General principle of operation

The main working body of the wind generator is the blades, which rotate the wind. Depending on the location of the axis of rotation, wind turbines are divided into horizontal and vertical:

• Horizontal wind turbines the most widespread. Their blades have a design similar to an aircraft propeller: in the first approximation, these are plates inclined relative to the plane of rotation, which convert part of the load from wind pressure into rotation. An important feature of a horizontal wind generator is the need to ensure the rotation of the blade assembly in accordance with the direction of the wind, since maximum efficiency is ensured when the direction of the wind is perpendicular to the plane of rotation.
• blades vertical wind generator have a convex-concave shape. Since the streamlining of the convex side is greater than the concave side, such a wind generator always rotates in the same direction, regardless of the direction of the wind, which makes the rotary mechanism unnecessary, unlike horizontal windmills. At the same time, due to the fact that at any time only a part of the blades performs useful work, and the rest only oppose rotation, The efficiency of a vertical windmill is much lower than that of a horizontal one.: if for a three-bladed horizontal wind generator this figure reaches 45%, then for a vertical one it will not exceed 25%.

Since the average wind speed in Russia is low, even a large windmill will rotate quite slowly most of the time. To ensure sufficient power supply, it must be connected to the generator through a step-up gearbox, belt or gear. In a horizontal windmill, the blade-gear-generator assembly is mounted on a pivoting head that enables them to follow the direction of the wind. It is important to note that the swivel head must have a limiter that prevents it from making a full turn, since otherwise the wiring from the generator will be cut off (the option using contact washers that allow the head to rotate freely is more complicated). To ensure rotation, the wind generator is supplemented by a working weather vane directed along the axis of rotation.

The most common blade material is large diameter PVC pipe cut lengthwise. Along the edge, metal plates are riveted to them, welded to the hub of the blade assembly. Drawings of this kind of blades are the most widely distributed on the Internet.

The video tells about a wind generator made by hand

Calculation of a bladed wind generator

Since we have already found out that a horizontal wind generator is much more efficient, we will consider the calculation of its design.

Wind energy can be determined by the formula
P=0.6*S*V³, where S is the area of ​​the circle described by the ends of the propeller blades (sweeping area), expressed in square meters, and V is the estimated wind speed in meters per second. You also need to take into account the efficiency of the windmill itself, which for a three-blade horizontal circuit will average 40%, as well as the efficiency of the generator set, which at the peak of the current-speed characteristic is 80% for a generator with excitation from permanent magnets and 60% for a generator with excitation winding. Even an average of 20% of the power will be consumed by a step-up gearbox (multiplier). Thus, the final calculation of the radius of the windmill (that is, the length of its blade) for a given power of a permanent magnet generator looks like this:
R=√(P/(0.483*V³))

Example: Let's take the required power of the wind power plant as 500 W, and the average wind speed as 2 m/s. Then, according to our formula, we will have to use blades with a length of at least 11 meters. As you can see, even such a small power will require the creation of a wind generator of colossal dimensions. For more or less rational constructions with a blade length of no more than one and a half meters, which are more or less rational in the conditions of making their own hands, the wind generator will be able to produce only 80-90 watts of power even in strong winds.

Not enough power? In fact, everything is somewhat different, since in fact the load of the wind generator is fed by batteries, the windmill only charges them to the best of its ability. Therefore, the power of the wind turbine determines the frequency with which it will be able to supply energy.

A wind generator made from a car generator can help in a situation where there is no way to connect to a power line in a private house. Or serve as an auxiliary source of alternative energy. Such a device can be made from improvised materials, using the achievements of craftsmen. Photos and videos will demonstrate the process of creating a homemade wind turbine.

There is a huge species diversity of wind turbines and drawings of their manufacture. But any design includes the following mandatory elements:

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

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

wind wheel

The blades are perhaps the most important part of a wind turbine. 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. Blades from a pipe are easy to manufacture, are cheap and are not affected by moisture. The wind turbine manufacturing process 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 meter long, then a pipe with a diameter of 20 cm will do.
2. We cut the pipe with a jigsaw along into 4 parts.
3. We make a wing from one part, which will serve as a template for cutting subsequent blades.
4. We smooth out the burr on the edges with an abrasive.
5. The blades are fixed to an aluminum disk with welded strips for fastening.
6. Next, the generator is screwed to this disk.

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

Only after the successful completion of this procedure, you should proceed to check the accuracy of rotation of the blades, they should rotate in the same plane without skew. An error of 2 mm is allowed.

Mast

For the manufacture of the mast, an old water pipe with a diameter of at least 15 cm, 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 upwards. For efficient operation of the wind turbine, the blade is raised above the obstacle by at least 1 m.

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

Advice. The assembled mast has a considerable weight, with manual installation you will need a counterweight from a pipe with a load.

Alteration of the generator

For the manufacture of a windmill generator, a generator from any car is suitable. Their designs are similar to each other, and the alteration comes down to rewinding the stator wire and making the rotor on neodymium magnets. Holes are drilled in the poles of the rotor to fix the magnets. Install them by alternating poles. The rotor is wrapped in paper, and the voids between the magnets are filled with epoxy.

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

The new winding is rewound along the coil onto the stator tooth. You can make a bulk winding, it's convenient for anyone. The greater the number of turns, the more efficient the generator will be. Coils are wound in one direction according to a three-phase scheme.

