Design And Construction Of A 2.5KVA Automatic Voltage Stabilizer

ABSTRACT

This work is on a 2.5kva Automatic Voltage Stabilizer. It is designed to meet up with the AC voltage safety, stability and accuracy demand in industries and in homes. Voltage stabilizers 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 stabilize 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 stabilize 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      AIM/OBJECTIVE OF THE PROJECT

1.3      SIGNIFICANCE OF THE PROJECT

1.4      SCOPE OF THE PROJECT

1.5      LIMITATION OF THE PROJECT

1.6      PROBLEM STATEMENT

1.7      APPLICATION OF THE PROJECT

1.8      DEFINITIONS OF TERMS

1.9      METHODOLOGY

1.10   PROJECT ORGANIZATION

CHAPTER TWO

2.0      LITERATURE REVIEW

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

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

In Nigeria and some other parts of the world today, the electricity power supply to consumers (at homes and industries) are not maintained at a stipulated voltage say 240 volts.  But the electronics gadgets and some other power operated machines, that we use in our homes, offices and industries requires power with constant or nearly constant voltage for their efficiency, and to avoid damage by the voltage [Harper C, 1977].

Voltage stabilizer is an electronic control circuit or device that is capable of providing a constant or nearly constant output voltage even when there is variation in load or input voltage as low as 90 volt can be boast up to 240 volt by stabilizer at output stage without any voltage fluctuation [Harper C, 1977].

1.1   BACKGROUND OF THE PROJECT

There are many fundamental different types of stabilizers in use some of which are electron mechanically tap changer, solid state tap changer etc. voltage, stabilizer came into being not by normal design and plain, but as a means of solving electrical “Crisis” situation.  This crisis situation does rarely occur in developed countries of the world such as Britain, American, Germany.

Their system of generation, transmission and distribution of electricity is such that a devoid of variation of fluctuation in the supplied voltage.  Now, by the definition given by K.G Jackson and R. Feinberg, a voltage stabilizer is a piece device incorporated in a circuit to maintain a constant output voltage from a poorly generated power supply.  A voltage stabilizer like any other piece of equipment is a combination of many electrical and like any other piece of equipment is a combination of many electrical and electronic and circuit with the aim of getting the assemble to perform a specified desired task or function [Oakes, I 1997].

1.3  AIM/OBJECTIVE OF THE PROJECT

The aim of this work is to construct a device whose function is to maintain constant voltage and power line conditioning to the equipment load under a wide variety of conditions, even when the utility input voltage, frequency or system load vary widely. The objectives of this work are:

1. To build the system prototype
2. To maintain the stable voltage level thereby providing a constant supply in spite of any fluctuations or changes in supply in order to protect the home appliances.

• To prevent the life span of electronic any electrical and electric devices that makes the use of it.1.4  SIGNIFICANCE OF THE PROJECT

The Automatic voltage stabilizer is a device built to electromechanically sustain a constant voltage level. It is a device built to maintain a constant voltage level. It can also use electromechanical components. This study will serve as a means of becoming familiar with relay and autotransformer which are the major components used in this work.

The study will make the reader to understand the need for having a stable voltage all the time.

1.4                                         THE SCOPE OF THE PROJECT

The design and construction of an Automatic Voltage stabilizer is the project we are construction.  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.

As we have mentioned earlier, this device is a protective device that protects our electrical and electronic appliances out of current and voltage fluctuation. This is how it works.  When this system is plugged into the socket or supply, it will receive a minimum voltage of 100v and filter the current and voltage thereby brings out suitable voltage output to be used by the devices in it [Jackson, K.G, 1981].

So, we are building or constructing this device to reduce risk and damages the fluctuation of current / voltage caused by power fluctuations.

1.5                                        LIMITATION OF THE PROJECT

The system design shall be capable of operating at an input frequency range of -15% to +10% of nominal, without clearing protective devices or causing component failure within the AVS. When generator or utility power is restored, the AVS shall automatically restart. Upon turn on or restart, the output of the AVS shall not exceed the specified output regulation limits [Michael T, 1993].

If the input voltage or frequency exceeds programmable minimum or maximum set points for a programmable time period (factory set for 10 seconds), the AVS shall electronically shut off. When electrical parameters are back within acceptable limits for a programmable time period (factory set for 60 seconds), the AVS shall automatically restart to provide conditioned power to the load. If the input parameters are within acceptable limits, but the output voltage is outside of acceptable programmed limits, the AVS shall electronically shut off and require a manual restart.

The AVS shall be capable of operating at 100% rated load capacity continuously, 200% rated load for 10 seconds, 500% rated load for 1 second and 1000% rated load for 1 cycle. Operating efficiency shall be a minimum of 96%, typical at full load.

Transformer winding shall be continuous copper with electrostatic tripled shielding and K-13 rated for the purpose of handling harmonic currents.

Response Time: The AVS shall respond to any line voltage variation in 1/2 cycle while operating linear or non-linear loads, with a load power factor of 0.60 of unity. Peak detection of the voltage sine wave shall not be permitted to avoid inaccurate tap switching due to input voltage distortion.

Operating Frequency: The AVS shall be capable of operating at +10% to -15% of the nominal frequency, 50Hz or 60Hz.

Rating: this device shall be rated at 2.5kVA.

Access Requirements: The AVS shall have removable panels on the front, rear and sides as required for ease of maintenance and/or repair.

Metering: An input meter is provided to display line voltages

Ventilation: The AVS isolation transformer shall be designed for convection cooling. If fan cooling is required for the solid state electronic switching devices.

1.6                                               PURPOSE OF THEPROJECT

The main purpose of this study is to maintain constant voltage and power line conditioning to the equipment load under a wide variety of conditions, even when the utility input voltage, frequency or system load vary widely.

1.7                                              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 stabilizer 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.

1.9                                         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.

1.10                                                  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.

Prime rating: the rating given to a generator when it is used in lieu of mains power at a varying load. There is normally an overload allowed at this rating of 10% above the prime rating for 1 hour in 12.

Single phase power: The electricity produced from one phase of a three phase winding or from a dedicated singles phase winding.

Standby power: Maximum power a generator will give normally restricted to 1 hour in 12 for standby purposes only.

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

Watts: The total energy supplied by a circuit.

Surge: Overvoltage supply of electricity causing damage in sensitive equipment (opposite of Brown out).

Surge Suppression: Electronic equipment designed to restrain surges such as lightning strikes.

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

Base load rating. The rating given to a generator when it is used for continuous supply of electricity at a given load 24/7.

Black out. A national or wide area power failure, causing major disruption. For example.

Brown out. A drop in the mains voltage (not a total failure) that can cause degradation of lighting and electronic equipment.

1.10                                                  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.

• Design and calculation for automatic voltage stabilizer.

1. Studying of various component of automatic voltages stabilizer circuit.
2. Construct a automatic voltages stabilizer circuit.

1.11                                  PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this works is on the introduction to an automatic voltage regulator. In this chapter, the background, significance, objective, aim, scope, limitation and problem, definition of terms of an automatic voltage regulator were discussed.

Chapter two is on literature review of an automatic voltage regulator. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, discussion, recommendation and references.