Abstract Abstract
This paper presents an overview of the maglev wind turbine design features. A vertical axis wind This paper presents an overview of the maglev wind turbine design features. A vertical axis wind turbine (VAWT) is introduced by magnetic levitation technology to optimize the performance. The turbine (VAWT) is introduced by magnetic levitation technology to optimize the performance. The system utilize nature of permanent magnet to levitate the turbine component and thus minimize system utilize nature of permanent magnet to levitate the turbine component and thus minimize energy losses while rotating, which is the major problem that faced by conventional wind turbine. energy losses while rotating, which is the major problem that faced by conventional wind turbine. The selection of magnet materials in the design of wind turbine system will be discussed. The selection of magnet materials in the design of wind turbine system will be discussed. The Maglev
The Maglev Wind Turbine is expected to bring wind power technology to the next level.Wind Turbine is expected to bring wind power technology to the next level. Furthermore, the system can be suited in use for rural and urban areas of low wind speed regions Furthermore, the system can be suited in use for rural and urban areas of low wind speed regions such as Malaysia, the country which has low wind speed, approximately 1.5m/s to 2.0m/s. A model such as Malaysia, the country which has low wind speed, approximately 1.5m/s to 2.0m/s. A model of wind turbine is built to perform several tests such as starting wind speed, rotational speed at of wind turbine is built to perform several tests such as starting wind speed, rotational speed at constant wind speed, and time taken to stop rotation completely. The results obtained will be constant wind speed, and time taken to stop rotation completely. The results obtained will be compared with the model of conventional wind turbine.
CHAPTER 1 CHAPTER 1 INTRODUCTION INTRODUCTION 1.1 General 1.1 General
Human have invented thousand of machines and appliances that utilize energy to make the daily Human have invented thousand of machines and appliances that utilize energy to make the daily works easier, for instance to heat our house, to get ourselves from place to place. Some of this works easier, for instance to heat our house, to get ourselves from place to place. Some of this machines use electricity, while others, like automobiles use the energy stored in gasoline. Much of machines use electricity, while others, like automobiles use the energy stored in gasoline. Much of the energy supply comes from coal, oil, natural gas, or radioactive element. In fact, all these natural the energy supply comes from coal, oil, natural gas, or radioactive element. In fact, all these natural resource deposits took millions of years to form. They are considered non renewable which means resource deposits took millions of years to form. They are considered non renewable which means once they are removed from the ground, they are not immediately replaced within the human time once they are removed from the ground, they are not immediately replaced within the human time scale. This current issue is frequently discussed at the level of whole world in order to look for a scale. This current issue is frequently discussed at the level of whole world in order to look for a solution.
solution.
Nowadays, we will ultimately need to search for renewable or virtually inexhaustible energy for the Nowadays, we will ultimately need to search for renewable or virtually inexhaustible energy for the human development to continue. Renewable energy is defined as the energy generated by the human development to continue. Renewable energy is defined as the energy generated by the natural resources such as wi
natural resources such as wind, sun light, water which are nd, sun light, water which are quickly replace itself quickly replace itself and is usually inand is usually in never ending supply. The exploration of renewable energy is the only approach to reduce our never ending supply. The exploration of renewable energy is the only approach to reduce our dependence on fossil fuels. Among those renewable energy resources, wind energy is the only dependence on fossil fuels. Among those renewable energy resources, wind energy is the only resource that will be concerned in this paper. Wind energy was first harvested centuries ago, when resource that will be concerned in this paper. Wind energy was first harvested centuries ago, when early windmills were used to power millstones, pumps, and forges. More recently, the wind is early windmills were used to power millstones, pumps, and forges. More recently, the wind is harnessed by using a special collector, called wind turbine to produce a clean, safe source of harnessed by using a special collector, called wind turbine to produce a clean, safe source of electricity.
electricity.
