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DESIGN OF MPPT BASED HYBRID WIND AND FUEL-CELL
ENERGY SYSTEM
Ch Rambabu, M Sunil Kumar and N Sri Harish Sri Vasavi Engineering College, Tadepalligudem, W.G.Dt., A.P.-534101
Abstract The wind energy conversion system can deliver the
maximum power when the load impedance matches with the source impedance under a given wind
speed. Since the load and wind speed are varying
dynamically, the maximum power point tracking
(MPPT) becomes more complex. A wind-generator
(WG) maximum-power-point tracking (MPPT)
system is presented in the present work, consisting
of a high efficiency buck-type dc/dc converter and a
control unit running the MPPT functions. The
advantages of the MPPT method are that no
knowledge of the WG optimal power characteristic
or measurement of the wind speed is required and
the WG operates at a variable speed. Thus, the system features higher reliability, lower complexity
and less mechanical stress of the WG.
A hybrid algorithm is used for tracking the
maximum power. In this method, on power
variation, the duty cycle is adjusted in according to
the variation in rectifier output voltage.
Key words: Maximum Power Point Tracking
(MPPT), Wind Energy Conversion System (WECS).
1. Introduction The worldwide concern about the environment has
led to increasing interest in technologies for
generation of renewable electrical energy. The
ever-increasing demand for conventional energy
sources has driven society towards the need for research and development of alternative energy
sources. Many such energy sources, such as wind
energy, fuel-cells and photovoltaic‟s are now well
developed, cost effective and they are widely used.
These sources offer the advantages of load shifting,
customer demand, production of power in
environmentally friendlier ways, and emergency
backup power[1]-[5]. These generation systems
allow utility companies to locate small energy
generating or storage units closer to the customer.
These sources face many hurdles, such as cost, grid
interface issues, power. Today more than ever, environmental concerns have taken a prominent
seat in the forefront of people's minds. The
coupling of this with rapid advancements in the
field of wind turbine generation has made this
mode of electricity production a realistic option on
the commercial scale. It has become more and
more possible to produce 'green' electricity at
reasonable rates, which translates into profit that
may become more significant[4]-[7].
Wind energy system consists of a turbine coupled to a generator and the turbine is rotated by means
of the wind energy. Most modern wind power is
generated in the form of electricity by converting
the rotation of turbine blades into electrical current
by means of an electrical generator. Wind
generators (WGs) have been widely used both in
autonomous systems for supplying power to remote
loads and in grid-connected applications. Although
WGs have a lower installation cost compared to
fuel cells, the overall system cost can be further
reduced using high-efficiency power converters,
controlled such that the optimal power is acquired according to the atmospheric conditions. In
windmills (a much older technology) wind energy
is used to turn mechanical machinery to do physical
work, like crushing grain or pumping water[17].
Wind power is used in large-scale wind farms for
national electrical grid as well as in small
individual turbines for providing electricity to rural
residences or grid-isolated locations. The countries
with the highest total installed capacity are
Germany (20,621 MW), Spain (11,615 MW), USA
(11,603 MW), India (6,270 MW) and Denmark (3,136 MW). Maximized electricity generation by
wind turbines is an interesting topic in electrical
engineering and many types of variable speed
generating systems have been researched to achieve
this goal. Use of a variable speed generating system
in wind power applications can increase the
captured wind energy by 10-15% annually [17].
This can yield a significant revenue increase over a
20 or 30 years life of operation. The designers of
small turbines (up to about 40 KW) stress
simplicity over complexity and the machines are designed for little or no maintenance. Integrated
horizontal axis wind-rotor designs, simplified to
reduce the number of moving parts have emerged
as the most successful general configuration. The
variability and intermittent character of renewable
resources requires the system to have back-up
generation capability and/or energy storage, the
latter usually a battery bank. A nominal battery
bank voltage of 120 or 240V is common. In battery
charging stations, batteries are connected in series
and in parallel and the whole battery bank is
charged through a wind turbine [12]-[17].
2. Wind Energy Conversion System Wind energy is transformed into mechanical energy
by means of a wind turbine that has one or several blades. The turbine is coupled to the generator
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
297
ISSN:2249-5789
system by means of a mechanical drive train. It
usually includes a gearbox that matches the turbine
low speed to the higher speed of the generator.
