Design And Construction Of 2KVA Inverter

ABSTRACT

This project presents the design and construction of a DC to AC inverter system. It is designed to meet up with the power demand in the offices/homes in the absence of power supply from National Supply Authority.

It is designed in such a way that it will take up to 12V DC from battery and inverts it to an output of 220V, 50Hz AC. It makes no noise during operation and not hazardous like carbon monoxide is generated to the surrounding. This is the feature makes it safe to used anywhere when compared to generator.

Also, the circuit is capable of charging the battery [i.e 12V source] where there is power supply from supply Authority. This greatly reduces the cost of operation of the system

TABLE OF CONTENT

TITLE PAGE

CERTIFICATION

DEDICATION

ACKNOWLEDGMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

INTRODUCTION

• BACKGROUND OF THE STUDY

1.2   PROBLEM OF STATEMENT

1.3   AIM AND OBJECTIVE

1.4   SCOPE OF THE PROJECT

1.5   METHODOLOGY

1.6 MOTIVATION

1.7   LIMITATION OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

2.0 INVERTER

2.1 HISTORY OF INVERTER

2.2.1 GENERAL FEATURES OF THE PROTECT

2.2.1 POWER SUPPLY UNIT

2.2.2 CHANGENG OVER UNIT

2.2.3 SWITCHING UNIT

2.2.4 UNDER AND OVER VOLTAGE PROTECTION UNIT

2.2.5 OSCILLATOR UNIT

2.3 TYPES OF INVERTERS

2.4 COMPARISON WITH THE GENERATOR

CHAPTER THREE

3.0   CONSTRUCTION AND METHODOLOGY

3.1   COMPONENTS AND FUNCTION

3.1.1 RESISTOR

3.1.2 CAPACITOR

3.1.3 DIODE

3.1.4  TRANSISTOR

3.1.5 NE555 TIMER

3.1.6        RELAY

3.1.7 REGULATOR

3.1.8 BATTERY

3.1.9 SWITCHES AND SOCKET

3.1.10 METER (VOLT/AMPERE)

3.1.11 LAMINATION

3.1.12 FUSE

3.1.13 TRANSFORMER

3.2 METHODOLOGY

3.2.1 STAGES INVOLVED IN THE PROJECT

3.2.2 DESCRIPTION OF VARIOUS STAGE IN THE INVERTER POWER UNIT

3.2.3  POWER AMPLIFYING STAGE OR INVERTING STAGE

3.2.4 MULTI-VIBRATOR

3.2.5 CONSTRUCTION OF THE CASING

3.2.6 HOUSING OF THE WHOLE COMPONENT

3.2.7 ARRANGEMENT OF COMPONENT ON VERO BOARD

CHAPTER FOUR

4.0 TESTING, DESIGN AND DISCUSSION

4.1.1 TRANSFORMATION STAGE

4.1.2 TRANSFORMER DESIGN

4.1.3 FREQUENCY DIVISION COUNTER

4.1.4 FREQUENCY UNIT

4.1.5 COMPONENT TESTING

4.1.6 TESTING OF THE INVERTER

4.1.7 STAGE BY STAGE TESTING

CHAPTER FIVE

CONCLUSION AND RECOMMENDATION

5.1 CONCLUSION

5.2 RECOMMENDATION

REFERENCES

CHAPTER ONE

INTRODUCTION

• Background of the Study

An inverter is an electronics device or circuitry that changes direct current (D.C) to Alternating current [AC]. The device make used of an in–built automatic circuit to achieve a complete automation of the entire system. The input voltage, output voltage, frequency and overall power handling depend on the design of a specific device or circuitry.

An inverter is very important element that cannot be neglected in this Country as it is deeply fasten into the fabric of the society for the obvious reason of inadequate power supply. It is an important element in homes to power household devices like electric bulbs, electric cooker, refrigerator, television set e.t.c. It also finds applications in various places work/offices to power devices like air conditioners, computers e.t.c.

In spite of constant repair and efforts put forward by the stake holders in electricity industry to ensure stable power supply, yet the power generation and distribution across the country is very bad, low and it very far from being enough.

However power failure has resulted in people buying generators for their daily activities. Businesses are not functioning due to failure of power supply. These are the reason that make necessary of designing and construction of inverter and other standby system that can deliver maximum output power to the load.

