulation is achieved and, is hereby presented in this project.
Different techniques have been employed in the design of AVR circuits in recent times but, in the design and construction of this particular type, high rise voltage, excess current due to dangerous condition externally like lightening effect which may appear on the power supply lines were effectively isolated.

The system chips and fragile devices were protected likewise low voltage fluctuations make-brake power supply from public power supply were taken good care of in this AVR construction.

1.2 Objective Of This Project

The automatic voltage regulator of rating 2KVA is a natural choice for remote control device for the consistent voltage level fluctuation of our power supply system. Therefore, we bear the following in mind as our objective while carrying out this project;

To fully understand the automatic means of controlling and regulating the system, Its practices, design, construction, operation and application in public electric power system engineering
To test the electric power behaviour of systems or appliances connected to AVR. Also to perform both practices network computers, televisions, amplifier sets and other sensitive devices intended to be protected from direct connection to public electric power supply.
To practically engage in and fully understand the AVR operational modes and technology or configuration in electrical design and construction
To enhance power regulation and stabilization technology via automatic voltage regulation for our electrical and electronics appliances due to voltage variation and, incessant power –fluctuations.

Chapter Four

4.0 Conclusion And Recommendation

4.1 Conclusion

The importance of power supply in our everyday life cannot a be over-emphasized since most of our economic activities are dependent on power supply. It is certain that all the electrical and electronic appliances used in industries, institution, homes and offices will be at its best operation when the power supply is made constant and optimum but the reverse is the case if otherwise.

One of the short comings militating against the ultimate or required output of any appliance is fluctuation in power supply, not only does this situation affect the systems output but also it is possible to introduce fault into the system.

Consequently, damage to some of the delicate components of the system may occur, especially components operated beyond their capacity. In otherwords, constant output of power supply is necessary for effective performance of any electronic system.

The automatic voltage regulator (AVR) is one of those devices used to maintain constant level of power voltage in a power system. The AVR in its operation is automatic and is very sensitive to variations in voltage level and stabilizes its output.

Hence, THE IMPORTANCE OF VOLTAGE REGULATION ARE:

Lighting : the lamp characteristics are very sensitive to changes in voltage. For example, if the supply voltage to an incandescent lamp decreases by 6% of the rated value, then illuminating power may decrease by 20%. Consequently, if the supply is 6% above the rated value, the life of the lamp may be reduced by 50% due to rapid deterioration of the filament
In case of power load consisting of induction motors, the voltage variations may cause erratic operations. If the supply voltage is above the normal, the motor may operate with a saturated magnetic circuit, with consequent large magnetizing current, heating and low power factor. In the other hand, if the voltage is too low, it will reduce the starting torque of the motor considerably.
Too wide variation of voltage cause excessive heating of distribution transformers. This may reduce their rating to a considerably extent.

It is thus very clear from the discussions that voltage variation in power system must be kept to a minimum level in order to deliver good service to the consumers via voltage stabilization techniques and regulation.

Also, the AVR can be seen as a protective device to electrical and electronic appliances because of the auto transformer relays and other control devices like transistors used in this project. Going by it’s name and mode of operation, the AVR can handle different voltage levels with the range of its control and optimize them to be usable to the appliances.

4.2 Recommendation

In the construction of this automatic voltage Regulator which is geared towards understanding the basic ideology, knowledge, theories , principles and operations of the AVR, we, having gone through various procedures involved in the construction of such an important equipment, recommend that strict adherence to the laid down steps and operational conditions discussed in this project.

The construction of 2000VA automatic voltage regulator is interesting and educating albeit some constraints we encountered which took us into advancement in electrical and electronics power and voltage regulation.