How to make a low-speed generator for a windmill from neodymium magnets. Homemade generator for a windmill, diagrams, photos, videos.

To make a homemade windmill, you first need a generator, and preferably a low-speed one. This is the main problem, it is quite difficult to find such a generator. The first thing that comes to mind is to take a standard car generator, but all car generators are designed for high speeds, battery charging starts from 1000 rpm. If you install an autogenerator on a windmill, then it will be difficult to achieve such speeds, you will need to make an additional pulley with a belt or chain drive, all this complicates and makes the design heavier.

For a windmill, you need a low-speed generator, the best option is an axial-type generator with neodymium magnets. Since there are practically no such generators for sale at an affordable price, an axial generator can be made independently.

In this case, the stator will be a disk with coils, the rotor will be two disks with permanent magnets. When the rotor rotates, the stator coils will generate a current that we need to charge the batteries.

Homemade generator: making a stator.

Stator - the fixed part of the generator consists of coils that are placed opposite the rotor magnets. The internal size of the coils is usually equal to the external size of the magnets that are used in the rotor.

For winding coils, you can make a simple fixture.

The thickness of the copper wire for the coils is approximately 0.7 mm, the number of turns in the coils must be counted individually, the total number of turns in all coils must be at least 1200.

The coils are placed on the stator, the coil leads can be connected in two ways, depending on how many phases the generator will have.

A three-phase generator will be more efficient for a wind generator, so it is recommended to connect the coils in a star.

To fix the coils on the stator, they are poured with epoxy. To do this, you need to make a mold for pouring from a piece of plywood so that the liquid resin does not spread, you need to make boards from plasticine or a similar material. At this stage, it is necessary to provide lugs for attaching the stator.

It is important that a perfectly flat plane is obtained, therefore, before pouring, the matrix with coils must be installed on a flat surface. Before pouring, the coils must be carefully checked with a multimeter and laid out on the matrix in a circle so that then the rotor magnets are opposite the coils.

Liquid epoxy resin is poured into the matrix at the level of the edge of the coils; before pouring, the mold must be lubricated with petroleum jelly.

When the resin completely hardens, we disassemble the matrix and remove the finished stator with coils.

The stator is fixed on the generator housing with bolts or studs with nuts.

In this design, the rotor will be double-sided, the stator with coils will be in the middle between the rotating disks with magnets.

On each hub disk, you need to arrange magnets in a circle, changing the poles in sequence.

When the rotor disks are installed, the magnets should be directed towards each other with different poles.

Magnets need to be glued to the discs with superglue and filled with epoxy, the top of the magnets should remain uncoated.

Making a rotor for a homemade video generator.

To fix the stator on the wind turbine, you need to make a metal base, the stator is attached to it with bolts or studs.

We assemble the entire structure, while leaving a minimum gap between the stator and the rotor, the smaller the gap, the more efficiently the generator will generate energy. A diode bridge must be connected to the output of the coils.

As a result, you will get an axial generator on neodymium magnets. A homemade generator can operate at low speeds and still generate enough energy to charge batteries, which is important when installing a wind turbine in areas where light winds prevail.

Windmill generator video.

Homemade generator for a 2.5 kW windmill video.

Verification: 72146f0e872f9296

By the way, the screw turns out to be quite good. Therefore, the last screw was made from an aluminum pipe 1.3 m (see above)

I marked out the pipe, cut out blanks with a grinder, pulled it together with bolts at the ends and processed the package with an electric planer. Then he untwisted the package and processed each blade separately, adjusting the weight on electronic scales.

Protection against hurricane winds is made according to the classical foreign scheme, i.e. the axis of rotation is offset from the center. Here is a link to the site http://www.otherpower.com/otherpower_wind.html

Those who wish to learn more will find here all the questions they are interested in, and absolutely free of charge! This site helped me a lot, especially with the drawings of the tail. Here is an example of drawings from this site.

I adjusted my windmill tail by sawing.

The whole structure is mounted on two 206 bearings, which are mounted on an axle with an internal hole for the cable and welded to a two-inch pipe.

The bearings fit snugly into the wind turbine housing, which allows the structure to rotate freely without any effort and backlash. The cable runs inside the mast to the diode bridge. (See drawings above)

pictured is the original

It took a month and a half to make a wind head, not taking into account two months of searching for solutions, now we have the month of February, it seems like snow and cold for the whole winter, so I haven’t done the main tests yet, but even at this distance from the ground, a 21 watt car bulb burned out. I'm waiting for spring, I'm preparing pipes for the mast. This winter has flown by me quickly and interestingly.

VIDEO can be viewed here, (double click on the video opens a direct link to youtube), Yes, if you like or dislike, display your opinion.

A little time has passed since the moment when I posted my windmill on the site, but spring didn’t really come, it’s still impossible to dig the ground to wall up the table under the mast, the ground is frozen and dirt is everywhere, so there was time for testing on a temporary 1.5m stand Enough, but now more.

After the first tests, the screw accidentally hooked the pipe, I was trying to fix the tail so that the windmill did not go out from under the wind and see what the maximum power would be. As a result, the power managed to fix about 40 watts, after which the screw safely shattered into chips. Unpleasant, but probably good for the brain. After that, I decided to experiment and wound a new stator. To do this, I made a new mold for filling coils. I carefully lubricated the mold with automotive lithol so that the excess would not stick. The coils are now slightly reduced in length, thanks to which 60 turns of 0.95 mm winding thickness 8 mm fit into the sector (in the end, the stator turned out to be 9 mm), and the length of the wire remained the same.