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

final assembly

The generator frame is welded from a 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, a calm day should be chosen for the final assembly and installation of the mast. The blades under the influence of a strong wind can bend and break on the mast.

To use batteries to power equipment that runs on 220 V, 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.

To prevent the battery from failing from overcharging, you will need a voltage controller. You can make it yourself if you have sufficient knowledge in electronics, or buy ready-made. There are many controllers for alternative energy mechanisms on the market.

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

Wind turbine maintenance

A wind generator, like any other device, needs technical control and maintenance. For the smooth operation of the windmill, the following work is periodically carried out.

1. The current collector requires the most attention. Generator brushes need cleaning, lubrication and preventive adjustment every two months.
2. At the first sign of a blade malfunction (trembling and imbalance of the wheel), the wind generator is lowered to the ground and repaired.
3. Once every three years, metal parts are coated with anti-corrosion paint.
4. Regularly check the fastenings and tension of the cables.

Now that the installation is complete, you can connect appliances and use electricity. At least as long as it's windy.

DIY windmill generator: video

Wind turbine generator from a car generator

Alternator from a car Advantages: cheap, easy to find, already assembled.

Disadvantages: Extreme speed required, gear or pulley required, low energy output, current collector requires constant maintenance.

Suitability for wind farm: low.

The main problem with the use of auto generators for windmills- the fact that they were invented for very high speeds - to obtain wind energy, you have to perform a lot of significant transformations. Even a small and relatively fast windmill requires a speed of 600 rpm, which is not even close to sufficient for an auto generator. This means that it will be necessary to use gears or pulleys so that most of the energy is spent on rotation. A standard auto generator is electromagnetic - that is, part of the generated energy must be sent to the anchor through brushes and current collectors in order to create a magnetic field. The generator, which uses electricity to create a field, is the least efficient and most difficult. However, it is easier to calibrate since the magnetic flux can be changed by setting the field strength. In addition, brushes and current collectors tend to wear out, requiring consistent care. The generator can still be rewound to produce power at the lowest possible speeds. This may be a method of replacing the existing stator turns with the most frequent turns of the narrowest alloy steel.

Magnetic wind turbine generator

Homemade generator with permanent magnets Advantages: low price per kilowatt-hour, high efficiency. can be getting a lot of power, amazingly strong design.

Disadvantages: Labor-intensive, difficult project requiring finishing on a lathe.

Suitability for a wind farm: excellent.

Numerous experiments have shown that a handmade permanent magnet generator is a more massive and economical solution for a wind turbine. It is able to operate unsurpassed at low speeds of rotation, while at high speeds it practically delivers amps due to its own efficiency. Most often handmade generators are made from Volvo brake discs, as they are extremely strong and have integrated thrust bearings. Since such a generator produces an unstable current, a valve is required to convert it into a constant current and then charge the battery. A three-phase generator gives the best results, but it is more difficult to build than a mono-phase one, so when building a generator, you need to decide whether you can build a three-phase one or limit yourself to a single-phase one. A wind turbine generator 7 feet across puts out over 60 amps into a 12 volt battery, that's over 700 watts. At peak power it can deliver even 100 A. So far this conclusion is more excellent.

Conversion asynchronous generator for windmill

Convertible asynchronous alternator Advantages: cheap, easy to find, relatively easy to re-equip, excellent service at low speeds.

Disadvantages: resulting capacity is limited by internal resistance, inefficient at high speeds, requires finishing on a lathe.

Suitability for wind farm: medium.

A conventional asynchronous electric motor that produces an unstable current can quite simply exist and be rebuilt into a generator with permanent magnets. Experiments show that the resulting oscillator works great at extremely low speeds, but soon becomes inefficient at high speeds. The asynchronous motor does not have any wires in the core, only variable plates of aluminum and steel (they look smooth from the outside). If you gouge grooves in the center of the core and insert permanent magnets there, the electric motor will be a permanent magnet generator. In practice, such a generator produces about 10-20 A. It very soon becomes ineffective: with an increase in wind speed, the number of resulting amperes grows non-cardinally, while the rest of the capacity is spent on heating the generator itself. The asynchronous electric motor is wound with a very narrow wire and cannot be helped by a great power current. For the same 7-foot windmill, the peak current draw is the same only 25 A. If you are comfortable with small current at high wind speeds, an asynchronous motor may turn out to be a good solution. It is recommended to choose a three-phase motor. Since such a generator produces an unstable current, a valve is required to convert it into a constant current and then charge the battery.

Windmill DC Generator

DC generator Advantages: common and already organized, some work well at low speeds.

Wind turbine generator

The price of electricity is constantly growing and this forces the owners of country houses to look for new sources of electricity. It may be alternative. that is, renewable sources of electricity - wind farms, which are otherwise called wind turbines. They generate electrical energy with the help of moving air masses, that is, wind. Stationary windmills are able to fully provide power to a residential building or even a small industrial facility and accumulate a resource in order to provide energy in a calm period.

Problems with purchasing generators

When building a windmill, many are faced with the problem of choosing a generator, but it is quite difficult to buy them, since they are very expensive, this is a rather specific thing and there are not so many of them. That is why you have to somehow get out of the situation and adapt to realities. Most often, it is easier to make a generator for a windmill yourself.

What can a generator be made of?

