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Modeling of Non-Conventional Energy Sources- Solar and Wind Hybrid Model
Ishraque Ahmad1, Jai Karan Singh2
Index Terms— Modeling and simulation of power systems, peak-power tracker (PPT), renewable-energy systems, Hybrid power system(HPS)
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In India the total installed Capacity of Generation (as on 28-02-2011) was 171926.40 MW. On May 2012, it increased to 202 GW. Various Power Sources i.e. Thermal, Hydro and Nuclear called as Conventional sources accounts for most of the contribution in Gener- ation of Power.[10]
Contribution of various power sources to genera-
tion of Electricity is:
Power Plant | Electricity Generated |
Thermal | 64.75 % |
Hydroelectric | 21.73 % |
Nuclear | 2.78 % |
Renewable Energy Sources | 10.73 % |
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(This information is optional; change it according to your need.)
India’s Energy demand, more than 50% is met most- ly through Thermal power plant dependent on coal re- serves. This fossil fuel is fast exhausting and also causing pollution.
Due to the rapid Industrialization and Advancing Technol- ogies, the country’s energy demand has grown an aver- age of 3.6% per annum over the past 30 years. The total demand for electricity in India is expected to cross
950,000 MW by 2030.
Loss of power due to transmission and distribution is extremely high; varying between 30 to 45%.India’s eco- nomic growths is adversely affected by power cuts result- ing from shortage of electricity. India faced a power deficit of 73,050 million units between April 2007 and March
2008, according to an audit.
We have to seek alternative sources of Energy; Renewable Energy sources are the most promis- ing fields in the search. The term Green energy can be associated with environment-friendly Genera- tion,transport,storage and control of electrical energy
.Solar power, wind power and the natural flow of water
are resources that comply with our definition of Green
Energy. [10]
1] Thermal power: 111324.48 MW which is 64.75% of to-
tal installed capacity.
2] Coal based Thermal Power: 92418.38 MW which is
53.75% of total installed capacity
3] Gas Based Thermal Power: 17706.35 MW which is
10.3% of total installed capacity.
4] Oil Based Thermal Power: 1,199.75 MW which is 0.9
% of total installed capacity.
5] The state of Maharashtra is the largest producer of
thermal power in the country.
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1] The installed capacity was 37367.4 MW
1] 20 Nuclear power reactors produce 4,780 MW
It is still undeveloped .The share of Renewable Energy in the energy sector is less than 1% of India’s total energy needs. [10]
Since the natural fossil energy resources are limited on this planet, we have to put our focus on Green power gen- eration like solar and wind power.
Hybrid Power Systems (HPS) are the power systems com-
bining different power systems.HPS being combination of more than one energy source, the system need not have to be dependent on any one system ; making the system more efficient and reliable.
The main objectives of this paper is implementing and develop a software application to analyse and simulate a real hybrid solar-wind system connected to a local grid using Matlab Simulink environment. The hybrid unit contains two complete generating plants, a solar plant
and a wind system.The two sources are connected in paral-
lel, the power is connected to a DC to AC inverter and is then supplied from the inverters output to a single phase load.
We propose to design the supervisory control system via model predictive control (MPC) which computes the
power references for the wind and solar subsystems at each sampling time while minimizing a suitable cost function. The
power references will be sent to two local controllers which drive the wind and solar subsystems to the desired power
reference values. MPC is a popular control strategy Hybrid
Electric systems combine wind and solar photovoltaic tech-
nologies offering several advantages over either single sys- tem. Using these predictions, the input/set-point trajectory that minimize a given performance index over a finite-time horizon will be computed solving a suitable optimization problem subject to constraints. In this work, we discuss how we can incorporate practical considerations (for example, how to extend the life time of the equipments by reducing the peak values of inrush or surge currents) into the formulation of the MPC optimization problem by determining an appro- priate cost function and constraints.
Nowadays, the use of fossil fuel is growing exponen- tially. The sources of electricity such as coal, gas and oil has been reduced from year to year. So there is a need to find another source to produce stable electricity generation. Another effect of the lack of other sources is that the price of oil and gas is hiking. Because of these reasons, the use of renewable energy become essential and must be applied soon.