Statistics have shown that the number of business that have been closed down simply because of power failure, cannot be over emphasized, so mankind need inverter seriously in other to restore technology development, business and medical controls. However the background of the study lies within the reason why the construction of inverter should be forwarded the factor that increase the quality of inverter marketability.

Finally, the success of this study will beneficial to the society. Mass production of inverters will lead to improve standard of living of the people and the nation will move forward in it pursuit of technology development (http://www.falana.tripid.com/tope/index.blog?entry id=195483copy).

1.2   PROBLEM OF STATEMENT

Faced with the problem of load power supply from supply authorities, noise pollution, air pollution, cost of the popular alternative, generator sets, there is need for a less noisy, pollution free and cheap solution to power problem.  Then, this project is to provides a back-up and power by 220v A.C input and change to D.C sources to charge a 12v battery and change back to AC source with a reliable power supply of 2000VA output to power a standard house/offices.

1.3   AIM AND OBJECTIVE

The aim of this project is to design and construct a 2KVA inverter with an inbuilt charging system that take a 220V input that will be charged when there is supply from mains and change to D.C and later change back to A.C with the operation of inverter with output of 2000VA to power a standard offices/house.

The Objective are:

• To design and construct an inverter that will be able to power essential loads in a house
• To provide a noiseless source of electricity generation
• To provide a source of electricity power with low maintenance cost and zero fuel cost
• To design and construct an alarm circuit that beeps when the load on the inverter is beyond the inverter capacity.

1.4   SCOPE OF THE PROJECT

The scope of this project based on the design and construction of a 2KVA inverter and its operation, with the output power rating of 2KVA an maximum 7.27A  and output voltage of 220V AC sources from a 12v inbuilt battery. This project is basically designed for single phase domestic loads.

1.5   METHODOLOGY

• To study of the previous work on the project so as to improve it efficiency
• Draw a block diagram
• Studying of various components of charge controller and inverter circuit
• Constructs an inverter circuit

1.6 MOTIVATION

With the obvious advantages of the inverter being a cheaper [in the long term] and cleaner source of energy, it is a device that can power essential leads. In the absence of supply from power supply utilities in the country. Inverter are the best when it comes to back-up since they can come up very fast and they generate little or no noise unlike generators. Even in an area with constant power supply, power outage due to natural cause and fault are usually unannounced. It therefore very important to prevent causality and loss of good will by having a reliable back-up power installed (OYETUNJITOBI,S. (2015), construction of 2KVA inverter Electrical/Electronic Engineering Project Power Option HND II Final Year Unpublished).

1.7   LIMITATION OF THE PROJECT

The major limitation of this project is that it cannot operate equipment or an electronic device that is above its rated current.

• Also the used of bulky transformer instead of copper transformer which is lighter and smaller in size but more expensive is another limitation.

CHAPTER TWO

LITERATURE REVIEW

2.0  INVERTER

An enabling technology, power electronics does it job with intelligence, precision and efficiency. It used the smartness of advanced control technology with the efficient conversion of electric power into the precise from required to control a function or process. In a industrial and commercial products, it is gaining ground mostly visible among inverters which converts direct current (DC) into a single or poly phase AC voltage at a desire aptitude and frequency whose power rating now runs from 1000W, 20MW and more.

The operation of certain devices such as sensitive electronic equipment used for data processing, communications and control functions requires continuous and disturbance free AC power. inversion is the process by which an AC voltage or current or both is being produced from DC source and AC source. Both processors are affected in a similar way i.e by means of periodic communication, or switching of the supply to be transferred in such a manner that the desired type of output result.

The generation of electric power involves various sources power evolving from some primary energy sources such as:

1. Conversion of electromagnetic radiation in a photo voltage cell
2. A rotating generator

• Conversion of chemical energy in a fuel, cell or a battery

1. Conversion of kinetic energy by the magnetic hydro dynamic process.

2.1 HISTORY OF INVERTER

        The quest to convert DC power to AC power has been since the late 19^th century and from them to the mid-20^th century, DC to AC power conversion was accomplished by using rotary converters or motor generator sets (Ma Sets). In the early 20^th century, vacuum tubes and gas filled tube was used as switches in inverter circuits. The origin of electromagnetic converts explains the source of term inverters.

Early AC to DC converters used on inductor or synchronous AC motor directly connected to a generator (dynamo) so that the commutator of a generators reversed its connection at exactly the right moment to produce a DC source. It later development a synchronous converters in which the motor and generator winding are combined into one armature with a slip rings at one end and a commutator at the other with only one field frame. This result is a DC in and AC out. So, with Ma-sets, the DC can be considered to be separated generated from the AC with synchronous convert.

