Choosing the right generator for a windmill. How to assemble a wind generator with your own hands for your home Do-it-yourself windmill from a generator

It is difficult not to notice how the stability of electricity supplies to suburban facilities differs from the provision of urban buildings and enterprises with electricity. Admit that you, as the owner of a private home or cottage, have more than once encountered interruptions, associated inconveniences and damage to equipment.

The listed negative situations, along with the consequences, will no longer complicate the lives of lovers of natural spaces. Moreover, with minimal labor and financial costs. To do this, you just need to make a wind power generator, which we describe in detail in the article.

Options for manufacturing a useful household system that eliminates energy dependence are described in detail here. In addition, a wind generator built with your own hands according to our advice will help to significantly reduce daily costs.

• Legality of installing a wind generator
• The principle of operation of a wind turbine
• Classification of types of energy generators
• Wind-electric installation of rotor type
  • Starting stage of installation manufacturing
  • Advantages and disadvantages of the rotary windmill model
• Axial wind turbine with neodymium magnets
  • Distributing and securing magnets
  • Single-phase and three-phase generators
  • Rules for winding a reel
  • Final assembly of the device
• Conclusions and useful video on the topic

Legality of installing a wind generator

Alternative energy sources are the dream of any summer resident or homeowner whose plot is located far from central networks. However, when we receive bills for electricity consumed in a city apartment and look at the increased tariffs, we realize that a wind generator created for domestic needs would not hurt us.

After reading this article, perhaps you will make your dream come true.

Wind generator - perfect solution to provide a suburban facility with electricity. Moreover, in some cases, installing it is the only possible solution.

In order not to waste money, effort and time, let's decide: are there any external circumstances that will create obstacles for us during the operation of the wind generator?

To provide electricity to a summer house or small cottage, a small wind power plant with a power not exceeding 1 kW is sufficient. Such devices in Russia are equated to household products. Their installation does not require certificates, permits or any additional approvals.

In order to determine the feasibility of installing a wind generator, it is necessary to find out the wind energy potential of a particular area (click to enlarge)

No taxation is provided for the production of electricity, which is spent on meeting one’s own household needs. Therefore, a low-power windmill can be safely installed, using it to generate free electricity, without paying any taxes to the state.

However, just in case, you should ask if there are any local regulations regarding individual power supply that could create obstacles in the installation and operation of this device.

Wind generators, which are able to satisfy most of the needs of the average farm, cannot cause any complaints even from neighbors

Your neighbors may have claims if they experience inconvenience caused by the operation of the windmill. Don't forget that our rights end where other people's rights begin.

Therefore, when purchasing or independently manufacturing a wind generator for your home, you need to pay serious attention to the following parameters:

• Mast height. When assembling a wind generator, you need to take into account the restrictions on the height of individual buildings that exist in a number of countries around the world, as well as the location own plot. Please be aware that structures taller than 15 meters are prohibited near bridges, airports and tunnels.
• Noise from gearbox and blades. The parameters of the generated noise can be set using special device, and then document the measurement results. It is important that they do not exceed established noise standards.
• On-air interference. Ideally, when creating a windmill, protection against TV interference should be provided where your device can cause such troubles.
• Environmental Services Claims. This organization can prevent you from operating the installation only if it interferes with the migration of migratory birds. But this is unlikely.

When creating and installing a device yourself, learn these points, and when purchasing a finished product, pay attention to the parameters that are in its passport. It’s better to protect yourself in advance than to be upset later.

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The feasibility of installing a wind turbine is justified primarily by the sufficiently high and stable wind pressure in the area

It is necessary to have a sufficiently large area, the useful area of ​​which will not be significantly reduced due to the installation of the system

Due to the noise that accompanies the operation of a windmill, it is advisable that there be at least 200 m between the neighbors’ homes and the installation

The steadily increasing cost of electricity provides a convincing argument in favor of installing a wind generator.

The installation of a wind generator is possible only in areas where the authorities do not hinder, but rather encourage, the use of green energy

If there are frequent interruptions in the region where a mini power plant is being built that processes wind energy, the installation will minimize the inconvenience

The owner of the system must be prepared for the fact that investments in ready product the funds will not pay off immediately. The economic effect can become noticeable in 10 - 15 years

If the payback of the system is not the last moment, you should think about building a mini power plant with your own hands

The principle of operation of a wind turbine

A wind generator or wind power plant (WPP) is a device that is used to convert the kinetic energy of wind flow into mechanical energy. The resulting mechanical energy rotates the rotor and is converted into the electrical form we need.

The wind turbine includes:

• blades forming a propeller,
• rotating turbine rotor,
• the generator axis and the generator itself,
• an inverter that converts alternating current into direct current, which is used to charge batteries,
• battery.

The essence of wind turbines is simple. As the rotor rotates, a three-phase alternating current is generated, which then passes through the controller and charges the battery direct current. The inverter then converts the current so that it can be consumed to power lights, radios, TVs, microwaves, and so on.

The detailed design of a wind generator with a horizontal axis of rotation allows you to clearly imagine which elements contribute to the conversion of kinetic energy into mechanical, and then into electrical

This diagram of the operation of a wind turbine allows you to understand what happens with the electricity produced by the operation of the wind generator: part of it is accumulated, and the other is consumed

In general, the operating principle of a wind generator of any type and design is as follows: during the rotation process, three types of force effects occur on the blades: braking, impulse and lifting. The last two forces overcome the braking force and set the flywheel in motion. On the stationary part of the generator, the rotor generates a magnetic field to electricity followed the wires.

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To make a wind energy generator, an engine from unnecessary household appliances is suitable. The more volts per revolution, the more efficient the system will be.

A bushing is attached to the motor rotor, on which the blades of the device are fixed. It is better to cover the frontal assembly with a protective cover

The front part with the motor and blades must be balanced with the tail part. The shoulder of the tail made of a pipe or lath should be longer; a shank of any shape is attached to its edge

The mast holding the windmill must have at least three supports; the structure must be connected to a ground loop and a lightning rod must be installed

Classification of types of energy generators

There are several criteria by which wind power plants are classified.

So, windmills differ in:

• number of blades in the propeller;
• blade manufacturing materials;
• the location of the axis of rotation relative to the surface of the earth;
• pitch feature of the screw.

There are models with one, two, three blades and multi-blades.

Products with a large number The blades begin to rotate even in light winds. They are usually used in such work when the rotation process itself more important than receiving electricity. For example, for extracting water from deep wells.

It turns out that wind generator blades can be made not only from hard materials, but also from affordable fabric

The blades can be sailed or rigid. Sailing products are much cheaper than rigid ones, which are made from metal or fiberglass. But they have to be repaired very often: they are fragile.

Regarding the location of the axis of rotation relative to the earth's surface, there are vertical and horizontal models. And in this case, each variety has its own advantages: vertical ones react more sensitively to every breath of wind, but horizontal ones are more powerful.

Wind generators are divided according to step characteristics into models with fixed and variable pitch.

The variable pitch allows you to significantly increase the rotation speed, but this installation has a complex and massive design. Wind turbines with a fixed pitch are simpler and more reliable.

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After disassembly, all that was left of the fairly damaged autogenerator was the stator, for which the housing was welded separately

In order to restore specifications engine, you need to rewind 36 stator coils. Rewinding requires a wire with a diameter of 0.56 mm. Turns need to be made in 35 pieces

Before attaching the blades, the repaired engine must be assembled, coated with varnish or at least epoxy, and the surface must be painted.

The wires are connected in parallel, three wires are output for connection to the power source

The axis intended to ensure rotation is made of pipe bend 15. Bearings are welded to the axis, which are welded through the pipe section 52

The tail is made from galvanized sheet steel 4 mm thick, bent at the edges and installed in the groove selected in the rail

The blades are cut from polymer sewer pipe, attached to the triangle connected to the engine with screws

An almost free wind generator can be made from scrap parts: an engine from an old car and a piece of sewer pipe.

Wind-electric installation of rotor type

Let's figure out how to make a simple windmill with a vertical axis of rotation of the rotor type with your own hands.

This model may well meet the electricity needs garden house, various outbuildings, and also illuminated in the dark local area and garden paths.

