Design And Construction Of A Solid State Automatic Voltage Regulator

ABSTRACT

The control of irregular voltage supply with fluctuation so as to become stable is carried out using this voltage regulators. Conventional regulators make use of mechanical relays which have a slow switching period but in this work regulators was built around solid state device such as TRIAC. This automatic voltage regulator is designed and constructed in a way that it makes use of silicon controlled rectifier which helps in reducing instability in the system and as well as having an increased switching period. This project demonstrates the use of Microcontrollers in power devices. The Microcontroller allows for accurate monitoring of the mains voltage and display on a seven-segment display. Depending on the voltage level of the mains, the Microcontroller triggers the appropriate TRIAC connected to an auto-transformer in order to stabilize the output voltage fed to the loads or appliances.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRCT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• AIM/OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• APPLICATION OF THE PROJECT
• LIMITATION OF THE PROJECT
• SCOPE OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1      HISTORITICAL BACKGROUND OF VOLTAGE STABILIZER

2.2      REVIEW OF AC VOLTAGE STABILIZERS

2.3      CONSTANT-VOLTAGE TRANSFORMER

2.4       REVIEW OF AN AUTOTRANSFORMER AND ITS OPERATION

CHAPTER THREE

3.0      CONSTRUCTION METHODOLOGY

3.1      BLOCK DIAGRAM OF THE SYSTEM

3.2      CIRCUIT DIAGRAM

3.3      CIRCUIT DESCRIPTION

3.4      SYSTEM OPERATION

3.5      COMPONENTS LIST

3.6      VOLTAGE STABILIZER CONTROLLER SECTION

3.7      THE BUCK-BOOST PRINCIPLE

3.8     PULSES-DRIVE CIRCUIT AND THE TRANSFORMER

3.9     DESCRIPTION OF MAJOR COMPONENTS USED

CHAPTER FOUR

4.1            RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      CASING AND PACKAGING

4.3      ASSEMBLING OF SECTIONS

4.4      TESTING OF SYSTEM OPERATION

4.5     COST OF PRODUCTION

CHAPTER FIVE

• CONCLUSIONS
• RECOMMENDATION

5.3     REFERENCES

CHAPTER ONE

• INTRODUCTION

Automatic voltage regulator is a wonderful invention of science, which is an electric device designed to regulate a constant voltage in a settable level. The main working of a regulator depends upon the laws of electromechanical physics. It is consist of many active and passive electrical components like adopters, capacitors, diodes and thermostats.

There are many functions of an automatic voltage regulator. AVR or automatic voltage regulator can be used with lot of electric appliances for various reasons. The basic functions of the automatic voltage regulators are:

First and foremost, it is used as a rectifier and as a potential divider. Rectifier is also an electric device used to convert the alternate current (A.C) to direct current (D.C) for further electric processing. Most of the electric appliances require a direct current for their working and can’t work on alternate current. Regarding potential dividers, they are electric devices used for the break out of input voltage to bring it to a desired output voltage as per the requirements. Thus while using an automatic voltage regulator we can make use of a rectifier and a potential divider at the same time. Means you can save money because you will have to buy a single automatic voltage regulator instead of purchasing a potential divider and a rectifier for your electric appliances.

There are many appliances in our homes which need stable electric power for their running and there might be some damage to the whole electric appliance if there comes any variation in the input current and voltage. Sometimes this may be fatal also but electricity is a very merciless killer. To avoid any mishap to the electric appliances and to us also, which may arise due to any variation in the voltage or current supply, a voltage stabilizer is essential to be used a complement to other electric devices.

AC automatic voltage regulator can also be used in amplifiers. Amplifiers are other electric devices that compare the sensing voltages to the reference voltages and help to amplify the effect. You might have seen amplifiers attached to your home sound systems which boost up the sound effects. The actual sound quantity will be lower but if the same input is given to an amplifier, the resultant sound quality and quantity just increases to multiples of the input waves. The basic running procedure in them is the difference of provided voltages. AC Automatic voltage regulators help in maintaining a desired voltage for the generators within specified limits. Thus automatic voltage regulator is also the important part for our amplifier to work.

The previous analog/servo-types of automatic voltage regulators are now replaced by digital stabilizer. These types of automatic voltage regulators are higher in functionality and performance. They are equipped with self functioning controls and start up functions which make them very useful and easy to handle. Digital converters increase their precision levels. Simplified operating switches make them very precise than human handlings. If any fault occurs in the functioning of the automatic voltage regulators, self diagnostics technique detects the fault in no time. This leads to more security of the function. The maintenance tool helps in maintaining an online monitor. Reduced number of parts and wiring in these typically modern automatic voltage regulators make them more reliable. Automatic changes are easily dealt with the help of full duplex control systems.

