LOW EXPENSE VERTICAL AXIS WIND TURBINE USING PERMANENT MAGNETS

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1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 2, March-April 2016, pp , Article ID: IJMET_07_02_026 Available online at Journal Impact Factor (2016): (Calculated by GISI) ISSN Print: and ISSN Online: IAEME Publication LOW EXPENSE VERTICAL AXIS WIND TURBINE USING PERMANENT MAGNETS Ramu S Assistant Professor Sree Narayana Institute of Technology, Adoor, Kerala Abhilash M, Ajay M, Aravind S, Hariprasad M Students, Sree Narayana Institute of Technology, Adoor, Kerala ABSTRACT Wind turbines are devices that convert the wind's kinetic energy into electrical power. The result of over a millennium of windmill development and modern engineering, today's wind turbines are manufactured in a wide range of horizontal axis and vertical axis types. The smallest turbines are used for applications such as battery charging for auxiliary power. Slightly larger turbines can be used for making small contributions to a domestic power supply while selling unused power back to the utility supplier via the electrical grid. Arrays of large turbines, known as wind farms, have become an increasingly important source of renewable energy and are used in many countries as part of a strategy to reduce their reliance on fossil fuels. Key word: Design, Material Selection, Modelling, Analysis Cite this Article Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M, Low Expense Vertical Axis Wind Turbine Using Permanent Magnets. International Journal of Mechanical Engineering and Technology, 7(2), 2016, pp INTRODUCTION When If the efficiency of a wind turbine is increased, then more power can be generated thus decreasing the need for expensive power generators that cause pollution. This would also reduce the cost of power for the common people. The wind is literally there for the taking and doesn't cost any money. Power can be generated and stored by a wind turbine with little or no pollution. If the efficiency of the common wind turbine is improved and widespread, the common people can cut back on their power costs immensely. Ever since the Seventh Century people have been utilizing the wind to make their lives easier. Windmills have 5-6 blades. While past windmills have had 48 blades. Past windmill also had to be manually directed into the editor@iaeme.com

2 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets wind, while modern windmills can be automatically turned into the wind. The sail design and materials used to create them have also changed over the years. In most cases the altitude of the rotor is directly proportional to its efficiency. As a matter of fact, a modern wind turbine should be at least twenty feet above from an obstruction, though it is even more ideal for it to be thirty feet above and five hundred feet away from any obstruction. Different locations have various wind speeds. Some places, such as the British Isles, have few inhabitants because of high wind speeds, yet they are ideal for wind generation. Some geographic features such as mountains also have an influence upon wind. Mountains can create mountain breezes at night, because of the cooler air owing down the mountain and being heated by the warmer valley air causing a convection current. Valleys are affected in much the same way. In the daytime, the cooler air is above the valleys and the hot air is above the mountains. The hot air above the mountain rises above the valleys and cools, thus creating a convection current in the opposite direction and creating a valley wind. The oceans create convection currents, as well as they mountains or valleys. In the day, the hotter air is above the same and the cooler air is above the ocean. The air heats up over the sand and rises above the ocean and then cools, creating the convection current. At night, the cooler air is above the sand and the warmer air is above the ocean, so the air heats up over the ocean and cools over the sand. Actually there are two types of windmills (the horizontal axis windmills and the vertical axis windmills). The horizontal axis windmills have a horizontal rotor much like the classic Dutch four-arm wind-mill. The horizontal axis windmills primarily rely on lift from the wind. As stated in Bernoulli's Principle, "a fluid will travel from an area of higher pressure to an area of lower pressure. It also states, "As the velocity of a fluid increases, its density decreases." Based upon this principle, horizontal axis windmill blades have been designed much like the wings of an airplane, with a curved top. This design increases the velocity of the air on top of the blade thus decreasing its density and causing the air on the bottom of the blade to go towards the top. Creating lift.the blades are angled on the axis as to utilize the lift in the rotation. The blades on modern wind turbines are designed for maximum lift and minimal drag. Vertical axis windmills, such as the Durries (built in 1930) use drag instead of lift. Drag is resistance to the wind, like a brick wall. The blades on vertical axis windmills are designed to give resistance to the wind and are as a result pushed by the wind. There have been many improvements to the windmill over the years. Windmills have been equipped with air breaks, to control speed in strong winds. Some vertical axis windmills have even been equipped with hinged blades to avoid the stresses at high wind speeds. Some windmills, like the cyclo- turbine, have been equipped with a vane that senses wind direction and causes the rotor to rotate into the wind. Wind turbine generators have been equipped with gearboxes to control [shaft] speeds. Wind turbines have also been equipped with generators which convert shaft power into electrical power. Many of the sails on windmills have also been replaced with propeller- like aerofoils. Some windmills can also stall in the wind to control wind speed. But above all of these improvements, the most important improvement to the windmill was made in 1745 when the fantail was invented. The fantail automatically rotates the sails into the wind. Most wind turbines start to generate power at 11 m/s and shut down at speeds near 32m/s. Another variable of the windmill's efficiency is its swept area. The swept area of a disc shaped wind wheel is calculated as: Area equals pi times diameter squared divided by four (pi equals 3.14).Another variable in the productivity of a windmill is the wind speed. The wind speed is measured by an anemometer. Another necessity for a windmill is the tower. There are many types of editor@iaeme.com