The electricity is one of the most
needed energy because people need it in day to day life. There is need of generation of electricity because the resources that are used for electricity generation will be reduced year by year. In conventional way, the elec- tricity is generated using coal, oil gas and etc. Since uel energy sources reduce every year, renewable energy is needed. The electricity generated by using these sources is more efficient and environmental friendly.
Conventional energy sources are deplet- ing .Focus should be shifted on RES as a long term so- lution. [10]
Achieving major renewable energy production goals requires addressing key fundamental challenges in the opera- tion and reliability of intermittent (variable output) renewable resources like solar- and wind-based energy generation sys- tems. Specifically, unexpected drops in energy production of a solar or wind energy system may require quick start units to cover the shortfall while unexpected increases require the abil- ity to absorb the unscheduled generation. One way to deal with the variable output of wind and solar energy generation systems is through the use of integrated energy generation systems using both wind and photovoltaic energy, which are also tightly integrated with distributed energy storage systems (batteries) and controllable energy loads like, for example, a water production system that operates at controllable time intervals to meet specific demand. With respect to previous results on control of wind and solar systems, most of the ef- forts have focused on standalone wind or solar systems. Spe- cifically, there is a significant body of literature dealing with control of wind energy generation systems while several con- tributions have been made to the control of solar-based ener- gy generation systems. However, there are few works that have focused on the control of standalone hybrid wind-solar energy generation systems. A reduced-order nonlinear model was used to design a controller to regulate the wind power generation to complement the power generated by a photovol- taic subsystem and to satisfy a specific power demand. A slid- ing mode control techniques were used to control the power generated by a photovoltaic array in order to satisfy the total instantaneous power demand in a highly uncertain operating environment. A supervisory control system was developed to satisfy the load power demand and to maintain the state of charge of the battery bank to prevent blackout. In a recent work a cost-effective control technique was proposed for max- imum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measur- ing the irradiance of the photovoltaic or the wind speed. How- ever, no attention has been given to the development of su- pervisory control Systems for standalone hybrid wind-solar energy generation systems that take into account optimal allo- cation of generation assignment between the two subsystems. [2]
3. PROPOSED METHODOLOGY
The block diagram of solar power plant as shown in fig3.1
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Photovoltaic panels consist of several modules; modules are composed of cells which are in series. Photovoltaic cells transform luminous energy (solar) into electrical energy.
The equivalent circuit of a photovoltaic cell is shown in fig3.2
It consists of an ideal source producing a current IPh, pro- portional to incident light, in parallel with a diode D. Shunt re- sistance Rp models the effect of leak current but in many cas- es this can be neglected due to its relative large value.[1]
.Modules put together form a panel .Panels form an array
.Each PV cell is rated for 0.5- 0.7 v and a current of 30
mA/sq.cm.[1]
quality, connection of wind farms to weak grids, prediction of wind power and changes in operating strategies of conven- tional power plants.
Wind turbines are used to convert the wind power into elec- tric power. Electric generator inside the turbine converts the mechanical power into the electric power. Wind turbine sys- tems are available ranging from 50w to 2-3 MW.
Mechanical output of turbine of wind generator is depend- ent on the speed of turbine. For small turbines, wind speed is about 3.5m/s. large wind power plants require wind speed of
6m/s. But wind speeds higher than this are available in many
locations.
India has the fifth largest installed wind power capacity in
the world.
It is estimated that 6000 MW of additional wind power capacity
will be installed in India by 2012.Wind power accounts for 6% of India’s total installed power capacity and it generates 1.6% of the country’s power. [10]
w ind generator
rectifier DC/DC
converter
DC/AC
inverter
utility line
Fig.3.2 PV cell model
fig3.4 Block Schematic for Wind Power Plant
w ind generator
rectif ier DC/DC
converter
DC-DC Converter
battery
DC/AC
inverter
DC load
AC load
fig3.3: solar panel
fig 3.5 The grid-connected application
Wind Power is very popular nowadays, because of the high power that can be achieved in a efficient way.
