The document summarizes a numerical analysis and design of a software module for a hybrid wind-diesel power system. It discusses the motivation for hybrid systems due to rising energy costs and pollution. It then provides an overview of wind energy potential and applications. The document describes the software module that simulates the operation of wind turbines, diesel generators, loads and batteries in a hybrid system. It also compares the software results to experimental data, showing good agreement between the two. The conclusion is that the software can efficiently model hybrid systems and aid in their design and optimization.
1. NUMERICAL ANALYSIS AND DESIGN OF
SOFTWARE MODULE FOR HYBRID WIND- DIESEL
POWER SYSTEM –GENERAL APPLICATION
By
Suresh Mashyal
Dept. of Mechanical Engg.
M. M. Engineering College, Belgaum
India
2. INTRODUCTION
In view of rising costs, pollution & fear of depletion of oil and coal, the government
around the world are encouraging to seek energy from renewable source of energy such
as wind, biomass, solar and tidal energy.
The potential of wind energy of a source is very large. The energy available in the
winds over the earth’s surface is estimated to be 2.1 X 10 7 MW, which is of same order
of magnitude as the present energy consumption on the earth.
The utilization of energy from wind is widely used for reducing the dependence on
fossil fuel.
Wind mill also used in isolated or less developed area, where either grid connection can
not reach or would be too costly.
3. CAUSES OF WIND
Winds are caused from two main factors
Heating & cooling of the atmosphere
The rotation of the earth with respect to atmosphere & its motion around the sun.
APPLICATION OF WIND ENERGY
The important application of wind energy system is to generate electricity.
Generate heat from friction of moving parts which might be used in the industrial
applications like production of chemicals, plastic materials and textile processing.
Process agricultural products like in crop drying, milk processing, food
processing, frost protection, water pumping and ventilation.
4. ELECTRICITY FROM WIND
Wind possesses energy due to its motion and wind energy devices, which slow
down the wind motion by obstructing it and absorb some of this energy to convert
into electricity.
Wind
Wind
turbine
generator
Inverter
converter
controlling unit
AC/DC
Load
Wind machines harness the kinetic energy of the wind.
K E = 0.5MV2
Where
= 0.5ρAV3
M= mass of air = ρAV
V=Wind velocity
ρ = density of the material
A= cross sectional area
5. WIND ENERGY SCENARIO IN INDIA
In India, the grid connected wind power has now gained a larger attention and
acceptability as compared to other renewable tech available.
Wind energy installed in the country is around 20000 MW and more than hundred
billion units of electricity is fed to the state grids.
The graph shows statewise installed capacity and it is seen that the largest
installation is in TN mainly higher winds are available .
Wind pow er installed capacity in India
2000
Capacity, MW
1500
1000
500
0
A.P.
Guj
Kar
M.P.
Maha.
Raj.
T.N. Others
6. WIND ENERGY GROWTH RATE IN INDIA
The graph shows wind energy is clearly fastest growing in terms of its utilization
from last five years compared to other renewable forms of energies. This is mainly due to
ease of installation, reliable and high life time.
Growth rate of energy forms
30
24.2
20
17.3
15
10
0.5
COAL
0.5
NUCLEAR
0.8
OIL
1.5
HYDRO
GEO.
SOLAR
0
1.9
NAT. GAS
4.3
5
WIND
% growth
25
7. TYPES OF WINDMILL
Horizontal axis windmill: These wind machines rotate about a horizontal
axis. The advantages include self starting, more efficiency.
Vertical axis windmill: These wind machines rotate on a vertical axis. The
advantages include do no have to be oriented into the wind, easier to maintain
because generator is located at the base of the turbine.
8. LITERATURE REVIEW
M. A. Elhadidy and Shaahid, “Decentralized hybrid wind diesel power system to
meet residential loads” , Energy conversion and management 46(2005), have
collected hourly mean wind speed data of period 1986-1997 recorded at Dhahran in
Saudi Arabia.They have analyzed to investigate potential of utilizing hybrid wind
diesel energy conversion systems to meet the load requirements of a hundred typical
two bed room residential buildings with annual electrical energy demand of 3512
MWh.
S. S. Choi, R. Larkin, “ Performance of an autonomous diesel wind turbine power
system”, Electrical power systems research, Studied the feasibility of installing a 2.5
MW wind farm within an isolated power system in western Australia. This network is
present being supplied by several diesel generators.
M. T. Iqbal, “Simulation of a small wind fuel cell hybrid energy system” Renewable
energy 28 (2003), has presented the paper which describes simulation results of a
small 500W wind fuel cell hybrid system. Dynamic modeling of various components
of this small isolated system is presented. Simulink is used for the dynamic
simulation of this hybrid system. Transient response of the system to a step change in
the load current and wind speed in a number of possible situations are presented.
Analysis of simulation results and limitations of a wind fuel cell hybrid energy
system are discussed.
9. HYBRID WIND - DIESEL SOFTWARE MODULE
A system which consists of wind turbine & diesel engine is called a
hybrid wind-diesel power system.
The main application & strategy of designed hybrid wind diesel system
The designed software it is possible to simulate operation of different system
constituents like windmill, diesel engine, load, battery and various charts is used to
predict the performance of the hybrid system.
When the WECS generating excess energy ie above the hourly demand, the excess
energy is stored in the battery until it gets fully charged.
The purpose of introducing battery storage is to export energy depending upon the
situation.
Diesel engine is operated online at times when the WECS fails to satisfy the load &
when the battery storage is depleted.
10. THEORETICAL ANALYSIS:
Relation between Vc , Vr , & Vf
Cut-in speed(Vc): It is minimum wind
speed at which turbine starts generating
power.