The blades of this rotor-type installation with a vertical axis of rotation are clearly made from elements cut from a metal barrel

Our goal is to produce a wind turbine with a maximum power of 1.5 kW. To do this we will need the following elements and materials:

• 12 V car generator;
• 12 V gel or acid battery;
• semi-hermetic switch of the “button” variety for 12 V;
• converter 700 W – 1500 W and 12V – 220V;
• a bucket, large-capacity pan or other capacious container made of stainless steel or aluminum;
• car charge or battery charging warning lamp relay;
• car voltmeter (you can use any one);
• bolts with nuts and washers;
• wires with a cross section of 4 square mm and 2.5 square mm;
• two clamps for securing the generator to the mast.

In the process of completing the work, we will need a grinder or metal scissors, a construction pencil or marker, a tape measure, wire cutters, a drill, a drill, keys and a screwdriver.

Starting stage of installation manufacturing

We start making a homemade windmill by taking a large metal container cylindrical shape. Usually, old boiling water, a bucket or pan is used for this purpose. This will be the basis for our future wind turbines.

Using a tape measure and a construction pencil (marker), apply markings: divide our container into four equal parts.

When making cuts in accordance with the instructions contained in the text, under no circumstances cut through the metal all the way through.

The metal will have to be cut. For this you can use a grinder. It is not used for cutting containers made of galvanized steel or painted sheet metal, because this type of metal will certainly overheat.

For such cases, it is better to use scissors. We cut out the blades, but do not cut them all the way through.

Now, while we continue work on the tank, we will remodel the generator pulley.

In the bottom of the former pan and in the pulley you need to mark and drill holes for the bolts. Work at this stage must be approached with the utmost care: all holes must be located symmetrically so that no imbalance occurs during the rotation of the installation.

This is what the blades of another design with a vertical axis of rotation look like. Each blade is manufactured separately and then mounted into a common device

We bend the blades so that they do not stick out too much. When we perform this part of the work, we be sure to take into account which direction the generator will rotate.

Usually the direction of its rotation is clockwise. The bending angle of the blades affects the impact area air flow and the speed of rotation of the propeller.

Now you need to attach a bucket with blades prepared for work to the pulley. We install the generator on the mast, securing it with clamps. All that remains is to connect the wires and assemble the circuit.

Be prepared to write down the wiring diagram, wire colors, and pin markings. You will certainly need it later. We fix the wires on the mast of the device.

To connect the battery, you need to use wires with a cross section of 4 mm². It is enough to take a segment of 1 meter in length. That's enough.

And in order to connect a load to the network, which includes, for example, lighting and electrical devices, wires with a cross-section of 2.5 mm² are sufficient. Install the inverter (converter). For this you will also need a 4 mm² wire.

Advantages and disadvantages of the rotary windmill model

If you did everything carefully and consistently, then this wind generator will work successfully. In this case, no problems will arise during its operation.

If you use a 1000 W converter and a 75A battery, this installation will provide electricity for video surveillance devices, security alarms and even street lighting.

The advantages of this model are:

• economical;
• elements can be easily replaced with new ones or repaired;
• no special conditions are required for operation;
• reliable in operation;
• provides complete acoustic comfort.

There are also disadvantages, but not too many of them: the performance of this device is not very high, and it has a significant dependence on sudden gusts of wind. Air currents can simply disrupt an improvised propeller.

Axial wind turbine with neodymium magnets

Since neodymium magnets appeared in Russia relatively recently, axial wind generators with iron-free stators began to be made not so long ago.

The appearance of magnets caused a rush of demand, but gradually the market became saturated, and the cost of this product began to decline. It became available to craftsmen, who immediately adapted it to their various needs.

An axial wind turbine on neodymium magnets with a horizontal axis of rotation is a more complex design that requires not only skill, but also certain knowledge

If you have a hub from an old car with brake discs, then we will take it as the basis for the future axial generator.

It is assumed that this part is not new, but has already been used. In this case, it is necessary to disassemble it, check and lubricate the bearings, thoroughly clean away sedimentary deposits and all rust. Don't forget to paint the finished generator.

The hub with brake discs, as a rule, goes to craftsmen as one of the components of an old car that has been scrapped, and therefore needs thorough cleaning

Distributing and securing magnets

Neodymium magnets must be glued to the rotor disks. For our work, we will take 20 magnets 25x8mm. Of course, a different number of poles can be used, but it is necessary to observe following rules: the number of magnets and poles in a single-phase generator should be the same, but if we are talking about a three-phase model, then the ratio of poles to coils should be 2/3 or 4/3.

When placing magnets, the poles alternate. It is important not to make a mistake. If you are not sure that you will place the elements correctly, make a hint template or apply the sectors directly to the disk itself.

If you have a choice, buy rectangular rather than round magnets. In rectangular models, the magnetic field is concentrated along the entire length, and in round models, in the center.

Opposing magnets must have different poles. You won't confuse anything if you use a marker to mark them with minus or plus signs. To determine the poles, take magnets and bring them close to each other. If the surfaces attract, put a plus on them, if they repel, then mark them with minuses. When placing magnets on disks, alternate poles.

The magnets are installed in compliance with the rule of alternating policies, plasticine sides are located along the outer and inner perimeters: the product is ready to be filled with epoxy resin

To securely fasten the magnet, you need to use high-quality and as strong glue as possible.

To enhance the reliability of fixation, you can use epoxy resin. It should be diluted as indicated in the instructions and filled with it on the disc. The resin should cover the entire disc, but not run off it. You can prevent the possibility of dripping by wrapping the disk with tape or making temporary plasticine barriers made of a polymer strip around its perimeter.

Single-phase and three-phase generators

If we compare single-phase and three-phase stators, the latter will be better. A single-phase generator vibrates when loaded. The cause of vibration is the difference in the amplitude of the current, which arises due to its inconsistent output at a time. The three-phase model does not have such a disadvantage. It is characterized by constant power due to phases that compensate each other: when the current increases in one, it decreases in the other.

According to the testing results, the output of the three-phase model is almost 50% greater than that of the single-phase model. Another advantage of this model is that in the absence of unnecessary vibration, acoustic comfort increases when the device operates under load.

That is, a three-phase generator practically does not hum during its operation. When vibration is reduced, the service life of the device logically increases.

In the fight between three-phase and single-phase devices, three-phase invariably wins, because it does not hum so much during operation and lasts longer than single-phase

Rules for winding a reel

If you ask a specialist, he will say that before winding the coils, you need to perform a careful calculation. A practitioner in this matter will rely on his intuition.

We chose a not very high-speed generator option. Our charging procedure for a twelve-volt battery should begin at 100-150 rpm. Such initial data require that the total number of turns of all coils be 1000-1200 pieces. We just have to divide this figure between all the coils and determine how many turns there will be on each.

A windmill at low speeds can be more powerful if the number of poles increases. The frequency of current oscillations in the coils will increase. If a larger cross-sectional wire is used to wind the coils, the resistance will decrease and the current will increase. Don't lose sight of the fact that higher voltage can "eat up" current due to winding resistance.

The winding process can be made easier and more efficient if you use a special machine for this purpose.

It is not at all necessary to do such a routine process as winding coils by hand. A little ingenuity and an excellent machine that can easily cope with winding are already there

The performance characteristics of homemade generators are greatly influenced by the thickness and number of magnets that are located on the disks. The total total power can be calculated by winding one coil and then spinning it in a generator. The future power of the generator is determined by measuring the voltage at specific speeds without load.

Let's give an example. With a resistance of 3 ohms and 200 rpm, 30 volts comes out. If you subtract 12 volts of battery voltage from this result, you get 18 volts. Divide this result by 3 ohms and get 6 amperes. The volume is 6 amperes and will go to the battery. Of course, in the calculation we did not take into account the losses in the wires and on the diode bridge: the actual result will be less than the calculated one.

Usually the coils are made round. But, if you stretch them out a little, you will get more copper in the sector and the turns will be straighter. If you compare the size of the magnet and the diameter of the inner hole of the coils, then they should match each other or the size of the magnet may be slightly smaller.

Ready-made coils should correspond in size to the magnets: they should be slightly larger than the magnets or equal in size to them

The thickness of the stator we make must be correctly related to the thickness of the magnets. If the stator is made larger by increasing the number of turns in the coils, the interdisk space will increase and the magnetic flux will decrease. The result may turn out to be this: the same voltage is generated, but due to the increased resistance of the coils, we will receive less current.

