In this article, we will take a closer look at how to make a wind generator with your own hands. After all, the life of a modern person without electricity is difficult to imagine. And even small interruptions in the supply of electricity sometimes become a "paralyzing moment" for a normal life in your own home. And such problems, we have to admit, for some suburban villages or settlements in rural areas - alas, are not uncommon. This means that you need to somehow protect yourself from troubles, acquire a backup energy source. And if we take into account the constantly growing tariffs, then having our own source, and even working almost “for free”, becomes the cherished dream of many home owners.
One of the directions of development of "free energy" in our time is the use of wind energy. Many have probably seen impressive pictures of huge wind turbines successfully used in some European countries - in some places the share of wind generated energy already reaches several tens of percent of the total. So the temptation arises - shouldn't I try to make a wind generator with my own hands in order to get independence from the power grids once and for all?
This is a reasonable question, but the ardor of the "dreamer" should be somewhat cooled at once. To create a truly high-quality, efficient power generation plant requires a lot of knowledge in mechanics and electrical engineering. You need to be a very experienced jack of all trades - there is a whole series of operations of high complexity that require precise design and a qualified approach in execution. For the totality of these reasons, as can be judged from the discussions on the forums, quite a lot of "applicants" either did not receive the expected result, or completely abandoned the conceived project.
Therefore, this article will provide an overview picture showing common problems and directions for their solution in the process of creating wind turbines. It will be possible to roughly assess the scale of the work and soberly weigh your capabilities - is it worth it to undertake it yourself.
What is a wind turbine? General structure of the system
There are several ways to obtain electrical energy - due to exposure to a stream of photons (light, for example, solar panels), due to certain chemical reactions (widely used in batteries), due to temperature differences. But the conversion of kinetic energy into electrical energy is currently used most widely. This transformation takes place in special devices called generators.
The principle of operation of the generator of the converter of kinetic energy into electrical energy was disclosed and described back in the 19th century by Faraday.
The principle of the device of the simplest electric generator It consists in the fact that if the conducting frame is placed in a changing magnetic field, then an electromotive force will be induced in it, which, when the circuit is closed, will lead to the appearance of an electric current. And a change in the magnetic flux can be achieved by rotating this frame in a magnetic field, either created by permanent magnets, or appearing in the excitation windings. When the position of the frame changes, the value of the magnetic flux crossing it changes. And the higher the rate of change, the greater the indicators and the induced EMF. Thus, the more revolutions are transferred to the rotor (rotating part of the generator), the more voltage can be achieved at the output.
The diagram is certainly shown with great simplifications, just to clarify the principle.
The transmission of rotation to the rotor of the generator can be carried out in different ways. And one of the ways to find a free source of energy that will set the kinematic part of the device in motion is to "catch" the force of the wind. That is, in about the same way as the creators of windmills once managed to do it.
Thus, the device of a wind generator implies the presence of a generating device and a mechanism for transmitting its rotational motion to the stator, that is, a wind turbine. In addition, a design that ensures reliable installation of the system becomes a prerequisite, since it often has to be placed at a considerable height so that natural or artificial obstacles do not interfere with full-fledged "wind catching". In some cases, a kinematic transmission is also used, designed to increase the number of rotor revolutions.
One example of an overdrive transmission from a wind turbine to a generator But that is not all. The presence and speed of wind are often extremely variable values. And making the consumption of the generated energy dependent on the "whims of the weather" is unreasonable. Therefore, a wind generator usually works in conjunction with an energy storage system.
The generated current is rectified, stabilized and, through a special controller device, either goes directly to further consumption, or is redirected to charging the powerful batteries included in the circuit. From the batteries through an inverter that converts direct current into alternating current of the desired voltage and frequency, power is supplied to the points of consumption. Batteries become a kind of buffer link: if the current load is less than the current (very dependent on wind strength) generator power, or if consumption devices are not connected at all for some time, then the batteries are being charged. If the load becomes higher than the generated power, the batteries are discharged.
An interesting point - it is this feature of the wind power plant that allows you to plan the power of the generator itself, not based on the peak load indicators (the inverter will be more responsible for this), but based on the predicted energy consumption over a certain period (for example, a month).
Of course, simpler schemes can be used in everyday life. For example, a wind turbine is simply serving some low voltage lighting equipment, etc.
Pros and cons of wind farms For example, let's first look at the simplest design of a wind generator, which even a middle school student can assemble. The practical application of such a "power plant" is not very wide, but just to expand your understanding and acquire some skills - why not?