New wind turbine designs use multi pole, low
speed generators, usually synchronous with field
winding or permanent magnet excitation, in order to eliminate the gearbox. Some turbines include a
blade pitch angle control for controlling the amount
of power to be transformed. Stall controlled
turbines do not allow such control. Wind speed is
measured by means of an anemometer [5]. A
general scheme of Wind energy conversion system
is shown in Fig 1.
Fig.1Block diagram of wind energy conversion system
A wind turbine is a device for converting the
kinetic energy in wind into the mechanical energy
of a rotating shaft. Usually that rotating mechanical
energy is converted immediately by a generator
into electrical energy. In the large turbines, there is
generally a generator on top of the tower. The
generator is usually connected to the turbine shaft
through gears which turn the generator at a
different speed than the turbine shaft. Fancy power
electronic controls convert the electricity into the
correct frequency and voltage to feed into the
power grid (probably 50 Hertz depending on which country you live in).The electrical generator
transforms mechanical energy from the wind
turbine into electrical energy. The generator can be
synchronous or asynchronous. In the first case, an
excitation system is included or permanent magnets
are used. Variable speed systems require the
presence of a power electronic interface, which can
adapt to different configurations. The compensating
unit may include power factor correction devices
(active or passive) and filters [3].
The speed and direction of the wind impinging upon a wind turbine is constantly changing. Over
any given time interval, the wind speed will
fluctuate about some mean value. The degree of the
fluctuations is characterized by the standard
deviation of the wind speed during that time
interval. The power extracted by the wind turbine is
a function of the wind and, thus, it will have a
mean value during the time interval in
considerations and variations about that mean. A
"power curve" is typically used to define the
performance of a wind turbine [1].
It is the relationship between the average hub-
height wind speed and the average generator power during the averaging time interval, assuming
certain standard atmospheric conditions. Also, a
wind turbine will have a cut in wind speed at which
the turbine starts to generate power, a rated wind
speed, at which it starts to generate rated power,
and a cut-out wind speed at which it is shut down
for safety. The power obtained by the turbine is a
function of wind speed. This function may have a
shape such as shown in Fig.2. For variable speed
WECS the upper part of the curve between and can
be kept linear, equal to the reference power [10].
The following notations are used: Pr: reference power, maximum power that the
turbine can attain
Vr: reference power wind speed, wind speed for
which reference power isachieved.
Vci: cut-in wind speed, wind speed at which the
turbine starts to produce power
Vco: upper limit of the wind speed called cutout
wind speed, at which the turbine can operate.
Fig.2 Typical power curve of a wind turbine
The wind output Pw is a function of wind velocity
Vw such that:
Pw=Pr if Vci≤Vr≤Vco (1)
Pw=0 if 0<Vr<Vci or Vr>Vco (2) The wind speed can be found by using the formula:
)(m
rmw
H
HVV (m/s) (3)
Vm: measured wind speed at height Hm in m/s
Hr : rotor height in meters
: Ground surface friction coefficient (1/7) Pr : rated power of wind generator in kW
Wind energy conversion system consists of wind
turbine coupled with wind generators. Depending
on the application, there are different types of
generators and turbines available.
3. Mathematical Model of Wind Turbine A wind energy conversion system is basically
comprised of two main components, the
aerodynamic component and the electrical
component. The turbine forms a major constituent
of the aerodynamic system. The energy that could be captured from wind by a specific turbine
depends on its design particulars and operating
conditions. In this section all aspects related to the
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
298
ISSN:2249-5789
power conversion, from kinetic wind energy to
rotational energy, that are of relevance for the
stability model are explained.
The kinetic energy Ek of a mass of air m having the
speed Vw is given by:
2
2wK V
mE
(4)
The power associated to this moving air mass is the
derivative of the kinetic energy with respect to time
can be expressed as follows:
22 .2
1.
2
1ww
Ko qVV
t
m
t
EP
(5)
Where q represents the mass flow given by the
expression:
q=VW.A (6)
Where ρ: Air density.
A: Cross section of the air mass flow.
Ek: kinetic energy of the air.
Only a fraction of the total kinetic power can be
extracted by a wind turbine and converted into rotational power at the shaft. This fraction of power
(Pwind) depends on the wind speed, rotor speed and
blade position (for pitch and active stall control
turbines) and on the turbine design. The
aerodynamic efficiency Cp is defined as follows:
o
windP
P
PC
(7)
For a specific turbine design, the values of Cp(α, β) are usually presented as a function of the pitch
angle (β) and the tip speed ratio (α). The tip speed
ratio is given by:
w
tur
V
R
(8)
Where R : The radius of the turbine blades.