You can take permanent magnet motors, car generators, stepper motors or asynchronous, as well as generators from broken gas generators. That is, any electric motors can be used, since all of them, under certain conditions, can work as generators, but with different efficiency. Also, their alterations can be both serious and not very serious, and, sometimes, with the investment of some funds. Why remodel? Everything is easy to explain - all these motors are high-speed, except for steppers, at least 1000 rpm. If we talk about the speed parameters of a windmill, then when calculating it, taking into account the wind speed and the size of the structure itself, it turns out that the speed of the windmill, even the fastest, is only from two hundred to four hundred revolutions per minute, despite the strong wind.

Of the low-speed generators, there are only, as already mentioned, stepper motors. In fact, this is an engine that turns you at a certain angle, that is, a step when a voltage pulse is applied to the windings. Such a motor has several windings, and there are a lot of magnets in the rotor. All these qualities make it possible to use a stepper motor as a generator for a windmill. If you give rotation to the shaft of such an engine from the outside, then it will begin to efficiently generate electricity.

To be sure that this motor is stepper, you need to make sure that it rotates in jerks, and not smoothly, that is, an effect called "sticking" is created. When you try to short-circuit all the outputs of the motor, the shaft starts to rotate harder, then this motor has already begun to generate electricity. It should be noted that all DC motors are tested in this way. That is, if you check any engine, do the above operation and the shaft becomes more difficult to rotate, then this electric motor can be used as a generator and therefore you need to carefully study its characteristics.

Homemade windmill generator

Some craftsmen make the generator themselves. Such a homemade product is a single-phase generator with a magnetic system with so-called "claw" poles, similar to those used in automobile generators, but the "claws" in the former are located axially, not radially. The magnetic field is generated by eight N42 neodymium magnets attached to the rotor. When the rotor begins to rotate, the "claws" create a change in the magnetic field in the coil, at the output of which an alternating voltage is formed.

Generators for wind turbines

• Generator energy wind 1 kW.

Generator for wind farm with a power of 1 kW.

Price: 32,500 rubles.

Generator for wind farm power of 2 kW.

Price: 40,000 rubles.

Generator for a wind farm with a capacity of 3 kW.

Price: 68 000 rubles.

Generator to 4 kW.

Price: 85,000 rubles.

Generator for wind farm with a power of 5 kW.

Price: 130,000 rubles.

Generator for wind farm power of 6.5 kW.

Price: 200,000 rubles.

Generator for wind farm power of 8 kW.

Price: 240,000 rubles.

Generator for wind power plant 10 kW.

Wind power generator. How to make a windmill and an electric generator yourself.

Chapter. ECO power supply

So, the most popular option is to use windmills to generate electricity.

It would seem - what is easier, made a windmill, planted an electric generator on its axis and voila! Get electricity!

But not everything is so simple. Let's look at why.

All windmills or wind turbines are driven (rotated) by the force of the wind. We have already talked about the power of the wind flow. And it is clear that we will not be able to get more energy from the generator in principle.

Another important characteristic of a windmill is the so-called. KIEV - wind energy utilization factor. For the best examples of windmills, it is only 40-45%! (Although one can come across statements about almost 60-80% of KIEV. This, to put it mildly, is an exaggeration of the sellers of these windmills. Therefore, expect that the windmill will use the wind by hardly 25-30% and do not forget to divide the calculated windmill power by 3 -4 This is what you can really get from a wind turbine if you use an ideal electric generator.

By the way, about the power of the windmill. You may not believe it, and it looks really paradoxical, but the only thing that determines the power of a windmill (except wind speed) is its area. Sometimes it is called the "sweeping area". Many formulas of mathematical proofs and practical proofs can be given, but the power of a windmill with one blade (which sweeps - describes a circle with a diameter D), and a windmill with 6 blades of this diameter is the same! Believe it or not, but it's true!

The fact is that the wind perceives the blades not as separate “planks” and presses on each one in turn, but as a circle, a disk. Therefore, only the area is important, not the number of blades. The wind, spinning the blades of the windmill, gives it speed. In addition to the angular velocity of rotation, the blade also has a linear velocity. And consequently, since it is not spinning in a vacuum, it begins to meet air resistance, which grows in proportion to the cube of speed. Moreover, the blade is not a flat plate, but a certain aerodynamic profile, which has both a specific thickness and an angle of rotation. And this profile during rotation "stumbles" on the air of the "interblade" space. And it turns out that the more flow power we are going to collect by increasing the number of blades, the more air resistance they experience during rotation. As a result - what is written above - the power of the windmill depends on the sweeping area, and not on the number of blades.

Thus, we come to another important characteristic of a windmill - speed. The speed of a windmill is a value that shows how much the linear speed of the blade is greater than the speed of the wind. If you find out, for example, that a windmill has a speed of 7, then this means that the tip of its blade has a linear speed of 7 times the speed of the wind. And with a wind of 10 m / s, the tip of the blade flies through the air at a speed of 70 m / s, i.e. 250 km / h! So I strongly do not recommend trying to stop the blade with your hands. They just cut like a razor.

We will return to speed and its calculation, but now let's see why it is important specifically for the process of generating electricity.

It has long been customary in Rus' that electricity is produced here with the help of special devices - generators. There are many designs of generators, but in terms of docking with a windmill, we are interested in electric generators that produce electricity as a result of rotation. In fact, why should we seek good from good. The windmill supplies us with rotation, and we must use it.