3 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M towers. Some towers have guy wire to support them and others don't. The towers without guy wires are called freestanding towers. Something to take into consideration about a tower is that it must support the weight of the windmill along with the weight of the tower. 2. SCOPE OF WORK To utilize the available wind resources and to reduce the usage of non-renewable energy resources. Wind energy is by far the fastest-growing renewable energy resource. The wind energy industry so far has been supported by market incentives backed by government policies fostering sustainable energy resources. Large-scale wind facilities approaching the output rating of conventional power plants, control of the power quality is required to reduce the adverse effects on their integration into the network. These wind turbines can be used to provide constant lighting. Building s rooftops can be an excellent location for this type of wind mill, both because the electric power generation is close to the user and because they allow taking advantages of faster winds and also it is possible for generating power in rural areas and hilly tops where electric transmission lines are difficult to reach. It can be installed in more locations like highways, in parking areas etc. 3. LITERATURE REVIEW The forces and the velocities acting in a Darrieus turbine are depicted. The resultant velocity vector W, is the vectorial sum of the undisturbed upstream air velocity U, and the velocity vector of the advancing blade. Types of vertical axis wind turbines are as follows Darrieus Wind Turbine Commonly described as Eggbeater turbines, or Darrieus turbines, were named after the French inventor, Georges Darrieus. They have good efficiency, but produce large torque ripple and cyclical stress on the tower, which contributes to poor reliability. They also generally require some external power source, or an additional Savonius rotor to start turning, because the starting torque is very low. The torque ripple is reduced by using three or more blades which results in greater solidity of the rotor. Solidity is measured by blade area divided by the rotor area. Newer Darrieus type turbines are not held up by guy-wires but have an external superstructure connected to the top bearing. The Darrieus design, the aerofoils are arranged so that they are symmetrical and have zero rigging angle, that is, the angle that the aerofoils are set relative to the structure on which they are mounted. This arrangement is equally effective no matter which direction the wind is blowingin contrast to the conventional type, which must be rotated to face into the wind. When the Darrieus rotor is spinning, the aerofoils are moving forward through the air in a circular path. Relative to the blade, this oncoming airflow is added vectorially to the wind, so that the resultant airflow creates a varying small positive angle of attack to the blade. This generates a net force pointing obliquely forwards along a certain line-of- action. This force can be projected inwards past the turbine axis at a certain distance, giving a positive torque to the shaft, thus helping it to rotate in the direction it is already travelling in. The aerodynamic principles which rotate the rotor are equivalent to that in autogiros, and normal helicopters in autorotation. As the aerofoil moves around the back of the apparatus, the angle of attack changes to the opposite sign, but the generated force is still obliquely in the direction of rotation, because the wings are symmetrical and the rigging angle is zero. The rotor spins at a rate unrelated to the editor@iaeme.com