Various designs have been proposed in order to create a high efficient wind turbine which able to Various designs have been proposed in order to create a high efficient wind turbine which able to generate maximum electric power. They may either the design of shapes of the turbine blades, the generate maximum electric power. They may either the design of shapes of the turbine blades, the
axis of rotation, and other useful modification. Recently, an advance technique, Magnetic Levitation axis of rotation, and other useful modification. Recently, an advance technique, Magnetic Levitation (Maglev) is incorporated into turbine system in order to fulfill the needs of those energy industries. (Maglev) is incorporated into turbine system in order to fulfill the needs of those energy industries. The
The MaglevMaglev wind turbine, which was first unveiled at thewind turbine, which was first unveiled at the Wind Power AsiaWind Power Asia exhibition in Beijing, isexhibition in Beijing, is expected take wind power technology to the next level with magnetic levitation
expected take wind power technology to the next level with magnetic levitation..The turbine usesThe turbine uses permanent magnets (neodymium), not electromagnets and therefore, it does not require electricity to permanent magnets (neodymium), not electromagnets and therefore, it does not require electricity to run. This design claims that the friction between the turbine blades and the base can be reduced run. This design claims that the friction between the turbine blades and the base can be reduced significantly and thus produces maximum power output. This task can be a success by using pairs of significantly and thus produces maximum power output. This task can be a success by using pairs of permanent magnet which attached to both the turbine blades and the fixed base of machine. A permanent magnet which attached to both the turbine blades and the fixed base of machine. A repulsive force will be produced to lift the blades above the base. The turbine blades will be repulsive force will be produced to lift the blades above the base. The turbine blades will be levitated instead of mounted them (using ball bearing) to the base of the machine. It will allow them levitated instead of mounted them (using ball bearing) to the base of the machine. It will allow them to rotate with minimum friction and minimize the energy loss. This system can operate under low to rotate with minimum friction and minimize the energy loss. This system can operate under low (as low as 1.5m/s) and high wind speed (exceeding 40m/s) condition. From the study, the generation (as low as 1.5m/s) and high wind speed (exceeding 40m/s) condition. From the study, the generation capacity of maglev wind turbine is 20% over conventional wind turbines and decrease operational capacity of maglev wind turbine is 20% over conventional wind turbines and decrease operational costs by 50%
costs by 50%..This make the efficiency of the system become higher than the conventional windThis make the efficiency of the system become higher than the conventional wind turbine.
turbine.
1.2 Objective 1.2 Objective
The objective of this report is to
The objective of this report is to design a Maglev wind turbine to design a Maglev wind turbine to meet the following requirementsmeet the following requirements
1. Improve the starting wind speed 1. Improve the starting wind speed
2. Able to rotate with high speed 2. Able to rotate with high speed
3. Longer time to stop rotation completely 3. Longer time to stop rotation completely
CHAPTER 2 CHAPTER 2 LITERATURE REVIEW LITERATURE REVIEW 2.1 Wind Energy 2.1 Wind Energy
Wind is the flowing of air. This phenomenon occurs in the whole world and it is caused by uneven Wind is the flowing of air. This phenomenon occurs in the whole world and it is caused by uneven heating on the earth’s surfaces which causes the air is flow from hotter regions with higher pressure heating on the earth’s surfaces which causes the air is flow from hotter regions with higher pressure to colder regions with lower pressure. There are some reasons to support in using the wind energy to to colder regions with lower pressure. There are some reasons to support in using the wind energy to produce electricity power. Wind power available in the atmosphere is much greater than current produce electricity power. Wind power available in the atmosphere is much greater than current world energy consumption. The exploitation of wind power is only limited by the economic and world energy consumption. The exploitation of wind power is only limited by the economic and environmental factors, since the resource available is far larger than any practical means to develop environmental factors, since the resource available is far larger than any practical means to develop it. Renewable energy produced from the wind has attracted a lot of attention and support in recent it. Renewable energy produced from the wind has attracted a lot of attention and support in recent year’s .However, this green energy is often criticized for its low output and
year’s .However, this green energy is often criticized for its low output and lack of reliability.lack of reliability.
2.2 Wind Turbine 2.2 Wind Turbine
The basic working principle of a wind turbine is: When air move quickly, in the form of wind, and The basic working principle of a wind turbine is: When air move quickly, in the form of wind, and their kinetic energy is captured by the turbine blades. The blades start to rotate and spin a shaft that their kinetic energy is captured by the turbine blades. The blades start to rotate and spin a shaft that leads from the hub of the rotor to a generator and produce electricity. The tradition generator leads from the hub of the rotor to a generator and produce electricity. The tradition generator experience lots of problem such as highly inefficient, expensive, high maintenance cost, hazardous experience lots of problem such as highly inefficient, expensive, high maintenance cost, hazardous to wildlife, and take up too much land, require high starting wind speed to operate.
to wildlife, and take up too much land, require high starting wind speed to operate.
In general, they are two types of wind turbine according to the axis they are rotating about. In general, they are two types of wind turbine according to the axis they are rotating about. Horizontal axis wind turbine (HAWT) is the type of wind turbine which has a main rotor shaft and Horizontal axis wind turbine (HAWT) is the type of wind turbine which has a main rotor shaft and electrical generator at the top of tower and pointed to the direction of wind. Most of them possess a electrical generator at the top of tower and pointed to the direction of wind. Most of them possess a gearbox which turns the slow rotation of turbine blades into faster rotation that is more suitable to gearbox which turns the slow rotation of turbine blades into faster rotation that is more suitable to
drive an electrical generator.
drive an electrical generator. As for the Vertical axis wind turbine (VAWT) consists of generator As for the Vertical axis wind turbine (VAWT) consists of generator and gearbox which are placed at the ground and thus there is no need for a tower to support them as and gearbox which are placed at the ground and thus there is no need for a tower to support them as in HAWT. The main rotor shaft is arranged vertically to allow the turbine blades rotate without in HAWT. The main rotor shaft is arranged vertically to allow the turbine blades rotate without facing to the direction of the wind.
facing to the direction of the wind.