So, when building a windmill, you will definitely come across the fact that there are NO generators suitable for a windmill. Well, actually, they are in nature, they are even mass-produced. But buying them is quite problematic both in price and if possible. This is too specific a thing, that's why they are expensive and there are few of them. Therefore, you will either have to adapt what is, or make the generator yourself.

And what do we have to eat electricity? From finished. Choice of food is generally poor. These are permanent magnet motors, stepper motors, automobile generators, asynchronous motors, generators from dead gas generators. In general, almost any electric motors. We will analyze them in detail later. According to all theories, every electrical machine is reversible. Those. any electric motor under appropriate conditions can work as a generator. with some degree of efficiency. With this or that seriousness, degree and price of alteration.

Why can't we just use what we have? Yes, because it's all fast! You can take this exclamation mark as a sign of mourning. Well, except for stepper motors. They are, by definition, slow moving. The rest of all engines - generators are designed for 1000 rpm and above (i.e. 15-20 rpm). Appropriate speed they must be given to obtain the opposite effect - the generation of electric current. For example, it would seem that the most affordable and cheapest option for a decent generator of 0.5 kW - automobile, comes across a figure of 2-3 thousand rpm. The engine of the car, even at idle, keeps rotating at a speed of 800 rpm. Plus, the animation of the motor and generator pulleys is 1: 2 at least. The generator is already spinning at 1500 rpm. And if you give in to the gas and “turn off” the engine to 3-4 thousand (an ordinary case), then the generator gives out its half a kilowatt. At 5-8 thousand revolutions / min.

The same goes for other motors. Whatever you grab - less than 1000 rpm and not find anything.

Returning to the speed parameter of the windmill and recalculating it taking into account the wind speed, the size of the windmill, you will be surprised to find that the speed of the windmill shaft is not so high. 200-400 rpm for the fastest windmills and with a good strong wind!

Let's put a multiplier, you say, and increase the turnover by 5-10 times! (By the way, what reduces speed is a gearbox. And what increases it is a multiplier). Well, in fairness, I’ll say - so, in general, that’s what is done. But only on very large and powerful windmills, in order to spin large and powerful generators. On windmills with a power of less than 500 watts, multipliers are a luxury. A reliable and high-quality maintenance-free multiplier with low losses is an expensive device in itself. And its price, respectively, is transferred to the cost of electricity generated. Therefore, the use of a multiplier in a small "home" windmill is unreasonable in any way. Unless he got it for free.

And from low-speed generators, we have only stepper motors. What is a stepper motor? This is an engine that rotates its shaft at a certain angle (step) when a voltage pulse is applied to its windings. Such motors usually have several windings, and the rotor is literally crammed with magnets. This gratifying fact allows you to use stepper motors as a generator. When the shaft of a stepper motor is given rotation from the outside, it begins to generate electricity, and very efficiently.

"Calculating" a stepper motor is easy. When the shaft rotates, it does not rotate smoothly, but as if in shocks. This effect is called "sticking". If you short-circuit all the motor leads, then it will become noticeably more difficult to rotate the shaft. This means that the stepper motor is already generating electricity. By the way, this is the general principle of checking DC motors for “lice”. If, when shorting the conclusions, it became more difficult to rotate the motor shaft, then the electric motor in terms of using it as an electric generator is not hopeless and it makes sense to remove its characteristics.

It is not difficult to get a low-power stepper motor. Any printer that can be bought at an online auction for 100-300 rubles contains at least 2 of them. One “chased” the head, the other - paper. Scanner - 1, old 5.25-inch drives - also 1. This is good news. The bad news is that only very low power stepper motors are readily available! 1-2-3 watts. Getting a stepper motor of at least 30-50 watts is a rare success, consider that you have an excellent generator in your pocket!

Where to use a 2 watt stepper? Yes, in general, charge the battery of a mobile phone, player, etc. This power is enough. Do you need 10-20 watts? Well, put 10 of these engines. They are cheaper than eggshells after Easter.

Well, if you want to get 200-300 watts from a windmill, and preferably cheaply (keep in mind the cost / return ratio), then most likely you will have to make the generator yourself. It is difficult, but absolutely realistic if you still decide to make a wind power generator.

Wind turbine generator 2m

I suggest you get acquainted with our development of a generator for a windmill, which is distinguished by the fact that the magnets and coils are located axially, along the axis of rotation of the generator

The generator itself is 4-phase (the ratio of the number of magnets to the number of coils is 3/4). This and the fact that the cores of the magnetic cores are located at an angle to the magnets made it possible, in the latest version of the generator, to achieve a small tooth effect. I didn’t measure it, but since the assembled generator is pulled by Lego with the left hand, I can assume that the moment is no more than 50 ... 60 grams per meter. Generator weight - 6.9 kg.

The second feature is magnetic circuits - 22 microns nanocrystalline tape of our Ukrainian production. The core based on it works with much lower losses at frequencies of tens of kHz.

Cores are relatively expensive.

Now we are designing a similar generator for 10 kW, a similar engine (though three-phase), and of course a windmill with an adjustable head (centrifugal blade angle regulator).

Windmill Generator

Windmill from a car generator without alteration

Each "Kulibin" has his own vision of how to make a simple wind generator at home. After a long search on the Internet, I have developed some general idea. The idea is not new or unique, but it is easy to implement and relatively inexpensive.