The Wind is identified as a key natural energy resource, which contributes to reducing undesirable emissions due to
fossil fuel power plant operation. Worldwide installed wind power capacity has reached 120GW at the end of 2008 with a
36% increase in comparison to the previous year.
However, with the increase of wind power penetration, the
technical and operational challenges associated with wind energy have also become more apparent. These challenges include, the elimination of power fluctuations, improving power
The AC/DC/AC converter is divided into two components: the rotor-side converter (Crotor) and the grid-side converter (Cgrid). Crotor and Cgrid are Voltage-sourced converters that use forced-commutated power electronic devices to syn- thesize an AC voltage from a DC voltage source. A capacitor connected on the DC side acts as the DC voltage source. A coupling inductor L is used to connect Cgrid to the grid. The three-phase rotor winding is connected to Crotor by slip rings and brushes and the three-phase stator winding is directly connected to the grid. The power captured by the wind turbine is converted into electrical power by the induction generator
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and it is transmitted to the grid by the stator and the rotor wind- ings. The control system generates the pitch angle command and the voltage command signals Vr and Vgc for Crotor and Cgrid respectively in order to control the power of the wind turbine, the DC bus voltage and the reactive power or the voltage at the grid terminals. [4]
Hybrid Electric systems combine wind and solar pho- tovoltaic technologies offering several advantages over either single system. Wind speeds are low in summer when the sun shines the brightest and longest. The wind is strong in winter when less sunlight is available. Because the peak operating times for wind and solar systems occur at different times a day and year, hybrid systems are likely to produce power when required.
The hybrid unit contains two complete generating plants, a solar plant and a wind system.The two sources are connected in parallel, and the power is connected to a DC to AC inverter and is then supplied from the inverters output to a single phase load.
The development path of solar wind hybrid systems in
India since 1994 an aggregate capacity of 1.07 MW of aero- generators or hybrid systems was installed under the pro- gramme up to December 2010.Almost 57% of the total cumu- lative installations in the country are followed by Goa,Karnataka,West Bengal, Manipur and Tamil Nadu.
In this hybrid system, there are three subsystems: wind
subsystem, solar subsystem, and a lead-acid battery bank which is used to overcome periods of scarce generation. [4]
fig3.6. wind-solar energy generation
fig3.7: block schematic of hyprid power plant (wind and solar)
For calculating electrical power from wind generator,equation
of electrical power is given as,
Power = ½ ×ρ ×A×Cp×
×Ng×Nb where,
ρ= Density of air
V=velocity of wind
A= Area of cross section of blade movement
Cp =Power coefficient
Ng = Wind generator efficiency
Nb = Bearing Efficiency
Our visit to the meteorological department of Nag- pur. For the analysis of hybrid system we collect the data of solar radiation and wind speed from January to March
month. The hybrid system which is design in simulink showing the result of January month .as from the result solar power model is feasible for Nagpur city but the wind power model is not feasible,because the wind speed in Nagpur is below 10 km/hr. wind power model will be ap- plied in coastal areas.
The value of average solar radiation for a week of a Janu- ary
3 r.org
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The equations relating , are :
= x sinα
Where,
α is the elevation angle :
x sin(α+β)
β is the tilt angle of the module measured from the hori- zontal surface
The elevation angle is given as α = 90 - Φ +δ
Where,
Φ is the latitude;
δ is the declination angle
But declination angle is given as
δ = 23.45ᵒ sin (284+d)]
The power incident on a PV module depends not only on the power contained in the sunlight,but also on the angle between the module and the sun.When the absorbing surface and the sunlight are perpendicular to each other,the power density on the surface is equal to that of the sunlight i.e,the power density will always be at its maximum when the PV module is per- pendicular to the sun.
