Design And Construction Of A 3.5 kVASolar Inverter With Charge Protection

ABSTRACT

This work is on design and construction of a 12VDC to 220VAC solar panel. Solar inverter converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a critical component in a photovoltaic system, allowing the use of ordinary AC-powered equipment.

In solar inverter, Solar panels produce direct electricity with the help of electrons that are moving from negative to positive direction. Most of the appliances that we use at home work on alternative current. This AC is created by the constant back and forth of the electrons from negative to positive. In AC electricity the voltage can be adjusted according to the use of the appliance.  As solar panels only produce Direct current the solar inverter is used to convert the DC to AC.

 TABLE OF CONTENTS

Title Page

Approval Page

Dedication

Acknowledgement

Abstract

Table of Content

CHAPTER ONE

1.0      Introduction

1.1      Objective of the project

1.2      purpose of the project

1.3     solar inverter advantages

1.4      solar inverter disadvantages

1.5      application of an inverter

CHAPTER TWO

2.0     Literature review

2.1      Historical background of photovoltaic cell

2.2         Theoretical review of solar cell

2.3          Review of solar cell efficiency

2.4      Review of solar cell materials

2.5      Review of early inverters

CHAPTER THREE

3.0     Construction

3.1      Basic designs of a solar inverter

3.2      block diagram of the system

3.3      Description of solar inverter units

3.4      Modified sine wave power solar inverter circuit using ic 4093

3.5      Circuit operation

 3.6      Description of components used

3.7      How to choose the best inverter battery

CHAPTER FOUR

RESULT ANALYSIS

4.0      Construction Procedure and Testing

4.1      Casing and Packaging

4.2      Assembling of Sections

4.3      Testing of System Operation

4.4      Cost Analysis

CHAPTER FIVE

5.0      Conclusion

5.1      Recommendation

5.2      References

 CHAPTER ONE

1.0                                                         INTRODUCTION

Solar panels produce direct electricity with the help of electrons that are moving from negative to positive direction. Most of the appliances that we use at home work on alternative current. This AC is created by the constant back and forth of the electrons from negative to positive. In AC electricity the voltage can be adjusted according to the use of the appliance.  As solar panels only produce Direct current the solar inverter is used to convert the DC to AC.

An inverter produces square waves or a sine wave which can be used for running lights, televisions, lights, motors etc. However these inverters also produce harmonic distortion. Expensive inverters make use of lots of steps to produce a sine wave and thus are found in residential solar inverters. Basically inverters should be a large one so that it supplies enough power to all the necessary appliances.

Many people using solar inverters these days which prove that its necessity has been increased in the current years. A Solar inverter is similar to a normal electric inverter but uses the energy of the Sun, that is, Solar energy. A solar inverter helps in converting the direct current into alternate current with the help of solar power. Direct power is that power which runs in one direction inside the circuit and helps in supplying current when there is no electricity. Direct currents are used for small appliance like mobile e phones, MP3 players, IPod etc. where there is power stored in the form of battery. In case of alternative current it is the power that runs back and forth inside the circuit. The alternate power is generally used for house hold appliances. A solar inverter helps devices that run on DC power to run in AC power so that the user makes use of the AC power. If you are thinking why to use solar inverter instead of the normal electric one then it is because the solar one makes use of the solar energy which is available in abundant from the Sun and is clean and pollution free.

Solar inverters are also called as photovoltaic solar inverters. These devices can help you save lot of money.  The small-scale grid  one have just two components i.e. the panels and inverter while  the off grid systems are complicated and consists of batteries which allows users to use appliances during the night when there is no Sunlight available.  The solar panel and the batteries that are placed on rooftops attract Sun rays and then convert the Sunlight into electricity. The batteries too grab the extra electricity so that it can then be used to run appliances at night.

1.1                                               OBJECTIVE OF THE STUDY

The main objective of the study is to design and construct a device that can collect an input dc voltage from the solar panel and convert it to 220vac output which can be use to power ac appliances.

1.2                                                PURPOSE OF THE STUDY

The purpose of a solar inverter is to transform direct current (DC) generated by a PV system into alternating current (AC), which can be sent into an AC appliances. These inverters can be used either in concert with battery systems or to directly power certain devices. They also tend to have a few identifying features that are specifically intended to be used with Photo Voltaic arrays, such as maximum power point tracking (MPPT).

1.3                                         SOLAR INVERTER ADVANTAGES

After knowing in detail what a solar inverter is and how different useful it is to make appliances work at residential and industrial levels students should also know the advantages and disadvantages.