ωtur: The turbine angular speed.
Vw : Speed
The aerodynamic efficiency Cp(α, β) is usually
defined as a form of a two-dimensional lookup
characteristic (for different values of α and β) by
actual measurement. The variation of the power coefficient Cp with variation of the tip speed ratio is
shown in Fig 3.
Fig.3 Power coefficient versus tip speed ratio
A two dimensional, cubic line-interpolation method
is used for calculating points between measured values. The high accuracy of the interpolation
method avoids the need of entering a large number
of points. Alternatively, analytical approaches for
approximating the aerodynamic efficiency Cp(α, β)
characteristic could be used. Finally, the
mechanical power extracted from the wind is
calculated using:
22 ).,(.2
wPmech VCRP
(9)
The aerodynamic efficiency Cp(α, β) characteristic
can be calculated using special software for
aerodynamic designs that is usually based on blade-
iteration techniques or it can be obtained from
actual measurements. The power coefficient of wind turbine can be expressed by:
6432
1
5
)(),( ceccc
cC i
c
i
p
(10)
Where c1, c2, c3, c4, c5 and c6 are the constants they
depend on mechanical characteristics of the wind
turbine.
4. Modelling of Permanent Magnet
Synchronous Generator The wind turbine drives a permanent magnet
synchronous generator whose terminal voltage
equations can be described by the following set in a matrix form [7]
][]][[][ m
abcabcabcabc PiRV
(11)
Assuming that zero-sequence quantities are not
present and applying Park‟s transformation, equation may be rewritten in a rotor reference
frame as
mrdqrqqq iLipLRV )( (12)
qqrddd iLipLRV )(
(13)
Where R - Stator phase winding resistance,
Lq - Stator inductance in the quadrature axis,
Ld - Stator inductance in the direct axis,
ωr - Rotor angular velocity of the generator,
λm - Amplitude of the flux linkages
established by a permanent magnet as viewed from
the stator phase windings,
p - operator d/dt.
The expression for the electromagnetic torque in
the rotor reference frame is
qmdqqde iiiLLp
T
)(
22
3
(14)
Where P is a number of poles of the PM generator.
The relationship between the rotor angular velocity of the generator ωr, and the mechanical angular
velocity of the rotor ωm, may be expressed as
2r m
P (15)
The rotational speed and the torque may be related
as:
er TpP
JT
21
(16)
Where T1 = input torque to the machine.
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
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ISSN:2249-5789
Let us assume that the output corresponds to the
torque developed by the wind turbine Tp, stator
voltages of the generator are sinusoidal so that:
rsa VV cos
(17)
)
3
2cos(
rsb VV
(18)
)3
2cos(
rsc VV
(19)
Expressing equations (17), (18), and (19) in a rotor
reference frame me may write:
sq VV
(20)
0dV
(21)
Where Vs: amplitude of the stator voltage.
For practical permanent magnet synchronous
machines Ld=Lq=L. Under this assumption,
substituting (20) and (21) into (12) the voltage
equation in q-axis may be written:
mrqr
q ipLR
LpLRV
222 )()(
(22)
If ωr2L2 is neglected, then the equation (22) is
linear. For this approximation to be valid, it is
required that Vq,ωr and Te, are to be equal to or
greater than zero. Thus with ωr2L2 being neglected,
Ld=Lq=L, and substituting (20), equation (17)
becomes:
rmqs ipLRV )(
(22)
The energy that a wind turbine will produce
depends on its wind speed power curve and the
wind speed frequency distribution at the installation
site. Electrical power generated by wind turbine is
given by: 3....5.0. wpgtw VACP
(23)
Vw : Wind speed at projected height in m/s
: Factor to account for air density (1.225 kg/m2 at sea level)
Cp : Power coefficient (0.35 for a good design)
A : Wind turbine rotor swept area in m2
t : Turbine efficiency
g : Generator efficiency
5. Fuel-Cells A fuel cell is an electrochemical cell that converts
chemical energy from a fuel into electric energy.
Electricity is generated from the reaction between a
fuel supply and an oxidizing agent [8]. The reactants flow into the cell, and the reaction
products flow out of it, while the electrolyte
remains within it. Fuel cells can operate
continuously as long as the necessary reactant and
oxidant flows are maintained [9].