Plywood is used to make the stator mold. However, sectors for coils can be marked on paper using plasticine as borders.

If you place fiberglass fabric on top of the coils at the bottom of the mold, the strength of the product will increase. Before application epoxy resin You need to lubricate the mold with Vaseline or wax, then the resin will not stick to the mold. Some people use tape or film instead of lubricant.

The coils are fixed to each other. In this case, the ends of the phases are brought out. The six wires brought out should be connected in a star or triangle. By rotating the assembled generator by hand, it is tested. If the voltage is 40 V, then the current will be approximately 10 amperes.

Final assembly of the device

The length of the finished mast should be approximately 6-12 meters. With such parameters, its base must be concreted. The windmill itself will be fixed to the top of the mast. In order to be able to reach it in the event of a breakdown, it is necessary to provide a special mount at the base of the mast, which will allow the pipe to be raised and lowered using a hand winch.

The mast with a wind generator attached to it rises high, but the prudent craftsman made a special device that allows the structure to be lowered to the ground if necessary

To make a screw, you can use PVC pipe diameter 160 mm. It will be used to cut a two-meter propeller consisting of six blades from its surface. It is better to develop the shape of the blades yourself experimentally. The goal is to increase torque at low rpm.

The propeller should be protected from excessive strong wind. To solve this problem, use a folding tail. The generated energy is stored in batteries.

For the attention of our readers, we have provided two options for do-it-yourself 220 V wind generators that use increased attention not only owners of country real estate, but also ordinary summer residents.

Both wind turbine models are effective in their own way. These devices can demonstrate especially good results in steppe areas with frequent and strong winds. And they are not so difficult to build with your own hands.

Conclusions and useful video on the topic

This video shows an example of a wind turbine with a horizontal axis of rotation. The author of the device explains in detail the nuances of the design of the installation, made by hand, draws the audience's attention to mistakes that may be made in the process self-made wind generator, gives practical advice.

Please note that getting to the device, raised to a decent height, is not so easy. Reinstalling such a wind turbine will most likely be problematic. Therefore, the folding design of the mast in this case will not be superfluous at all.

This video shows a rotary windmill with a vertical axis of rotation. This installation is located low, made in an original way and is highly sensitive: even a slight wind sets the blades of the device in motion.

If you live in an area where winds are not considered a rare phenomenon, using this particular source of alternative energy may be the most effective for you. The above examples of self-made windmills prove that making them with your own hands is not so difficult. Wind energy is a publicly accessible and renewable resource that can and should be used.

1. Basic Concepts
2. What generator do you need?
3. Choosing according to the wind
4. About security
5. Wind, aerodynamics, KIEV
6. What to expect from the classics?
7. Verticals
8. Lopadniki
9. Mini and micro
10. Sailboats
11. Homemade generator
12. Conclusion

Russia occupies a dual position with regard to wind energy resources. On the one hand, due to the huge total area and the abundance of flat areas, there is generally a lot of wind, and it is mostly even. On the other hand, our winds are predominantly low-potential and slow, see Fig. On the third, in sparsely populated areas the winds are violent. Based on this, the task of installing a wind generator on the farm is quite relevant. But to decide - buy enough expensive device, or make it yourself, you need to think carefully about which type (and there are a lot of them) to choose for what purpose.

Basic Concepts

1. KIEV – wind energy utilization coefficient. If a mechanistic flat wind model is used for calculations (see below), it is equal to the efficiency of the rotor of a wind power plant (WPU).
2. Efficiency – end-to-end efficiency of the APU, from the oncoming wind to the terminals of the electric generator, or to the amount of water pumped into the tank.
3. Minimum operating wind speed (MRS) is the speed at which the windmill begins to supply current to the load.
4. The maximum permissible wind speed (MAS) is the speed at which energy production stops: the automation either turns off the generator, or puts the rotor in a weather vane, or folds it and hides it, or the rotor itself stops, or the APU is simply destroyed.
5. Starting wind speed (SW) - at this speed, the rotor is able to turn without load, spin up and enter operating mode, after which the generator can be turned on.
6. Negative starting speed (OSS) - this means that the APU (or wind turbine - wind power unit, or WEA, wind power unit) to start at any wind speed requires mandatory spin-up from an external energy source.
7. Starting (initial) torque is the ability of a rotor, forcibly braked in the air flow, to create torque on the shaft.
8. Wind turbine (WM) is part of the APU from the rotor to the shaft of the generator or pump, or other energy consumer.
9. Rotary wind generator - an APU in which wind energy is converted into torque on the power take-off shaft by rotating the rotor in the air flow.
10. The range of rotor operating speeds is the difference between MMF and MRS when operating at rated load.
11. Low-speed windmill - in it the linear speed of the rotor parts in the flow does not significantly exceed the wind speed or is lower than it. The dynamic pressure of the flow is directly converted into blade thrust.
12. High-speed windmill - the linear speed of the blades is significantly (up to 20 or more times) higher than the wind speed, and the rotor forms its own air circulation. The cycle of converting flow energy into thrust is complex.

Notes:

1. Low-speed APUs, as a rule, have a KIEV lower than high-speed ones, but have a starting torque sufficient to spin up the generator without disconnecting the load and zero TAC, i.e. Absolutely self-starting and usable in the lightest winds.
2. Slowness and speed are relative concepts. A household windmill at 300 rpm can be low-speed, but powerful APUs of the EuroWind type, from which the fields of wind power plants and wind farms are assembled (see figure) and whose rotors make about 10 rpm, are high-speed, because with such a diameter, the linear speed of the blades and their aerodynamics over most of the span are quite “airplane-like”, see below.

What generator do you need?

An electric generator for a domestic windmill must generate electricity over a wide range of rotation speeds and be able to self-start without automation or external power sources. In the case of using APU with OSS (spin-up wind turbines), which, as a rule, have high KIEV and efficiency, it must also be reversible, i.e. be able to work as an engine. At powers up to 5 kW, this condition is satisfied by electric machines with permanent magnets based on niobium (supermagnets); on steel or ferrite magnets you can count on no more than 0.5-0.7 kW.

Note: asynchronous alternating current generators or collector ones with a non-magnetized stator are completely unsuitable. When the wind force decreases, they will “go out” long before its speed drops to MPC, and then they will not start themselves.

The excellent “heart” of the APU with a power from 0.3 to 1-2 kW is obtained from an alternating current self-generator with a built-in rectifier; these are the majority now. First, they maintain an output voltage of 11.6-14.7 V over a fairly wide speed range without external electronic stabilizers. Secondly, the silicon valves open when the voltage on the winding reaches approximately 1.4 V, and before that the generator “does not see” the load. To do this, the generator needs to be spun up quite decently.

In most cases, a self-generator can be directly connected, without a gear or belt drive, to the shaft of a high-speed high-pressure engine, selecting the speed by selecting the number of blades, see below. “High-speed trains” have a small or zero starting torque, but the rotor, even without disconnecting the load, will have time to spin sufficiently before the valves open and the generator produces current.

Choosing according to the wind

Before deciding what type of wind generator to make, let’s decide on the local aerology. In gray-greenish(windless) areas of the wind map, only a sailing wind engine will be of any use(We’ll talk about them later). If you need a constant power supply, you will have to add a booster (rectifier with voltage stabilizer), charger, powerful battery, inverter 12/24/36/48 V DC to 220/380 V 50 Hz AC. Such a facility will cost no less than $20,000, and it is unlikely that it will be possible to remove long-term power of more than 3-4 kW. In general, with an unwavering desire for alternative energy, it is better to look for another source.

In yellow-green, low-wind places, with a need for electricity of up to 2-3 kW, you can take on a low-speed one yourself vertical wind generator . There are countless of them developed, and there are designs that are almost as good as industrially manufactured “blade blades” in terms of KIEV and efficiency.

If you plan to buy a wind turbine for your home, then it is better to focus on a wind turbine with a sail rotor. There are many controversies, and in theory everything is not yet clear, but they work. In the Russian Federation, “sailboats” are produced in Taganrog with a power of 1-100 kW.

In red, windy regions, the choice depends on the required power. In the range of 0.5-1.5 kW, homemade “verticals” are justified; 1.5-5 kW – purchased “sailboats”. “Vertical” can also be purchased, but will cost more than a horizontal APU. And finally, if you need a wind turbine with a power of 5 kW or more, then you need to choose between horizontal purchased “blades” or “sailboats”.