I added about 30% talc to the epoxy.

The screw is now made with a more durable pipe 160mm and three-bladed, blade length 800mm.

New tests immediately showed the result, now GENA gave out up to 100 watts, a 100-watt halogen car bulb burned at full heat, and in order not to burn it out in strong gusts of wind, the bulb turned off.

measurements on a car battery 55 Ah.

Now the final tests on the mast, I will describe the result later.

Well, it's already the middle of August, and as I promised, I'll try to finish this page.

First what I missed

The mast is one of the critical structural elements

One of the joints (a pipe of a smaller diameter goes inside a larger one)

and swivel

now the rest

3-bladed screw (red sewer pipe with a diameter of 160mm)

To begin with, I changed several screws and settled on a 6-blade one with an aluminum pipe with a diameter of 1.3m, although a screw with a 1.7m PVC pipe gave more power.

The main problem was to make the battery charge from the slightest rotation of the screw, and here the blocking generator came to the rescue, which even with an input voltage of 2v gives the battery a charge - albeit with a small current, but better than a discharge, and in normal winds all the energy goes to the battery through VD2 (see the diagram), and there is a full charge.

The design is assembled directly on the radiator, semi-mounted, if the installation is correct, it works without problems. In some cases, to start the blocking generator, it is possible to reduce the resistance R1 to 500 ohms, the transformer is a ferite ring with a diameter of 45 mm, a cross section of 8 mm by 8 mm (can be wound on a line trance from an old TV set), wound with a 1 mm wire, first wound 60 turns, and evenly on top wound 21 turns

The charge controller also used a home-made one, the circuit is simple, blinded as always from what was at hand, the load is two turns of nichrome wire (when the battery is charged and the wind heats up to red) I put all transistors on radiators (with a margin), although VT1 and VT2 practically do not heat up, but VT3 must be installed on the radiator! (with prolonged operation of the controller, VT3 heats up decently)

photo of the finished controller

simple schematic

The connection diagram of the windmill to the load looks like this

Back view

My load, as planned, is the light in the toilet and summer shower + street lighting (4 LED lamps that turn on automatically through a photo relay and illuminate the yard all night, with sunrise, the photo relay is activated again, which turns off the lighting and the battery is charging. And this is on the dead Battery (removed from car last year)

the protective glass is removed in the photo (at the top of the photo sensor)

I bought a photorelay ready for a 220V network and converted it to power from 12V (I jumped the input capacitor and soldered a 1K resistor to the zener diode in series)

Now the MOST IMPORTANT!!!

From my experience, I advised to start with making a small windmill, gain experience and knowledge and observe what you can get from the winds of your area, After all, you can spend a lot of money, make a powerful windmill, and the wind power is not enough to get the same 50 watts and your windmill will be like submarine in the garage. Here BETTER A TITS IN HANDS THAN A WOODWOPER IN JO-E!!!

The simplest anemometer. A square side is 12 cm by 12 cm, a tennis ball is tied on a 25 cm thread.

I made this anemometer

Many readers often ask the question, how much does such a gene give out?

I had to make a short video

We never think about how strong even a small breeze can be, but it’s worth looking at how fast the turbine sometimes spins and you immediately understand how powerful it is.

Wind, you are mighty wind ... (photo from the yard)

The process of upgrading the windmill is completed, this is how it looks at this stage. In the video, its operating mode (I filmed it with a camera, so the discreteness of the screw is visible, in fact it spins as if undermined). Operates in very low winds BLOCKING GENERATOR.

The beginning of the rise to the wind

And here already in the wind

All calculations of the wind generator (thanks to Nikolai) can be seen here

Here are some sites where you can find a lot of interesting things

Feel free to check out these sites!

For Kharkiv residents and not only

Good luck to all!!!

I would be glad if at least a little bit helped someone, all questions on the wall or email

For everyone who has read this article, I offer an excursion into another successfully repeated design

For a long time I did not return to this article, more than two years have passed since the writing of this article, during this time the design has been repeated many times, I can judge this from the feedback received by e-mail. Many repeated the design one-on-one with my version, but those who turned to me for help, I advised to do only a three-phase version, and the result was much higher.

With the permission of Alexei Viktorovich Mikhalchuk, I post one of the worthy repetitions, the design of a three-phase generator.

Prior to meeting me, Alexei prepared almost everything to repeat my design, subsequently they did not change anything, except for I convinced the generator to be three-phase. To the surprise of Alexey, the generator turned out to be quite good, it charged the battery quite quickly, but since the design was temporary (Alexey did not believe in success until the last), this generator was subsequently dismantled, it was decided to add magnetic poles, and more reliably make the design. Subsequently, a 16-pole axial generator was born, I can say that it exceeded all expectations, even mine.

I won't repeat the description. Just a brief summary of some data

12 coils of wire 1.18 took 1.5 kg, 75 turns per coil.
The thickness of the coil is equal to the thickness of the magnet - 8mm
The inner diameter of the coils is equal to the diameter of the magnets -25 mm
Magnets 16 pairs 25*8
Steel discs thickness 10 mm diameter 25cm
Blades made of aluminum pipe with a diameter of 300 mm
Metal thickness 4mm blade length -1m

Such a generator produces more than 500 watts without any problems!