A wind generator from a car generator is a good alternative to a factory device, which costs from several tens to several hundred thousand rubles. For assembly, you will need to build blades, a mast and slightly change the design of the generator.
About homemade windmills for the home
Particular interest in wind energy is manifested at the level of the domestic sphere. This is understandable if you look out of the corner of your eye at the next bill for consumed energy. Therefore, all sorts of craftsmen are activated, using all the possibilities of obtaining electricity inexpensively.
One of these possibilities, quite real, is closely related to a wind turbine from an automobile generator. An already finished device - a car generator - just needs to be equipped with correctly made blades in order to be able to remove some value of electrical energy from the generator terminals.
True, it will work effectively only if there is windy weather.
An example from the practice of household use of wind generators. A well-designed and quite effective practical wind turbine design. A three-blade propeller is installed, which is a rarity for household appliances
The use of virtually any automotive generator is acceptable for wind turbine construction. But they usually try to choose a powerful model capable of delivering high currents for the case. Here, at the peak of popularity, the design of generators from trucks, large passenger buses, tractors, etc.
In addition to the generator, a number of additional parts will be required to make a wind turbine:
- two- or three-blade propeller;
- car battery;
- electrical cable;
- mast, support elements, fasteners.
The propeller design for two or three blades is considered the most optimal for a classic wind generator. But the household project is often far from the engineering classics. Therefore, most often they try to pick up ready-made screws for home construction.
An impeller from a car fan, which will be used as a propeller for a home wind turbine. Lightness and large usable area for air force allows these options to be used.
This, for example, can be an impeller from an external unit of a split air conditioning system or from a fan of the same car. But when there is a desire to follow the traditions of designing wind turbines, you will have to build a wind turbine propeller from start to finish with your own hands.
Before deciding on the assembly and installation of a wind generator, it is worth evaluating the climatic data of the site and calculating the payback. Information from a very interesting article that we recommend for review will provide a significant help in this.
Wind turbine design
There is a huge variety of wind turbines and drawings for their manufacture. But any design includes the following required elements:
- generator;
- blades;
- storage battery;
- mast;
- the electronic unit.
With some skills, you can make a wind generator with your own hands.
In addition, it is necessary to think over in advance the control and distribution system of electricity, draw an installation diagram.
Advantages and Disadvantages of Using a Car Generator
The use of a car generator as an element of a wind farm provides significant advantages:
- There is a ready-made generator that can be used without intervention in the design or with some upgrades.
- A car generator produces a stable voltage, which is important for wind turbines with their constantly changing rotational speed.
- The standard equipment is used, which is available and does not require intervention in the structure.
- Automotive alternators are widespread, making them repairable and available for replacement when needed.
Along with the advantages, there are some disadvantages:
- An automobile generator requires high rotation speed, which requires the use of an overdrive or design changes to the device.
- The service life of an automobile generator is limited to approximately 4000 operating hours (on average). Even a new generator will not withstand even a year of continuous operation and will require repair.
- The excitation system of some generators requires voltage to be applied to the coil, forcing redesign and installation of permanent magnets.
Despite the existing drawbacks, a car generator is considered the best option possible when creating a wind farm on your own.
We make a wind wheel
The blades are perhaps the most important part of a wind turbine. The operation of the remaining units of the device will depend on the design. They are made from different materials. Even from a plastic sewer pipe. The blades from the pipe are easy to manufacture, are cheap and are not affected by moisture. The manufacturing procedure for the wind turbine is as follows:
- The length of the blade must be calculated. The pipe diameter should be equal to 1/5 of the total footage. For example, if the blade is a meter long, then a pipe with a diameter of 20 cm will do.
- We cut the pipe lengthwise into 4 parts with a jigsaw.
- We make a wing from one part, which will serve as a template for cutting out subsequent blades.
- Smooth the burrs at the edges with an abrasive.
- The blades are fixed to an aluminum disc with welded strips for fastening.
- Next, a generator is screwed to this disk.
Wind wheel blades
After assembly, the wind wheel needs balancing. It is fixed horizontally on a tripod. The operation is carried out in a closed from the wind room. In case of correct balancing, the wheel should not move. If the blades rotate themselves, then they need to be sharpened until the whole structure is balanced.
Only after successful completion of this procedure, you should proceed to checking the accuracy of rotation of the blades, they should rotate in the same plane without skewing. An error of 2 mm is allowed.