Rated speed(Vr): Speed at which
turbine will generate designed power.
Furling speed(Vf): Corresponds to high
wind speeds during which the turbine
ceases to generate power and is shut
down. The wind speed at which shut
PeR
Power
Vc
Vr
Wind speed
Wind turbine power v/s wind speed.
Vf
down occurs is called furling speed.
11. Electrical power out put:
The electrical power out put (Pe )is basically depends on the wind turbine
characteristics like cut-in, rated and furling speed .
Pe = 0
Pe = a + bv
( v < vc )
2
( vc ≤ v ≤ v R )
Where the coefficients a and b are
2
Pe = PeR
(v R < v < v F )
P v
a = 2eR c 2
vc −vR
Pe = 0
(v > v F )
b =
P
eR
2
2
vR −vc
And the rated electrical power output at rated wind speed is expressed as
1
3
PeR = C pη ρ A vR
2
Cp
is power coefficient =
Watt
Power extracted by wind turbine
Power available in wind turbine
Where
v = Wind velocity in m/s
η =Overall conversion efficiency
p =Density of air =1.2 kg/m3
A = Swept area in m2
12. * EXPERIMENTAL SETUP
The experimental work is carried out at energy systems engineering department.
BVB college of engineering, Hubli. Where a hybrid wind diesel power is installed. The
experimentation is conducted using lamp load connected across the hybrid system. The
line diagram of the experimental setup is shown below,
Diesel
genset
Battery bank
Load
Experimental setup
13. ABOUT SOFTWARE
Visual basic software is used for developing and designing the hybrid system.
It is a programming language for developing sophisticated professional applications for
Microsoft windows.
It makes use of graphical user interface to create robust and powerful applications.
Coding in GUI environment is quite traditional, the number of options open to the user is
much greater, allowing more freedom to the user and developer.
Other features such as user friendliness, faster application development and internet
features make Visual basic an interesting tool to work with.
14. RESULTS AND DISCUSSION
Input parameters required for software
The input parameters required to run the software are as follows, but while
entering care to be taken that all input data are separated by comma,
Wind speed in m/s
Time in hrs
Load in watt
16. Out put of the software:
Simulate operation of different system constituents.
Various charts
Load vs Time
Wind speed vs Time
Wind speed vs Power output
Battery status vs Time
Energy stored vs Time
Current total power generated by wind mill in Watt.
Battery status after every interval in Ahr.
Diameter of the turbine in meter.
Total run time of Hybrid wind diesel system.
Finally produces brief report.
18. Various charts obtained from software:
The various charts obtained from software after entering the input
parameters are as follows,
Power output vs wind speed
Wind speed vs Time
20. Comparison of Software and Experimental results of wind
turbine characteristics:
Software
Experimental
% Error
Cut in speed (m/s)
3.3
3
9.8
Rated speed (m/s)
11.1
11
1.7
Furling speed (m/s)
24.4
25
2.4
We can conclude that there is good agreement between the software and
experimental result of wind turbine characteristics. The comparison shows close
value with in 10% error, which is thought to be quite acceptable.
21. Comparison of Software and Experimental power output:
Comparison of software & experimental results
Power Output, W
600
Software result
500
Experimental result
400
300
200
100
0
4
4.6
4.7
5.3
5.3
5.4
6.3
6.7
8.1
Wind speed (m/s)
The above graph shows the comparison of software results after entering
the input data wind velocity in the software module and experimental results after
calculation. It shows a good agreement with in 5% error, Which can be acceptable.
22. Comparison of analytical and software results of battery status:
Battery status (Ahr)
Com parison of analytical & s oftw are re s ults of e ne rgy
s tore d in batte ry
40
Analytical results
35
sof tw are results
30
25
20
15
10
5
0
7.1
7.2
7.3
7.4
7.5
8
8.1
8.2
8.3
Time (hrs)
We can conclude that there is good agreement between analytical and
software results of battery status in terms of Ahr after every interval.
23. CONCLUSION
The software developed simulates operation of wind diesel hybrid system with respect
to the constituents like wind mill, Diesel genset, load and battery.
It can be efficiently used for the monitoring of existing system.
The software aids in design and analysis of hybrid wind diesel system and indicates
that thorough analysis of site and load characteristics are essential for deployment of
these systems.
The software module predicts wind turbine characteristics and other features like
power generation, battery status, total run time of diesel engine, wind turbine power
before actual installation of system on site.
In future a significant portion of energy needs would be met through hybrid power
without disturbing the ecosystem.
It has proven to be viable option both with respect technology and economics.
24. FUTURE SCOPE
Design and analysis of hybrid system can be done using computational fluid dynamics
software for precise results.
Analysis of electrical parameters can be included in software.
Flexibility in the format of input data.
Interfacing with Microsoft office can be included.
25. REFERENCES
• G.M. Joselin Herbert, “ A review of wind energy technologies”, Renewable and
•
•
•
•
•
sustainable reviews, 28(2006) pg 180-230.
M. A. Elhadidy , S. M. Shaahid, “ Decentralized/Stand alone hybrid wind diesel
power systems to meet residential loads of hot coastal regions”, Energy
conversion and management 46(2005) pg 2501-2513.
A. N. Celik, “ A simplified model for estimating yearly wind fraction in hybrid
wind diesel energy system”, Renewable energy 31(2006) pg 105-118.
Iqbal M. T. “ Simulation of a small wind fuel cell hybrid energy system”
Renewable energy 28 (2003) pg 511-522.
Gary L. Johnson, a text of “ Wind energy system”, edition-2000
G. D. Rai, “ Non-conventional energy systems” Khanna publishers, Fourth
edition-2001.