A PRESENTATIONONRENEWABLE ENERGY DISTRIBUTED POWER SYSTEM WITH WIND POWER AND BIOGAS GENERATOR

By Your Name

2008UEE

ACKNOWLEDGEMENT

I take this opportunity to express my deep sense of

gratitude and respect towards Sh. V.K Jain,Associate Professor , Department of ElectricalEngineering.I would also like to thank seminar in-charge Sh.Ashok Kumar Agarwal, Associate Professorand Prof. K. R. Niazi, Head of Department forgiving me a platform to present this seminar.Their great pedagogic articulation has helped a lotIn understanding of the IEEE papers.

CONTENTS

Distributed Power System Independent Systems Wind Power System Biogas Power System Wind Biogas Renewable Energy System Simulation results Conclusion References

DISTRIBUTED POWER SYSTEM Distributed generation, also called on-site generation,

dispersed generation, embedded generation, decentralized generation, decentralized energy or distributed energy.

DPS – small set of co-operating units generating electricity with diversified primary energy carriers (renewable and non-renewable) , while the co-ordination of their operation takes place by utilization of power electronics systems.

 Can be connected to the power grid or work independently feeding separated receivers, from one or several homes/farms, small industrial plants to large local communities.

When DPS generate more power than receivers and local energy storage systems requirement, they provide surplus power to the grid.

The major aim of DPS is to supply remote, off-grid communities where the costs of connection to the long distance transmission or distribution grid are too high.

DGP - mass-produced, small, and site-specific.

Their development arose out of: Concerns over perceived externalized costs of central

plant generation, particularly environmental concerns The increasing age, deterioration, and capacity

constraints upon T&D for bulk power The increasing relative economy of mass production of

smaller appliances over heavy manufacturing of larger units and on-site construction

Higher relative prices for energy, higher overall complexity and total costs for regulatory oversight, tariff administration, and metering and billing

The DPS attraction The additional premium for DG is rapidly declining as

demand increases and technology progresses. Sufficient and reliable demand will bring economies of scale, innovation, competition, and more flexible financing, which will make DG clean energy a part of the more diversified future.

Distributed generation reduces the amount of energy lost in transmitting electricity because the electricity is generated very near to where it is used.

In this report we examine Wind and Biogas distributed

energy systems. Wind power is fluctuating and so a special kind of

power plant should be built to avoid shortages of wind power. Biogas is introduced to balance the electricity of wind power

TYPES OF DISTRIBUTED ENERGY RESOURCE SYSTEMS

There are many types DPS such as: DPS with wind power and solar power DPS with wind power and fuel cell DPS with wind power, solar power and fuel cell DPS with wind power and biogas

Controlled sources and Uncontrolled sources Controlled sources -output power can be easily

controlled to the goal power Uncontrolled sources – output, unpredictable and

independent of human action.

Biogas and wind power plants are environmentally uncontrolled sources

ADVANTAGES OF DISTRIBUTED POWER Standardized designs A goal of distributed power is the

availability of standardized off-the-shelf modules or designs which could be combined in a variety of ways to meet a specific application. This has obvious benefits in development time and engineering costs.

Ease of customizing much easier to modify, redesign, or replace a smaller power module allocated to the unique portion of the system than to redesign a larger central power supply

Maintainability possible to localize and isolate faults much more readily and hence will allow repairs to be made with a minimum of down time.

Reliability enhanced if it consists of a paralleled configuration of n+ y modules

(n is the minimum number of modules necessary to meet a given load requirement and y is a number of additional units which gives the system the ability to tolerate y failures without impact)

Efficiency higher efficiency due to ease of control

INDEPENDENT POWER SYSTEMS

In order to understand the distributed power system we need to look into the wind and biogas power systems independently.