4 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets windspeed, and usually many times faster. The energy arising from the torque and speed may be extracted and converted into useful power by using an electrical generator. The blades of a Darrieus turbine can be canted into a helix, e.g. three blades and a helical twist of 60 degrees, similar to Gorlov s water turbines The aeronautical terms lift and drag are, strictly speaking, forces across and along the approaching net relative airflow respectively, so they are not useful hereunder rare conditions, Darrieus rotors can self-start, so some form of brake is required to hold it when stopped. A Darrieus wind turbine used to generate electricity on the Magdalen Islands Giromill A subtype of Darrieus turbine with straight, as opposed to curved, blades. The cycloturbine variety has variable pitch to reduce the torque pulsation and is self-starting.the advantages of variable pitch are: high starting torque; a wide, relatively flat torque curve; a lower blade speed ratio; a higher coefficient of performance; more efficient operation in turbulent winds; and a lower blade speed ratio which lowers blade bending stresses. Straight, V, or curved blades may be used. Giromill VAWTs are also self-starting. Figure 1 Orking of Darrieus Wind Turbine 3.2. Savonius Wind Turbine Savonius turbines are one of the simplest turbines. Aerodynamically, they are dragtype devices, consisting of two or three scoops. Looking down on the rotor from above, a two-scoop machine would look like an S shape in cross section. Because of the curvature, the scoops experience less the drag when moving against the wind than when moving with the wind. The differential drag causes Savonius turbine to spin. Because they are drag-type devices, Savonius turbines extract much less of the wind s power than other similarly-sized lift-type turbines. Much of the swept area of a Savonius rotor may be near the ground, if it has a small mount without an extended post, making the overall energy extraction less effective due to the lower wind speeds found at lower heights Advantages of Savonius Turbines Savonius turbines are used whenever cost or the reliability is much more important than efficiency. For example, most anemometers are Savonius turbines, because efficiency is completely irrelevant for that application. Much larger Savonius turbines have been used to generate electric power on deep-water buoys, which need small amounts of power and get very little maintenance. Design is simplified because, editor@iaeme.com

5 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M unlike with Horizontal Axis Wind Turbines (HAWTs), no pointing mechanism is required to allow for shifting wind direction and the turbine is self-starting. They can sometimes have long helical scoops, to give smooth torque. The most ubiquitous application of the Savonius wind turbine is the Flettner Ventilator which is commonly seen on the roofs of vans and buses and is used as a cooling device. The ventilator was developed by the German aircraft engineer Anton Flettner in the 1920s. It uses the Savonius wind turbine to drive an extractor fan. The vents are still manufactured in the UK by Flettner Ventilator Limited Small Savonius wind turbines are sometimes seen used as advertising signs where the rotation helps to draw attention to the item advertised. They sometimes feature a simple two- frame animation. 4. CHARACTERSTICS AND SPECIFICATIONS OF WIND TURBINES The Source of Winds In a macro-meteorological sense, winds are movements of air masses in the atmosphere mainly originated by temperature differences. The temperature gradients are due to uneven solar heating. In fact, the equatorial region is more irradiated than the polar ones. Consequently, the warm and lighter air of the equatorial region rises to the outer layers of the atmosphere and moves towards the poles, being replaced at the lower layers by a return flow of cooler air coming from the Polar Regions. This air circulation is also affected by the Coriolis forces associated with the rotation of the Earth. In fact, these forces defect the upper flow towards the east and the lower flow towards the west. Actually, the effects of differential heating dwindle for latitudes greater than 30ºN and 30ºS, where westerly winds predominate due to the rotation of the Earth. These large-scale air flows that take place in all the atmosphere constitute the geostrophic winds. The lower layer of the atmosphere is known as surface layer and extends to a height of 100 m. In this layer, winds are delayed by frictional forces and obstacles altering not only their speed but also their direction. This is the origin of turbulent flows, which cause wind speed variations over a wide range of amplitudes and frequencies. Additionally, the presence of seas and large lakes causes air masses circulation similar in nature to the geostrophic winds. All these air movements are called local winds The Power of Wind The power in the wind can be computed by using the concepts of kinetics. The wind mill works on the principle of converting kinetic energy of the wind to mechanical energy. The kinetic energy of any particle is equal to one half its mass times the square of its velocity Wind Speed This is very important to the productivity of a windmill. The wind turbine only generates power with the wind. The wind rotates the axis (horizontal or vertical) and causes the shaft on the generator to sweep past the magnetic coils creating an electric current editor@iaeme.com