Generator assembly diagram
Manufacturing the mast
For the manufacture of the mast, an old water pipe with a diameter of at least 15 cm and a length of about 7 m is suitable.If there are buildings within 30 m from the proposed installation site, then the height of the structure is adjusted upward. 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 the pegs for fastening 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; for manual installation, you will need a counterweight from a pipe with a load.
Redesigning a car generator
For the manufacture of a wind turbine generator, a generator from any car is suitable. Their designs are similar to each other, and the alteration is reduced to rewinding the stator wire and making a rotor on neodymium magnets. Holes are drilled in the rotor poles 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.
Car generator
In the same way, you can remake an 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 loose winding, it's as convenient as anyone. The more the number of turns, the more efficient the generator will be. The coils are wound in one direction in a three-phase scheme.
A ready-made generator is worth trying out and measuring the data. If at 300 rpm the generator produces about 30 volts, this is a good result.
Generator for wind turbine from car generator
Final assembly
The generator frame is welded from a profile pipe. The tail is made of galvanized sheet metal. The pivot shaft is a tube with two bearings. The generator is attached to the mast in such a way that the distance from the blade to the mast is at least 25 cm. For safety reasons, it is worth choosing a windless day for the final assembly and installation of the mast. The blades under the influence of strong wind can bend and break on the mast.
To use batteries to power equipment that operates on a 220 V network, you will need to install a voltage conversion inverter. The battery capacity is selected individually for the wind generator. This indicator depends on the wind speed on the ground, the power of the connected equipment and the frequency of its use.
Wind generator device
To prevent the battery from being damaged by overcharging, you will need a voltage controller. You can make it yourself if you have sufficient knowledge in electronics, or you can buy a ready-made one. There are many controllers on the market for alternative energy mechanisms.
Advice. To prevent the blade from breaking in strong winds, a simple device is installed - a protective weather vane.
Two-blade propeller for generator without alteration
In principle, if you put a high-speed two-blade propeller with a diameter of 1-1.2 meters on the generator, then such turns are easily achieved with a wind of 7-8 m / s. This means that you can make a wind turbine without altering the generator, only it will work in a wind of 7m / s. Below is a screenshot with the data of a two-blade propeller. As you can see, the speed of such a propeller with a wind of 8m / s is 1339 rpm.
Since the propeller speed grows linearly depending on the wind speed, then (1339: 8 * 7 = 1171 rpm) at 7m / 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 amperes * 13 = 84.5 watts). The useful power of the propeller, 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 with 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 (14: 1200 * 1673 = 19.5 volts), and under battery load (19.5-13 = 6.5: 0.4 = 16.2 amperes * 13 = 210 watts). As a result, you get 210 watts of power minus 40 watts per coil and 170 watts of usable power remains. At 12 m / s, it will be something like 2008 rpm, no-load voltage 23.4 volts, current 26 amperes, minus 3 amperes for excitation, and then 23 amperes battery charging current, power 300 watts.
If you make a screw with 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 a two-blade propeller turned out to be the most optimal for a generator without alteration.
In principle, if you count on winds from 7m / s and above, then such a wind generator will work well and produce 300 watts at 12 m / s. In this case, the cost of the wind turbine will be very 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 converted 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 magnetised, 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, a generator without alteration can be compared with a converted one, but it will not give anything in a wind less than 8 m / s.
Self-excitation of a car generator
In order for the generator to self-excite without a battery, a couple of small magnets must be put in the rotor. If the excitation coil is powered from a battery, then it constantly and regardless of whether the wind generator generates energy or not, it will consume its 3 amperes and charge the battery. To prevent this from happening, you need to put a blocking diode so that the current is only in the battery, and does not go back.
The excitation coil can be powered from the generator itself, minus from the body, 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 from the speakers, if small, then drill and insert, or lay between the claws and fill with epoxy.
You can also use a so-called pill, 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 diagram of the generator's self-excitation. In general, the generator itself is excited since 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, the current will flow into the excitation winding (rotor).
Since the wind generator will be very small with a propeller with a diameter of only 1 meter, no protection from strong wind is needed and nothing will happen to it if there is a strong mast and a strong propeller.
There are 28 volt generators, but if you use them to charge a 12 volt battery, then you need half the speed, about 600 rpm. But since the voltage will not be 28 volts, but 14, the excitation coil will give only half the power and the generator voltage will be less, so nothing will come of it. You can, of course, try to put the rotor at 12 volts into a generator whose stator is wound at 28 volts, then it should be better and charging will start earlier, but then two identical generators are needed to replace the rotor, or look for a rotor or stator separately.