In VAWT system, the generator and gearbox is placed on the ground rather than on the top. There is In VAWT system, the generator and gearbox is placed on the ground rather than on the top. There is no need of the support from a tower make it more accessible for maintenance. The key of vertical no need of the support from a tower make it more accessible for maintenance. The key of vertical arrangement of the rotor shaft enable the turbine blades need not to be pointed to the direction of arrangement of the rotor shaft enable the turbine blades need not to be pointed to the direction of wind. This is suitable for them to be installed on high variable wind speed region. They can utilize wind. This is suitable for them to be installed on high variable wind speed region. They can utilize wind from varying direction. In addition,
wind from varying direction. In addition, they have larger surface areas and can operate in low windthey have larger surface areas and can operate in low wind speed region compare with HAWT.
speed region compare with HAWT.
However, most of the new designs of VAWT experience some common problems. Due to the wind However, most of the new designs of VAWT experience some common problems. Due to the wind speeds are very low close to ground level, so although their arrangement may save a tower, but the speeds are very low close to ground level, so although their arrangement may save a tower, but the wind speeds will be very low on the lower part of rotor. This causes the overall efficiency of the wind speeds will be very low on the lower part of rotor. This causes the overall efficiency of the vertical axis machines is not impressive. Also, the machine need
vertical axis machines is not impressive. Also, the machine need guy-wiresguy-wires to hold it in place putsto hold it in place puts stress on the bottom bearing as all the weight of the rotor is on the bearing. Guy wires attached to stress on the bottom bearing as all the weight of the rotor is on the bearing. Guy wires attached to the top bearing increase downward thrust in wind gusts. Solving this problem requires a the top bearing increase downward thrust in wind gusts. Solving this problem requires a superstructure to hold a top bearing in place to eliminate the downward thrusts of gust events in guy superstructure to hold a top bearing in place to eliminate the downward thrusts of gust events in guy wired models.
wired models.
The idea for VAWTs has been blowing around for decades. However, VAWTs are not commonly The idea for VAWTs has been blowing around for decades. However, VAWTs are not commonly deployed due mainly to the serious disadvantages mentioned above, they appear novel to those not deployed due mainly to the serious disadvantages mentioned above, they appear novel to those not familiar with the wind industry or wind farm. This has often made them the subject of wild claims familiar with the wind industry or wind farm. This has often made them the subject of wild claims
and investment scams over the last 50 years
and investment scams over the last 50 years[3] [4][3] [4]. Despite many advance technology available so far . Despite many advance technology available so far has attracted interest about improving the VAWT s
has attracted interest about improving the VAWT s ystem.ystem.
2.3 Magnetic Levitation 2.3 Magnetic Levitation
Magnetic levitation (maglev) is a method in
Magnetic levitation (maglev) is a method in which an object is swhich an object is suspendeduspended with no support other thanwith no support other than magnetic fields
magnetic fields. The. The magnetic forcmagnetic force produced is used to counteract the effects of thee produced is used to counteract the effects of the gravitationalgravitational force
force and lift up the object. There are many advantages for utilizing magnetic levitation that is toand lift up the object. There are many advantages for utilizing magnetic levitation that is to minimize friction, make force measurement, design, and entertaining devices. Recently, this minimize friction, make force measurement, design, and entertaining devices. Recently, this advance technology is applied into transportation system in which non contacting vehicle travel advance technology is applied into transportation system in which non contacting vehicle travel safely at very high speed while suspended, guided, and propelled above a guide way by magnetic safely at very high speed while suspended, guided, and propelled above a guide way by magnetic fields. The concept of magnetically levitated vehicle stimulates the development of useful fields. The concept of magnetically levitated vehicle stimulates the development of useful application in various fields such as the po
application in various fields such as the power generation.wer generation.
