Simulation Of Wind Turbine Power Generator: Impact Of Wind Turbines In The Nigerian Grid System

ABSTRACT

This study is on the wind turbine power generator and its impact on Nigeria grid system. Wind turbine power generation which is the focus of this study is one of the fastest growing technologies in energy generation industry nowadays. The erratic and epileptic state of power in this country and the concern about global warming should be a great concern for all and should drive us into strong demand for wind generation. The main advantages of electricity generation from wind are the absence of harmful emissions, very clean and the almost infinite availability of the wind that is converted into electricity. In Nigeria, where the wind power prospect is estimated to be high or moderate has not connected this renewable resources to the grid. It is not just enough to say that the wind turbines should be connected to the grid because there are sufficient wind speeds to drive the wind turbine. Mostly, the stability and reliability studies must be carried out whenever wind power is to be connected to power system to predict severe consequences on the power system to which the wind generators will be connected. This research demonstrates a model of a wind energy conversion system that operates at different wind speed, with results simulated in MATLAB SIMULINK. The wind turbine system is made up of three parts or subsystems namely the aerodynamic, mechanical and electrical blocks. The system is designed by modeling differential equations for each block and then simulated in SIMULINK environment. The Squirrel Case Induction Generator, horizontal axis wind turbine system with complexities of all three parts of the wind turbine model were analyzed using the mathematical equations, with each block modeled and designed separately, then all three blocks joined together to give the complete unit. Wind speed data from Ogoja community in southern part of Nigeria was used to test the simulation performance. The system simulation was tested and worked satisfactorily, with different wind speed giving proportionate mechanical torque and turbine speed. This model therefore demonstrates that wind energy could be extracted in the region even at varying wind speed.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• PROBLEM STATEMENT
• OBJECTIVE OF THE PROJECT
• ADVANTAGES OF WIND POWER
• LIMITATION OF WIND POWER
• APPLICATION OF WIND-TURBINE
• METHODOLOGY
• PROJECT ORGANIZATION

CHAPTER TWO

2.0      LITERATURE REVIEW

• AN OVERVIEW OF WIND TURBINE
• HISTORICAL BACKGROUND OF WIND MILLS
• WIND ENERGY IN NIGERIA
• TYPES OF WIND TURBINE
• EFFICIENCY OF THE WIND TURBINE SYSTEM
• REVIEW OF PREVIOUS WORKS
• POWER IN THE WIND
• INTEGRATING WIND ENERGY GENERATORS TO THE GRID

CHAPTER THREE

3.0     METHODOLOGY

3.1      SYSTEM BLOCK

3.2     AERODYNAMIC SUBSYSTEM MODELING

3.3      MECHANICAL SUBSYSTEM MODELING

3.4      GENERATOR MODEL

CHAPTER FOUR

• SIMULATION RESULT

CHAPTER FIVE

• CONCLUSION
• REFERENCES

CHAPTER ONE

1.0                                          INTRODUCTION

1.1                            BACKGROUND OF THE STUDY

Demand for renewable energy has been increasingly justified over the last couple of years as world powers turn to clean, green energy while over dependence on fossil fuel generation is still prominent in developing countries. Nevertheless, there is an expectation that renewable energy sources will play a wider role over the next two decades in energy with wind energy projected to contribute 1.1 trillion kilowatt-hours (kWh) of a total of close to 4 trillion kWh of renewable energy expected to be generated by year 2030. Furthermore, research suggests that solar and wind energy are currently the most likely to provide economically affordable alternate energy sources, because other renewable energy sources like tidal remain costly and inefficient. It is obvious that wind and solar energy studies will be the center of future renewable engineering efforts. With wind energy however, developing offshore wind turbines fit for tackling the substantially higher wind speeds accessible offshore while avoiding the issues of horizon and noise pollution is the way to go.

Despite the abundance of energy resources in Nigeria, the country is still in short supply of electrical power. Only about 40% of the nation’s over 140 million has access to grid electricity [A.S. Sambo, 2006]. Even the electricity supply to the consumers that are connected to the grid is erratic. There is therefore the need to harness renewable energy potential (such as wind, solar e.t.c) for reliable power supply in this country. Also the concern about global warming and continued apprehensions about nuclear power around the world should drive us into strong demand for wind generation. Wind turbine converts wind energy into electrical energy, which is fed into electricity supply system. The main advantages of electricity generation from renewable energy sources, such as wind, are the absence of harmful emissions, very clean and almost infinite availability of wind that is converted into electricity [J.G. Slootweg, 2001]. Wind generation has been described to be one of the mature and cost effective resources among different renewable energy technologies [J. Bhola, 2009].Wind is a natural phenomenon related to the movement of air masses caused primarily by the differential solar heating of the earth’s surface [A.S. Sambo, 2005]. Wind is a classical example of a stochastic variable; due to this stochastic nature, wind energy cannot be controlled, but can be managed. This is because wind power is available only when the wind speed is above a certain threshold [T. F Brady, 2009].