Note: Many manufacturers, especially the second tier, offer kits of parts from which you can assemble a wind generator with a power of up to 10 kW yourself. Such a kit will cost 20-50% less than a ready-made kit with installation. But before purchasing, you need to carefully study the aerology of the intended installation location, and then select according to the specifications suitable type and model.

About security

Parts of a wind turbine for domestic use in operation can have a linear speed exceeding 120 and even 150 m/s, and a piece of any hard material weighing 20 g, flying at a speed of 100 m/s, with a “successful” hit, it kills a healthy man outright. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

In addition, most wind turbines with a power of more than 100 W are quite noisy. Many generate air pressure fluctuations of ultra-low (less than 16 Hz) frequencies - infrasounds. Infrasounds are inaudible, but are harmful to health and travel very far.

Note: in the late 80s there was a scandal in the United States - the largest wind farm in the country at that time had to be closed. Indians from a reservation 200 km from the field of its wind farm proved in court that their health disorders, which sharply increased after the wind farm was put into operation, were caused by its infrasounds.

Due to the above reasons, installation of APUs is allowed at a distance of at least 5 of their heights from the nearest residential buildings. In the courtyards of private households, it is possible to install industrially manufactured windmills that are appropriately certified. It is generally impossible to install APUs on roofs - during their operation, even low-power ones, alternating mechanical loads arise that can cause resonance of the building structure and its destruction.

Zhukovsky's idea was this: the air travels a different path along the upper and lower surfaces of the wing. From the condition of continuity of the medium (vacuum bubbles by themselves do not form in the air) it follows that the velocities of the upper and lower flows descending from the trailing edge should be different. Due to the small but finite viscosity of the air, a vortex should form there due to the difference in speeds.

The vortex rotates, and the law of conservation of momentum, just as immutable as the law of conservation of energy, is also valid for vector quantities, i.e. must also take into account the direction of movement. Therefore, right there, on the trailing edge, a counter-rotating vortex with the same torque should form. Due to what? Due to the energy generated by the engine.

For aviation practice, this meant a revolution: by choosing the appropriate wing profile, it was possible to send an attached vortex around the wing in the form of a circulation G, increasing its lift. That is, by spending part, and for high speeds and loads on the wing – most of the motor power, you can create an air flow around the device, allowing you to achieve better flight qualities.

This made aviation aviation, and not part of aeronautics: now the aircraft could create the environment it needed for flight and no longer be a toy of air currents. All you need is a more powerful engine, and more and more powerful...

KIEV again

But the windmill does not have a motor. On the contrary, it must take energy from the wind and give it to consumers. And here it turns out - his legs were pulled out, his tail got stuck. We used too little wind energy for the rotor’s own circulation - it will be weak, the thrust of the blades will be low, and the KIEV and power will be low. We will give a lot to the circulation - the rotor will be on Idling spinning like crazy, but consumers again get little: they barely applied the load, the rotor slowed down, the wind blew away the circulation, and the rotor stopped.

Law of energy conservation " golden mean" gives right in the middle: we give 50% of the energy to the load, and for the remaining 50% we turn up the flow to the optimum. Practice confirms the assumptions: if the efficiency of a good pulling propeller is 75-80%, then the efficiency of a bladed rotor that is also carefully calculated and blown in a wind tunnel reaches 38-40%, i.e. up to half of what can be achieved with excess energy.

Modernity

Nowadays, aerodynamics, armed with modern mathematics and computers, is increasingly moving away from inevitably simplifying models towards an accurate description of the behavior of a real body in a real flow. And here, in addition to the general line - power, power, and once again power! – side paths are discovered, but promising precisely when the amount of energy entering the system is limited.

The famous alternative aviator Paul McCready created an airplane back in the 80s with two chainsaw motors with a power of 16 hp. showing 360 km/h. Moreover, its chassis was tricycle, non-retractable, and its wheels were without fairings. None of McCready's devices went online or went on combat duty, but two - one with piston engines and propellers, and the other a jet - for the first time in history flew around the globe without landing at the same gas station.

The development of the theory also affected the sails that gave birth to the original wing quite significantly. “Live” aerodynamics allowed the yachts to operate in winds of 8 knots. stand on hydrofoils (see figure); to accelerate such a monster to the required speed with a propeller, an engine of at least 100 hp is required. Racing catamarans sail at a speed of about 30 knots in the same wind. (55 km/h).

There are also finds that are completely non-trivial. Fans of the rarest and most extreme sport - base jumping - wearing a special wing suit, wingsuit, fly without a motor, maneuvering at a speed of more than 200 km/h (picture on the right), and then smoothly land in a pre-selected place. In which fairy tale do people fly on their own?

Many mysteries of nature were also resolved; in particular, the flight of a beetle. According to classical aerodynamics, it is not capable of flying. Just like the founder of the stealth aircraft, the F-117, with its diamond-shaped wing, is also unable to take off. And the MIG-29 and Su-27, which can fly tail first for some time, do not fit into any idea at all.

And why then, when working on wind turbines, not a fun thing and not a tool for destroying their own kind, but a source of a vital resource, do you need to dance away from the theory of weak flows with its flat wind model? Is there really no way to move forward?

What to expect from the classics?

However, one should not abandon the classics under any circumstances. It provides a foundation, without relying on which one cannot rise higher. Just as set theory does not abolish the multiplication table, and quantum chromodynamics will not make apples fly up from the trees.

So, what can you expect with the classical approach? Let's look at the picture. On the left are types of rotors; they are depicted conditionally. 1 – vertical carousel, 2 – vertical orthogonal (wind turbine); 2-5 – bladed rotors with different numbers of blades with optimized profiles.

On the right along the horizontal axis is the relative speed of the rotor, i.e., the ratio of the linear speed of the blade to the wind speed. Vertical up - KIEV. And down - again, relative torque. A single (100%) torque is considered to be that which is created by a rotor forcibly braked in the flow with 100% KIEV, i.e. when all the flow energy is converted into rotating force.

This approach allows us to draw far-reaching conclusions. For example, the number of blades must be selected not only and not so much according to the desired rotation speed: 3- and 4-blades immediately lose a lot in terms of KIEV and torque compared to 2- and 6-blades that work well in approximately the same speed range. And the outwardly similar carousel and orthogonal have fundamentally different properties.

In general, preference should be given to bladed rotors, except in cases where extreme low cost, simplicity, maintenance-free self-starting without automation are required, and lifting onto a mast is impossible.

Note: Let's talk about sailing rotors in particular - they don't seem to fit into the classics.

Verticals

APUs with a vertical axis of rotation have an undeniable advantage for everyday life: their components requiring maintenance are concentrated at the bottom and no lifting is required. There remains, and even then not always, a self-aligning thrust bearing, but it is strong and durable. Therefore, when designing a simple wind generator, the selection of options should begin with verticals. Their main types are presented in Fig.

Sun

In the first position is the simplest one, most often called the Savonius rotor. In fact, it was invented in 1924 in the USSR by J. A. and A. A. Voronin, and the Finnish industrialist Sigurd Savonius shamelessly appropriated the invention, ignoring the Soviet copyright certificate, and began serial production. But the introduction of an invention in the future means a lot, so in order not to stir up the past and not disturb the ashes of the deceased, we will call this windmill a Voronin-Savonius rotor, or for short, VS.

The aircraft is good for the home-made man, except for the “locomotive” KIEV at 10-18%. However, in the USSR they worked a lot on it, and there are developments. Below we will look at an improved design, not much more complex, but according to KIEV, it gives bladers a head start.

Note: the two-blade aircraft does not spin, but jerks jerkily; The 4-blade is only slightly smoother, but loses a lot in KIEV. To improve, 4-trough blades are most often divided into two floors - a pair of blades below, and another pair, rotated 90 degrees horizontally, above them. KIEV is preserved, and the lateral loads on the mechanics weaken, but the bending loads increase somewhat, and with a wind of more than 25 m/s such an APU is on the shaft, i.e. without a bearing stretched by cables above the rotor, it “tears down the tower.”

Daria

Next is the Daria rotor; KIEV – up to 20%. It is even simpler: the blades are made of a simple elastic tape without any profile. The theory of the Darrieus rotor is not yet sufficiently developed. It is only clear that it begins to unwind due to the difference in the aerodynamic resistance of the hump and the tape pocket, and then it becomes sort of high-speed, forming its own circulation.