Fig.4 Block Diagram of a Fuel Cell
Anode Reactions :2H2 => 4H+ + 4e-
Cathode Reactions: O2 + 4H+ + 4e- => 2 H2O
Overall Cell Reactions: 2H2 + O2 => 2 H2O
The output voltage of a single fuel cellis given by
(24)
ENernst = Thermodynamic potential of the cell.
Vact = Voltage drop due to the activation of anode and cathode.
Vohmic= Ohmic voltage drop resulting from the
resistances to the conduction of protons through the
solid electrolyte and the electrons through its path.
Vcon = Voltage drop resulting from the reduction in
concentration of the reactants gases.
The thermodynamic potential (ENernst) represents
the fuel cell open circuit voltage and the other three
voltages activation voltage drop (Vact), ohmic
voltage drop (Vohmic) and concentration voltage
drop (Vcon) represent reductions in this voltage to supply the useful voltage across the cell electrodes,
VFC, for a certain operation current [16].
Thermodynamic Potential/ Cell Reversible Voltage
(ENernst):
( )
* ( )
( )+ (25)
Where ∆G=change in the free Gibbs energy(J/mol)
F=Constant of Faraday (96.487 C)
∆S=Change of the entropy (J/mol) R= Universal constant of the gases (8.314 J/Kmol)
PH2=Partial pressures of hydrogen (atm)
PO2=Partial pressures of oxygen (atm)
T=Cell operation temperature (K)
Tref=Reference temperature (K)
( ) * ( )
( )+ (26)
Using the standard pressure and temperature (SPT)
values for change in G, change in S and Tref
equation can be simplified. The activation voltage
drop, which takes into account both the anode and
the cathode over-voltage is given by:
[ ( ) ( )] (27)
Where iFC=Cell operating current(A)
ξ's=Parametric coefficient of each cell model
CO2= Concentration of oxygen in the catalytic
interface of the cathode (mol/cm2)
Ohmic Voltage Drop (Vohmic) can be represented using Ohm‟s law as:
( ) Where Rc=Resistance to electron flow
RM=Resistance to the flow of protons
Concentration Voltage Drop (Vcon) is given by the
equation:
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
300
ISSN:2249-5789
(
) (28)
Where B=Parametric coefficient (V) J=Actual current density (A/cm2)
Jmax= Maximum current density (A/cm2)
Fuel Cell Power is the instantaneous electric power
of each fuel cell is given by:
(29)
Where iFC=Cell operating current(A)
VFC= Output voltage of the fuel cell (V)
PFC= Output power of each fuel cell (W)
The voltage-current (V-I) and power-current (P-I)
characteristics of the fuel cell system are shown in
fig 5
Fig.5 Voltage-Current (V-I) and Power-Current (P-
I) Characteristics of the fuel cell
6. Maximum Power Point Tracking The maximum power tracking from wind energy
initially by using the mechanical sensors was
explained by R.Chedid, F.Mrad, and M.Basma. But
the accurate mechanical sensors are required for
tracking the maximum power. Wang, Q., Chan, L
explained about maximum power point tracking by
the mechanical characteristics of wind turbine. But these Methods are very difficult to implement. But
now by the invention of power electronic devices
the power tracking using dc-dc converters are also
possible. The wind speed varies continuously and
the load also changes continuously. In order to
match the load with the wind energy conversion
system we require a power electronic interface
between the wind energy conversion system and
the load. The basic block diagram of the wind
energy conversion system is shown in fig 6.
Fig 6 Block Diagram of WECS
The power output varies with the load impedance
being connected. The load impedance is varying
continuously and the wind speed is also not
constant. So the system by itself cannot reside in
the region of maximum power operating region,
which is more desired. Thereby the importance and
complexity becomes increased for making the system to operate in the maximum power operating
point (MPOP). The technique by which a system is
maintained or made to operate in the MPOP is
called maximum power point tracking (MPPT). If a
maximum power point tracker is not incorporated
in the WEC system, the WECS will deliver a power
that is always lesser than the power that can be
delivered by it. Maximum power point tracking is
basically a software algorithm that is the heart of a
WECS. By the maximum power point tracking algorithm, the WECS is being operated at or
nearest to the maximum power point.