Some moments of the manufacture of the generator look at the photo

During the operation of this generator, a significant flaw in the design was revealed, Alexei neglected protection from hurricane winds, so the blades were destroyed. For everyone who repeats the design with the WIND, YOU CAN'T JOKE, you need to make protection from hurricane winds, it will come out cheaper than changing the blades every time.

At the moment, Aleksey has corrected the shortcomings, and the windmill brings him significant help.

Here Alexey threw a few more photos after the modernization of the windmill

and a short video

on the left is a wind generator from an asynchronous generator, on the right is the generator that is in the description. Well, that's all for now, saw weights, Lord, they are golden!

For Kharkiv residents and not only

So I decided to post photos of my small wind generator. I built this windmill without pursuing any special goals in terms of providing myself with electricity, but simply to test the capabilities of wind turbines in general and, in particular, generators of such configurations on permanent magnets. For my generator, I ordered the small necessary magnets, as they are very powerful and allow you to make generators with iron-free stators. Photographing all the steps in reverse order when dismantling the windmill.

The idea of ​​building a wind turbine haunted me for a long time, but somehow it didn’t get to the point, then there was no time, then moving, then something else. Now I live in a private house, I have a plot of land for a garden and a city. From the east and south, open areas, but from the north and west, wind currents cover small hills. Although the winds do not indulge, they blow constantly, and I thought - you still need to take your soul away and finally make the dream come true.

But when it came to practice, everything turned out to be not so simple, at first there was very little information about wind turbines, books gave a deeper understanding of generators and answers to some questions, but new questions and problems appeared in practice. The most important thing in a windmill is a generator, but I couldn’t decide on its choice, the first thing that came to mind was to use an autogenerator, but it was not designed for low speeds and it was necessary to invent a gearbox for it, and this entailed a strong increase in weight and dimensions of the wind turbine.

It was also necessary to make blades from something and calculate from the profile and dimensions so that they could work well and at the same time be durable and weigh a little. Yes, and protection from strong winds is also needed. But it was necessary to start, I started the easiest, from the mast, and everything else along it.

To save pipes on the mast, I collected ferrous metal at a local point, and in return gave my unnecessary scrap metal. I picked up small pieces of pipes, starting with a diameter of 325 mm, about 1.5 m long, to fit in the trunk of my car. From these pipes I welded a mast 12m long. For the foundation, I got a defective foundation block from a high-voltage support. For him, he dug a two-meter hole and lowered a block, a block 3 meta long, so one meter remained on the surface, which will be the base of the mast. I buried the support and rammed the soil. To fix the mast, it was necessary to somehow fix the brackets, for them I welded a frame from the corners on the block.

At the ends of the brackets to the anchor bolts, I welded plates of 16 mm iron measuring 50 x 50 cm, interconnected by powerful loops. I bought soft 10 mm cables and turnbuckles on the market, everything is anodized, does not rust. Welded and buried the anchor under a removable winch. The winch also had to be made homemade, using a ready-made worm gear. In addition, I installed a U-shaped support about 2m high, on which the mast should rest. Since there was nowhere to hurry - the mast was made without haste and therefore it turned out, in my opinion, beautiful and

And then God, seeing my work, blessed me to enter the forum http://forum.ixbt.com/topic.cgi?id=48:4219-74#1829. I re-read it all, registered, and began to gain experience. I started to remake the autogenerator, and when I translated from English "overseas" sites (Hugh Pigot and others) on building end-face generators without iron in the coils, I really wanted to try and do it myself, at least in miniature. I decided to build a working scaled-down model to give out up to 1 amp per 12-volt battery.

For the manufacture of the rotor, I bought in Znamenka at the Acoustics enterprise http://akustika-ag.de/cgi-bin/p.cgi?a 24 pcs. disk neodymium magnet 20*5 mm. I found a hub from the wheel of a walk-behind tractor, according to my drawings, the turner machined two steel disks with a diameter of 105 mm and a thickness of 5 mm, a spacer sleeve 15 mm thick and a shaft. I glued and half filled with epoxy magnets, 12 pieces for each, alternating their polarity.

Below is a photo of my windmill.

For the manufacture of the stator, I wound 12 coils with enamel wire with a diameter of 0.5 mm, 60 turns per coil (I took the wire from the demagnetization loop of an old unusable color kinescope, there is enough of it). I soldered the coils sequentially end to end, start to start, etc. It turned out one phase (I was afraid that there would be not enough voltage). I sawed out a shape from 4 mm plywood, rubbed it with wax.

It is a pity that the entire form in the collection was not preserved. I put waxed paper on the lower base (I stole it from my wife in the kitchen, she makes pastries on it), put a form with a round in the center on it. Then he cut out two circles from fiberglass. One laid on the waxed paper of the lower base of the form. He laid out the coils soldered together. I laid the conclusions from the stranded insulated wire into shallow grooves cut with a hacksaw.

I filled it all with epoxy. I waited about an hour for the air bubbles to all come out, and the epoxy spread evenly over the entire mold and soaked the coils, topped up where necessary, and covered with a second circle of fiberglass. I put a second sheet of waxed paper on top and pressed it with the upper base (a piece of chipboard). The main thing is that both bases are strictly flat. In the morning I disconnected the mold and removed a beautiful transparent 4mm thick stator.

It is a pity that epoxy is not suitable for a more powerful windmill, because. afraid of high temperature.

