DESIGN AND CONSTRUCTION OF A 5KVA INVERTER
ABSTRACT This project presents the design and construction of a 5kVA Square Wave inverter system that can supply for 11 Hrs. It complements the unreliable and epileptic power supply from the Power Holding Company of Nigeria (PHCN). The output of the square wave inverter is similar to modified sine wave output except that the output of the latter goes to zero volts for a time before switching positive or negative. Square wave inverters are designed to satisfy the efficiency requirements of the photovoltaic systems while being less expensive than pure sine wave inverters. These inverters are capable of operating a wide variety of loads; electrical and household items including but not limited to TV, VCR, and satellite receiver, computer, and printer. Literature review of the past project work was carried out and improvements were made in the area of overvoltage & under-voltage protection, voltage level indication & drain protection. The result of the experiment performed shows that the constructed inverter work satisfactorily, with an error of 0.034%on the charging protection This work also carried out a switching function which switches when the main power supply is restored from the inverting mode to mains and at the same time provides the means for prolonging the lifespan of the battery by preventing it from overcharging and over-usage. TABLE OF CONTENTTITLE PAGE i CERTIFICATION PAGEiidedicationacknowledgmentsabstractTABLE OF CONTENTSviLIST OF FIGURESixCHAPTER ONE1. Introduction11.1 Background of the study11.2 Problem statement21.3 Aim and Objective21.4 Scope of the project31.5 Methodology 31.6 Motivation 31.7 Report Outline 4CHAPTER TWO: LITERATURE REVIEW2.0 INTRODUCTION 52.1 Review of the past project 62.2 Power supply 72.3 Transformer 82.3.1 Core Characteristic of a Transformer 92.3.2 Different Types of Winding 92.3.3 EMF Equation of the Transformer 102.3.4 Voltage Transformer Ratio (K) 112.4 Rectifier 122.4.1 DC Filter 132.5 Oscillator 142.5.1 Multivibrator 22.214.171.124 AstableMultivibrator 126.96.36.199 Mono Stable Multivibrator 188.8.131.52 Bistable Multivibrator 152.6 Operational amplifier as comparator 162.7 Review of Component 162.7.1 Zener Diode 172.7.2 Relay 184.108.40.206 Relay Operation 182.7.3 Transistor 220.127.116.11 Advantages of a MOSFET over BJT 192.7.4 Capacitor 18.104.22.168 Application of Capacitor 202.7.5 Resistor 22.214.171.124 Fixed Resistor 126.96.36.199 Variable Resistor 212.8 Battery 22 CHAPTER THREE: DESIGN AND CALCULATION3.1 Theoretical Background 233.2 Analysis and Design 243.2.1 Transformer Design 243.2.1.1 Conductor Diameter of the Transformer 273.2.2 Rectifier 283.2.3 Expected Duration of the inverter in its inverting mode (Battery) 293.2.4 Delay Unit 303.2.5 Oscillator 313.2.6 Driver Stage 323.2. 7 Amplification Stage 333.3 Implementation 37 CHAPTER FOUR: CONSTRUCTION AND TESTING4.1 Construction 384.2 Final Design Test 404.3 Result Obtained 404.2.1 Result Obtained from Inverter 414.3 Discussion of Result Obtained 43 CHAPTER FIVE: CONCLUSION AND RECOMMENDATION5.1 Summary 455.2 Conclusion 455.3 Recommendation 46REFERENCES 47APPENDICES 48 CHAPTER ONE:INTRODUCTION1.1 Background of the study Electricity supply is one of the economic infrastructural facilities that are indispensable to a nation’s economic development. The efficiency of the supply of electricity will not only influence returns on investment on existing enterprises, but it also plays a major role in the creation of an economic environment that influences decisions on a potential investment.The electricity which is the main source of power for our domestic consumption, industrial development, the center of learning, and medical centers should really be rehabilitated into the enhancement of productivity.However, power failure has resulted in people buying generators for their own daily activity. Other businesses are also not functioning due to the absence of a constant power supply. These are the reasons that necessitate the designing and construction of an inverter and another standby system that can deliver maximum output power to the load. As society grows from simple to complex, mankind began to spread all over the earth and so it becomes necessary to enjoy power using an inverter.Statistics have shown that the number of business that has been closed simply because of power problem and cannot be overemphasized, so mankind need inverter seriously in other to restore technology development, businesses, communications, learning center and medical centers. However, the background of the study lies within the reason why and the construction of the inverter should be forwarded and factors that enhance inverter marketability.Finally, the success of this study will be beneficial to society at large. Mass production of inverters will lead to improving the standard of living of the populace and the nation will move forward in its pursuit of technological development.
1.2 Problem StatementAs a result of continuous power failure and fluctuation in power supply by the Power Holding Company of Nigeria (PHCN), sensitive appliances and systems are affected by the interruption power supply. Then, this project is to provide a backup and reliable power supply of 5000kva to power a standard five-bedroom flat.
1.3 Aim and objectiveThe aim of this project is to design and construct a circuit that will take a 24v dc input from the battery and provide a 5000VA output that will be able to supply a standard five-bedroom flat. The objectives are:-v To design a circuit that will convert dc to ac power for various appliances used in domestic homes.v To provide a noiseless source of electricity generation.v To have a source of generating electricity that has no negative effect on the environment (i.e. no greenhouse effect).v To provide a source of electrical power with low maintenance cost and zero fuel cost.
1.4 Scope of the ProjectThe Scope of this project is to design and construct an inverter with an output power rating of 5kVA, the maximum output current of 22.72A, the output voltage of 220V AC from a 24V DC input This project is basically designed for single-phase domestic loads. The project is to be realized using simple and relatively cheap components available in the local markets.
1.5 Methodologyv To achieve the aim and objectives of this work, the following are the steps involved.v Study of the previous work on the project so as to improve its efficiency.v Draw a block diagram.v Design and calculation for charge controller and inverter.v Studying of various component charge controllers and inverter circuits.v Construct a charge controller and an inverter circuit.1.6 MotivationThe inverter is the best when it comes to backup since they can come up very fast and they generate little or no noise, unlike the generator. Even in an area with a constant power supply, power outages due to natural causes and faults are usually unannounced. It is therefore very important to prevent causalities and loss of goodwill by having a reliable backup power installed.
1.7 Report OutlineThis report is made up of five chapters. The first chapter gives an introduction to the general concept of power and gives the motivation and objectives which the project report seeks to achieve. It also explains the scope of the project and the problem statement. The second chapter discusses the critical review of the technical and academic literature on previous works, methodology and it also identifies modifications made.The third chapter discusses the principle of operation of the power inverter, design, and calculation of all the basic stages. Chapter four of this project report contains the final construction and design process, soldering, maintenance. etc. testing and test result were also compiled. The fifth chapter contains the conclusion and recommendation of this report..