The Design And Construction A 2.5KVA Automatic Voltage Regulator

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. This work is on a 2.5kva Automatic Voltage regulator. It is designed to meet up with the AC voltage safety, stability and accuracy demand in industries and in homes. Voltage regulators are useful in devices such as computer Power supplies, alternators and central power station generator plants, voltage stabilizer control the output of the plant. This project is designed to regulates an AC input voltage of 160-250V to give an AC output voltage of 220V at 50Hz automatically. The automatic feature can be achieved by the electronics devices used such voltage comparator IC, electro-magnetic device (relay), auto- transformer and other electronics devices.

In this project, 2.5KW was designed to control and regulates an AC input voltage of 160-250V to produce an output of 220V all at 50Hz.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGMENT

ABSTRACT

TABLE OF CONTENTS

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

1.2      PROBLEM STATEMENT

1.3      AIM/OBJECTIVE OF THE PROJECT

1.4      SIGNIFICANCE OF THE PROJECT

1.5      SCOPE AND LIMITATION OF THE PROJECT

1.6      APPLICATION OF THE PROJECT

1.7      DEFINITIONS OF TERMS

CHAPTER TWO

2.0      LITERATURE REVIEW

• HISTORICAL BACKGROUND OF THE PROJECT
• STAGES IN THE DEVELOPMENT OF VOLTAGE REGULATOR
• REGULATOR GRADING
• TYPES OF REGULATOR

CHAPTER THREE

3.0      CONSTRUCTION METHODOLOGY

• BLOCK DIAGRAM
• CIRCUIT DIAGRAM
• CIRCUIT DESCRIPTION
• SYSTEM OPERATION
• DESCRIPTION OF MAJOR COMPONENTS USED
• COST ANALYSIS

CHAPTER FOUR

4.0      RESULT ANALYSIS

• CONSTRUCTION PROCEDURE
• CASING AND PACKAGING
• ASSEMBLING SECTION
• SYSTEM TESTING
• DESIGN PRECAUTION

CHAPTER FIVE

• DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1      DISCUSSION

• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.0                                                     INTRODUCTION

• BACKGROUND OF THE PROJECT

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.

These 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 bythe 11.5VD.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                                              PROBLEM STATEMENT

The rate at which our appliances get burnt is higher most especially appliances without transformer such as our cell phone chargers and lanterns. And this problem is usually caused by either over voltage or under voltage. Due to this problems, a voltage regulator was designed which regulates under and over voltages to normal 220vac. An automatic voltage regulator regulates the AC voltage and keeps from lower or higher to normal. It protects any electronic device connected to it from getting damaged.

• AIM/OBJECTIVE OF THE PROJECT

This work is aimed at building a device that maintain stable voltage level to provide a constant supply despite of any fluctuations or changes in supply in order to protect the home appliances.

The objectives are:

1. To build the system prototype model
2. To protect devices from damages cause by varying utility input voltages.

• To prolong the life span of electronic or any electrical devices that makes the use of it.

1.4    SIGNIFICANCE OF THE PROJECT

The Automatic voltage stabilizer is a voltage regulator planned to mechanically sustain a constant voltage level. It is very device to maintain a constant voltage level. It can also use electromechanical components. It can be used majorly to regulate one or more DC or AC depending on the design. Therefore, the functions of this equipment are very wide and can be used majorly for various purposes. Electronic voltage regulators can be used majorly for various purposes. It has various functions like it can be used mainly for stabilizing the DC voltages that can be used by the processor and its main parts. In central power station generator plants and automobile alternators, voltage regulators control the output of the plant. In this distribution system, it may be installed at along distribution lines so that all clients recognize steady voltage self-regulating of how much power is drawn from the line. There are many functions of operating the AC depending upon the design. It is very good option to maintain the constant voltage level. Automatic voltage regulator is a superb invention of science, which is an electric device designed to authorize a constant voltage in a settable level. It is very helpful to maintain the preferred voltage for the generators within particular limits. The main working of it depends upon the laws of electromechanical physics. It consists of numerous vigorous and unreceptive electrical parts like thermostats, adopters and diodes. Apart from this, there are many reliable Automotive Suppliers in India that produce many kinds of equipments like generator, regulator and other major parts. They are well known for various kinds of functions and various specifications.

1.5                           THE SCOPE / LIMITATION OF THE PROJECT

The scope of this work covers building an automatic voltage stabilizer.  We are working on this machine because we have some idea on how this machine can be constructed and also on how it works.  We are also doing this because we want to learn more about it.

The AVS shall consist of an all copper, multiple tapped, triple shielded isolation transformer and contain independently controlled inverse parallel electronic switches for each of the 7 taps per phase to provide tight voltage regulation. The phase current shall be monitored for zero current recognition to initiate any required tap change. Linear devices shall be used for line synchronization to prevent phase shift errors normally associated with simple CT zero current crossing acquisition. The system shall be microprocessor controlled.

As we have mentioned earlier, this device is a protective device that protects our electrical and electronic appliances out of current and voltage fluctuation. The range of input voltage should be 100 to 280V.

• The range of output voltage should be 220v.
• There should be no change in the waveform or the frequency of input/output voltages.
• The material used in it should not be too much expensive otherwise there would be no use of making it at home by going through all the trouble, can just buy a cheap one from market instead. Therefore it should not be expensive.
• A total of 4 relays are used in the circuit.

1.6                                         APPLICATIONS OF THE PROJECT

• Voltage regulator is used to automatically adjust the output voltage of the power supply circuit or power supply equipment
• It can be widely used in places require stable power supply voltage, such as industrial and mining enterprise, oil, railways, construction sites, schools, hospitals, telecommunications, hospitals, research and other department as of computer, precision machine tools, computer tomography(CT),precision instruments, test equipment, elevator lighting, imported equipment and production lines and more.

1.7                                                     DEFINITION TERMS

HV: High Voltage. Any electricity supply in excess of 650volts. Primarily used for the transmission of electricity over long distances.

Kva: Kilo volt amps. A measurement of the electrical ‘pressure’ and ‘quantity’ to a building.

Loads:  The equipment that is using the electricity supplied to a building.

Long power cut: Failure of the mains power external to your building, in excess of 30 minutes to 24 hours.

LV:  Low Voltage. Electricity supply from 110volts to 650 volts.

Power cut: A failure of the mains electricity by factors outside of your premises.

Winding: The copper wire that produces electricity when it passes through a magnetic field.

Watts: The total energy supplied by a circuit.

AVRs. Automatic voltage regulators. The electronic device which controls the output voltage of an alternator.