The NeoPower voltage regulators have different sizes. There are automatic voltage regulators which are so small that they can be easily placed on a small printed circuit board. They are portable and easy to handle. Some automatic voltage regulators are very gigantic in size. They may cover a volume of a small house sometimes. Thus there is a tremendous variety in the automatic voltage regulators and each has its own specifications. The variation of stabilizer can be judged by the names of automatic voltage regulators. Each name indicates its specific functioning and differences from others and there are more than fifty names to an automatic voltage regulator. Regarding the prices of automatic voltage regulators, it goes the natural way. If you will buy a smarter one, it will cost you more and you will buy an older model with normal functioning, it will cost you less. But keep in mind that whether an AC automatic voltage regulator costs less or high, it becomes irrelevant when it comes to the importance of an regulator in our daily lives.

• BACKGROUND OF THE PROJECT

There are many fundamental different types of regulator 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.  An automatic voltage regulator 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.

• OBJECTIVE OF THE PROJECT

The objective 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 AVR 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.

• SIGNIFICANCE OF THE PROJECT

Using triacs in place of mechanical relays, this project provides automatic voltage regulation for connected AC loads and appliances. Since no relays are used, the regulator is silent and doesn’t suffer from problems of wear as with mechanical relays. A seven segment display also shows input and output voltage levels.

1.4                                         THE SCOPE OF THE PROJECT

The design and construction of an Automatic Voltage Regulator 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.

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 AVR. When generator or utility power is restored, the AVR shall automatically restart. Upon turn on or restart, the output of the AVR shall not exceed the specified output regulation limits.

If the input voltage or frequency exceeds programmable minimum or maximum set points for a programmable time period (factory set for 10 seconds), the AVR shall electronically shut off. When electrical parameters are back within acceptable limits for a programmable time period (factory set for 60 seconds), the AVR 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 AVR shall electronically shut off and require a manual restart.

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

Rating: this device shall be rated at kVA.

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

1.7                                      APPLICATIONS OF STABILIZERS

Fluctuation in electricity is one of the major problems that affect their production. Due to high demand of electricity to sustain their operations, it results to low voltage output which can damage equipments. Therefore, these companies need specialized devices to help them protect their equipments from early wear and tear. Voltage regulators are electromechanical constituents that control the regular voltage outputs. During peak consumption of electricity, the sudden flow of power can damage electric or electronic machines. On the other hand, if there is low output of voltage, a machine may fail to function. Servo Voltage Stabilizer provide safe output to guard varieties of equipments including ultra modernized music systems, medical equipments LCD, Home Theater, industrial machines and more. They are designed with special features to protect equipments which include line noise spike protection, primary switching technology, auto reset, and overload cutoff protection. In order to preserve the life of machines, these devices are recommendable in any operation. They assure that machines are working well all the time especially in peak timings. Basically, these equipments are used to control the input voltage fluctuations and at the same time, to maintain an output voltage of +/-0.5% accuracy. They also help lower MDI and in saving power consumption. There is plenty of Servo Voltage Stabilizer Manufacturers India that provides range of stabilizers. They serve range of applications in many industries e.g., Information Technology, Data processing, Chemical and Textile, Air conditioning, medical and more. During power interruptions, generators play a very important role in supplying continuous electricity. These equipments give the residents, workers and industries the peace of mind that they can continue doing their work without breaks. These emergency power system guarantees that there will be normal circuits and they can continue whatever important tasks they are doing. For businesses, power interruptions can lead to lost of sales and profits. With assurance that everything will run well even without electricity, electricity standby power assures full performance of every equipment at all times. Since stabilizers are needed to maintain every electric or electronic device, stabilizer for generator guarantees that they are working at full performance even for a long time. Generators are big investment for any home or business. Therefore, they must be protected too from electrical surges. Generator Voltage Regulators are specially designed to control the voltage output. Regularly, the voltage output must be in the range of 120 to 240 volts. Therefore, these generator stabilizers provide support that equipments will function at their best even in the event of power fluctuations or interruptions.

1.8                                                     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.

1.9                       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 work is on the introduction to an automatic voltage stabilizer. In this chapter, the background, significance, objective limitation and problem of an automatic voltage stabilizer were discussed.

Chapter two is on literature review of an automatic voltage stabilizer. 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, recommendation and referenc