2.4 Maglev Wind Turbine 2.4 Maglev Wind Turbine
Unlike the maglev vehicle, the vertically oriented blades of the wind turbine are suspended in the air Unlike the maglev vehicle, the vertically oriented blades of the wind turbine are suspended in the air above the base of the machine by using permanent magnet which produces magnetic force to lift up above the base of the machine by using permanent magnet which produces magnetic force to lift up the blades. This system does not require the electricity to operate because no electromagnets are the blades. This system does not require the electricity to operate because no electromagnets are involved. Since the turbine blades are suspended by magnetic force produce by the permanent involved. Since the turbine blades are suspended by magnetic force produce by the permanent magnet, there is no need of ball bearing to retain the blades. This allows the friction between the magnet, there is no need of ball bearing to retain the blades. This allows the friction between the blades and ball bearing can be reduced significantly and thus, minimizes the energy loss. This also blades and ball bearing can be reduced significantly and thus, minimizes the energy loss. This also
helps reduce maintenance costs and increases the lifespan of the generator. The
helps reduce maintenance costs and increases the lifespan of the generator. The MaglevMaglev windwind turbine, which was first unveiled at the
turbine, which was first unveiled at the Wind Power AsiWind Power Asia exhibition in Beijing, is expected takea exhibition in Beijing, is expected take wind power technology to the next level with magnetic levitation.
CHAPTER 3 CHAPTER 3 METHODOLOGY METHODOLOGY 3.1 Introduction 3.1 Introduction
A model of wind turbine is built for the use of an experiment to determine the starting wind speed to A model of wind turbine is built for the use of an experiment to determine the starting wind speed to operate. The arrangement of component of the model is flexible and it can be treated as maglev and operate. The arrangement of component of the model is flexible and it can be treated as maglev and conventional wind turbine.
conventional wind turbine.
The experiment contains three tests to analyze the performance of model. The first test is the wind The experiment contains three tests to analyze the performance of model. The first test is the wind speed that needed to start to rotate the turbine blades. The second test is rotational speed of wind speed that needed to start to rotate the turbine blades. The second test is rotational speed of wind turbine model under constant wind speed. The third test the time taken by the model to completely turbine model under constant wind speed. The third test the time taken by the model to completely stop rotation. The rotational speed of turbine blades and wind speed is measured by tachometer and stop rotation. The rotational speed of turbine blades and wind speed is measured by tachometer and anemometer respectively.
anemometer respectively.
3.2 Theory 3.2 Theory
A model is built using affordable material for the purpose of analysis. The type of VAWT is being A model is built using affordable material for the purpose of analysis. The type of VAWT is being used is the Savonius type wind turbine. The amount of magnetic force that needs to counteract the used is the Savonius type wind turbine. The amount of magnetic force that needs to counteract the weight of the wind turbine must b
weight of the wind turbine must be determined before the type of mae determined before the type of magnet material is selected.gnet material is selected.
From the law of attraction From the law of attraction
(1.0) (1.0)
Then, the equation is rewritten as below to calculate the magnetic force between two poles Then, the equation is rewritten as below to calculate the magnetic force between two poles
(2.0) (2.0)
Where
Where F F : : Magnetic Magnetic force, force, NN : Magnetic poles, A. m : Magnetic poles, A. m :
: PPeerrmmeeaabibilliity ty oof f ffrree ee sspapacce e 44π π xx , , NN// R
R : : Distance Distance between between two two poles, poles, mm
The magnetic poles of the magnet can be calculated by using following equation The magnetic poles of the magnet can be calculated by using following equation
(3.0) (3.0)
Where
Where : : Coercive Coercive force, force, A/mA/m : Magnetic poles, A. m : Magnetic poles, A. m A
A : : Pole Pole face face area,area,
Assuming the distance, r is constant. Then from the equations (2.0) and (3.0), the equation can be Assuming the distance, r is constant. Then from the equations (2.0) and (3.0), the equation can be rearranged
rearranged
(4.0) (4.0)
According to the equilibrium of forces, According to the equilibrium of forces,
(5.0) (5.0)
(6.0) (6.0)
Where
Where : : Magnetic Magnetic force, force, NN
m
m : : total total mass mass of of the the wind wind turbine turbine that that need need to to be be levitate, levitate, kgkg g
Figure 1: Free body diagram of magnetically l
Figure 1: Free body diagram of magnetically levitated objectevitated object
Therefore, the magnetic force must have equal forces to the weight of the wind turbine so that it will Therefore, the magnetic force must have equal forces to the weight of the wind turbine so that it will levitate. Also, the type of magnet materials with known characteristics can be determined using the levitate. Also, the type of magnet materials with known characteristics can be determined using the above equation provided the weight of model that needs to be levitated.
above equation provided the weight of model that needs to be levitated.
The conventional wind turbine is made by removing the magnet attached to both fixed base and The conventional wind turbine is made by removing the magnet attached to both fixed base and turbine blades, and replacing with a ball bearing.
3.3 CAD Drawings 3.3 CAD Drawings
Figure 2: Modeling of Maglev Wind Turbine Figure 2: Modeling of Maglev Wind Turbine
3.4 Bill of Materials 3.4 Bill of Materials
Part Material
Part Material
1.