6 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets 4.3. Blade Length This is important because the length of the blade is directly proportional to the swept area. Larger blades have a greater swept area and thus catch more wind with each revolution. Because of this, they may also have more torque 4.4. Base height The height of the base affects the windmill immensely. The higher a windmill is, the more productive it will be due to the fact that as the altitude increases so does the winds speed Base Design Some base is stronger than others. Base is important in the construction of the windmill because not only do they have to support the windmill, but they must also be subject to their own weight and the drag of the wind. If a weak tower is subject to these elements, then it will surely collapse. Therefore, the base must be identical so as to insure a fair comparison. Figure 2 Block Diagram of Vertical Axis Wind Turbine 5. INDIAS MARKET OVERVIEW OF WIND ENERGY OVERVIEW The development of wind power in India began in the 1990s, and has significantly increased in the last few years. Although a relative newcomer to the wind industry compared with Denmark or the US, India has the fifth largest installed wind power capacity in the world. In India s growth rate is highest among the other top four countries. The worldwide installed capacity of wind power reached 157,899 MW by the end of USA (35,159 MW), Germany (25,777 MW), Spain (19,149 MW) and China (25,104 MW) are ahead of India in fifth position. The short gestation periods for installing wind turbines, and the increasing reliability and performance of wind energy machines has made wind power a favoured choice for capacity addition in India. India has a vast supply of renewable energy resources. India has one of the world s largest programs for deployment of renewable energy products and systems 3,700 MW from renewable energy sources installed editor@iaeme.com

7 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M Table I Capacity of Indias Wind Powerplants States with potential Potential MW Installed MW Andra Pradesh Gujarat Madya Pradesh Maharashtra Orissa Karnataka Rajastan Tamil Nadu West Bengal MATERIALS USAGE IN CURRENT WIND TURBINES A wide range of materials are used in wind turbines. There are substantial differences between small and large machines and there are projected changes in designs that will accommodate the introduction of new material technologies and manufacturing methods. To arrive at a total, the material usage is weighted by the estimated market share of the various manufacturers and machines types. In general the materials used for wind turbines are Steel, Aluminium, Copper and PVC Pipes In this project we have used Aluminium discs and PVC Pipes. The following are certain important properties present in the materials Young s modulus Its defined as the ratio of stress and strain, where the strain does not have units. Therefor youngs modulus has the units of stress, N/mm2, MPa, GPa The value for PVC is 10 GPa Hooke s law This law states that stress is directly proportional to strain within the elastic limit. Yield stress it is the value of stress at which the material continues to deform at constant load conditions. The value for PVC Pipe is 20MPa Ultimate stress It is the maximum stress induced in the specimen and it occurs in the plastic region. The value for PVC Pipe is 6.89 MPa Fracture Stress As the reduction in cross sectional area continues, the load bearing capacity of specimen reduces gradually. At a certain stage cross sectional of specimen is so small that it cannot sustain the load and hence it breaks. The stress at which the specimen breaks is known as fracture stress. It is generally less than ultimate stress for ductile and plastics materials Hardness It is the measure of resistance to penetration and abrasion, which is a function of stress required to produce some specified type of failure. It is generally expressed as a number. Toughness The ability of material to absorb energy in the plastic range is editor@iaeme.com