This paper therefore describes the wind energy potential and the impact in Nigeria and the conditions to be met before the wind generator can be connected to the existing grid and how it can be connected.

1.2                                   PROBLEM STATEMENT

Natural gas is being used in gas turbines as a means of power generation in most countries, majority of which are in Africa. The effects of these fuels in the atmosphere led to the need for green energy, a clean and sustainable alternate source of energy generation. Different countries are facing devastating effects from the climate change, stormy rain, hurricane, great flood, etc., leading to different countries conducting research in renewable energy sources which will produce power without damaging the environment. Wind energy is abundant on the Earth and has a low or no impact in environmental pollution. The energy is generated naturally from wind; hence fuel needed for wind turbines is free and occurs every day. This study shows a wind energy system modeled and runs at various wind speeds, similar to wind speeds found in some parts of the world.

1.3                          AIM AND OBJECTIVES OF STUDY

The aim of the project is to design with the aid of mathematical modeling a wind energy conversion system that will produce energy at varying speed and test results using simulations. The following are the objectives:

1. Model a wind energy conversion system by using mathematical equations.
2. Simulate the system design using MATLAB SIMULINK Software, version R2017a.

• Test to see the effects of varying wind speeds.

1. Simulate the aerodynamic, mechanical and electrical component design.
2. This paper will describes the wind energy potential in Nigeria and the conditions to be met before the wind generator can be connected to the existing grid and how it can be connected.
3. The effect the new generation source might have on the existing power network will also be discussed.

• Wind speed data from Ogoja community in southern part of Nigeria was used to test the simulation performance.

1.4                           ADVANTAGES OF WIND POWER

• It’s a clean fuel source. Wind turbine does not pollute the air like power plants that rely on combustion of fossil fuels, such as coal or natural gas. Wind turbines do not produce atmospheric emissions that cause acid rain or greenhouse gases.
• It’s sustainable. Wind is actually a form of solar energy. Winds are caused by the heating of the atmosphere by the sun, the rotation of the Earth, and the Earth’s surface irregularities. For as long as the sun shines and the wind blows, the energy produced can be harnessed to send power across the grid.
• Wind power is cost-effective. It is one of the lowest-priced renewable energy technologies available today, costing between four and six cents per kilowatt-hour, depending upon the wind resource and the particular project’s financing.
• Wind turbines can be built on existing farms or ranches. This greatly benefits the economy in rural areas, where most of the best wind sites are found. Farmers and ranchers can continue to work the land because the wind turbines use only a fraction of the land. Wind power plant owners make rent payments to the farmer or rancher for the use of the land, providing landowners with additional income.

1.5                             LIMITATION OF WIND POWER

• One of the major problems with wind energy is that the wind turbines do not always face the wind, and therefore do not always produce energy.
• Wind resource development might not be the most profitable use of the land. Land suitable for wind-turbine installation must compete with alternative uses for the land, which might be more highly valued than electricity generation.
• Turbines might cause noise and aesthetic pollution. Although wind power plants have relatively little impact on the environment compared to conventional power plants, concern exists over the noise produced by the turbine blades and visual impacts to the landscape.
• Turbine blades could damage local wildlife. Birds have been killed by flying into spinning turbine blades. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.
• Energy produced by wind turbine requires expensive storage during peak production time.
• Wind energy can be harnessed only in those areas where wind is strong enough and weather is windy for most parts of the year.Usually places, where wind power set-up is situated, are away from the places where demand of electricity is there. Transmission from such places increases cost of electricity.
• The average efficiency of wind turbine is very less as compared to fossil fuel power plants. We might require many wind turbines to produce similar impact.
• Maintenance cost of wind turbines is high as they have mechanical parts which undergo wear and tear over the time.

1.6                             APPLICATION OF WIND-TURBINE

Wind-turbine generators have been built a wide range of power outputs from kilowatt or so to a few thousand kilowatts, machine of low power can generate sufficient electricity for space heating and cooling of names and for operating domestic appliances.

Pumping Application:- A typical wind powered pumping application is one that might use a horizontal –axis wind used to pump irrigation water. Large number water pumping wind mills have been used in Indian forms other applications that are being developed include the pumping of water for aqueducts or for pumped-hydro storage of energy.

Direct Heat Application :- Mechanical motion derived from wind power can be used to drive heat pumps or to produce heat from the friction of solid materials, or by the chaining of water or other fluids or in other cases, by the use of centrifugal or other types of pumps in combination with restrictive orifices that produces heat from friction and turbulence when material having a high heat capacity such as water, stones, electric etc. or the heat may be used directly for such application as heating and cooling of water.

Electric Generation Applications: – Wind power can be used in centralized applications to drive synchronous a.c. electrical generator. In such applications, the energy is fed directly into power networks through voltage step-up transformers.

1.8                                         METHODOLOGY

In the course of carrying this study, numerous sources were used which most of them are by visiting libraries, consulting journal and news papers and online research which Google was the major source that was used.

1.9                                                         PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied,  chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.