Parsing design errors
Assembling a wind generator in a domestic environment with your own hands is, of course, not an error-free business. Even in the design of industrial wind turbines, engineers make mistakes. But they learn from mistakes, which is confirmed by well-established household structures.
So, among the errors in the construction of household wind generators, such a detail as the absence of a braking module in the generator design often appears. The standard design of such devices (automobile or tractor) does not provide for such a part. This means that the generator needs to be modified.
However, not every "designer" wants to do this delicate matter. Many people ignore this detail, hoping for "maybe". As a result, in a strong wind, the propeller spins up to incredibly high speeds. Generator bearings do not stand up, break the seats of the aluminum covers. Rotor wedge occurs.
Destroyed wind turbine due to design flaws. Errors in the design and installation of such structures lead to serious consequences.
A flaw related to the absence of a wind vane rotation limiter belongs to the same topic. Often this component is simply forgotten to be installed and is remembered only when the wind currents begin to spin the cock around its axis, like a whirligig in the program “What? Where? When?". The result is disastrous.
The minimum damage is twisting and breaking of the electrical cable, and in severe cases, the separation of the entire structure.
Another notable assembly error is the miscalculation of the center of gravity point based on the weather vane. In this case, the device can function normally for some time. But over time, a misalignment forms on the bearing assembly, the freedom of rotation is limited, and the efficiency of the structure in terms of energy output decreases sharply.
Often, they try to directly power the battery with the current received from the generator. Very soon, they begin to wonder why the battery does not hold a charge or if 2-3 cans are broken.
This is a commonplace and natural mistake, since in any case, the battery charge must take place under conditions of certain currents and voltages. Control of this process is needed here.
Device maintenance
In order for the wind turbine to work for many years and without interruptions, it is necessary to carry out periodic technical control and maintenance.
- The collector should be cleaned, lubricated and adjusted every 2 months.
- Repair blades if vibration or imbalance occurs during rotation.
- Paint metal elements with anti-corrosion paint every 3 years.
- Check and adjust the mountings and the mast 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 energy source, independent of stationary power supply, will never be superfluous.
Video
Wind is a clean source of inexpensive energy that is fairly easy to obtain. In our opinion, everyone has the right to choose where to get electricity from. For these purposes, there is nothing more practical and effective than building a wind generator with your own hands from scrap materials.
General scheme of a wind generator
Wind turbine assembly
Most of the tools and materials mentioned in this manual can be purchased from a hardware store. Also, we strongly recommend that you look for the components below from a used dealer or your local landfill.
Security is our top priority. Your life is much more valuable than a cheap source of electricity, so follow all the safety rules associated with building a wind turbine. Fast rotating parts, electrical discharges and harsh weather conditions can make a wind turbine quite dangerous.
The design of this home wind turbine is simple and efficient, while being quick and easy to assemble. You can use wind energy without any restrictions.
Wind turbine components
This manual uses a treadmill DC motor (power supply 260V, 5A), with a 15 cm threaded sleeve attached to it.At a wind speed of about 48 km / h, the output current reaches 7 A. This is a small, simple and cheap unit with which you can start harnessing wind power.
You can use any other DC motor that produces at least 1V at 25 RPM and can operate at more than 10 amperes. If necessary, you can change the list of required components (for example, find the bushing separately from the motor - a circular saw blade with a 1.6 cm shaft adapter is suitable for this purpose).
Wind turbine assembly tools
Drill
- Drills (5.5mm, 6.5mm, 7.5mm)
- Jigsaw
- Gas wrench
- Flat head screwdriver
- Adjustable wrench
- Vise and / or clamp
- Cable stripping tool
- Roulette
- Marker
- Compasses
- Protractor
- Tap for tapping 1/4 "x20
- Assistant
Materials for assembling a wind generator
Carrier bar:
- Square pipe 25x25 mm (length 92 cm)
- Masking flange for pipe 50 mm
- Branch pipe 50 mm (length 15 cm)
- Self-tapping screws 19 mm (3 pcs.)
Note: if you have the opportunity to use a welding machine, then weld a piece of 50 mm pipe 15 cm long into a square pipe, without using a flange, pipe and self-tapping screws.