At a local hardware store, I bought pipes, an adapter tee, a plug and a few meters of 3/8-16 wires (some 3/8-16 all thread). For this creation, I found a GM 7127 alternator in my stock. On the Internet, I found a company that sells high-voltage stator coils, another company sells transmission, and from a third I bought an electronic controller to easily monitor the process of charging my battery .

At a local hardware store, I bought pipes, an adapter tee, a plug and a few meters of 3/8-16 wires (some 3/8-16 all thread). For this creation, I found a GM 7127 alternator in my stock. On the Internet, I found a company that sells high-voltage stator coils, another company sells transmission, and from a third I bought an electronic controller for ease of monitoring the process

charging my battery.

After painting, the whole mechanism looks much nicer. I installed a small diode at the top of the turbine strut and wired it to the coil. This is not a permanent magnet generator. The light will allow the coil to self-excite and indicate when the alternator is not producing a charge and can be disconnected from the battery

The photo above shows how I already installed the carbon fiber blades. I painted the hub and blade mounts white. It remains to wait for a windless day or a practically windless day to test my design “in the field”. I bought a 7127 alternator from AutoZone, a stator upgrade kit from MTM cientific, carbon fiber blades and hub from Picou Builders Supply, Co Inc., pipes and other small parts from a local hardware store. I spent $135.00 in total. Once I've installed the mechanism on top of the tower and connected it, I can calculate the cost per watt.

When installing on site, I decided to remove the blades to make the installation process easier and not damage the blades when lifting and installing.

After more careful calculations, I found that with the current length of the flagpole, I would not be able to correctly install the mechanism in place. I cut 16″ of pipe according to the new calculations, but for some reason the new pipe was 0.015″ too thick. With a file and sandpaper after 2 hours I got the desired diameter.

Thanks to an assistant, I lifted my turbine onto the platform, but it turned out that on the platform I could not lift and properly balance the turbine on my own in order to fix it on the rack. At this I decided to stop and tied the turbine to the platform so that in case of strong wind it would not fall down.

In the photo above you can see three 10′ pieces of 3/4″ cable. You can buy at any hardware store at an affordable price.

Thanks to my engineering skills, I assembled a three-legged lift for the convenience of lifting and installing the wind turbine myself.

Finally the turbine started working. It remains only to connect it to the battery

The wind was strong enough last night, but the turbine "was on top". At times, the wind gust reached 35 - 40 miles / hour. With such a wind, the turbine created noise, but the main thing is that it withstood such a test. Due to a factory limitation, the car alternator does not start producing current until the wind speed reaches 12 mph. But for my needs this is a lot. The problem with a car alternator is that at zero speed it does not generate or show voltage, and at low speed until the current starts to be generated, it consumes it. Such voltage changes practically ruined my battery. I put off putting the turbine on a flagpole a bit and bought some little bells and whistles to make a permanent magnet alternator.

I rewound the stator winding I bought online. Initially, the stator had 4 turns of #14 wire. I calculated that I could replace them with 10 turns of #18 wire. (A few years ago, I already changed the stator winding of a conventional car to a smaller number of turns with a larger wire diameter. In this case, the motor generates more current and has more power. I miscalculated and made a winding of 11 turns, instead of the planned 10. When laying the first layer (phase) everything went like clockwork, but laying an additional 4 wires in the last layer turned out to be a difficult task.

I tried to make holes in the old stator with a press, but to no avail. Desperate to get results with the press, I carved a finger-deep pocket for a new magnet.

My idea to manually rewind the stator failed. Some winding rings were in contact with the metal core and created a short circuit. I had to buy a 38V Ametek DC tape motor. I marked the caps and spaced them out for convenience. The chamfered rotor I bought gives good starting torque. I hooked up a voltmeter and with a hand pull I got just over 9 volts.

I machined the flange to mount the motor/generator to the same mount I used for the car alternator.

The new stator is not as big as its predecessor, the car generator, but even with a light breeze, the whole structure came into action. It was necessary to go this way from the very beginning, but as they say: “We learn from mistakes!” The fuse diode prevents the generator from going into motor mode. To generate more than 13 volts to overcome the resistance of the battery and start charging, there is enough wind force equal to 7-8 miles / hour. It looks like it was worth the effort. I think we need to prepare documentation for such a successful model.

Above you see a photo of my old battery pack. As you can see, there is not enough visibility in it. I'm currently working on a new measuring board that I plan to hang above the battery. The instrumentation board will consist of a battery charge indicator, load resistor, cooling fan, rectifier bridge, charging regulator and fuse terminal block. The next day, with 10 mph winds, my battery was fully charged and the charge controller switched the relay to mains. I connected the electric meter and “Oh, marvelous!” the arrow on it showed a little more than 16 V at 3 A and 8 ohms. (I connected four 2 ohm 100W resistors in series.) Not a bad start!

Here's a photo of the spinning mechanism I'm currently working on. The Ametek generator is mounted on the right, and the tail is mounted on the curved part of the pipe at the back. In very strong winds, the entire structure of the generator turns downwind, raising and wrapping the tail. As soon as a calm day falls, I will again begin to install the updated structure. With a wind speed of 40 mph, the blades spin against the flagpole and make a sound like a helicopter trying to land on my roof. Neighbors began to complain and this served as an additional incentive for rework.