1. Shaft Shaft Stainless Stainless SteelSteel 2.
2. Wind Wind Turbine Turbine CardboardCardboard 3.
3. Permanent Permanent Magnet Magnet Ceramics MagnetCeramics Magnet 4.
4. Fixed Fixed Base Base WoodWood
1 1 2 2 3 3 4 4 1. Shaft 1. Shaft 2. Wind Turbine 2. Wind Turbine 3. Permanent 3. Permanent Magnet Magnet 4. Fixed Base 4. Fixed Base
3.5 Procedures 3.5 Procedures
Test 1: The starting wind speed of wind
Test 1: The starting wind speed of wind turbine modelturbine model
1. The model is assembled to be the maglev wind turbine 1. The model is assembled to be the maglev wind turbine
2. A fan is placed in
2. A fan is placed in the direction parallel to the maglev the direction parallel to the maglev wind turbine model.wind turbine model.
3. The fan is switched on and the wind produced is directed to the model. 3. The fan is switched on and the wind produced is directed to the model.
4. The model is replaced by anemometer and the fan is switched on again. The wind speed is 4. The model is replaced by anemometer and the fan is switched on again. The wind speed is recorded
recorded
5. The test is repeated by using conventional wind turbine model. 5. The test is repeated by using conventional wind turbine model.
Test 2: The rotational speed of wind turbine model at constant wind speed Test 2: The rotational speed of wind turbine model at constant wind speed
1. The steps 1 until 4
1. The steps 1 until 4 in test 1 are repeated. The in test 1 are repeated. The wind speed is measured by using anemowind speed is measured by using anemometer.meter.
2. The reading of rotational
2. The reading of rotational speed of model is recoded after 1 speed of model is recoded after 1 minute for five times.minute for five times.
3. The test is repeated by using conventional wind turbine model. The distance between the maglev 3. The test is repeated by using conventional wind turbine model. The distance between the maglev
and conventional wind turbine model with the fan is made sure to be the same. and conventional wind turbine model with the fan is made sure to be the same.
Test 3: The time taken b
Test 3: The time taken by wind turbine model to stop rotationy wind turbine model to stop rotation
1. The steps 1 until 3
1. The steps 1 until 3 in test 1 are repeated.in test 1 are repeated.
2. The fan is then switch
2. The fan is then switch off after 5 minutes and a card bock off after 5 minutes and a card bock is placed in front of it.is placed in front of it.
3. The time at which the
3. The time at which the model to stop its rotation completely is recorded.model to stop its rotation completely is recorded.
4. Steps 2 and 3
4. Steps 2 and 3 are repeated for two times.are repeated for two times.
5. The test is repeated by using conventional wind turbine model. 5. The test is repeated by using conventional wind turbine model.
CHAPTER 4 CHAPTER 4
RESULTS AND DISCUSSIONS RESULTS AND DISCUSSIONS
4.1 Results 4.1 Results
Test 1: The starting wind speed of wind
Test 1: The starting wind speed of wind turbine modelturbine model
Wind
Wind Turbine Turbine Model Model Starting Starting Wind Wind Speed Speed (m/s) (m/s) Average Average (m/s)(m/s) Maglev
Maglev 1.9 1.9 1.5 1.5 1.4 1.4 1.601.60 Conventional
Conventional 4.2 4.2 4.5 4.5 4.6 4.6 4.594.59
Test 2: The rotational speed of wind turbine model at constant wind speed of 5.63 m/s Test 2: The rotational speed of wind turbine model at constant wind speed of 5.63 m/s
Wind
Wind Turbine Turbine Model Model Rotational Rotational Speed Speed (RPM) (RPM) AverageAverage (RPM) (RPM) Maglev Maglev 666.00 666.00 666.00 666.00 630.00 630.00 618.00 618.00 630.00 630.00 640.80640.80 Conventional Conventional 292.80 292.80 294.00 294.00 235.80 235.80 270.00 270.00 237.00 237.00 265.92265.92
Test 3: The time taken b
Test 3: The time taken by wind turbine model to stop rotationy wind turbine model to stop rotation
Wind
Wind Turbine Turbine Model Model Time Time Taken Taken (s) (s) Average Average (s)(s) Maglev
Maglev 14.1 14.1 15.7 15.7 13.7 13.7 14.514.5 Conventional
4.2 Discussion 4.2 Discussion
From the test 1, the wind turbine model with magnetic levitation starts to rotate at lower From the test 1, the wind turbine model with magnetic levitation starts to rotate at lower wind speed than that of
wind speed than that of conventional wind turbine, which is 1.6m/s anconventional wind turbine, which is 1.6m/s and 4.59m/s respectively.d 4.59m/s respectively.