I inserted 2 bearings into the hub, in them a shaft with a key, on the shaft the first rotor disk with magnets glued and half-filled with epoxy, then a spacer sleeve 15 mm thick. The thickness of the stator with filled coils is 4mm, the thickness of the magnets is 5mm, total 5+4+5=14mm. Edges of 0.5 mm are left on the rotor discs so that the magnets rest against centrifugal force (just in case). Therefore, we subtract 1 mm. 13mm left. The gaps are 1mm. So the spacer is 15mm.

Then the stator (a transparent disk with coils), which is attached to the hub with three copper 5 mm bolts, they can be seen in the photo. After that, a second rotor disk is placed, which abuts against the spacer sleeve. You need to be careful not to get your finger under the magnets - they pinch it very painfully. (Opposite magnets on the discs should have different polarity, i.e. attract.)

The gaps between the magnets and the stator are adjusted by copper nuts placed on copper bolts on both sides of the hub. A propeller is put on the remaining protruding part of the shaft with a key, which is pressed against the rotor through the washer (and if necessary, the bushing) and the grower. It is desirable to close the nut with a fairing (I never did it). But he made a visor roof over the rotor and stator, sawing an aluminum saucepan so as to capture part of the bottom and part of the side wall.

The propeller was made from a meter-long piece of duralumin irrigation pipe with a diameter of 220 mm and a wall thickness of 2.5 mm. I drew a two-bladed propeller on it and sawed it out with an electric jigsaw. (From the same piece, I also cut out three blades 1 m long for a windmill on an autogenerator, and as you can see, there is still left). I rounded the front edge of the blades “by eye” with a radius equal to half the thickness of the duralumin, and sharpened the rear edge with a chamfer of approximately 1 cm at the ends and up to 3 cm towards the center.

In the center of the propeller, I first drilled a hole with a 1mm drill for balancing. You can balance directly on the drill, putting the drill on the table, or hang it on a thread from the ceiling. You need to balance very carefully. I separately balanced the rotor disks and the propeller separately. After all, the speed reaches 1500 rpm.

Since there is no magnetic sticking, the propeller rotates merrily from the slightest breeze, which you don’t even feel on the ground. With a working wind, it develops high speeds, I have a direct-on 2A ammeter, so it often goes off scale on a 12-volt old car battery. True, at the same time, the tail begins to take shape and rise up, i.e. automatic protection against strong wind and excessive speed is activated.

Protection is made on the basis of an inclined axis of rotation of the tail.
Further on the final assembly of the wind turbine and the mast, the continuation of the article on the windmill

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 house or cottage, have repeatedly encountered interruptions, inconveniences and damage to equipment associated with them.

The listed negative situations, together with the consequences, will no longer complicate the life of lovers of natural spaces. And 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.

We have described in detail the options for manufacturing a system that is useful in the economy, eliminating energy dependence. According to our advice, an inexperienced home craftsman will be able to build a wind generator with his own hands. A practical device will help to significantly reduce daily expenses.

Alternative energy sources are the dream of any summer resident or homeowner whose site is located far from the central networks. However, when we receive bills for electricity consumed in a city apartment, and looking 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.

A wind generator is an excellent solution for providing a suburban facility with electricity. Moreover, in some cases, its installation is the only possible way out.

In order not to waste money, effort and time, let's decide: are there any external circumstances that will create obstacles for us in the process of operating a wind turbine?

To provide electricity to a summer house or a small cottage, it is enough, the power of which will not exceed 1 kW. Such devices in Russia are equated to household products. Their installation does not require certificates, permits or any additional approvals.

As an example, let's take one module of the Belashov MGB-300-144-2 low-speed generator.

Fig. one Fig. 2 Fig. 3

Modular low-speed Belashov generator MGB-300-144-2, designed for technical devices that convert a large moment of force, at low speeds, into electrical energy and can be used for wind turbines, manual emergency power plants, damless hydroelectric power plants, and so on ...

In this design of a single-phase low-speed generator, two rows of multi-turn windings are used, but two more rows of multi-turn windings can be placed inside this generator, making it two-phase, which will double the generator power. Depending on the number of modules, the consumer can independently complete any parameters of the generator from individual modules, for the required voltage, the required current and the specified number of revolutions.

The first question that buyers usually ask is the efficiency of low-speed generators, while they do not know that this value is not defined, which depends on many parameters or quantities, and above all on how the generator itself was made. I will give a specific example of how the efficiency of a generator affects if the multi-turn stator windings are not made correctly or with high quality, since this detail is very important and affects many characteristics of a low-speed generator.

When manufacturing multi-turn stator coils for a low-speed generator, it must be taken into account that there are rectangular or round wires and many types of windings, but in this case we will consider only three types of windings shown in Fig. 4:

Row winding of multi-turn windings pos.1

Winding of multi-turn windings in a checkerboard pattern pos.2

Winding of multi-turn windings in random form (in bulk) pos.3.

Fig. four

The most important characteristic of the coil is the winding coefficient (the degree of filling of the winding space of a multi-turn coil with copper) - the ratio of the area of ​​the copper coil to the area of ​​the winding space:

Where:

W is the number of turns of the coil,

Q - wire section with insulation, mm²

S - cross-sectional area of ​​the winding window, mm².