8 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets known as toughness. Toughness per unit volume of the material is known as modulus of toughness. 7. PRINCIPLE OF GENERATOR OPERATION 7.1. Generator The generator uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct electric current through Faraday s law of induction. A dynamo machine consists of a stationary structure, called the stator, which provides a constant magnetic field, and a rotating winding called armature which turn within that field. The motion of the wire within the magnetic field causes the field to push on the electrons in the metal, creating an electric current in the wire. On small machines constant magnetic field may be provided by one or more permanent magnets; larger machines have constant the magnetic field provided by one or more electromagnets, which are usually called field coils. The commutator was needed to produce direct current. When a loop wire rotates in a magnetic field, the potential induced in it reverses with each half turn generating an alternating current. However, in early days of electric experimentation, alternating current generally no known use. The few uses for electricity, such as electroplating, used direct current provided by messy liquid batteries. The generation of electricity by a dynamo is based on a principle of magnetism called induction. When the lines of force that pass from the north to the south pole of a magnet are cut by a wire there is produced or induced in the wire a current of electricity. That is, if we take a loop or coil of wire which has no current in it and a magnet which also has no current, and move the loop or coil between the poles, a momentary current is produced. If a series of loops or coils are used instead of one loop, a current may be generated continuously. This method of generating electric current is called induction. Figure 3 Magnetic Field Showing Loop of Wire Rotating Between the North (N) and South (S) Poles of A Magnet 7.2. Direction of an Induced Current The direction of an induced current depends upon two factors: (1) the direction of the motion of the wire, and (2) the direction of the magnetic lines of force. A very valuable method of determining the direction of current used in practical life is called Fleming's Rule. Place the thumb, forefinger, and center finger of the right hand so as to form right angles to each other. If the thumb points in the direction of the motion of the wire, and the fore finger in the direction of the magnetic lines of force, the center finger will point in the direction of the induced current. It is very important to know editor@iaeme.com

9 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M the direction of the current in revolving a loop of wire between the poles of a magnet in order to understand the working of a generator. The loop of wire between the poles of the magnet. If the loop is rotated to the right, as indicated by the arrow head, the wire XB moves down during the first half of the revolution. As the result of the first half of the revolution, the current would flow in the direction AYBX. Repeat the reasoning for the second half of the revolution. Notice that for every complete revolution, the current reverses its direction twice. As the strength of the current depends upon the number of lines of force cut, so the induced electromotive force starts at zero, goes to a maximum, and then back to zero in the first half-turn. That is, the induced electromotive force reaches its maximum when the loop is in a horizontal position because it cuts the most lines of force at this position. It cuts the least number of lines of force at the beginning and at the end of each half-vertical revolution. 8. DESIGN OF WIND TURBINE 8.1. Design of Blade Wind turbine blades have on aero foil type cross section and a variable pitch. While designing the size of blade it is must to know the weight and cost of blades. In the project nine blades with vertical shaft are used, it has a height and width of 100cm and 6inch respectively. So if one Blade moves other blades comes in the position of first blade, so the speed is increases. Since we are making a low cost wind turbine, the blades are made using PVC pipes. Figure 4 Design of Blades 8.2. Shaft Designing While designing the shaft of blades it should be properly fitted to the blade. The shaft should be as possible as less in thickness and light in weight for the nine blade, the shaft used is very thin in size are all properly fitted. So no problem of slipping and fraction is created, we are cycle rims at the top and bottom side they are easily available, cheap and works perfectly. Length of shaft is 1m editor@iaeme.com

10 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets Figure 5 Shaft Designing 8.3. Design of Bearing For the smooth operation of Shaft, bearing mechanism is used. To have very less friction loss the two ends of shaft are pivoted into the same dimension bearing. The Bearing has diameter of 2.54cm. Bearing are generally provided for supporting the shaft and smooth operation of shaft. We have used ball bearings for the purpose of ease of maintenance An Electric Dynamo For generation of electricity from the designed our vertical axis wind turbine, we chose generator that can be made by our surrounding materials. We select an old ceiling fan, since it have the windings in it. We remove the rotating aluminium disk ie the rotor and placed permanent magnets (neodymium) between the air gaps.14 magnets were placed according to the coils and closed the fan. Figure 6 Ceiling Fan with Magnet Placed editor@iaeme.com