Most of the existing wind turbine requires high starting wind speed to operate. They are not suitable Most of the existing wind turbine requires high starting wind speed to operate. They are not suitable used to generate electricity power in certain country such as Malaysia, which has low and unsteady used to generate electricity power in certain country such as Malaysia, which has low and unsteady wind speed. Therefore, starting wind speed becomes an important element that must be included in wind speed. Therefore, starting wind speed becomes an important element that must be included in the design of wind turbine. The concept of maglev wind turbine is introduced to fulfill this the design of wind turbine. The concept of maglev wind turbine is introduced to fulfill this requirement.
requirement.
Maglev wind turbine is able to start to rotate at lower wind speed compare with conventional wind Maglev wind turbine is able to start to rotate at lower wind speed compare with conventional wind turbine. This can be explained in terms of friction force. In general, there are two friction force exist turbine. This can be explained in terms of friction force. In general, there are two friction force exist in an operating wind turbine. Since the turbine blades are attached to the shaft by using ball bearing, in an operating wind turbine. Since the turbine blades are attached to the shaft by using ball bearing, a friction force is produced between them. Also, there is another friction forces exist between the a friction force is produced between them. Also, there is another friction forces exist between the turbine blades and the fixed base.
turbine blades and the fixed base. In wind turbine In wind turbine with magnetic levitation, the latwith magnetic levitation, the latter one can beter one can be eliminate because the turbine blades are lift up by magnetic force. This wind turbine need only eliminate because the turbine blades are lift up by magnetic force. This wind turbine need only overcome the moment inertia and friction forces between the shaft and bearing before it start to overcome the moment inertia and friction forces between the shaft and bearing before it start to rotate.
rotate. Instead, the Instead, the conventional wind turbine conventional wind turbine needs to overcome needs to overcome moment inertia and moment inertia and both theboth the friction forces, and thus needs higher wind speed which results in more energy to start to rotate. In friction forces, and thus needs higher wind speed which results in more energy to start to rotate. In addition, magnetic levitation wind turbine requires less maintenance compare with the conventional addition, magnetic levitation wind turbine requires less maintenance compare with the conventional wind turbine. This is because the disadvantage of using bearing is it will wear off as the time goes wind turbine. This is because the disadvantage of using bearing is it will wear off as the time goes on. Therefore, the bearing needs to be replaced after some time so that the wind turbine is operating on. Therefore, the bearing needs to be replaced after some time so that the wind turbine is operating efficiently.
From test 2, the maglev wind turbine model has a higher rotating speed than the From test 2, the maglev wind turbine model has a higher rotating speed than the conventional wind turbine under constant wind speed of 5.63m/s. The rotational speeds of maglev conventional wind turbine under constant wind speed of 5.63m/s. The rotational speeds of maglev wind turbine and conventional wind turbine are 10.68rpm and 4.43rpm. This result can be explained wind turbine and conventional wind turbine are 10.68rpm and 4.43rpm. This result can be explained in terms of energy conversion. According to the law of energy conservation, part of kinetic energy in terms of energy conversion. According to the law of energy conservation, part of kinetic energy in flowing wind is converted into kinetic energy due to rotating turbine blades, and then produces in flowing wind is converted into kinetic energy due to rotating turbine blades, and then produces electric energy. However, the arrangement of the components of wind turbine limits this conversion electric energy. However, the arrangement of the components of wind turbine limits this conversion and results in energy loss in terms of heat and sound. The following equation can be used to and results in energy loss in terms of heat and sound. The following equation can be used to illustrate this phenomenon.
illustrate this phenomenon.
The total kinetic energy of flowing wind suppl
The total kinetic energy of flowing wind supply to wind turbiney to wind turbine
∆Kinetic Energy (flowing wind) = kinetic energy (wind before entering wind turbine) - Kinetic ∆Kinetic Energy (flowing wind) = kinetic energy (wind before entering wind turbine) - Kinetic
Energy (wind after exiting wind turbine) Energy (wind after exiting wind turbine)
According to law of energy conservation According to law of energy conservation
∆Kinetic Energy (flowing wind) - kinetic energy (rotating turbine blades) – Energy Loss = 0 ∆Kinetic Energy (flowing wind) - kinetic energy (rotating turbine blades) – Energy Loss = 0
And therefore, And therefore,
∆Kinetic Energy (flowing wind) = kinetic energy (rotating turbine blades) + Energy Loss ∆Kinetic Energy (flowing wind) = kinetic energy (rotating turbine blades) + Energy Loss
Figure 3: Conversion of energy in M
Figure 3: Conversion of energy in Maglev Wind turbineaglev Wind turbine
Therefore, the conventional wind turbine experiences much energy loss in term of heat and sound. Therefore, the conventional wind turbine experiences much energy loss in term of heat and sound. More kinetic energy is needed to overcome the friction forces exist between the bearings attached to More kinetic energy is needed to overcome the friction forces exist between the bearings attached to the turbine blades and bottom. This make the rotational speed of conventional wind turbine become the turbine blades and bottom. This make the rotational speed of conventional wind turbine become lower than the maglev one. Higher rotational speed means higher kinetic energy of rotating turbine lower than the maglev one. Higher rotational speed means higher kinetic energy of rotating turbine blades and hence more electric energy can be generated by maglev wind turbine.
blades and hence more electric energy can be generated by maglev wind turbine.