Engine:
DC motor from treadmill (power 260V, 5A) with 15 cm threaded sleeve attached to it
Diode bridge (30 - 50 A)
Bolts for the engine 8x19 mm (2 pcs.)
A piece of PVC pipe 7.5 cm (length 28 cm)
Shank:
Square piece of tin 30x30cm
Self-tapping screws 19 mm (2 pcs.)
Blades:
A piece of 20 cm PVC pipe, 60 cm long (if it is UV resistant, you will not need to paint it)
Bolts 6x20 mm (6 pcs.)
Washers 6 mm (9 pcs.)
A4 paper sheets (3 pcs.)
Scotch
Assembling the wind turbine
Cutting out the blades - we have three sets of blades (nine in total) and a thin strip of waste.
Place our 60cm PVC pipe on a flat surface along with a piece of square pipe (you can use any other sufficiently long object with a straight edge). Press them firmly together and draw a line on the PVC pipe where they touch along its entire length. This line will be called A.
Make marks at each end of line A, 1-1.5 cm away from the end of the pipe.
Glue three sheets of A4 paper together so that they form a long, straight piece of paper. You have to wrap the pipe with it, applying it in turn to the marks just made on it. Make sure the short side of the piece of paper fits snugly and evenly against line A, and the long side overlaps evenly where it overlaps itself. From each end of the pipe, draw a line along the edge of the paper. Let's call one of these lines B, the other C.
Take the pipe so that the end of the pipe closest to line B is facing up. Start where lines A and B intersect and make marks on line B every 145 mm, moving to the left of line A. The last segment should be about 115 mm long.
Flip the pipe up with the end closest to line C. Start at the point where lines A and C intersect, and also mark on line C every 145 mm, but move to the right of line A.
Using a square tube, connect the corresponding points on the opposite ends of the PVC pipe with lines.
Cut the pipe along these lines using a jigsaw so that you have four strips 145 mm wide and one about 115 mm wide.
Spread all the strips with the inside of the pipe facing down.
Make marks on each strip along the narrow side at one end, backing off the left edge by 115 mm.
Repeat the same from the other end, backing 30 mm from the left edge.
Connect these points with lines, crossing the strips of the cut pipe diagonally. Use a jigsaw to cut the plastic along these lines.
Place the resulting blades with the inner surface of the pipe down.
Make a mark on each diagonal cut line 7.5 cm from the wide end of the blade.
Make another mark at the wide end of each blade, 2.5 cm from the long, straight edge.
Connect these points with a line and cut the resulting corner along it. This will prevent the blades from being bent by the side wind.
Wind turbine blade processing
You must sand the blades in order to achieve the desired profile. This will increase their efficiency and also make them spin more quietly. The leading edge should be rounded and the trailing edge should be pointed. Any sharp corners should be rounded to reduce noise.
Shank cutting
The size of the tail is not critical. You need a piece of lightweight material measuring 30x30 cm, preferably metal (tin). You can give the shank any shape, the main criterion is its rigidity.
Drilling holes in square pipe - use a 7.5mm drill bit.
Place the motor on the front end of the square tube with the bushing protruding over the edge of the tube and the mounting bolt holes facing down. Mark the position of the holes on the pipe and drill through the pipe in the marked places.
Holes in the masking flange- this point will be described below, in the installation section of this manual, since these holes determine the balance of the structure.
Drilling holes in the blades- use a 6.5 mm drill.
Mark two holes at the wide end of each of the three blades along their straight (trailing) edge. The first hole should be 9.5 mm from the straight edge and 13 mm from the bottom edge of the blade. The second is at a distance of 9.5 mm from the straight edge and 32 mm from the lower edge of the blade.
Drill these six holes.
Drilling and tapping holes in the sleeve- use a 5.5 mm drill bit and a 1/4 "tap.
The treadmill motor comes with a bushing attached to it. To remove it, firmly secure the shaft protruding from the bushing with pliers and turn the bushing clockwise. It unscrews clockwise, which is why the blades rotate counterclockwise.
Make a sleeve template on a piece of paper using a pair of compasses and a protractor.
Mark three holes, each 6 cm from the center of the circle and equally spaced from each other.
Place this template on the core and punch the holes through the paper at the marked locations.
Drill these holes with a 5.5 mm drill bit.
Thread them with a 1/4 "x20 tap.
Screw the blades to the hub with 1/4 "x 20mm bolts. At this moment, the outer holes close to the bushing boundaries have not yet been drilled.