The torque is small, and in the starting positions of the rotor parallel and perpendicular to the wind it is completely absent, so self-spin is possible only with an odd number of blades (wings?) In any case, the load from the generator must be disconnected during spin-up.

The Daria rotor has two more bad qualities. Firstly, when rotating, the thrust vector of the blade describes a full rotation relative to its aerodynamic focus, and not smoothly, but jerkily. Therefore, the Darrieus rotor quickly breaks down its mechanics even in a steady wind.

Secondly, Daria not only makes noise, but screams and squeals, to the point that the tape breaks. This happens due to its vibration. And the more blades, the stronger the roar. So, if they make a Daria, it is with two blades, from expensive high-strength sound-absorbing materials (carbon, mylar), and a small aircraft is used for spinning in the middle of the mast-pole.

Orthogonal

At pos. 3 – orthogonal vertical rotor with profiled blades. Orthogonal because the wings stick out vertically. The transition from BC to orthogonal is illustrated in Fig. left.

The angle of installation of the blades relative to the tangent to the circle touching the aerodynamic foci of the wings can be either positive (in the figure) or negative, depending on the wind force. Sometimes the blades are made rotating and weather vanes are placed on them, automatically holding the “alpha”, but such structures often break.

The central body (blue in the figure) allows you to increase the KIEV to almost 50%. In a three-blade orthogonal, it should have the shape of a triangle in cross-section with slightly convex sides and rounded corners, and with a larger number of blades, a simple cylinder is sufficient. But the theory for the orthogonal gives an unambiguous optimal number of blades: there should be exactly 3 of them.

Orthogonal refers to high-speed wind turbines with OSS, i.e. necessarily requires promotion during commissioning and after calm. According to the orthogonal scheme, serial maintenance-free APUs with a power of up to 20 kW are produced.

Helicoid

Helicoidal rotor, or Gorlov rotor (item 4) is a type of orthogonal that ensures uniform rotation; an orthogonal with straight wings “tears” only slightly weaker than a two-bladed aircraft. Bending the blades along a helicoid allows one to avoid losses of CIEV due to their curvature. Although the curved blade rejects part of the flow without using it, it also scoops part into the zone of highest linear speed, compensating for losses. Helicoids are used less often than other wind turbines, because Due to the complexity of manufacturing, they are more expensive than their counterparts of equal quality.

Barrel raking

For 5 pos. – BC type rotor surrounded by a guide vane; its diagram is shown in Fig. on right. It is rarely found in industrial applications, because expensive land acquisition does not compensate for the increase in capacity, and the material consumption and complexity of production are high. But a do-it-yourselfer who is afraid of work is no longer a master, but a consumer, and if you need no more than 0.5-1.5 kW, then for him a “barrel-raking” is a tidbit:

• A rotor of this type is absolutely safe, silent, does not create vibrations and can be installed anywhere, even on a playground.
• Bending a galvanized “trough” and welding a frame of pipes is nonsense work.
• Rotation is absolutely uniform, mechanical parts can be taken from the cheapest or from the trash.
• Not afraid of hurricanes - too strong a wind cannot push into the “barrel”; a streamlined vortex cocoon appears around it (we will encounter this effect later).
• And the most important thing is that since the surface of the “barrel” is several times larger than that of the rotor inside, the KIEV can be over-unit, and the rotational moment already at 3 m/s for a “barrel” of three-meter diameter is such that a 1 kW generator with a maximum load of They say it’s better not to twitch.

Video: Lenz wind generator

In the 60s in the USSR, E. S. Biryukov patented a carousel APU with a KIEV of 46%. A little later, V. Blinov achieved 58% KIEV from a design based on the same principle, but there is no data on its testing. And full-scale tests of Biryukov’s APU were carried out by employees of the magazine “Inventor and Innovator”. A two-story rotor with a diameter of 0.75 m and a height of 2 m spun at full power in a fresh wind asynchronous generator 1.2 kW and withstood 30 m/s without breakdown. Drawings of Biryukov's APU are shown in Fig.

1. rotor made of galvanized roofing;
2. self-aligning double row ball bearing;
3. shrouds – 5 mm steel cable;
4. axis-shaft – steel pipe with a wall thickness of 1.5-2.5 mm;
5. aerodynamic speed control levers;
6. speed control blades – 3-4 mm plywood or sheet plastic;
7. speed control rods;
8. speed controller load, its weight determines the rotation speed;
9. drive pulley - a bicycle wheel without a tire with a tube;
10. thrust bearing - thrust bearing;
11. driven pulley – standard generator pulley;
12. generator.

Biryukov received several copyright certificates for his APU. First, pay attention to the cut of the rotor. When accelerating, it works like an aircraft, creating a large starting torque. As it spins, a vortex cushion is created in the outer pockets of the blades. From the wind's point of view, the blades become profiled and the rotor becomes a high-speed orthogonal, with the virtual profile changing according to the wind strength.

Secondly, the profiled channel between the blades acts as a central body in the operating speed range. If the wind intensifies, then a vortex cushion is also created in it, extending beyond the rotor. The same vortex cocoon appears as around the APU with a guide vane. The energy for its creation is taken from the wind, and it is no longer enough to break the windmill.

Thirdly, the speed controller is intended primarily for the turbine. It keeps its speed optimal from the KIEV point of view. And the optimum generator rotation speed is ensured by the choice of mechanical transmission ratio.

Note: after publications in the IR for 1965, the Armed Forces of Ukraine Biryukova sank into oblivion. The author never received a response from the authorities. The fate of many Soviet inventions. They say that some Japanese became a billionaire by regularly reading Soviet popular-technical magazines and patenting everything worthy of attention.

Lopadniki

As stated, according to the classics, a horizontal wind generator with a bladed rotor is the best. But, firstly, it needs a stable wind of at least medium strength. Secondly, the design for the DIYer is fraught with many pitfalls, which is why the fruit of long hard work in best case scenario illuminates the toilet, hallway or porch, or even turns out to be only able to promote itself.

According to the diagrams in Fig. Let's take a closer look; positions:

• Fig. A:

1. rotor blades;
2. generator;
3. generator frame;
4. protective weather vane (hurricane shovel);
5. current collector;
6. chassis;
7. swivel unit;
8. working weather vane;
9. mast;
10. clamp for the shrouds.

• Fig. B, top view:

1. protective weather vane;
2. working weather vane;
3. protective weather vane spring tension regulator.

• Fig. G, current collector:

1. collector with copper continuous ring busbars;
2. spring-loaded copper-graphite brushes.

Note: Hurricane protection for a horizontal blade with a diameter of more than 1 m is absolutely necessary, because he is not capable of creating a vortex cocoon around himself. With smaller sizes, it is possible to achieve a rotor endurance of up to 30 m/s with propylene blades.

So, where do we stumble?

Blades

Expect to achieve power on the generator shaft of more than 150-200 W on blades of any size cut from thick-walled plastic pipe, as is often advised, are the hopes of a hopeless amateur. A pipe blade (unless it is so thick that it is simply used as a blank) will have a segmented profile, i.e. its top or both surfaces will be arcs of a circle.

Segmented profiles are suitable for incompressible media, such as hydrofoils or propeller blades. For gases, a blade of variable profile and pitch is needed, for an example, see Fig.; span - 2 m. This will be a complex and labor-intensive product, requiring painstaking calculations in full theory, blowing in a pipe and full-scale testing.

Generator

If the rotor is mounted directly on its shaft, the standard bearing will soon break - there is no equal load on all the blades in windmills. You need an intermediate shaft with a special support bearing and a mechanical transmission from it to the generator. For large windmills, the support bearing is a self-aligning double-row one; V best models– three-tiered, Fig. D in Fig. higher. This allows the rotor shaft not only to bend slightly, but also to move slightly from side to side or up and down.

Note: It took about 30 years to develop a support bearing for the EuroWind type APU.

Emergency weather vane

The principle of its operation is shown in Fig. B. The wind, intensifying, puts pressure on the shovel, the spring stretches, the rotor warps, its speed drops and eventually it becomes parallel to the flow. Everything seems to be fine, but it was smooth on paper...