From test 3, the maglev wind turbine model take a longer time to stop its rotation completely From test 3, the maglev wind turbine model take a longer time to stop its rotation completely compare to conventional one. This test is carried out under the same wind speed. The time taken by compare to conventional one. This test is carried out under the same wind speed. The time taken by both the maglev wind turbine and conventional wind turbine to stop their rotation is 14.5s and 1.5s both the maglev wind turbine and conventional wind turbine to stop their rotation is 14.5s and 1.5s respectively. Since the flowing of wind is unpredictable and varies all the time. The wind may come respectively. Since the flowing of wind is unpredictable and varies all the time. The wind may come to a lower speed and even stop at every instant of time. Higher stopping time is desired because the to a lower speed and even stop at every instant of time. Higher stopping time is desired because the wind turbine can still rotate at lower speed in longer time when the speed of flowing wind decrease. wind turbine can still rotate at lower speed in longer time when the speed of flowing wind decrease. And when the wind speed increases, the wind turbine immediately rotate faster without achieve the And when the wind speed increases, the wind turbine immediately rotate faster without achieve the starting wind speed (if wind turbine stop in few seconds).
Selection of suitable hard or permanent magnet becomes an important consideration in the Selection of suitable hard or permanent magnet becomes an important consideration in the design of a maglev wind turbine. However, due to the cost limitation, the ceramics magnet material design of a maglev wind turbine. However, due to the cost limitation, the ceramics magnet material is used to construct the model. It is benefited if the characteristics of permanent magnet materials is used to construct the model. It is benefited if the characteristics of permanent magnet materials before build an actual maglev wind turbine system. For example, the temperature in which the before build an actual maglev wind turbine system. For example, the temperature in which the permanent magnet is applied can
permanent magnet is applied can never be reached the Curie never be reached the Curie temperature. temperature. Otherwise, the magnetOtherwise, the magnet will be demagnetized that is lost its magnetic properties. Since the maglev wind turbine is located will be demagnetized that is lost its magnetic properties. Since the maglev wind turbine is located outdoor, the surrounding temperature must ensured not to exceed the Curie temperature of outdoor, the surrounding temperature must ensured not to exceed the Curie temperature of permanent magnet. The arrangement of permanent magnet is also a crucial decision. Improper permanent magnet. The arrangement of permanent magnet is also a crucial decision. Improper arrangement of magnet may affect the distribution of magnetic field and thus cause magnetic force arrangement of magnet may affect the distribution of magnetic field and thus cause magnetic force produced is not vertically upward. Another phenomenon will happen due to improper arrangement produced is not vertically upward. Another phenomenon will happen due to improper arrangement
of magnet. Considering the following diagram of magnet. Considering the following diagram
Figure 4: The distribution of
Figure 5: The distribution of
Figure 5: The distribution of magnetic field when upper part of start to magnetic field when upper part of start to movemove
The magnetic field is distributed as show in figure 3 before the turbine start to move. When the The magnetic field is distributed as show in figure 3 before the turbine start to move. When the upper part start to move right hand side, the magnetic field will be concentrate on this direction. upper part start to move right hand side, the magnetic field will be concentrate on this direction. This make the magnetic force is larger at the right hand side than left one. The imbalance magnetic This make the magnetic force is larger at the right hand side than left one. The imbalance magnetic forces cause difficulty to the upper part start to move.
forces cause difficulty to the upper part start to move.
Although the magnetic levitation is incorporated into wind turbine system to increase the Although the magnetic levitation is incorporated into wind turbine system to increase the power output, there are still several ways to improve the performance of the system. Blade direction power output, there are still several ways to improve the performance of the system. Blade direction with respect to the wind should be individually controlled by sensor in order to move the blades and with respect to the wind should be individually controlled by sensor in order to move the blades and present less of an angle to the wind on the circular return path against wind flow. In other words, present less of an angle to the wind on the circular return path against wind flow. In other words, each blade function should be made as a controllable wing to provide maximum efficiency of the each blade function should be made as a controllable wing to provide maximum efficiency of the system. In addition, the function of guide wind should be introduced into maglev wind turbine system. In addition, the function of guide wind should be introduced into maglev wind turbine system to increase the speed of the wind and optimize the angle of attack for the turbine blades to system to increase the speed of the wind and optimize the angle of attack for the turbine blades to rotate.
rotate.