11 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M Table 2 Specification of Vertical Axis Wind Turbine Height Width Height Diameter Thickness Angle between blades Diameter Length Base Dimension Blade Dimensions Shaft Dimension 100cm 150cm 100cm 6 in in 40 degrees 2.54cm 100cm 9. OPERATIONS INVOLVED IN FABRICATION PROCESS 9.1. Gas Cutting A cutting torch is used to heat metal to kindling temperature. A stream of oxygen is then trained on the metal and metal burns in that oxygen and then flows out of the cut. For cutting, the set-up is a little different. A cutting torch has a 60- or 90-degree angled head with orifices placed around a central jet. The outer jets are for preheat flames of oxygen and acetylene. The central jet carries only oxygen for cutting. The use of a number of preheating flames, rather than a single flame makes it possible to change the direction of the cut as desired without changing the position of the nozzle or the angle which the torch makes with the direction of the cut, as well as giving a better preheat balance. Manufacturers have developed custom tips for Map, propane, and polypropylene gases to optimize the flames from these alternate fuel gases ARC Welding Arc welding uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes. The welding region is sometimes protected by some type of inert or semiinert gas, known as a shielding gas, and/or an evaporating filler material. The process of arc welding is widely used because of its low capital and running costs. The following gauge lengths of electrodes are used in this process 8, 10 and 12mm. The number of electrodes used in this fabrication is around electrodes Aluminium Welding Welding of aluminium is easily done and only requires a little extra equipment and skills. Extra equipment will be needed no matter what and if welding out of position it will require a journeyman skill level (that s an understatement). Aluminium welds very well with MIG and it is best used on thicker materials that are in the flat position. You can weld thinner materials and out of position but those areas are only for the highly skilled and experienced aluminium MIG Welders. In most cases even if you are an experienced welder this is going to be very difficult to learn because of the way the puddle looks and the fast travel speeds used to weld out of position editor@iaeme.com

12 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets 10. OPERATIONS MODELING OF VAWT The modelling of VAWT prototype is carried out in solid edge ST6, and this should be helpful in predict the failure of wind turbine at various load. The different parts of VAWT are shown in below Wind turbine The VAWT consists of nine blades of PVC sectioned pipes and has a diameter of 15 cm and a length of 1 m. As we consider about the weight it is the most efficient material that satisfies both strength and light weight with minimum cost. The nine blades are attached to the cycle rim with the help of nut and bolt. The rotation of the turbine is transmitted to the generator and power is generated. The turbine has the capacity to withstand 9.8 m/s velocity of wind. Since the power developed in wind turbine is directly proportional to cubic times of velocity of air and area of blades. Figure 7 Wind Turbine Joining between Blades and Rim The blades are attached to the rim though the nut and bolt. The bolts has length of 30 mm and 10mm diameter. Each blades consists of 8 nut and bolt joints. The nut and bolts are attached to the rim with help of a 3mm thickness metal plate editor@iaeme.com

13 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M Figure 8 Joining Between Blades and Rim Pulley A driven pulley is attached on the top of the generator. The driven pulley has a diameter of 10 cm and the driver pulley has a diameter of 6cm. the center to center distance between the pulley and turbine is made adjustable and we take the mean distance as 90cm. there is also a mechanism for adjusting the height of the generator through a lever mechanism. Figure 9 Pulley editor@iaeme.com

14 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets Belt Drive There is a belt drive that connected between the wind turbine and the driven pulley that is connected with the generator. Round belt is used as the transmission drive, because the area of contact is minimum and high efficient and cost effective. The length of the belt is 296 cm which can be find from the below equation. L= π (r1 + r2) + 2x + [(r1 r2)2/x] (1) Where x = center to center distance between the driver and the driven pulley. The angle of contact of the assembly is degree which can be calculated from the below equation. Ø = (180-2α) π/180 (2) Figure 10 Belt drive 11. THEORTICAL CALCULATIONS The wind mill works on the principle of converting kinetic energy of the wind to mechanical energy. The kinetic energy of any particle is equal to one half its mass times the square of its velocity, or mv 2 K.E = mv2 (3) K.E = kinetic energy m = mass v = velocity M is equal to its Volume multiplied by its density of air M = AV (4) Substituting equation (4) in equation (3) we get KE = AV.V 2 KE = AV 3 watts P= ρav 3 / 2 (5) P= power of the turbine ρ= density of air (1.225 kg/m3) A= Area of air in m 2 V= Velocity of striking air m/s A = length*breadth (m 2 ) A = πdl/2 (6) editor@iaeme.com