I connected the tape motor to the rotation mechanism. But it is still too early to mount the entire structure until I have finished the motor. When I opened it, I decided to replace the bearings and cover it with a layer of protective paint to protect it from the elements.

It may not be visible in the picture, but the wind force arrow has reached the figure of 13 miles / hour, which is 10 A at a voltage of 20 V = 200 watts.

How to make a wind generator with your own hands from a car generator

The choice of windmill design

Vertical rotors have to be installed at the bottom due to the large weight and dimensions, where the wind speed is 2 times lower, which reduces the power of the installation by 8 times. In some cases, they are used because of less noise, lack of orientation to the wind, low starting speed and ease of use.

The number of blades is most often chosen no more than three, due to the high rotation speed and less noise. In high winds, they can collapse, but in industrial designs, the angles of rotation of the blades change, which makes it possible to regulate the speed and reduce the rumble.

Alteration of the oscillator

Rotor manufacturing

Windmill assembly

The wind generator is serviced as follows:

• checking and adjusting the fasteners. An autogenerator without alteration to a wind generator is not suitable, because it requires a high rotation speed. The gearbox does not solve the problem, as the resistance to rotation increases. Without some experience, it is difficult to make an effective unit with your own hands. A well-made windmill will easily generate power up to 1 kW.

  How to make a wind generator with your own hands from a car generator

  
  How to make a wind generator with your own hands from a car generator Repair school. Contents 1 Choice

Do-it-yourself generator from a car generator

One of the most efficient sources of alternative energy is the wind turbine. Solar panels are becoming popular, but so far the electricity they generate is 3 times more expensive than that of a wind farm. In addition, the sun does not shine around the clock, cloudy weather reduces productivity by 5 times, and the efficiency of solar panels decreases by 5% annually.

What does a wind generator from a car generator look like

The choice of windmill design

The wind generator can have two axis arrangements. Preference is given to horizontal due to lower costs and 2 times higher efficiency.

View of a wind turbine with a horizontal axis

Vertical rotors have to be installed at the bottom due to the large weight and dimensions, where the wind speed is 2 times lower, which reduces the power of the installation by 8 times. In some cases, they are used because of less noise, lack of orientation to the wind, do-it-yourself generator from a car generator low starting speed and ease of use.

If special guides are made for drum vertical units, productivity will increase, and separation from strong wind will be excluded. The design is complex, but the result is worth it.

The number of blades is most often chosen no more than automotive three, due to the high speed of rotation and less noise. In high winds, they can collapse, but in industrial designs, the angles of rotation of the blades change, which makes it possible to regulate the speed and reduce the rumble.

A wind generator for 1 kW of industrial production, together with a complete set, costs about 50 thousand rubles. and higher. For most users, this amount is too large.

If you have the necessary skills and materials at hand, you can make a windmill with your own hands.

Alteration of the oscillator

At present, a windmill from a car generator is thoroughly designed for DIY. For many motorists, it can lie idle in the garage. Even if it has some kind of malfunction, the parts may come in handy, since a thorough rework will still be required. The generator requires high speeds, which can only be provided by strong winds. With the predominance of weak wind, this device is not suitable as a wind generator, even with alteration to lower speeds.

Before you start making a wind generator with your own hands, you need to keep in mind that it will additionally require a controller, a battery and an inverter, arranged in series one after another.

What does a complete wind turbine look like?

In general, the construction will cost a lot. In addition, the batteries will have to be replaced with new ones from time to time.

Rotor manufacturing

The oscillator rotor has an electromagnetic excitation winding, which requires additional control electronics and brushes with a collector.

If you make it yourself for permanent magnets, the design can be simplified by removing the collector. In addition, it is necessary to rewind the stator windings so that the device turns from high-speed to low-speed. It is also necessary to redo the iron rotor, which closes the magnetic lines to itself and as a result, the current in the stator coils will not be generated. The figure below shows a disassembled oscillator.

Disassembled generator

The non-magnetic nozzle on the old rotor shaft is machined from aluminum. Then a steel pipe bandage is put on it with an interference fit. Marking is made on it, and rectangular neodymium magnets with alternating poles are glued with superglue. Epoxy resin is poured between them, after which the surface is leveled.

Do-it-yourself neodymium magnet rotor

The generator generates enough power when rotating at about 6000 rpm. For it to be effective at 600 rpm, the stator winding must be rewound, increasing the number of turns by 5 times. The cross section of the wire must be reduced.

To get a powerful source of energy, you will need a homemade generator for a windmill with neodymium magnets.

The disadvantage of supermagnet generators is magnetic sticking, when it is difficult to move the shaft.

To reduce it, magnets are glued with a slight skew. In addition, the blades should also be made larger. The magnetic field will decrease if you sort through all the stator plates, separating them with a knife and a hammer. They are then flattened on the anvil with a rubber mallet. The assembly of the stator is carried out on a special equipment with clamping of the plates with clamps.

DIY wind wheel

The blades are made from a plastic or duralumin pipe, the diameter of which is 20% of the footage. A meter pipe with a diameter of 20 cm is cut lengthwise into 4 equal parts. A wing is made from one part, and the next ones are made after it, using it as a template. Blade edges are rounded and ground to remove burrs. The blades are mounted on an old disk from a circular saw, grinding off the teeth from it and drilling holes for installation.