At the same time, it should be taken into account that it is very difficult to wind multi-turn stator windings with a thick wire, and even more so to create its exact profile for proper entry into the rotor magnetic system. With a thinner wire, you can increase the winding coefficient, and with the help of a parallel or series connection of the stator windings, bring the calculated wire cross section to the desired value. For example, in the stator of a single-phase low-speed generator MGB-300-144-2, there are two rows of multi-turn windings, which were wound randomly with a wire having a diameter of 0.29 mm (since I did not have the opportunity to make a row winding). External multi-turn stator windings have 580 turns each. The internal windings of the stator consist of 360 turns. As a result, it turns out that the generator stator contains 16920 turns. This means that if on each multi-turn winding (taking into account the winding coefficient) we did not wind at least 20 turns, then in the end we get that we could not wind another 720 turns on our stator. If in each row of the stator of a low-speed generator there are two phases with two rows of multi-turn windings, then we will get that we have lost 1440 turns, Fig.5.

Fig. 5

Usually the winding ratio is in the range of 0.5 - 0.8, but you need to know that the higher the winding ratio, the better the performance of a low-speed generator will be. It is highest when staggered winding of multi-turn windings with self-sintered enameled wires. The advantage of these enameled wires is that they are glued together with varnish under the influence of heat or solvents. After sintering, a self-supporting winding is formed. The use of self-sintered enamelled wires has a cost and manufacturing advantage, since winding cores, adhesive tape, compound and impregnating materials can be saved. Moreover, it is necessary to pay special attention to the fact that for better cooling of multi-turn windings, self-sintering enameled stator coils must be tightly adjoined through a heat-conducting dielectric to the aluminum case of a low-speed generator, since for the normal operation of the generator, heat removal from multi-turn windings is the main task that affects the efficiency of the generator .

Manufacturers of low-speed generators for wind turbines, mini hydroelectric power plants or portable power plants must communicate to their customers all the advantages and disadvantages of these machines. Buyers need to know some important generator specifications:

The internal resistance of the multi-turn generator windings not only at 20°C, but also when the temperature of the multi-turn generator windings changes from 20°C to 80°C,

The short-circuit current of the multi-turn generator windings at a given number of revolutions, not only at 20 ° C, but also when the temperature of the multi-turn generator windings changes from 20 ° C to 80 ° C, where only r o,

The operating current of the generator at a given number of revolutions, not only at 20°C, but also when the temperature of the multi-turn generator windings changes from 20°C to 80°C, where r o + r n,

When manufacturing a stator or rotor from a steel magnetic circuit on which multi-turn windings are installed, it is necessary to know the braking torque of the generator rotor,

The operating voltage of the generator, at a given number of revolutions,

Generator open circuit voltage (without any load),

The method of heat removal from the multi-turn windings of the generator.

These specifications are needed to match the internal resistance of the multi-turn windings of the generator with the load, since in order to obtain the maximum power in the external circuit, the load resistance must be equal to the internal resistance of the generator. For example, if the multi-turn windings of a generator have high internal resistance, then this type of generator is less susceptible to fluctuations in the output voltage. For a generator with low internal resistance, the output voltage drop can exceed 40%. There are other subtleties in choosing low-speed generators. For example, if the measurement of the technical characteristics of the generator was carried out at a temperature of 20 ° C, then at a temperature of 70 ° C you can miss more than half of the power declared by the manufacturer, and so on ... We will prove this with specific examples.

A change in the temperature of the stator of a low-speed generator (as well as other electrical machines) causes a change in resistance inside the multi-turn windings during its operation and even in a non-working position when the low-speed generator was installed on a wind turbine located in the Sun.

Such a change in the resistance of a conductor from temperature, per each ohm of the resistance of a given conductor when its temperature changes by 1 ° C, is called the temperature coefficient "alpha" (a). Thus, the temperature coefficient characterizes the sensitivity of a change in the resistance of a conductor to a change in temperature. In this case, we have copper windings that have a temperature coefficient, a = 0.004041.

For example, knowing the temperature coefficient of copper, we can determine the internal resistance of the multi-turn stator windings, which occurred when the temperature of the stator changed, which heated up to 70 ° C in the Sun.

The formula for determining the temperature coefficient looks like this:

Where:

R 1 - resistance of a given conductor at one temperature - T 1,

R 2 - resistance of the same conductor, but at a different temperature - T 2,

A is the temperature coefficient of the metal from which the conductor is made,

T 2 - the final temperature of the windings from which the conductor is made conductor ° C,

T 1 - the initial temperature of the windings from which the conductor is made conductor °C.

1.

R 2 \u003d R 1 + R 1 ∙ a ∙ (T 2 - T 1)

R 2 \u003d 6 Ohm + 6 Ohm ∙ 0.004041 ∙ (70 - 20) \u003d 7.2738 Ohm

Where:

R 1 - resistance of multi-turn stator windings at 20 ° С = 6 Ohm,

T 2 - temperature of the stator of a low-speed generator heated by the Sun up to 70°C.

Let us determine the current of a low-speed generator, on the terminals of which there is a voltage of 12 Volts at an ambient temperature of = 20°C.

Let us determine the current of a low-speed generator, on the terminals of which there is a voltage of 12 volts at a temperature heated by the Sun up to 70 ° C.

Let us determine the power of a low-speed generator, on the terminals of which there is a voltage of 12 Volts at an ambient temperature = 20°C.

P = U ∙ I = 12 V ∙ 2 A = 24 W

Let us determine the power of a low-speed generator, on the terminals of which there is a voltage of 12 volts at a temperature heated by the Sun up to 70 ° C.