15 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M D = Diameter of the blade (m L = Length of the blade (m) 12. ANALYSIS OF VAWT Analysis of wind turbine blades are conducted in solid edge ST6. It gives maximum stress that can withstand, and the deflection diagram at maximum principle stress. Analysis conducted on blade material gives positive results Result of Analysis (a) The optimum power is generated when the wind is blow at 4 to 5m per second and deflection is minimum at this speed. The stress value that develop in the joining portion is found to be the maximum and its value is 5.65 MPa. Which is less than the ultimate stress. (b) The failure of the turbine blades occur, when the wind blows at a speed of 9.8 m/s and the deflection of the blades are maximum and the von misses stress is 6.9 MPa. At this condition a cracking on the joining face of the blades will occur. 13. STORAGE SYSTEM Figure 11 Analysis of Blades Inverter A power inverter, or inverter, is an electronic device or circuitry that changes direct current (DC) to alternating current(ac) The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or circuitry. The inverter does not produce any power; the power is provided by the DC source. A power inverter can be entirely electronic or may be a combination of mechanical effects (such as a rotary apparatus) and electronic circuitry. Static inverters do not use moving parts in the conversion process Batteries The runtime of an inverter is dependent on the battery power and the amount of power being drawn from the inverter at a given time. As the amount of equipment using the inverter increases, the runtime will decrease. In order to prolong the runtime of an inverter, additional batteries can be added to the inverter. Battery used for this construction is Lead Acid Battery editor@iaeme.com

16 Low Expense Vertical Axis Wind Turbine Using Permanent Magnets Figure 11 Block Diagram For The Battery And Inverter Setup 14. ADVANTAGE OF VERTICAL AXIS WIND TURBINE OVER HORIZONTAL AXIS WIND TURBINE There are several reasons why we would choose a vertical axis wind turbine over a horizontal axis windmill. 1. They are mounted lower to the ground making it easy for maintenance if needed 2. They start creating electricity at speeds of only 6 mph. 3. They may be able to build at locations where taller structures, such as the horizontal type can t 4. Higher power utilization 5. Lower noise level only DB, suitable for your living condition. 6. Safer operation Spin at slower speeds than horizontal turbines, decreasing the risk of Injuring birds and also decreasing noise level. 7. Simpler installation and maintenance besides the traditional installation site, it can be Mounted directly on a rooftop, doing away with the tower and associated guy lines. 8. Not affected by orientation variation no matter the wind blow from any orientation, VAWT can work without regard to its face. Economical and practical-although onetime investment expenses are larger, but you don t have to pay higher tariffs forever. 15. CONCLUSION Our work and the results obtained so far are very encouraging and reinforce the conviction that vertical axis wind energy conversion systems are practical and potentially very contributes to the production of clean renewable electricity from the wind even under less than ideal sitting conditions. It is hoped that they may be constructed used high-strength, low- weight materials for deployment in more developed nations and settings or with very low tech local materials and local skills in less developed countries. The Savonius wind turbine designed is ideal to be located on top of a bridge or bridges to generate electricity, powered by wind. The elevated altitude gives it an advantage for more wind opportunity. With the idea on top of a bridge, it will power up street lights and or commercial use. In most cities, bridges are a faster route for everyday commute and in need of constant lighting makes this an efficient way to produce natural energy. REFERENCES [1] Ashraf Ahmed, Student Member, IEEE, Li Ran, Senior Member, IEEE, and Jim R. Bumby New Constant Electrical Power Soft-Stalling Control for Small-Scale VAWTs IEEE TRANS- Actions On Energy Conversion, VOL. 25, NO. 4, DECEMBER editor@iaeme.com