In a certain case, it can consider to be “mechanically rectified AC”. Given the right auxiliary equipment, an rotary converter can be running backward, converting DC to AC. Hence an inverter can be referred to as a DC-AC CONVERTER.

In modern inverter circuits, the DC power source is connected to a primary of transformer through the center tap of the primary winding. A switch is rapidly switched it back and forth to allow current to flow following two alternate paths through one ends of the primary winding and the other. The alternation of the direction of flow current is the primary winding of the transformer produce an alternating current in the secondary winding. The electromechanical version of switching device includes two secondary contacts and spring supported moving contact. The spring holds the movable contact against one of the stationary contacts and the electromagnet pull the movable contacts to the opposite stationary contact. The current in the electromagnet is interrupted by the action of the switch, so that the switch continually switches rapidly back and forth. This is electromagnetic inverter switch called vibrator or buzzer was used in vacuum automobile radio. The latest inverter circuits have transistors, FETS, SCR, and other electronics switches incorporated in them because of their advantages over electromagnetic switches.

Recently, medium power inverters have undergo significant changes. The 2KVA-2MVA inverters serve in variable speed motor devices, uninterrupted power supply, power line conditioners and active filters. One improvement stems from new power transistor such as insulated gate bi-polar transistors with their increasing voltage and current carrying compatibilities and increasing switching frequencies. Others derives from the use of digital signal processors and such modern control techniques as fuzzy logic and neutral network as well as advances in the application of power converter that employs soft switching of the power  device IEE (1986). (http://www.falana.tripid.com/tope/index.blog?entry id=195483copy)

2.2.1 GENERAL FEATURES OF THE PROJECT

        The inverter circuit consists of the following units

2.2.1 POWER SUPPLY UNIT

In this unit, the source of power is derived from a DC source. The power associated with any circuit can be divided from the multiplication of the total voltage across the circuit and the total load current flowing through the circuit. This unit usually consist of an electrolytic capacitor for smoothing the output. The DC voltage is used of powering the relay base.

2.2.2 CHANGE OVER UNIT

This units is used to turn off the oscillator and change over from the inverter to the main power supply when is restored, it consist of a delay unit setting to 10sec for conversion of power.

2.2.3 SWITCHING UNIT

        This unit employs the push-pull amplifier arrangement in its operation. The operation i.e ON and OFF time depending on the switching time of the IC, the switching device used is the MOSFET was chosen for its fast switching speed, good thermal stability efficiency and reliability. The output of the IC is used to drive the MOSFET which causes an alternating currents to flow in the primary of a transformer. The result is an induced EMF which is boasted to 220V AC at the secondary of a transformer. The filtering device (capacitor connected at the sinusoidal output) is used to removing harmonics and hence providing a sinusoidal output waveform.

2.2.4 UNDER AND OVER VOLTAGE PROTECTION UNIT

The unit provides protection for the inverter circuit and applied load against under and over voltage. It operates by comprising the input voltage to the reference voltage and then adjusting (reducing or increasing the input as the situation may require) the input voltage to bring it as close as possible to the desired voltage level before feeding to the applied loads.

2.2.5 OSCILLATOR UNIT

The integrated used is SG3524 and it consists of all the control circuitry for regulating of power or switching regulator. The oscillator SG3524 of this type uses external capacitor CT. This capacitor produces a linear ramp voltage which is used as a line dependent references for the pulse width modulator capacitor.

2.3 TYPES OF INVERTERS  

Omogoroye (2002) said, there are various types of inverters at different rating from 500VA. 1KVA, 1.5KVA, 2KVA, 2.5KVA, 3KVA and 5KVA e.t.c

Also some are using transistors in their Astable, some are using IC NE555 timer in their Astable-multi-vibrator to generate in these following fields.

1. Uninterrupted power supply unit
2. Control panel of generator room

• Electronic speed control of an induction motor

2.4 COMPARISON WITH THE GENERATOR  

The generators generates a lot noise during operation and most of them do not have automatic start/stop in the event of power failure/restoration. They require highly inflammable product such as fuel which emits smoke and a bad odours. On the other hand, the inverter works noiselessly, provides completely automatic switching operations and does not require any special maintenance apart from battery used which requires routine service once in 15-20 days.