P = U ∙ I = 12 V ∙ 1.6497566608925183535428524292667 A = 19.7970799307102220242514229151192 W

Let us determine the drop in efficiency of a low-speed generator that is not working, but simply heated by the Sun when the temperature rises from 20°C to 70°C. This is the permissible temperature for the operation of electromechanical devices and assemblies. Even if we hypothetically imagine that the efficiency of a low-speed generator at 20°C was = 100% (which cannot be in nature), then we can find out what the power loss will be with an increase in the temperature of any electrical machines. Although many manufacturers of electric machines are trying to get around these sensitive issues so as not to scare away their customers.

24W = 100%

It follows from this that a low-speed generator, which has not even started working yet, but has already lost 17.52% efficiency, and this will only happen if the internal resistance of the stator is small at low voltage on the stator windings. With an increase in the voltage at the generator terminals, the internal resistance of the generator increases accordingly, which, accordingly, will entail even more losses in the efficiency of the generator. At the same time, we are talking only about the active resistance of the multi-turn stator windings, not including the reactance of the multi-turn stator windings, which is many times greater than the active resistance of the conductors. Consider a specific example, when the voltage at the generator terminals is increased, which will entail an increase in the internal resistance of the multi-turn stator windings.

2. Let us determine the resistance of the multi-turn stator windings with a change in temperature:

R 2 \u003d R 1 + R 1 ∙ a ∙ (T 2 - T 1)

R 2 \u003d 12 Ohm + 12 Ohm ∙ 0.004041 ∙ (70 - 20) \u003d 29.0952 Ohm

Where:

R 1 - resistance of multi-turn stator windings at 20 ° С = 12 Ohm,

R 2 - resistance of multi-turn stator windings at 70 ° C,

A - temperature coefficient of copper = 0.004041

T 1 - temperature of the stator of a low-speed generator at 20 ° C,

T 2 - temperature of the stator of a low-speed generator heated by the Sun up to 70°C.

Let us determine the current of a low-speed generator, on the terminals of which there is a voltage of 24 Volts at an ambient temperature = 20°C.

Let us determine the current of a low-speed generator, on the terminals of which there is a voltage of 24 Volts at a temperature heated by the Sun up to 70 ° C.

Let us determine the power of a low-speed generator, on the terminals of which there is a voltage of 24 Volts at an ambient temperature = 20°C.

P = U ∙ I = 24 V ∙ 2 A = 48 W

Let us determine the power of a low-speed generator, on the terminals of which there is a voltage of 24 Volts at a temperature heated by the Sun up to 70 ° C.

P = U ∙ I = 24 V ∙ 0.A = 19.7970799307102202425142291512 W

Let us determine the drop in efficiency of a low-speed generator that is not working, but simply heated by the Sun when the temperature rises from 20°C to 70°C.

48W = 100%
19.797079930710220242514229151192 W = X%

This is a clear example, when a low-speed generator, with an increase in the voltage at the generator terminals and a doubling of the internal resistance, which, without even starting to work, has already lost 58.76% of efficiency. As mentioned earlier, there was not even a mention of the reactance of the multi-turn stator windings, which is many times greater than the active resistance of the conductors. Because at the beginning of the generator operation, the active and inductive resistance of the multi-turn stator windings begins to increase, which depend on the number of magnetic systems, the number of multi-turn windings, the method of their connection and the speed of rotation of the rotor magnetic system. Therefore, if you are offered a low-speed generator, the power of which at 220 Volts exceeds 1000 W at 200 rpm, then draw your own conclusions ...

It must be emphasized that, depending on the design of the stator or rotor, the multi-turn windings of the Belashov generator can be connected in such a way that the amplitude of the alternating current signal is pulsating.

The pulsating alternating current shown in Fig. 6 has the following advantages:

AC frequency reduction,

Reducing the heating of multi-turn windings,

Reducing the inductive resistance of multi-turn windings.

Fig. 6

Moreover, if a conventional single-phase alternator, which is designed for 120 revolutions per minute, will produce a voltage of 12 V and have an alternating current signal frequency of 100 Hz, then when connecting multi-turn windings that produce a pulsating alternating current signal, the voltage and current will remain the same as for a conventional single-phase generator, but the frequency of the alternating pulsating current will be 50 Hz.

With these small examples, I clearly showed how one value can greatly affect the efficiency of a low-speed generator, but when developing generators or electrical machines, there are many. For example, when calculating a low-speed generator, one value can be extended to a normal characteristic, while the other two can significantly worsen its parameters. Therefore, it is advisable to approach each wind turbine or mini hydroelectric power station individually and specifically manufacture a low-speed generator, taking into account the ambient temperature, where it will operate at the calculated load, taking into account the distance from the primary converters, and so on ...

Consumers of low-speed generators should also be aware of other subtleties of this process. It is sad to tell you, but there are no, and cannot be, low-speed generators in the world. In this case, you have a very powerful machine, which is used by 5-30% of the capacity. For example, if you spin up the generator MGB-300-144-2, up to 2000 rpm, then we get 13833 watts. Consumers begin to understand this incident when the moment of purchase occurs, where the price of the generator does not correspond to the declared capacity, in relation to other electric machines. If the definition of the name is taken philosophically, then for the rich it will be a low-speed generator, and for everyone else it will be a powerful electric machine.