17 Ramu S, Abhilash M, Ajay M, Aravind S and Hariprasad M [2] Guoying Feng Zhizhang Liu, Bao Daorina, Zheng Gong School of Energy and Power Engi- neering Inner Mongolia University of Technology Hohhot, China. Experimental Research on Vertical Axis Wind Turbine 2009 IEEE. [3] Shengmao Li Engineering College Northeast Agricultural University Yan Li Engineering Col- lege Northeast Agricultural University Harbin, China Numerical study on the performance effect of solidity on the straight-bladed vertical axis wind turbine IEEE. [4] Yi Guo, S. Hossein Hosseini, John N. Jiang, and Choon Yik Tang Voltage/Pitch Control for Maximization and Regulation of Active/Reactive Powers in Wind Turbines with Uncertain- ties t49th IEEE Conference on Decision and Control December 15-17, 2010 Hilton Atlanta Hotel, Atlanta, GA, USA. [5] Jianzhong Zhang, Ming Cheng, Zhe Chen, Xiaofan Fu Pitch Angle Control for Variable Speed Wind Turbines DRPT April 2008 Nanjing China. [6] Faculty of Electrical Engineering, Automatic Control and Computer Science Opole Univer- sity of Technology.Tomasz Boczar Faculty of Electrical Engineering, Automatic Control and Computer Science Opole University of Technology Analysis of low- frequency acoustic signals emitted by low-power vertical axis wind turbine VAWT IEEE. [7] H. M. Hassan*, W. A. Farag, M. S. Saad, and Abdel Latif Elshafei Robust Dynamic Output Feedback Pitch Control for Flexible Wind Turbines 2012 IEEE [8] E. Muljadi C.P. Butterfield National Wind Technology Center National Renewable Energy Laboratory (NREL). PITCH-CONTROLLED VARIABLE- SPEED WIND TURBINE GENERATION Proceedings of Windpower 94, W, May 10-13, 1994, Washington D.C.: American Wind Energy Association; pp [9] Lei SONG, Zong-Xiao YANG*, Rui-Tao DENG Institute of Systems Science and Engineer- ing, Henan Engineering Laboratory of Wind Power Systems Henan University of Science and Technology,Xiao-Guang YANG Overall Department Performance and Structure Optimization for a New Type of Vertical Axis Wind Turbine Proceedings of the 2013 International Conference on Advanced Mechatronic Systems, Luoyang, China, September 25-27, [10] Wei Kou, Xinchun Shi, Bin Yuan, Lintao Fan Department of Electrical Engineering North China Electric Power University Modeling Analysis and Experimental Research on a Combined-Type Vertical Axis Wind Turbine 2011 IEEE. [11] M.Z.I.Sajid, Dr. K. Hema Chandra Reddy and Dr.E.L. Nagesh, Design of Vertical Axis Wind Turbine for Harnessing Optimum Power. International Journal of Mechanical Engineering and Technology, 4(2), 2013, pp [12] Iessa Sabbe MOOSA, Powder Metallurgy and Its Application In The Production of Permanent Magnets. International Journal of Mechanical Engineering and Technology, 4(6), 2013, pp [13] Piyush Gulve and Dr. S.B.Barve, Design and Construction of Vertical Axis Wind Turbine. International Journal of Mechanical Engineering and Technology, 5(10), 2014, pp [14] Placide JAOHINDY1, Franois GARDE1, Alain BASTIDE1. Aerodynamic and MechanicalSystem Modeling of a vertical axis wind turbine (VAWT) 2011 IEEE. [15] Tingna Shi1, Zhiyong Wu1, Ruying Gao2, Zhanfeng Song1, Changliang Xia1,3 1Department of Electrical Engineering and Automation, Tianjin University, Study on Independent Blade Pitch Control for Huge Wind Turbines Wind Energy, No.8, pp , editor@iaeme.com