On a windy day, try holding a boiler lid or a large saucepan by the handle parallel to the wind. Just be careful - the fidgety piece of iron can hit you in the face so hard that it breaks your nose, cuts your lip, or even knocks out your eye.

Flat wind occurs only in theoretical calculations and, with sufficient accuracy for practice, in wind tunnels. In reality, a hurricane damages windmills with a hurricane shovel more than completely defenseless ones. It’s better to change damaged blades than to do everything again. In industrial installations it is a different matter. There, the pitch of the blades, each individually, is monitored and adjusted by automation under the control of the on-board computer. And they are made from heavy-duty composites, not water pipes.

Current collector

This is a regularly serviced unit. Any power engineer knows that a commutator with brushes needs to be cleaned, lubricated, and adjusted. And the mast is made from a water pipe. If you can’t climb, once every month or two you’ll have to throw the entire windmill down to the ground and then pick it up again. How long will he last from such “prevention”?

Video: bladed wind generator + solar panel for power supply to a dacha

Mini and micro

But as the size of the paddle decreases, the difficulties fall according to the square of the wheel diameter. It is already possible to manufacture a horizontal bladed APU on your own with a power of up to 100 W. A 6-bladed one would be optimal. With more blades, the diameter of the rotor designed for the same power will be smaller, but they will be difficult to firmly attach to the hub. Rotors with less than 6 blades need not be taken into account: a 2-blade 100 W rotor needs a rotor with a diameter of 6.34 m, and a 4-blade of the same power needs 4.5 m. For a 6-blade, the power-diameter relationship is expressed as follows :

• 10 W – 1.16 m.
• 20 W – 1.64 m.
• 30 W – 2 m.
• 40 W – 2.32 m.
• 50 W – 2.6 m.
• 60 W – 2.84 m.
• 70 W – 3.08 m.
• 80 W – 3.28 m.
• 90 W – 3.48 m.
• 100 W – 3.68 m.
• 300 W – 6.34 m.

It would be optimal to count on a power of 10-20 W. Firstly, a plastic blade with a span of more than 0.8 m will not withstand winds of more than 20 m/s without additional protection measures. Secondly, with a blade span of up to the same 0.8 m, the linear speed of its ends will not exceed the wind speed by more than three times, and the requirements for profiling with twist are reduced by orders of magnitude; here a “trough” with a segmented pipe profile, pos. B in Fig. And 10-20 W will provide power to a tablet, recharge a smartphone, or illuminate a house-saving light bulb.

Next, select a generator. A Chinese motor is perfect - wheel hub for electric bicycles, pos. 1 in Fig. Its power as a motor is 200-300 W, but in generator mode it will give up to about 100 W. But will it suit us in terms of speed?

The speed index z for 6 blades is 3. The formula for calculating the rotation speed under load is N = v/l*z*60, where N is the rotation speed, 1/min, v is the wind speed, and l is the rotor circumference. With a blade span of 0.8 m and a wind of 5 m/s, we get 72 rpm; at 20 m/s – 288 rpm. A bicycle wheel also rotates at approximately the same speed, so we will take off our 10-20 W from a generator capable of producing 100. You can place the rotor directly on its shaft.

But here the following problem arises: after spending a lot of work and money, at least on a motor, we got... a toy! What is 10-20, well, 50 W? But you can’t make a bladed windmill capable of powering even a TV at home. Is it possible to buy a ready-made mini-wind generator, and wouldn’t it be cheaper? As much as possible, and as cheaply as possible, see pos. 4 and 5. In addition, it will also be mobile. Place it on a stump and use it.

The second option is if a stepper motor from an old 5- or 8-inch floppy drive is lying around somewhere, or from a paper drive or carriage of an unusable inkjet or dot matrix printer. It can work as a generator, and attaching a carousel rotor from cans to it (pos. 6) is easier than assembling a structure like the one shown in pos. 3.

In general, the conclusion regarding “blade blades” is clear: homemade ones are more likely for tinkering to your heart’s content, but not for real long-term energy output.

Video: the simplest wind generator for lighting a dacha

Sailboats

The sailing wind generator has been known for a long time, but soft panels on its blades (see figure) began to be made with the advent of high-strength, wear-resistant synthetic fabrics and films. Multi-bladed windmills with rigid sails are widely used around the world as a drive for low-power automatic water pumps, but their technical specifications are lower even than those of carousels.

However, a soft sail like a windmill wing, it seems, turned out to be not so simple. The point is not about wind resistance (manufacturers do not limit the maximum permissible wind speed): sailboat sailors already know that it is almost impossible for the wind to tear the panel of a Bermuda sail. Most likely, the sheet will be torn out, or the mast will be broken, or the whole vessel will make an “overkill turn.” It's about energy.

Unfortunately, exact test data cannot be found. Based on user reviews, it was possible to create “synthetic” dependencies for the installation of a Taganrog-made wind turbine-4.380/220.50 with a wind wheel diameter of 5 m, a wind head weight of 160 kg and a rotation speed of up to 40 1/min; they are presented in Fig.

Of course, there can be no guarantees for 100% reliability, but it is clear that there is no smell of a flat-mechanistic model here. There is no way a 5-meter wheel in a flat wind of 3 m/s can produce about 1 kW, at 7 m/s reach a plateau in power and then maintain it until a severe storm. Manufacturers, by the way, state that the nominal 4 kW can be obtained at 3 m/s, but when installed by forces based on the results of studies of local aerology.

There is also no quantitative theory to be found; The developers' explanations are unclear. However, since people buy Taganrog wind turbines and they work, we can only assume that the declared conical circulation and propulsive effect are not a fiction. In any case, they are possible.

Then, it turns out, IN FRONT of the rotor, according to the law of conservation of momentum, a conical vortex should also arise, but expanding and slow. And such a funnel will drive the wind towards the rotor, it effective surface it will turn out to be more swept, and KIEV will be over-unit.

Field measurements of the pressure field in front of the rotor, even with a household aneroid, could shed light on this issue. If it turns out to be higher than on the sides, then, indeed, the sailing APUs work like a beetle flies.

Homemade generator

From what has been said above, it is clear that it is better for homemade craftsmen to take on either verticals or sailboats. But both are very slow, and transmission to a high-speed generator is extra work, extra costs and losses. Is it possible to make an efficient low-speed electric generator yourself?

Yes, you can, on magnets made of niobium alloy, so-called. supermagnets. The manufacturing process of the main parts is shown in Fig. Coils - each of 55 turns of 1 mm copper wire in heat-resistant high-strength enamel insulation, PEMM, PETV, etc. The height of the windings is 9 mm.

Pay attention to the grooves for the keys in the rotor halves. They must be positioned so that the magnets (they are glued to the magnetic core with epoxy or acrylic) converge with opposite poles after assembly. “Pancakes” (magnetic cores) must be made of a soft magnetic ferromagnet; Regular structural steel will do. The thickness of the “pancakes” is at least 6 mm.

In general, it is better to buy magnets with an axial hole and tighten them with screws; supermagnets attract with terrible force. For the same reason, a cylindrical spacer 12 mm high is placed on the shaft between the “pancakes”.

The windings that make up the stator sections are connected according to the diagrams also shown in Fig. The soldered ends should not be stretched, but should form loops, otherwise the epoxy with which the stator will be filled may harden and break the wires.

The stator is poured into the mold to a thickness of 10 mm. There is no need to center or balance, the stator does not rotate. The gap between the rotor and stator is 1 mm on each side. The stator in the generator housing must be securely secured not only from displacement along the axis, but also from rotation; a strong magnetic field with current in the load will pull it along with it.

Video: DIY windmill generator

Conclusion

And what do we have in the end? The interest in “blade blades” is explained rather by their spectacular appearance than real performance qualities in a homemade version and at low power. A homemade carousel APU will provide “standby” power for charging a car battery or powering a small house.

But with sailing APUs it is worth experimenting with craftsmen with a creative streak, especially in the mini version, with a wheel 1-2 m in diameter. If the developers’ assumptions are correct, then it will be possible to remove all 200-300 W from this one, using the Chinese engine-generator described above.

Making a frame (spar) for a sail rotor is not difficult. In addition, sailing APUs are safe, and the sounds from them, infra- and audible, are not detected. And you don’t need to understand the rotor too high; one wheel diameter is enough.