Fig.7 Block Diagram for maximum power point
tracking A maximum power point tracker is basically a
converter connected in between the WECS source
and the load. The duty cycle is continuously
changed and operated at a value such that the
maximum power is tracked from the source [2]. By
maximum power transfer theorem, a source will
deliver its maximum power when the source impedance matches the load impedance. The duty
cycle of the converter is maintained in such a way
that the effective impedance seen by the wind
energy conversion system source will be equal to
the internal source impedance and hence maximum
power is delivered. In order to extract the
maximum wind power, an analysis was provided to
understand the probable displacement of the
operating point in the two operating zones of wind
turbine. Fig.8, represents the typical curve of wind
power variation according to the operating voltage and it shows that there are two operating zones: the
first is located on the right side of the MPP where
dp/dΩ < 0 and the second on the left side of the
MPP where dp/dΩ > 0. For searching the maximum
wind power operating point and tracking this point,
in order to reduce the error between the operating
power and the maximum power, in the event of
change of the wind speed, the control of the boost
converter perturbs periodically the operating point
of the wind turbine. By acquiring the output
voltage and current of PMSG, the control uses this
information to increase or decrease the duty cycle of the boost converter to change the operating point
of the wind turbine [3].
Fig.8 Probable displacement of the operating point
MPPT process in wind energy conversion system is
based on directly adjusting the dc/dc converter duty
SOURCE
(WECS+
FUEL CELL)
DC-DC
CONVERTER
+
MPPT
Load
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
301
ISSN:2249-5789
cycle according to the result of the comparison of
successive WG-output-power measurements.
Although the wind speed varies highly with time,
the power absorbed by the WG varies relatively
slowly, because of the slow dynamic response of
the interconnected wind-turbine/generator system [9]. Thus, the problem of maximizing the WG
output power using the converter duty cycle as a
control variable can be effectively solved using the
steepest ascent method according to the following
control law:
1
1
11 .
k
k
kkD
PCDD
(30) where Dk and Dk-1 are the duty-cycle values at
iterations k and k - 1, respectively (0 < Dk< 1);
ΔPk-1/ΔDk-1 is the WG power gradient at step k-1;
and C1 is the step change. In order to ensure that this method results in
convergence to the Wind Generator maximum
power point at any wind-speed level, it is adequate
to prove that the function P(D), relating the WG
power P and the dc/dc converter duty cycle D, has
a single extreme point coinciding with the WG
MPPs. It is obvious that at the points of maximum
power production , where is the WG rotor speed.
Applying the chain rule, the above equation can be
written as
0..
d
d
d
dV
dV
dD
dD
dP
d
dP e
e
WG
WG (31)
Where VWG is the rectifier output voltage level and
Ωe is the generator-phase-voltage angular speed. In
case of a boost-type dc/dc converter, its input
voltage is related to the output (battery) voltage and the duty cycle as follows:
WGV
VD 0
0
12
O
WGWG
VVdV
dD
(32)
Where V0 is the battery voltage level. The wind-
turbine rotor speed is related to the generator speed
as follows:
.pe
0
p
d
d e
(33)
Where p is the number of generator pole pairs. The
rectifier output voltage VWG is proportional to the
generator phase voltage Vph. Considering Fig. 9, it
is concluded that
0e
ph
d
dV
0
e
WG
d
dV
00 dD
dP
d
dP (34)
Thus, the function P(D) has a single extreme point,
coinciding with the WG MPOP, and the dc/dc
converter duty-cycle adjustment according to the
control law ensures convergence to the WG MPOP
under any wind-speed condition. The power
maximization process is shown in Fig.9.
Since the duty-cycle adjustment follows the
direction of dP/dD, the duty-cycle value is
increased in the high-speed side of the WG
characteristic, resulting in a WG-rotor-speed
reduction and power increase, until the MPOP is
reached.
Fig.9 MPP tracking process
Similarly when the starting point is in the low-
speed side, following the direction of dP/dD results
in duty-cycle reduction and the subsequent
convergence at the MPOP, since the WG rotor
speed is progressively increased.
7. Boost Converter A boost converter (step-up converter) is a power
converter with an output DC voltage greater than
its input DC voltage. It is a class of switching-mode power supply (SMPS) containing at least two
semiconductor switches (a diode and a transistor)
and at least one energy storage element. Filters
made of capacitors (sometimes in combination with
inductors) are normally added to the output of the
converter to reduce output voltage ripple.
A boost converter is used as the voltage increase
mechanism in the circuit known as the 'Joule thief'.
This circuit topology is used with low power
battery applications, and is aimed at the ability of a
boost converter to 'steal' the remaining energy in a
battery. This energy would otherwise be wasted since the low voltage of a nearly depleted battery
makes it unusable for a normal load [18].