Recently, there are many suggestions regarding the usage of permanent magnet to create a Recently, there are many suggestions regarding the usage of permanent magnet to create a
to produce electricity continuously. But, if the concept is investigated deeply, the perpetual motion to produce electricity continuously. But, if the concept is investigated deeply, the perpetual motion is found not practical.
is found not practical. For instance, if For instance, if two magnets are attached ttwo magnets are attached to turbine blades and the o turbine blades and the outer outer surface (surrounding the turbine blades), the repulsive force produced will continuously push the surface (surrounding the turbine blades), the repulsive force produced will continuously push the turbine blades to rotate. This phenomenon may happen at long time but not forever. This is because turbine blades to rotate. This phenomenon may happen at long time but not forever. This is because both of magnet material will locate the poles themselves and achieve an equilibrium condition. both of magnet material will locate the poles themselves and achieve an equilibrium condition. Once reach equilibrium state, the repulsive force would not appear between the two magnets and the Once reach equilibrium state, the repulsive force would not appear between the two magnets and the wind turbine stop from rotation.
CHAPTER 5 CHAPTER 5
CONCLUSION CONCLUSION
The Vertical Axis Wind Turbine (VAWT) with magnetic levitation performs better than the The Vertical Axis Wind Turbine (VAWT) with magnetic levitation performs better than the conventional wind turbine. This is because, the maglev VAWT model has lower starting wind speed conventional wind turbine. This is because, the maglev VAWT model has lower starting wind speed (1.6 m/s) compare to
(1.6 m/s) compare to conventional one (4.59m/s). conventional one (4.59m/s). The rotational speed of maThe rotational speed of maglev VAWT is higher,glev VAWT is higher, that is 640.80rpm, while the conventional model is 265.92rpm at constant wind speed of at 5.63m/s. that is 640.80rpm, while the conventional model is 265.92rpm at constant wind speed of at 5.63m/s. The time taken for the maglev wind turbine to stop rotating is longer than that of conventional The time taken for the maglev wind turbine to stop rotating is longer than that of conventional which is
which is 14.5s and 1.5s 14.5s and 1.5s respectively. respectively. Therefore, the Therefore, the Maglev wind turbine Maglev wind turbine is suitable is suitable for thefor the application of urban areas to provide green energy.
CHAPTER 6 CHAPTER 6
REFERENCES REFERENCES
[1] Tony Burton, David Sharpe, & Nick Jenkins (2001), Wind Energy: Handbook , Asia: John Wiley and Sons, inc. [1] Tony Burton, David Sharpe, & Nick Jenkins (2001), Wind Energy: Handbook , Asia: John Wiley and Sons, inc. [2] Erich Hau(2006), Wind turbines: fundamentals, technologies, application, economics
[2] Erich Hau(2006), Wind turbines: fundamentals, technologies, application, economics,, New York: Springer Berlin New York: Springer Berlin heidelberg
heidelberg
[3] Ion Paraschivoiu (2002), Wind Turbine Design: with emphasis on Savonius concept, Canada: International Press [3] Ion Paraschivoiu (2002), Wind Turbine Design: with emphasis on Savonius concept, Canada: International Press [4] Peter Campbell (1996), Permanent magnet materials and their application
[4] Peter Campbell (1996), Permanent magnet materials and their application,,United Kingdom: Cambridge UniversityUnited Kingdom: Cambridge University Press
Press
[5] Society of Automotive Engineers (1992), Maglev, New York: Society of Automotive Engineers [5] Society of Automotive Engineers (1992), Maglev, New York: Society of Automotive Engineers [6] F. C.
[6] F. C. Moon, Pei-Zen Chang (1994)Moon, Pei-Zen Chang (1994) , Superconducting levitation: applications , Superconducting levitation: applications to bearings and to bearings and magnetic transportation magnetic transportation ,, WILEY-VCH
WILEY-VCH
[7] China Makes Huge Breakthrough in Wind Power Technology, Retrieved August 1, 2009 from [7] China Makes Huge Breakthrough in Wind Power Technology, Retrieved August 1, 2009 from
http://www.worldwatch.org/node/4217 http://www.worldwatch.org/node/4217
[8] Background of MAGLEV, Retrieved September 3, 2009 from [8] Background of MAGLEV, Retrieved September 3, 2009 from
http://inventors.about.com/library/inventors/blrailroad3.htm http://inventors.about.com/library/inventors/blrailroad3.htm
CHAPTER 7 CHAPTER 7
APPENDIXES APPENDIXES
Figure A.1. Prototype of Maglev Wind
Figure A.1. Prototype of Maglev Wind TurbineTurbine
Figure A.2. Magnetically levitated turbine blades Figure A.2. Magnetically levitated turbine blades
Equipments Equipments
Figure
Equipment Set-Up Equipment Set-Up
Figure