In order to make a low-speed generator shown in figure 4 having:

good cooling,

modular design,

High degree of reliability

Reliable insulation resistance,

Small dimensions and light weight,

A generator that can be easily adjusted in current and voltage,

Generator, which can be manufactured from a few watts to hundreds of kW,

Dielectric stator, generator which has no hysteresis loss,

Dielectric stator, generator which has no eddy current losses,

An oscillator that can automatically detect the voltage of the incoming signal,

A generator whose dielectric stator has no armature reactance losses,

A generator that has a monitoring and control system that is capable of automatically changing machine parameters,

A DC electric machine that is capable of operating from one or more independent sources of various voltages and currents, and in southern countries from the energy of solar panels.

In the manufacture of a low-speed generator, it is necessary to ensure that the wind turbine or mini hydroelectric power station itself in the process of operation can change the design value of the generator by switching the multi-turn stator windings or individual modules in such a way as to obtain the maximum power of the generated signal from the installation.

In order to manufacture a high-quality low-speed generator, it is necessary to receive from the customer a technical assignment for its development, which will help determine for what purposes this generator will be used. For example, we need a low-speed generator for a wind turbine with a maximum power of 800 W at 400 rpm, and for this we need to know.

Approximate terms of reference for the development of a low-speed generator MGB-300-144-2.

1. Appointment. The low-speed generator is intended for a wind power installation in a separate individual house or a remote settlement, which is located far from the main power grid.

2. Scope. Provision of local electric lighting to power household appliances, radios, televisions, radios, refrigerators and other low-power household consumers up to (500 - 800) W.

3. Specifications and requirements for the generator.

3.1. Generator power at 400 rpm - 800 watts.

3.2. Generator power at 300 rpm - 500 watts.

3.7. Short circuit current at 50 rpm - 1.46 A.

3.8. AC frequency at 500 rpm - 100 Hz.

3.9. AC frequency at 300 rpm - 60 Hz.

3.11. The number of phases of the generator is one.

3.12. Excitation - magnetoelectric. Material of magnets Nm30Di5k8rt with residual magnetic induction Br - 1.25 T.

3.13. Ambient temperature from - 40°С to + 60°С.

3.14. The initial moment of rotation of the screw is not more than - 0.02 kg∙m.

3.15. Overall dimensions of the generator:

3.16. Outer case diameter - 320 mm.

3.17. Body length without shaft - 130 mm.

3.18. Length of the generator with a shaft - 220 mm.

3.19. The mass of the generator is not more than (to be specified).

3.20. Voltage outlet from the generator through the connector (the type of connector and its location is being specified).

3.21. Automatic tracking and control system for changes in the design value of the generator (the type of system is being specified).

3.22. The design of the generator:

3.23. The generator is collapsible. The generator consists of a housing containing four identical removable modules and one removable shaft.

3.24. The design of identical modules allows their use both for the first and for the second phase.

3.25. The generator housing is made in a closed version.

3.26. Number of multi-turn stator coils - 36 pcs.

3.27. Maximum voltage on one stator coil at 600 rpm. - 13 V.

3.28. Natural cooling method - IC 0041 GOST 20459-87.

3.29. Marine version - tropical, according to the degree of protection - IR 44 GOST 17494 - 87.

3.30. Insulation of conductive parts of the generator - class "B".

3.31. Generator operation mode - long (S1).

3.32. According to all requirements, the generator must comply with GOST 183 - 74.

3.33. When calculating and designing the generator, all technical characteristics and parameters of the machine may differ from the technical specifications by 5 - 10%.

3.34. Separate clauses of the ToR can be specified and supplemented by mutual agreement of the parties.

However, in order to draw up a technical task for the development of a low-speed generator, it is necessary first of all to select the type of wind turbine, make its preliminary calculation and determine:

wind turbine type,

wind turbine wheel diameter,

The average annual airflow rate,

What power is the wind turbine designed for?

The coefficient of utilization of wind energy by a wind turbine,

Torques of various types of wind turbines and so on…

In order to use the air flow of the wind turbine to the full, it is necessary to proceed from the fact that the material point of the base of the screw of each blade, depending on the circumference of the wind turbine screws, must travel a distance equal to the speed of the wind flow.

For example, let's calculate the number of revolutions of a low-speed generator when using a wind turbine having:

Screw diameter 2 m,

Air flow velocity = 6 m/s.

From the table placed in the Patent of the Russian Federation № we determine the maximum power of the air flow at 6 m / s, which \u003d 836.54 W.

Let us determine the circumference around the wind turbine propellers, which is calculated by the formula:

L = P ∙ D
L = 2 m ∙ 3.1415926535897932384626433832795 = 6.283185307179586476925286766559 m

Where:

L is the circumference,

D - circle diameter = 2 m,

P - the ratio of the circumference to the diameter of the circle = 3.1415926535897932384626433832795.

Let us determine the time during which each blade of the wind turbine passes around its axis at a wind speed of 6 m/s.

6 m/s: 6.283185307179586476925286766559 m = 0.s

Let us determine the maximum number of revolutions of the wind turbine in one minute, with a wind speed of 6 m/s, knowing that 1 minute contains 60 seconds.

0.954929658551372014613302580235 rpm = 1 sec
X about = 60 sec

Let us determine the power of the wind turbine if, using a low-speed generator, we set the load on the wind turbine blades to 30% of the maximum power of the air flow.

836.54 W = 100%
X W = 30%

Let us determine the number of revolutions of a low-speed generator, which will change when the wind turbine is loaded by 30% of the maximum power of the wind flow.