The amount of solar radiation incident on a tilted module surface is the component of the incident solar radiation which is perpendicular to the module surface.The figure shows how to calculate the radiation incident on a tilted surface (
) given either the solar radiation measured on horizontal sur- face( ) or the solar radiation measured perpendicular to the sun( )
Where,
d is the day of the year such that d= 1 on the 1 st January
From above equations a relationship between 
and
can be determined as
= Shorisin (α+β)
Sinα
Based on the mathematical equations, a model for a PV module is developed using MATLAB/Simulink. The PV module that has been design is shown in Figure The input quantities (solar irradiance, W/m2, temperature, 0C and voltage, Vm) to- gether with the manufacturer data are used to calculate the module current for PV. Vm is the voltage of the maximum pow- er point and roughly independent of irradiance. The average value of this voltage during the day can be estimated as 80% of the open circuit voltage. The output for PV module is mod- ule current (A) and power (W).
fig.4.1 radiation incident on a tilted surface
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Fig 4.2.Simulation model of solar power system
fig.4.3 output of solar power system ( voltage vs time)
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Fig 4.4 simulation model of wind generator
Fig 4.5 output of wind generator ( voltage vs time)
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Fig 4.6 simulation model of hybrid power system (solar and wind)
Fig4.7 output of hps (voltage vs time)
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This project presents the modeling of a solar-wind hybrid system. Based on presented mathematical models was real- ized a Matlab/Simulink application useful for analyse and simulate a real hybrid solar-wind system connected to a local grid. Application is built on modular architecture to facilitate easy study of each component module influence.
Blocks like wind model, solar model, energy conversion
and load are implemented and the results of simulation are also presented. With the proposed application many situations can be studied. An important study is the behavior of hybrid system which allows employing renewable and variable in time energy sources while providing a continuous supply. Applica- tion represents a useful tool in research activity and also in teachin
[1] I.a. adejumobi, s.g. oyagbinrin, f. G. Akinboro & m.b. olajide4 “hybrid solar and wind power: an essential for formation communication technology in frastructure and people in rural communities”inijrras 9 (1) october 2011,pp130 to 138.
[2] W ei qi, jinfeng liu, xianzhong chen, and panagiotis d. Christofides,
“supervisory predictive control of standalone wind/solar energy gen- eration systems”, ieee transactions on control systems technology, vol. 19, no. 1, january 2011,pp199 to 206
[3] Luiz antonio de souza ribeiro, osvaldo ronald saavedra, shigeaki leite
de lima, and josé gomes de matos “isolated micro-grids with renewa- ble hybrid generation: the case of lençóis island”,ieee transactions on sustainable energy, vol. 2, no. 1, january 2011,pp 1 to 11
[4] Toshiro hirose and hirofumi matsuo , “standalone hybrid wind-solar power generation system applying dump power control without dump load”, ieee transactions on industrial electronics, vol. 59, no. 2, febru- ary 2012,pp988 to 997.
[5] U_ur fesl, raif bayir, mahmut ozer “design and implementation of a domestic solar-wind hybrid energy system.” March 10, 2010 from ieee xplore.
[6] Pragya nema1, r.k. nema2, saroj rangnekar1 “pv-solar / wind hybrid
energy system for gsm/cdma type mobile telephony base station” in- ternational journal of energy and environment volume 1, issue 2,
2010 pp.359-366.
[7] Chedid, member ieee & h. Akiki saifur rahman, senior member ieee “ a decision support technique for the design of hybrid solar-wind pow- er system” ieee transactions on energy conversion, vol. 13, no. 1, march 199.
[8] Jan t. Bialasiewicz, senior member, ieee, and eduard muljadi, senior
member, ieee “analysis of renewable-energy systems using rpm-sim simulator” ieee transactions on industrial electronics, vol. 53, no. 4,
august 2006
“
[9] M. Muralikrishna and v. Lakshminarayana hybrid (solar and wind)
energy systems for rural electrification” vol. 3, no. 5, october 2008issn
1819-608 arpn journal of engineering and sciences
[10] b. Gupta “generation and economic consideration”,katson publication
2nd edition, chapter1,pp1 to 10
[10] www.mathwork.
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