Measure the distance between the straight edges of the tips of each blade. Adjust them so that they are equidistant. Mark and tap each hole in the hub through each blade.
Make marks on each blade and bushing so that you do not confuse the attachment points for each at a later stage in the assembly.
Unscrew the blades from the hub, drill and thread these three outer holes.
Manufacturing of a protective sleeve for the engine.
Draw on our piece of PVC pipe with a diameter of 7.5 cm along its length two parallel lines at a distance of 2 cm from each other. Cut the pipe along these lines.
Cut one end of the pipe at a 45 ° angle.
Place the pointed pliers in the resulting slot and inspect the pipe through it.
Make sure the bolt holes on the motor are centered in the middle of the slot in the PVC pipe and place the motor in the pipe. This is much easier with an assistant.
Mounting
Place the motor on the square tube and screw it to it using 8x19mm bolts.
Place the diode on a square tube behind the motor, 5 cm away from it. Screw it to the pipe with a self-tapping screw.
Connect the black wire coming from the motor to the positive input terminal of the diode (it is marked with AC on the positive side).
Connect the red wire coming out of the motor to the “negative” input of the diode (it is marked AC on the “minus” side).
Position the shank so that the end of the square pipe opposite to the end of the motor is centered. Press the tail to the pipe using a clamp or vise.
Screw the shank to the pipe using two self-tapping screws.
Place all blades on the hub so that all holes line up. Using 6x20mm bolts and washers, screw the blades onto the hub. For the three holes in the inner circle (closest to the hub axis) use two washers, one on each side of the blade. For the other three, use one at a time (on the side of the blade closest to the bolt head). Pull it tight.
Securely secure the motor shaft (which passed through the hole in the bushing) with pliers and, putting on the bushing, turn it counterclockwise until it is fully screwed in.
Using a gas wrench, screw the 50 mm pipe firmly onto the masking flange.
Clamp the nipple in a vise so that the flange is horizontal over the vise jaws.
Place the square tube carrying the motor and tailpiece on the flange and achieve a perfectly balanced position.
Once balanced, mark the square pipe through the holes in the flange.
Drill these two holes using a 5.5mm drill bit. You may need to twist the tail and sleeve to do this so that they do not interfere with you.
Screw the square support pipe to the flange with two self-tapping screws.
The author has long been interested in the idea of using alternative energy. Having searched for information about various devices on this topic, the author found for himself a model of a wind turbine, which is easy to perform and not very expensive in terms of money.
Materials used by the author to create a wind turbine:
1) wires 3 \ 8-16
2) electronic charging controller
3) GM 7127 generator from AutoZone
4) stator upgrade kit - MTM cientific,
5) carbon fiber blades and hub - Picou Builders Supply, Co Inc.,
6) plumbing pipes
7) 38V DC Ametek tape drive motor
Consider the stages of creating a wind generator.
To begin with, the author purchased all the necessary components. Pipes and several meters of wires were bought from a hardware store. High voltage stator coils and transmission were ordered through online stores. An electronic controller was purchased to indicate battery charging.
After that, the author started assembling the main structure of the wind turbine.
The generator was mounted on a rack, and a small diode was installed on top of the turbine rack, which was connected by wires to the generator coil. Since this is not a permanent magnet generator, the light allows the coil to self-excite and show the moment when the generator does not produce a charge, and therefore can be disconnected from the battery.
Then the blades were made from carbon fiber. Then the author started painting. The author painted the generator itself red, and the hub and blade fasteners white.
After assembly and painting, the author only had to wait for a windless day to install the structure of the wind generator.
Before starting the installation, the author decided to remove the blades to facilitate the process of installing the generator on the top of the tower.
Carrying out one more calculations of the length of the flagpole, the author discovered an error due to which it was impossible to install the mechanism perfectly. Therefore, according to new calculations, the author cut off 16 "pipes, but it turned out to be a little thicker than necessary. Therefore, armed with files, the author began to eliminate all calculation flaws manually.
For the convenience of raising the wind turbine and installing it, the author assembled a three-legged lift and, with the help of an assistant and a home-made lift, the entire structure was lifted onto the rack platform, where it was strengthened and balanced.
As you can see in the photo, three cables leave the generator, which the author will connect to the energy storage system from the wind turbine.