Blades with segments are usually used for incompressible media. The air profile must have a complex shape to ensure high performance. The main work is performed by the outer ends of the blades. Craftsmen make them on stilettos, since the inner part near the rotor does not work. The figure below shows such a design, where the blades are welded to round steel rods.

View of a four-bladed wind wheel

The wind wheel is mounted horizontally on a tripod and balanced by grinding the blades until the structure is balanced. They must rotate in the same plane with a misalignment of no more than 2 mm.

Windmill assembly

The diameter of the wind wheel shaft must be at least 20 mm. If the generator has less, the shafts should be installed coaxially, connecting them with a coupling. The wind wheel is mounted on a key and additionally fastened with a nut screwed onto the axle.

The frame of the device is made of a profile pipe. The axis of rotation is a pipe mounted in two bearings. It is attached to the top of the mast. The weather vane is cut out of galvanized sheet 40x60 cm and fastened with bolts. The length of the tail is 1.5 m. The distance from the blades to the mast is at least 25 cm, so that they do not break when bending from a strong wind.

Generators work to recharge the battery, which should supply household appliances with 220V.

An inverter is needed to convert the voltage. If the battery is rotated quickly, the battery may be damaged due to the large amount of charging current. To prevent this from happening, you should install a voltage controller. You can buy it or make it yourself.

The wind generator is serviced as follows:

1. adjustment, cleaning and lubrication of the current collector every 2 months;
2. repair of the blade in case of unbalance and vibration;
3. painting of metal parts after 3 years;
4. checking and adjusting fasteners.

An autogenerator without alteration to a wind generator is not suitable, because it requires a high rotation speed. The gearbox does not solve the problem, as the resistance to rotation increases. Without some experience, it is difficult to make an effective unit with your own hands. A well-made windmill will easily generate power up to 1 kW.

Do-it-yourself generator from a car generator

A car generator is the most affordable generator, and if you plan to make a wind generator, then it is the car generator that immediately involuntarily comes to mind when looking for a generator. But without alteration to magnets and rewinding the stator, it is not suitable for a windmill, as the operating speed of car generators is 1200-6000 rpm.

Therefore, in order to get rid of the excitation coil, the rotor is converted to neodymium magnets, and in order to raise the voltage, the stator is rewound with a thinner wire. The result is a generator with a power of 150-300 watts at 10 m / s without using a multiplier (reducer). The screw is placed on such a converted generator with a diameter of 1.2-1.8 meters.

The car generator itself is very affordable and you can easily buy it used or new in the store, they are not expensive. But to remake the generator, you need neodymium magnets, a wire for rewinding, and this is still an additional waste of money. So, of course, you need to be able to do this, otherwise you can ruin everything and throw it in the trash. Without alteration, the generator can be used if you make a multiplier, for example, if the gear ratio is made 1:10, then at 120 rpm, the 12 volt battery will start charging. In this case, the excitation coil (rotor) will consume about 30-40 watts, and all that remains will go to the battery.

But if you do it with a multiplier, then of course you get a powerful and large wind generator, but with a small wind, the excitation coil will consume its 30-40 watts and the battery will get little. Normal operation will probably be in wind from 5 m/s. In this case, the screw for such a windmill should be about 3 meters in diameter. The result is a complex and heavy structure. And the most difficult thing is to find a ready-made multiplier, suitable with minimal alterations, or making a homemade one. It seems to me that making a multiplier is more difficult and more expensive than converting a generator to magnets and rewinding a stator.

If the auto-generator is used without alteration, then it will start charging the 12 volt battery at 1200 rpm. I myself did not check at what speed charging starts, but after a long search on the Internet I found some information that indicates that at 1200 rpm the battery starts charging. There are mentions that the generator charges at 700-800 rpm, but it is not possible to verify this. I determined from the photographs of the stator that the stator winding of modern VAZ generators consists of 18 coils, and each coil has 5 turns. I calculated what voltage should turn out according to the formula from this article Calculation of the generator. As a result, I just happened to have 14 volts at 1200 rpm. Of course, the generators are not all the same and I read somewhere about 7 turns in the coils instead of five, but basically 5 turns in the coil, which means that 14 volts is still achieved at 1200 rpm, we will proceed from this further.

Two-bladed propeller on the generator without alteration

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Since the propeller speed grows linearly depending on the wind speed, then (1339: 8 * 7 = 1171 rpm) at 7 m / s the battery will start charging. At 8 m/s, the expected power, again, according to the calculation, should be (14:1200*1339=15.6 volts) (15.6-13=2.6:0.4=6.5 amps*13=84.5 watts). The useful power of the screw, judging by the screenshot, is 100 watts, so it will freely pull the generator and should give out even more revolutions than indicated when underloaded. As a result, 84.5 watts should be from the generator at 8 m / s, but the excitation coil consumes about 30-40 watts, which means that only 40-50 watts of energy will go to the battery. Very little, of course, since a generator converted to magnets and rewound at the same wind at 500-600 rpm will give out three times more power.

With a wind of 10 m / s, the revolutions will be (1339: 8 * 10 = 1673 rpm), the voltage at idle will be (14: 1200 * 1673 = 19.5 volts), and under load, the battery will be (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 net power. At 12 m / s it will be something like this 2008 rpm, no-load voltage 23.4 volts, current 26 amps, minus 3 amps for excitation, and that 23 amps battery charging current, power 300 watts.