836.54 W = 57.295779513082320876798154814 rpm
250.962 W = X rpm

In order to obtain a power of 250.962 W at a speed of 17.18873 rpm, it is necessary to install the required number of modules in the low-speed Belashov generator.

From the specifications, it can be seen that at 50 rpm, one low-speed generator module produces 17 watts of power.

Let us determine the power of a low-speed generator at 17.188733853924696263038846444 rpm.

50 rpm = 17 W
17.188733853924696263038846 rpm = X W

Let's determine the number of modules that at 17.18873385 rpm can provide power from a low-speed generator = 17 W.

5.84416951 W = 1 module
17 W = X modules

From preliminary calculations it can be seen that to generate power of 17 W at 17.18873385 rpm, we need 3 modules.

In this example, the preliminary calculation of the wind turbine is not specified:

wind turbine type,

Number of wind turbine blades

The mass of wind turbine blades and their shape,

The coefficient of propeller utilization at the declared speed of rotation of the wind wheel,

Wind turbine losses and more…

For a complete calculation of wind turbines, see the Patent of the Russian Federation №

Currently, there are no manufacturers producing on their own a complete set of equipment for wind turbines or mini hydroelectric power plants, which will be tied to the real area and specific conditions. These companies buy finished components from different manufacturers, complete the finished product and sell it to consumers. Even if the wind turbine is very good, it may not be suitable for a particular area or given climatic conditions. Things are better with low-speed Belashov generators, since from individual modules you can complete any generator parameters for any voltage, current and number of revolutions, where you can change the design value of the generator during operation. In production, they are much more economical, since from a set of identical modules it is possible to offer consumers various parameters of a low-speed generator.

After that, taking into account the received terms of reference, it is necessary to carefully calculate and develop each part of a low-speed generator:

Stator with multi-turn windings (taking into account changes in the temperature of multi-turn windings),

The number of multi-turn stator windings and the electrical circuit of their connection,

The shape of the multi-turn stator windings and the method of heat removal from them,

The shape of the magnets and magnetic circuits of the rotor magnetic system,

The device for reducing the magnetic systems of the rotor,

generator housing,

generator shaft,

Unfortunately, I did not have like-minded people, and in addition to inventions, I had to do all the calculations, development, design, manufacture of generators and other electrical machines myself.

In my opinion, all small-scale energy is developing in the wrong direction. The main strategic delusion is that any wind turbines or mini hydroelectric power plants should not produce the finished product on site, namely the voltage and power that the consumer claims. The alternative energy itself should receive as much energy of any type as possible at the primary points and then be transferred to the consumer without unnecessary losses, where the electrical signal must be converted on the spot into a finished product that will be used by the consumer. Now they receive the finished product on the spot and drive it to the consumer with great losses.

As you can see from the previous examples, this is not the right approach to the development of low-speed generators, wind turbines and mini hydropower plants. In order to correctly install a wind turbine or mini hydroelectric power station, you need to start with a thorough survey of the installation site, and then make a capital calculation of all components and components, then it will turn out what you were thinking about.

In conclusion, we can say that small wind power and small hydropower are largely discredited in the eyes of consumers against the backdrop of unscrupulous manufacturers and managers who are poorly versed in technology. Many producers promise big profits that can come from alternative energy, but forget to mention the problems that consumers of these generating plants can expect.

A video demonstrating the operation of a cassette-modular low-speed generator MGB-205-72-1.

In this video, a 40 watt incandescent lamp at 12 volts is used as a load.

Cassette-modular low-speed generator MGB-205-72-1 was demonstrated at the sixth international exhibition of electrical products and new technologies "Electro - 96" held from 2 to 6 July 1996 at the "Expocentre" of the Russian Federation in Moscow.

It should be emphasized that after a certain amount of time or long-term continuous operation, the magnetic system of a low-speed generator, consisting of permanent magnets, begins to weaken and crumble. If, at a rotation of 45 rpm, the Belashov MGB-205-72-1 cassette-modular low-speed generator in 1996 showed a bright burning of a 60-watt incandescent lamp at a voltage of 12 volts, then in 2019 it hardly masters a 40-watt light bulb. Some magnet manufacturers have given guarantees for their permanent magnets for 20 years, which practically confirms their commitment.

A video showing the operation of one module of the Belashov MGB-300-84-2 low-speed generator.

A video showing the operation of one module of the Belashov MGB-340-84-1 low-speed generator.

In this video, a 60 watt incandescent lamp at 12 volts is used as a load.

A video demonstrating the charging of the battery from the Belashov MGB-340-84 low-speed generator.

A 12 volt battery was used as a load. The low-speed Belashov MGB-340-84-1 generator at 30-40 rpm gives a charging current of at least one Ampere.

Video film about the mechanism of formation of a magnet and a magnetic system from atoms of a magnetic material.

The video film is devoted to the mechanism of formation of a magnet and a magnetic system from atoms of a magnetic material.

Video film about the world's first disc electric machine Belashov MDEMB-01.

The world's first disk electric machine Belashov MDEMB-01, in which one or many multi-turn windings of a disk dielectric rotor, without changing the direction of the current in the conductors, pass through one or many permanent horseshoe magnets. The magnets of the poles of the stator excitation system, which are located in the same row, can have a different direction of movement of magnetic fluxes. The disc dielectric machine Belashov MDEMB-01 was shown on the first channel of the central television in 1993.