The first tests showed the reliability of the design. In strong winds of about 35 mph, the generator started to make noise, but the mounts held up. However, during the tests, the main drawback of this generator was revealed, which the author missed. the fact is that the car generator does not start producing current until the wind reaches 12 mph
The wind was strong enough last night, but the turbine was “at its best”. At times the gust of wind reached 35-40 mph. With such a wind, the turbine made noise, but the main thing is that it passed such a test. Due to a factory limitation, the car generator does not start producing current until the wind force reaches 12 mph, and at zero rpm it does not generate power and does not display voltage. When the wind is less than 12 mph and the generator speed is low, it consumes the battery power itself until the start of the current generation, which practically spoiled it. Therefore, in order to fix the system and save the batteries, the author decided to upgrade the generator in such a way as to make it an alternator with a permanent magnet.
The stator winding has been rewound. Initially, the stator had 4 turns of wire # 14, these were replaced with 10 turns of wire # 18. Laying the last 4 wires in the last layer turned out to be a difficult task, the author even tried to make indentations in the stator using a press, but this did not bring results.
As a result, the whole idea of rewinding the stator failed, since some of the winding rings were in contact with the metal core and created a short circuit. Therefore, the author discarded this idea and purchased a 38V DC Ametek tape motor. The author marked the mouthguards and spread them for greater convenience. The purchased rotor with beveled grooves gave a pretty good starting torque, when tested on manual traction, the voltmeter showed a little more than 9 V.
In order to attach the alternator to the same mount that was used for the old car alternator, the author carved a flange.
The new stator is relatively smaller than its predecessor in size, but it starts to work even in the lightest wind. In order to overcome the resistance of the battery and start charging, a wind force of 7-8 mph is enough. In this case, the installed diode does not allow the generator to switch to motor mode.
And here is a photo of the system's battery pack.
In order for the windmill to turn relative to the wind, the author made a turning mechanism. The generator is mounted on the right, and the tail is attached to the curved section of the pipe at the back.
Many country house owners would like to use alternative energy sources. Residents of city apartments hold a similar opinion due to the constant increase in the cost of electricity. If you wish, you can assemble a simple wind generator and install it on your site.
Wind turbine installation legal issues
Before starting work on creating a wind generator with your own hands, you should understand the legality of using this unit. To provide a summer cottage with electricity, it is quite enough to use installations with a capacity not exceeding 1 kW. On the territory of Russia, they are considered household, and their use does not require a permit or certificate.
Also, the state does not provide for additional taxes on energy production for household needs. As a result, you can safely collect wind turbines with your own hands for your home and use free electricity. However, it is worthwhile to additionally consult with your local authorities for the presence of any legal regulations on this issue.
In addition, one should not exclude the possibility of complaints from neighbors if they begin to experience inconvenience when using this unit. Having decided to assemble a wind generator with your own hands, you should pay attention to several of its parameters:
In addition, claims from environmental services may arise if the wind turbine interferes with the migration of birds. However, such a situation is extremely unlikely.
Principle of operation
A wind generator is a device that converts the kinetic energy of the wind into mechanical energy with its subsequent conversion into electrical energy. This happens due to the rotation of the generator rotor. The unit consists of the following elements:
- Blades.
- Turbine rotor.
- Generator with moving axle.
- Inverter for converting AC to DC.
- Rechargeable batteries.
Three forces act on the blades, two of which, lifting and impulse, overcome the third (braking) and set the flywheel in motion. The rotational motion is transmitted to the rotor of the generator, and when it rotates, a magnetic field is created in the stator. As a result, an alternating current appears, which is then converted into direct current using a special controller and charges the battery.
Types of wind generators
Electrical installations of this type are usually classified according to several parameters. One of the main ones here can be considered the number of blades, since the multi-bladed ones begin to work even with a weak wind. Having decided to assemble a wind generator for your home with your own hands, you should remember that the blades can be sail or rigid. The easiest way is to make products of the first type, but they are not very durable and require frequent repairs.
Wind turbines also differ in the location of the axis of rotation - horizontal and vertical. Each of these types has both advantages and disadvantages. If vertical devices are more sensitive, then horizontal ones are high power. The last sign of wind turbine classification is a fixed or variable pitch. At home, it is easier to assemble a unit of the first type.
Rotary installation
It is quite simple to assemble such a wind farm with your own hands. At the same time, its capacity will be sufficient to meet all the needs for electrical energy in the garden area.
Preparatory stage
Owners of country houses can safely focus on installations with a capacity of about 1.5 kW. The simplest device will be a unit with a vertical axis of rotation. To create it, you will need the following parts and materials:
In addition, you will need bolts with nuts, a measuring tool, a grinder or metal scissors and a drill.