• Solar energy has always helped in reducing global warming and green house effect.
• Also use of solar energy helps in saving money many people have started using solar based devices
• A solar inverter helps in converting the Direct current into batteries or alternative current. This helps people who use limited amount of electricity.
• There is this synchronous solar inverter that helps small homeowners and power companies as they are large in size
• Then there is this multifunction solar inverter which is the best among all and works efficiently. It converts the DC power to AC very carefully which is perfect for commercial establishments
• This inverter is cost effective i.e. less expensive than generators
• Apart from solar inverters there are other devices too that make use of solar energy namely, solar cooker, heater.
• Solar inverters are the best way and they are better than the normal electric ones. Also their maintenance does not cost much money

1.4                                     SOLAR INVERTER DISADVANTAGES

• Initially you need to shell out a lot of money for buying a solar inverter
• It will work effectively and produce direct current only when the Sunlight is strong.
• The solar panels that are used to attract Sunlight requires lots of space
• The device can work efficiently only if the presence of the Sun is strong.
• Solar Inverters can work when there is no Sunlight but provided their battery is charged fully with the help of Sunlight

1.5                            APPLICATION OF THE AN INVERTER

DC power source utilization

Inverter designed to provide 115 VAC from the 12 VDC source provided in an automobile. The unit shown provides up to 1.2 amperes of alternating current, or enough to power two sixty watt light bulbs.

An inverter converts the DC electricity from sources such as batteries or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired voltage.

Uninterruptible power supplies

An uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier supplies DC power to recharge the batteries.

Electric motor speed control

Inverter circuits designed to produce a variable output voltage range are often used within motor speed controllers. The DC power for the inverter section can be derived from a normal AC wall outlet or some other source. Control and feedback circuitry is used to adjust the final output of the inverter section which will ultimately determine the speed of the motor operating under its mechanical load. Motor speed control needs are numerous and include things like: industrial motor driven equipment, electric vehicles, rail transport systems, and power tools. (See related: variable-frequency drive ) Switching states are developed for positive, negative and zero voltages as per the patterns given in the switching Table 1.The generated gate pulses are given to each switch in accordance with the developed pattern and thus the output is obtained. Thus the Simulink model and output voltage waveform of Symmetric multilevel inverter

Power grid

Grid-tied inverters are designed to feed into the electric power distribution system. They transfer synchronously with the line and have as little harmonic content as possible. They also need a means of detecting the presence of utility power for safety reasons, so as not to continue to dangerously feed power to the grid during a power outage. The subsystem which includes sinusoidal and triangular subsystem brief about the comparison of sine wave which is the modulated signal and is compared with carrier signal. When the reference signal is greater than or equal to carrier signal, then the output waveform is above the reference and otherwise it will be below the reference

Solar

A solar inverter can be fed into a commercial electrical grid or used by an off-grid electrical network. Solar inverters have special functions adapted for use with photovoltaic arrays, including maximum power point tracking and anti-islanding protection. Micro-inverters convert direct current from individual solar panels into alternating current for the electric grid. They are grid tie designs by default.

Induction heating

Inverters convert low frequency main AC power to higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power. Due to the reduction in the number of DC Sources employed the structure become more reliable and the output voltage has higher resolution due to increase in the number of steps and the reference sinusoidal voltage can be better achieved. This configuration recently becomes very popular in AC power supply and adjustable speed drive applications. This new inverter can avoid extra clamping diodes or voltage balancing capacitors. There are three kinds of level shifted modulation techniques, namely;

Phase Opposition Disposition (POD)

Alternative Phase Opposition Disposition (APOD) Phase Disposition (PD)

HVDC power transmission

With HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts the power back to AC. The inverter must be synchronized with grid frequency and phase and minimize harmonic generation.

Electroshock weapons

Electroshock weapons and tasers have a DC/AC inverter to generate several tens of thousands of V AC out of a small 9 V DC battery. First the 9VDC is converted to 400–2000V AC with a compact high frequency transformer, which is then rectified and temporarily stored in a high voltage capacitor until a pre-set threshold voltage is reached. When the threshold (set by way of an airgap or TRIAC) is reached, the capacitor dumps its entire load into a pulse transformer which then steps it up to its final output voltage of 20–60 kV. A variant of the principle is also used in electronic flash and bug zappers, though they rely on a capacitor-based voltage multiplier to achieve their high voltage.