Fig.10 boost converter basic diagram
8. MPPT Algorithm
Fig.11 Flow chart for MPPT algorithm
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
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ISSN:2249-5789
The wind energy conversion systems interface the
load by using power electronic converter .The
power electronic converter consisting of the boost
converter. The control of MPPT is done by using
boost converter .By varying the boost converter
duty ratio we can achieve maximum power tracking. Two different control variables are often
chosen to achieve the maximum power control,
Voltage feedback control and power feedback
control
In Voltage-Feedback Control the converter
terminal voltage is used as the control variable for
the system. The system keeps the wind energy
conversion system operating close to its maximum
power point by regulating the rectifier output
voltage and matches the voltage of the desired
voltage. However, this has drawbacks like the
effects of the wind speed are neglected. It cannot be widely applied to battery energy storage systems.
Power-Feedback Control Maximum power control
is achieved by forcing the derivative (dP/dV) to be
equal to zero under power feedback control. A
general approach to power feedback control is to
measure and maximize the power at the load
terminal. This has an advantage of unnecessarily
knowing wind energy characteristics. However,
this method maximizes power to the load not power
from the wind energy conversion systems.
Although a converter with MPPT offers high efficiency over a wide range of operating points,
but for a bad converter, the full power may not be
delivered to the load due to power loss.
Therefore, the design of a high performance
converter is a very important issue. In this present
work power feedback control is used to track the
maximum power from the system.
9. Simulation Results The wind energy conversion system is modeled in
MATLAB simulink simulation software. The
mathematical model of wind energy conversion
system is explained chapter two is used for
simulation. The MPPT algorithms were simulated
in the graphical simulation software Simulink for
which the graphical representation has been taken. The simulation is carried out using MATLAB
Simulink for 24 hours duration.The single line
diagram of the test system is shown in Fig.12 the
wind energy conversion system details
Fig.12 Single line diagram of the test system
For simulation purpose ER3100 model wind
turbine is used, for that turbine rated wind speed is 8.2m/s. At the rated wind speed turbine rotor
rotates at 270RPM. The turbine coupled to the
generator rotor by a tip speed ratio of 7.5 and the
generator rated speed is 3000RPM, at that speed
generator will produce the voltage of 400V. The
generator parameters taken for the simulation are
direct and quadrature axis inductance 8.5mH(Ld=Lq=8.5 mH). The source resistance of
conditions taken for the simulation first for the
constant load of 2000W and variable load of load
curve shown in the figure.
Fig.13 constant load curve for simulation (2000Watts)
When the load is directly connected to the wind
generator the output power fluctuates shown in fig.
This fluctuations may damage the load .To avoid
this condition the load is connected through the
power conditioner unit.
Without MPPT unit Maximum power is 12000W,
Average power is 10.25kW and energy taken from
the WECS on complete day.
Fig.14 power output without MPPT
Maximum power is 12000W
Average power is 10.25kW
When new method is used for the MPPT,
Maximum power is 12300W, Average power is
10.40kWand energy taken from the WECS on
complete day.
Fig.14 Power output using New MPPT Method
Maximum power is 12300W
Average power is 10.40kW
Table:1 comparison of Max. & avg. Power Power Without MPPT With MPPT
Max.Power 10100 10947
Average Power 9.17 9.87
%increase in
Max.Power
8.4%
% increase in average
power
7%
Ch Rambabu et al, International Journal of Computer Science & Communication Networks,Vol 1(3), 297-304
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ISSN:2249-5789
From the above results it is clear that using the new
method, the power output is increased by 8.4% in
case of constant load condition.
From the above results it is clear that when the load
changes continuously and wind speed change
continuously, the new method will respond quickly. The energy output of wind turbine on a particular
day using the simulation methods are given in
table. Load value is 1000 ohms.
10. Conclusion In this work WG maximum power tracking
controls are presented, comprising of a high-
efficiency boost-type dc/dc converter and control
unit. The advantages of the MPPT methods are no
knowledge of the WG optimal power characteristic
or measurement of the wind speed is required and
the WG operates at variable speed and thus
suffering lower stress on the shafts and gears. The
MPPT methods do not depend on the WG wind and
rotor-speed ratings or the dc/dc converter power rating. In this project a new method is used for the
maximum power point tracking of the wind energy
conversion systems. In this thesis, a new algorithm
is presented to track the maximum power from the
wind energy conversion system eliminating the
drawbacks under rapidly changing atmospheric or
load conditions. The average output power is
increased by 7%. From the above results it is clear
that using the new method the power output is
increased in case of constant load condition.
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