Manufacturing instruction
The basis of the future unit will be a cylindrical container, for example, a barrel or bucket. It is necessary to apply markings on it, dividing the container into four equal parts. After that, you should cut the metal (not completely) to get the blades. Holes are drilled in the pulley and the bottom of the container, which must be located strictly symmetrically so that an imbalance does not occur during operation.
After that, the blades are bent taking into account the direction of rotation of the generator used, most often in the clockwise direction. It should also be remembered that the bending angle of the blades affects the propeller speed. Having fastened the blades to the pulley, the generator is mounted on the mast using clamps.
The main part of the work on this is completed, and all that remains is to assemble the electrical circuit. To facilitate this task, it is worth sketching a wiring diagram when installing the generator on the mast. To connect the battery, use a 1-meter piece of wire with a cross section of 4 mm 2. In turn, to connect the unit to the network, it is worth using a 2.5 mm 2 conductor. The inverter is also connected with a larger wire.
If all the work was carried out in accordance with the instructions, then the wind turbine will work well, and problems should not arise during its operation. At the same time, the advantages of the rotary installation are much greater than the disadvantages. The latter include only a fairly high sensitivity to strong gusts of wind.
Axial unit
Since the market has become saturated with neodymium magnets, the cost of these products has dropped significantly. As a result, it is possible to assemble an efficient wind turbine on their basis. The basis of the axial generator will be a hub with brake discs from the machine. Before starting work, it must be cleaned, the bearings must be checked and lubricated, and painted.
Installing magnets
In total, you will need about 20 magnets measuring 20x8 mm. More of these products can be used if desired. However, in such a situation, two rules should be followed:
- If the generator is single-phase, then the number of magnets must correspond to the number of poles.
- For a three-phase device, the ratio of poles and coils should be 2/3 or 4/3, respectively.
The magnets are simply glued onto the rotor discs, but at the same time their poles should alternate. To do everything right, you should first make a cheat sheet template. Preference should be given to rectangular magnets, since during operation they create a magnetic field along the entire length. It should also be noted that the opposing magnets must have different poles.
Generator type selection
When comparing a single- and three-phase device, the second looks preferable. One of the main disadvantages of a single-phase generator is vibration that occurs during operation. The reason for their appearance lies in the difference in the amplitudes of the current, since its return is uneven. Thanks to the phase compensation in the three-phase model, a constant power is maintained.
In addition, the efficiency of a single-phase device is about 50% less. The advantages of a 3-phase generator do not end there. Since vibration does not occur during its operation, the noise indicators of the entire wind turbine will be significantly lower. At the same time, do not forget about increasing the service life if the choice fell on a three-phase generator model.
Making coils
In the windmill being created, the battery charging process should start at a rotor speed of 100-150 rpm. Thus, the total number of turns on all coils is in the range 1000-1200. If these figures are divided by the number of coils used, then the number of turns on each of them can be calculated.
It should be remembered that by increasing the number of poles, the power of the entire installation can be increased when operating at low speeds. The characteristics of a homemade generator are seriously influenced not only by the number of magnets, but also by their thickness. The total power of the generator can be calculated empirically. To do this, after the manufacture of one coil, it should be scrolled in the device and the voltage measured at a certain number of revolutions without load.
Further calculations are quite simple. We can assume that with a resistance of 3 ohms at 150 rpm, the output is 27 V. If you subtract the nominal voltage of the battery (in this case, 12 V) from this value, you get 15 volts. To determine the current strength, the result obtained (15 V) must be divided by the coil resistance (3 ohms), which gives 5 amperes. The coils must be fixed together immovably, and the ends of the phases brought out to the outside are connected by a triangle or a star. After assembling the generator, it should be checked for operability.
Final stage of assembly
The height of the mast should be on average 6 to 12 meters, and its base should be concreted. The wind turbine is mounted on the upper part of the mast and to simplify repair work, it is worthwhile to provide a mechanism for lifting and lowering it, which will be driven by a hand winch.
For the manufacture of a propeller, a PVC pipe with a diameter of 160 mm is perfect. The choice of the shape of the blades is carried out empirically, and the main task at this stage is to increase the torque when operating at low speeds. To protect the propeller from strong gusts of wind, it should be equipped with a folding tail.
Each of the considered wind turbine models has certain advantages and disadvantages. They can be quite effective in different regions, but the best results will be obtained in areas with frequent and strong winds.