Video: wind turbine production technology

A wind generator from a car generator is a good alternative to a factory device, which costs from several tens to several hundred thousand rubles. For assembly you will need to build blades, a mast and slightly change the design of the autogenerator.

About homemade windmills for home

Particular interest in wind energy is evident at the household level. This is understandable if you glance at the next bill for consumed energy. Therefore, all kinds of craftsmen are becoming more active, using all the possibilities of obtaining electricity inexpensively.

One of these possibilities, quite real, is closely related to a windmill from a car generator. A ready-made device - a car generator - just needs to be equipped with correctly made blades in order to be able to remove some value of electrical energy from the generator terminals.

True, it will work effectively only if there is windy weather.

Case Study household use wind generators. A well-developed and quite effective practical windmill design. A three-bladed propeller is installed, which is rare for household devices

The use of virtually any automobile generator is acceptable for constructing a windmill. But they usually try to choose a powerful model for the job, capable of delivering high currents. Here, the design of generators from trucks, large passenger buses, tractors, etc. is at the peak of popularity.

In addition to the generator, to manufacture a windmill you will need a number of components:

• two- or three-blade propeller;
• car battery;
• electrical cable;
• mast, support elements, fasteners.

The design of the propeller with two or three blades is considered the most optimal for a classic wind generator. But a household project is often far from an engineering classic. Therefore, most often they try to select ready-made screws for a home structure.

An impeller from a car fan that will be used as a propeller for a home wind turbine. Lightness and large useful area for air force allow the use of such options

This, for example, could be an impeller from an external unit of a split air conditioning system or from a fan of the same car. But when you want to follow the traditions of constructing wind generators, you will have to build the windmill propeller from start to finish with your own hands.

Before deciding to assemble and install a wind generator, it is worth assessing the climatic data of the site and calculating the payback. Significant assistance in this will be provided by information very interesting article, which we recommend for familiarization.

Wind generator design

There is a huge variety of types of wind generators and drawings for their manufacture. But any design includes the following mandatory elements:

• generator;
• blades;
• storage battery;
• mast;
• the electronic unit.

With some skills, you can make a wind generator with your own hands

In addition, it is necessary to think through the control and distribution system of electricity in advance and draw an installation diagram.

Advantages and disadvantages of using a car generator

Using a car generator as an element of a wind power plant provides significant advantages:

• There is a ready-made generator that can be used without intervention or with some modification.
• A car generator produces a stable voltage, which is important for windmills with their constantly changing rotation speed.
• Standard equipment is used that is accessible and does not require intervention in the design.
• Car alternators are widely available, making them repairable and easy to replace if necessary.

Along with the advantages, there are also some disadvantages:

• A car generator requires a high rotation speed, which requires the use of a step-up gearbox or changes in the design of the device.
• The resource of a car generator is limited to approximately 4000 hours of operation (on average). Even a new generator will not withstand even a year of continuous operation and will require repairs.
• The excitation system of some generators requires voltage to be applied to the coil, which forces them to change the design and install permanent magnets.

Despite the existing shortcomings, a car generator is considered the best option, possible with the independent creation of a wind power plant.

We make a wind wheel

The blades are perhaps the most important part of a wind generator. The operation of the remaining components of the device will depend on the design. They are made from different materials. Even from a plastic sewer pipe. Pipe blades are easy to manufacture, inexpensive and not susceptible to moisture. The procedure for manufacturing a wind wheel is as follows:

1. It is necessary to calculate the length of the blade. The diameter of the pipe should be equal to 1/5 of the total footage. For example, if the blade is one meter long, then a pipe with a diameter of 20 cm will do.
2. Using a jigsaw, cut the pipe lengthwise into 4 parts.
3. From one part we make a wing, which will serve as a template for cutting out subsequent blades.
4. We smooth out burrs on the edges with abrasive.
5. The blades are fixed to an aluminum disk with welded strips for fastening.
6. Next, the generator is screwed to this disk.

Blades for wind wheel

After assembly, the wind wheel needs balancing. It is mounted horizontally on a tripod. The operation is carried out in a room closed from the wind. If the balancing is carried out correctly, the wheel should not move. If the blades rotate on their own, then they need to be sharpened until the entire structure is balanced.

Only after successful completion of this procedure should you proceed to checking the accuracy of rotation of the blades; they should rotate in the same plane without distortion. Please allow 2mm error.

Generator assembly diagram

Making a mast

To make a mast, an old water pipe with a diameter of at least 15 cm and a length of about 7 m is suitable. If there are buildings within 30 m of the intended installation site, then the height of the structure is adjusted upward. For efficient work Blade wind turbines lift the obstacle at least 1 m above the obstacle.

The base of the mast and the pegs for securing the guy wires are concreted. Clamps with bolts are welded to the stakes. For guy wires, galvanized 6 mm cable is used.

Advice. The assembled mast has considerable weight; if installed manually, you will need a counterweight made of a pipe with a load.

Remaking a nuclear-powered generator

To make a windmill generator, a generator from any car is suitable. Their designs are similar to each other, and the modification boils down to rewinding the stator wire and making a rotor with neodymium magnets. Holes are drilled in the rotor poles to fix the magnets. Install them alternating poles. The rotor is wrapped in paper, and the voids between the magnets are filled with epoxy resin.

Car generator

In the same way, you can remake the engine from an old washing machine. Only the magnets in this case are glued at an angle to avoid sticking.

The new winding is rewound along the reel onto the stator tooth. You can make a random winding, depending on who you are comfortable with. The greater the number of turns, the more efficient the generator will be. The coils are wound in one direction according to a three-phase circuit.

The finished generator is worth testing and measuring data. If at 300 rpm the generator produces about 30 volts, this is a good result.

Generator for a windmill from a car generator

Final assembly

The generator frame is welded from profile pipe. The tail is made of galvanized sheet. The rotary axis is a tube with two bearings. The generator is attached to the mast in such a way that the distance from the blade to the mast is at least 25 cm. For safety reasons, it is worth choosing a calm day for the final assembly and installation of the mast. When exposed to strong winds, the blades can bend and break against the mast.

To use batteries to power equipment that operates on a 220 V network, you will need to install a voltage conversion inverter.

The battery capacity is selected individually for the wind generator. This indicator depends on the wind speed in the area, the power of the connected equipment and the frequency of its use.

Wind generator device

To prevent the battery from being damaged by overcharging, you will need a voltage controller. You can make it yourself if you have sufficient knowledge in electronics, or buy a ready-made one. There are many controllers available for sale for alternative energy production mechanisms.

Advice. To prevent the blade from breaking in strong winds, install a simple device - a protective weather vane.

Two-bladed propeller for a generator without modification

In principle, if you install a high-speed two-blade propeller with a diameter of 1-1.2 meters on the generator, then such speeds can easily be achieved in a wind of 7-8 m/s. This means you can make a windmill without modifying the generator, only it will work in winds of 7 m/s. Below is a screenshot with data for a two-blade propeller. As you can see, the speed of such a propeller in a wind of 8 m/s is 1339 rpm.

With a wind of 10 m/s, the speed will be (1339:8*10=1673 rpm), the voltage at idle (14:1200*1673=19.5 volts), and under battery load (19.5-13=6.5:0.4=16.2 amperes *13=210 watts). The result is 210 watts of power minus 40 watts per coil, leaving 170 watts of useful power. At 12 m/s it will be approximately 2008 rpm, no-load voltage 23.4 volts, current 26 amperes, minus 3 amperes for excitation, and then 23 amperes battery charging current, power 300 watts.

If you make the screw of a smaller diameter, the speed will increase further, but then the screw will not pull the generator when it reaches the battery charging threshold. I considered different options while writing this article and a two-blade propeller turned out to be the most optimal for the generator without modification.

In principle, if you count on winds of 7 m/s and above, then such a wind generator will work well and produce 300 watts at 12 m/s. At the same time, the cost of the windmill will be very small, essentially only the price of the generator, and the propeller and the rest can be made from what is available. Only the screw must be made according to calculations.

A properly converted generator begins to charge at 4 m/s, at 5 m/s the charging current is already 2 amperes, and since the rotor is on magnets, all the current goes to the battery.

At 7 m/s the charging current is 4-5 amperes, and at 10 m/s it is already 8-10 amperes. It turns out that only in a strong wind of 10-12 m/s can a generator without modification be comparable to a converted one, but it will not give anything in a wind less than 8 m/s.