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

In principle, if you count on winds from 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 quite small, in fact, only the price of the generator, and the screw and the rest can be made from what is. Only the screw must be done according to the calculations.

A correctly altered generator begins to charge already from 4 m / s, at 5 m / s the charging current is already 2 amperes, while 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 with a strong wind of 10-12 m/s, the generator without alteration can be compared with the altered one, but it will not give anything in a wind less than 8 m/s.

Self-excited car generator

The excitation coil can be powered from the generator itself, minus from the housing, and plus from the positive bolt. And in the teeth of the rotor you need to put a couple of small magnets for self-excitation. To do this, you can drill holes with a drill and put small neodymium magnets on the glue. If there are no neodymium magnets, then you can insert ordinary ferrite ones from the speakers, if they are small, then drill it and insert it, or lay it between the claws and fill it with epoxy.

You can also use the 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 in the figure is a self-excitation generator circuit. In general, the generator itself is excited as the rotor has residual magnetization, but this happens at high speeds, it is better to add magnets for reliability. A relay-regulator is included in the circuit, but it can be excluded. A decoupling diode is needed so that the battery does not discharge as without a diode, current will flow into the excitation winding (rotor).

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

There are generators for 28 volts, but if they are used to charge a 12 volt battery, then the revolutions need to be half as much, about 600 rpm. But since the voltage will not be 28 volts, but 14, then the excitation coil will give only half the power and the generator voltage will be less, so nothing will come of it. Of course, you can try in a generator whose stator is wound on 28 volts, put the rotor on 12 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.

Before starting work, you need to decide what kind of device you want to make, since there are several types of wind turbines:

• rotary;
• axial, on magnets, etc.

There are two axis positions:

• horizontal - the most common, the efficiency of this type is 2 times greater;
• vertical - installed at the bottom, as it has a lot of weight. And the wind below is quieter by 2 times and, therefore, the power of the device decreases by 8 times. The advantage is less noise and ease of use.

Regardless of the type of construction, for the manufacture of a homemade wind generator, stock up on:

• car generator;
• voltmeter;
• battery charging relay;
• voltage regulator for alternating current;
• material for the manufacture of blades;
• acid or helium battery;
• a box for closing the wire;
• capacity (stainless pan or aluminum bucket);
• 12 volt switch;
• electric three-core cable (section not less than 2.5 mm2);
• old water pipe (diameter not less than 15 mm, length 7 m);
• charging light;
• four bolts with nuts and washers;
• metal clamps for fastening.

In addition, you need to have special tools for work:

• grinder with discs;
• marker;
• screwdriver;
• drill and drills;
• metal scissors;
• set of spanners;
• gas keys of different numbers;
• wire cutters;
• roulette.

Rotary windmill

A rotary windmill (the easiest to manufacture) is usually assembled from two or four blades. Its design is simple, so everyone can make a windmill from a car generator, without special alterations and costs. The power of such a device is enough to supply energy to a small garden house.

The generator for the windmill is selected in accordance with the desired power. If we take a 12 volt generator as a basis, then we get a device up to 5 kW. The blades of the rotor must be of the same size, then the windmill from the car generator will work well.

In addition, the power of the structure will depend on the wind - on how fast it will blow on the blades. The windmill starts to rotate at 2 m/cm, and with more productivity it will work at 12 m/s. The efficiency of its operation is affected by the size of the blades into which the wind will blow. Measurements must be accurate.

How to make a wind generator

1. The first stage is the preparation of the rotor. A metal container (pot, bucket) is taken. Using a marker and tape measure, four identical parts are marked. The container is cut into blades with metal scissors or a grinder, without cutting to the end. The blades bend slightly at the edges, so the rotation speed increases. Do not use thin-walled tin materials for the blades or take a galvanized container - these materials can deform and heat up under load.
2. The direction in which the pulley rotates is determined. Rotate it to the right and left. Usually the pulley rotates clockwise, but it can also be counterclockwise.
3. Connect the rotor to the generator. Using a drill, holes are made in the bottom of the tank and the generator pulley. They must be symmetrical so that an imbalance does not occur during the movement of the blades. Attach the container with the blades to the generator (pulley) with bolts of the appropriate diameter.
4. The resulting device is placed on a mast, which is made from stocked old pipe. If there are buildings at a distance of 30 m from the structure, the height of the mast must be increased. It is necessary that it be 1 m higher than these buildings, then the windmill will work better, because there will be no obstacles for the wind. We fix it with a metal clamp.
5. Then the electrical wiring is installed and a closed circuit is assembled. All contacts are connected to the corresponding connectors. The wiring is fixed on the mast.
6. At the last stage, the inverter, battery, instrumentation and lighting are connected. Connect the inverter and the battery with a cable (section 3 mm square and size 1 meter), and for the remaining parts it is enough with a diameter of 2 mm square.

A homemade wind generator from a car generator is ready.

Advantages and disadvantages of the design

Like all devices, the wind generator has its positive and negative sides.

Device maintenance

To make the windmill work for many years and without interruption, it is necessary to carry out periodic technical control and maintenance.

1. Clean, lubricate and adjust the current collector once every 2 months.
2. Repair blades if vibration and imbalance occur during rotation.
3. Once every 3 years, paint metal elements with anti-corrosion paint.
4. Check and adjust mast anchors and cable.

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