WIND POWER SYSTEM

Wind power generators at Great Orton Wind cluster ©Wind Prospect / Cumbria Wind Farm

A basic wind energy system consists of Turbine (a propeller-like rotor, a gear box and

a generator) Tower Balance of System (BOS) package Battery system Some applications require a diesel, gas or

propane powered generator which operates when the wind is not blowing

Typically, wind speeds greater than 15 km/hr are needed before a wind energy system can begin to generate electricity.

wind power system.flv

The power in the wind

The power in the wind is proportional to: The area of windmill being swept by the

wind The cube of the wind speed The air density - which varies with altitude

Power = ½ x density of air x swept area x velocity cubed

Power =

Actual Wind power into watts

Where Pm is power (in watts) available from the machine, Cp is the coefficient of performance of the wind machine

Wind machine will only operate at its maximum efficiency for

a fraction of the time it is running due to variations in wind

speed. A rough estimate of the output from a wind machine

can be obtained using the following equation

Where, is the average power output (W) over the year, v is the mean annual wind speed (m/s)

PRINCIPLES OF WIND ENERGY CONVERSION

There are two primary physical principles by whichenergy can be extracted from the wind; these arethrough the creation of either lift or drag force

(orthrough a combination of the two)

The basic features that characterize lift and drag are:

Drag -direction of air flow Lift - perpendicular to the direction of air flow Generation of lift always causes a certain amount

of drag to be developed With a good aerofoil, the lift = 30*drag Lift devices are generally more efficient than

drag devices

LIFT & DRAG FORCES The Lift Force is

perpendicular to the direction of motion. (BIG)

The Drag Force is parallel to the direction of motion. (small)

α = low

α = medium<10 degrees

α = HighStall!!

Technical parameters used to characterize

rotors tip speed ratio (drag <1 , lift 13:1 ) coefficient of performance ( 25- 45 , 59.3) Solidity (%)

Wind speeds to consider: Start-up wind speed Cut-in wind Rated wind speed (optimum tip speed ratio) Furling wind speed

furling.flv

TIP-SPEED RATIOTip-speed ratio is the ratio of the

speed of the rotating blade tip to the speed of the free stream wind.

There is an optimum angle of attack which creates the highest lift to drag ratio.

Because angle of attack is dependant on wind speed, there is an optimum tip-speed ratio ΩR

VTSR =

Where,

Ω = rotational speed in radians /sec

R = Rotor Radius

V = Wind “Free Stream” Velocity

ΩR

R

ADVANTAGES AND DISADVANTAGES

Advantages  Can be used for both distributed generation or grid

interactive power generation using on-shore or off shore technologies

Ranges of power producing turbines are available. Micro-turbines are capable of producing 300W to 1MW and large wind turbines have typical size of 35kW-3MW

Wind turbine is suitable to install in remote rural area, to use for water pumping and grinding mills

Disadvantages The total cost can be cheaper than solar system but

more expensive than hydro Electricity production depends on- wind speed, location,

season and air temperature. Hence various monitoring systems are needed and may cost expensive

High percentage of the hardware cost (for large WT) is mostly spent on the tower designed to support the turbine

BIOGAS POWER SYSTEM A biogas plant uses the process of anaerobic

digestion to generate renewable electricity and heat. It ferments natural waste products and energy crops to generate green energy.

Highest energy efficiency: Biogas is converted in a combined heat-& power coupling (CHP), with an efficiency of 85%

Continuous operation: The anaerobic fermentation is a biological process that occurs continuously

Waste: Various wet waste flows can be processed into energy

Flexibility: Flows from different sources can be processed together

PLANT TYPESThree main types of simple biogas plants can be distinguished: Balloon plants – heat-sealed plastic or rubber bag (balloon), combining digester

and gas-holder. gas stored in the upper part of the balloon. The inlet and outlet are attached directly to the skin of the balloon. Materials - RMP (red mud plastic), Trevira and butyl. useful life-span -

2-5 years Floating-drum plants- underground digester and a moving gas-holder. gas-holder floats either directly on the fermentation slurry or in a

water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. If the drum floats in a water jacket, it cannot get stuck, even in substrate with high solid content.

Fixed-dome plants (most popular) digester with a fixed, non-movable gas holder, which sits on

top of the digester. When gas production starts, the slurry is displaced into the compensation tank. Gas pressure increases with the volume of gas stored and the height difference between the slurry level in the digester and the slurry level in the compensation tank.

Balloon plant Floating-drum plant

Fixed-dome plant

InputThere are many different input flows that can be

fermented: Energy crops such as corn, beet Manure from pigs, chickens Organic Biological Secondary flows and products Organic sludge

OutputAfter fermentation the biogas plant generates 3 outputs Electricity Heat: the heat generated during the combustion of

biogas can be used for use in other processes that require significant heat.