Self-excitation of a car generator

In order for the generator to self-excite without a battery, you need to put a couple of small magnets in the rotor. If the excitation coil is powered from a battery, then it will constantly, regardless of whether the wind generator generates energy or not, consume its 3 amperes and charge the battery. To prevent this from happening, you need to install a blocking diode so that the current flows only into the battery and does not go back.

You can also use a so-called tablet, that is, a relay-regulator like in a car, which will turn off the excitation if the battery voltage reaches 14.2 volts, so as not to overcharge. Below is a diagram of the self-excitation of the generator. In general, the generator itself is excited because the rotor has residual magnetization, but this happens at high speeds; it is better to add magnets for reliability. The circuit includes a relay regulator, but it can be excluded. A decoupling diode is needed so that the battery does not discharge because without the diode, current will flow into the field winding (rotor).

Since the wind generator will be very small with a propeller with a diameter of only 1 meter, no protection from strong winds is needed and nothing will happen to it if there is a strong mast and a strong propeller.

There are 28-volt generators, but if they are used to charge a 12-volt battery, then the revolutions needed are half as much, about 600 rpm.

But since the voltage will not be 28 volts, but 14, the excitation coil will provide only half the power and the generator voltage will be less, so nothing will come of it. You can, of course, try putting a 12-volt rotor in a generator whose stator is wound at 28 volts, then it should be better and charging will start earlier, but then you need two identical generators to replace the rotor, or look for a separate rotor or stator.

Analysis of design errors

Assembling a wind generator at home with your own hands is, of course, not an infallible task. Even in the designs of industrial wind turbines, engineers make mistakes. But they learn from mistakes, as evidenced by well-established household structures.

So, among the errors in the design of household wind generators, such a detail often appears as the absence of a braking module in the design of the generator. The standard version of such devices (automotive or tractor) does not provide such a part. This means that the generator needs to be modified.

However, not every “designer” wants to deal with this delicate matter. Many people ignore this detail, hoping for “maybe.” As a result, in strong winds the propeller spins to incredibly high speeds. The generator bearings cannot withstand it and break the seats of the aluminum covers. The rotor becomes wedged.

The same issue relates to the defect associated with the lack of a weather vane rotation limiter. Often this component is simply forgotten to be installed and remembered only when wind currents begin to spin the “cockerel” around its axis, like the spinning top in the program “What? Where? When?". The result is disastrous.

The minimum damage is kinking and breaking of the electrical cable, and in severe cases, destruction of the entire structure.

Another notable assembly error was the incorrect calculation of the center of gravity point on the base of the weather vane. In this case, the device may function normally for some time. But over time, a misalignment forms on the bearing assembly, freedom of rotation is limited, and the efficiency of the structure in terms of energy output decreases sharply.

Often, they try to directly power the battery with the current received from the generator. Very soon they begin to wonder why the battery does not hold a charge or they discover a breakdown of 2-3 cans.

This is a banal and natural mistake, since in any case, the battery must be charged under conditions of certain currents and voltages. Here we need control of this process.

Device maintenance

In order for a wind turbine to operate for many years without interruption, it is necessary to carry out periodic technical monitoring and maintenance.

1. The current collector needs to be cleaned, lubricated and adjusted once every 2 months.
2. Repair the blades if vibration and imbalance occur during rotation.
3. Once every 3 years, paint metal elements with anti-corrosion paint.
4. Check and adjust the mast fastenings and cable.

The efficiency of the device is affected by the area where the wind generator is installed (wasteland, presence of winds). But in any case, having this source of energy, independent of the stationary power supply, will never be superfluous.

Video

Payment for electricity today takes up a significant share of the cost of maintaining a home. IN apartment buildings, the only way to save money is to switch to energy-saving technologies and optimize costs using multi-tariff schemes (night mode is paid at reduced prices). And if you have a personal plot, you can not only save on consumption, but also organize an independent energy supply for your private home.

This is a normal practice that originated in Europe and North America, and over the last couple of decades it has been actively implemented in Russia. However, equipment for autonomous power supply is quite expensive; the payback to “zero” does not occur earlier than after 10 years. In some states, it is possible to return energy to public networks at fixed rates, this reduces the payback time. IN Russian Federation To obtain a “cashback” you need to go through a number of bureaucratic procedures, so most users of “free” energy prefer to build a wind generator with their own hands and use it only for personal needs.

Legal side of the issue

A homemade wind generator for the home is not prohibited; its manufacture and use does not entail administrative or criminal penalties. If the power of a wind generator does not exceed 5 kW, it is classified as a household appliance and does not require any approval from the local energy company. Moreover, you are not required to pay any taxes if you do not make a profit when selling electricity. In addition, a homemade generating windmill, even with such productivity, requires complex engineering solutions: it’s easy to make it. Therefore, the power of a homemade product rarely exceeds 2 kW. Actually, this power is usually enough to power a private home (of course, if you do not have a boiler and a powerful air conditioner).

In this case, we are talking about federal legislation. Therefore, before making a decision to make a windmill with your own hands, it would be a good idea to check the presence (absence) of regional and municipal regulations that may impose some restrictions and prohibitions. For example, if your house is located in a specially protected natural area, the use of wind energy (and this natural resource) may require additional approvals.

Problems with the law can arise if you have troublesome neighbors. Windmills for home are classified as individual buildings, so they are also subject to some restrictions:

Types of generators

Before deciding how to make a wind generator with your own hands, let’s consider the design features:

According to the location of the generator, the device can be horizontal or vertical

According to the generated voltage rating

Typical examples of homemade wind generators

The design of the wind generator is the same, regardless of the chosen scheme.

• A propeller that can be installed either directly on the generator shaft or using a belt (chain, gear) drive.
• The generator itself. This can be a ready-made device (for example, from a car), or a regular electric motor, which generates electric current when rotated.
• Inverter, voltage regulator, stabilizer - depending on the selected voltage.
• Buffer element - rechargeable batteries that ensure continuity of generation, regardless of the presence of wind.
• Installation structure: mast, roof mounting bracket.

Propeller

Can be made from any material: even from plastic bottles. True, flexible blades significantly limit power.

It is enough to cut cavities in them to take in the wind.

A good option is a household windmill made from a cooler. You get a finished design with professionally made blades and a balanced electric motor.

A similar design is made from a cooler for computer power supplies. True, the power of such a generator is scanty - unless you light an LED lamp or charge a mobile phone.

However, the system is quite functional.

Good blades are made from aluminum sheets. The material is available, it is easy to mold, and the propeller is quite light.

If you are creating a rotary propeller for a vertical generator, you can use tin cans, cut lengthwise. For powerful systems, halves are used steel barrels(up to a volume of 200 liters).

Of course, you will have to approach the issue of reliability with special care. Powerful frame, shaft on bearings.

Generator

As mentioned above, you can use a ready-made automobile motor or an electric motor from industrial electrical installations (household appliances). As an example: a wind generator made from a screwdriver. The entire structure is used: engine, gearbox, cartridge for attaching the blades.

A compact generator is obtained from a printer stepper motor. Again, the power is only enough to power LED lamp or smartphone charger. In nature - an irreplaceable thing.

If you are comfortable with a soldering iron and have a good understanding of radio engineering, you can assemble the generator yourself. Popular scheme: wind generator using neodymium magnets. Advantages of the design - you can independently calculate the power for the wind load in your area. Why neodymium magnets? Compact with high power.

You can remake the rotor of an existing generator.

Or create your own design, with the manufacture of windings.

The efficiency of such a windmill is an order of magnitude higher than when using a circuit with an electric motor. Another undeniable advantage is compactness. The neodymium generator is flat and can be placed directly in the center coupling of the propeller.

Mast

The manufacture of this element does not require knowledge of electronics, but the viability of the entire wind generator depends on its strength.

For example, a mast 10–15 meters high requires properly calculated guy wires and counterweights. Otherwise, a strong gust of wind may topple the structure.

If the generator power does not exceed 1 kW, the weight of the structure is not so large, and issues of mast strength fade into the background.

Bottom line

A homemade wind generator is not as complex a design as it might seem at first glance. Taking into account the high cost of factory products, you can save a lot by making a home wind power plant and completely available materials. Taking into account the small costs of creating a windmill, it will pay for itself fairly quickly.

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