Digestate: The digestate can be transformed into pellets suitable for fertilization of the fields or energy. In this way nothing is lost and we can turn this flow into an economically valuable product

THE WIND BIOGAS RENEWABLE ENERGY SYSTEM The wind power is influenced by the weather;

the output power is determined by the wind speed. It is known that the wind speeds are changed with time and space. Biogas is produced from anaerobic biodegradation of organic material in the absence of oxygen and the presence of anaerobic micro-organisms. The biogas produced by the waste of industry, agriculture and town is fired to drive the engine to generate electricity.

The biogas generation is under control and can provide electricity to balance the output power of wind generation.

DPS with wind and biogas

POWER FLOW IN THE SYSTEMThere are three cases according to the relationbetween these powers

CAPACITY OF HYBRID SYSTEM The output power is varied from the power of starting wind speed to the

rating power. The relation between the wind speed and the output power is shown as

Where, K is a parameter which is a constant for a particular location. The minimal power of wind generator can be easily gotten by equation

The output power of wind generator on whole day is presented as

The efficiency of engine is high from a power point to rating output power. Assuming that the output power of Biogas generator is Pb

Ps – start power, Pbe rated powerAssuming that the load is Pl, it is shown asPle - rated load The stable electricity supply is important to the user; hence the relation

between the capacity of wind generator, biogas generator and load is shown as

CONTROLLER The controller of the system is separated to two parts,

one of which is the controllers of wind generator and biogas generator, and the other is the chief controller.

The controller of wind generator is designed to get the max energy from the wind, the controller of biogas generator is designed to get the need power by adjusting the mass of the input biogas.

Wind Generator

The rotor speed of the wind turbine is controlled through the adjustment of ratio of Boost-bucker. The main idea behind this method is to control the reaction torque of the generator via changing the winding voltage and the output current.

VSCF wind turbine

Biogas Generator

SIMULATIONS

The hybrid system of wind generator and the biogas generator is made and the research on how to track the maximum point of the wind generator and how to make the output power follow the order quickly was done in the concerned paper.

But the whole system controller is on designing. The simulations are done first to validate the control ways.

The rating power of wind generator is 7 Kw ; the rating power of biogas generator is 20 Kw. The reference wind speed is 15m/s and the radius of wind turbine is 10m. The control result with the wind speed of 15m/s is shown. The gas engine simulation is at the rotor speed 1500 r/min.

Rotor Speed Controlled by ADRC

Output Power of Wind Generator Output Power of Biogas Generator

DC Voltage

CONCLUSIONS Renewable energy is attractive because of its

sustainability and its ability to lift the poorest nations to new levels of prosperity.

The biogas produced by waste and dead plant as well as the wind generator produced by tapping wind potential is seemingly widely getting used all over the world .

Efforts are being made to combine other generators to improve their respective usability.

Since the biogas generator is only restricted by the marsh gas pond, it is controllable and the capacity can be planned.

So the hybrid system of wind generator and biogas generator can be used to keep the output electricity stable and constantly monitored by simulations.

REFERENCES[1] Zhang Yanning1, Kang Longyun1, Cao Binggang2,

Huang Chung-Neng3, Wu Guohong4, Renewable Energy Distributed Power System With Wind Power and Biogas Generation, School of Electric Power, South China University of Technology, Guangzhou, China, IEEE T&D Asia 2009

[2] IURC Staff , Distributed Generation White Paper[A],2002,1,1N13

[3] M.T. Iqbal , Simulation of a small wind fuel cell hybrid energy system[J] , Renewable Energy 28 (2003) 511–522.

[4] F.H. Guan, D. Ｍ Zhao, X. Zhang, B.T Shan, Z. Liu. Research on Distributed Generation Technologies and its impacts on Power System, 2003.

[5] Kang Longyun, Zhang Yanning, Cao Binggang, Wind-Solar-Biogas Renewable Energy Distributed Power system, pp798-99, 2009.

[6] H. Murai", T. Takeda\ K. Hirose\ Y. Okui', Y. Iwase', K. Yukita', K. Ichiyanagi , study on charge patterns for uninterruptible power supply system with distributed generators,2009