- The principle of operation of wind turbines
- How to make a vertical type wind generator yourself
- Assembling the rotor
- We make the stator
- Generator assembly
- We make blades
- Assembling the structure of the wind turbine
- Electrical part
- Wind turbine result: efficiency calculation
Now it is quite possible to get free electricity from the wind. There are several options for wind turbines: with a vertical and horizontal axis. Almost everyone can assemble a vertical wind generator with their own hands, read how to do it correctly in our article.
The principle of operation of wind turbines
The principle of operation in all modifications of wind turbines is the same. In the process of rotation of the blades, three types of physical effects are formed: lifting, impulsive and braking forces. As a result of the action of these forces, the stator starts to move, and the rotor on the stationary part of the generator begins to create a magnetic field and an electric current moves along the wires.
There are a large number of versions of wind generators, they differ not only in power, but also in their appearance. The structure of most wind turbines includes: generator, blades, inverter, multiplier. An inverter is used to convert the received charge into direct current. The multiplier is a gearbox designed to increase the number of shaft revolutions. Gearboxes are not installed on all wind turbines, mainly only on large and powerful wind turbines.
Three-phase alternating current is generated by the rotation of the rotor. The received energy is directed through the controller to the battery. Further, the inverter converts the current and makes it stable, it is in this form that it can be supplied to power household appliances or lighting.
How to make a vertical type wind generator yourself
You can make a windmill yourself at home. First you need to decide on the type of wind generator. Depending on their design, wind turbines are:
- with vertical axis of rotation: Darrieus rotor, Savonius wind generator;
- with horizontal axis of rotation: parallel or perpendicular to the wind flow.
Some models of wind turbines combine several types of installations. Consider an example of creating a hybrid wind turbine that combines the design of wind generators such as Savonius and Darrieus.
Assembling the rotor
To assemble a rotor, you need to purchase:
- 6 neodymium magnets D30xH10 mm;
- 6 ferrite ring magnets D72xd32xh15 mm;
- 2 metal discs D230xH5 mm;
- epoxy or glue.
Saw blades of a suitable size can be used instead of metal blades. 6 neodymium magnets are placed on one disk, alternating their polarity, the angle between them should be 60 degrees at a diameter of 165 mm.
Ferrite ring magnets are placed on the second disc according to the same principle..
To prevent the magnets from moving during the operation of the windmill, they need to be poured at least halfway with epoxy glue..
We make the stator
First, you need to wind 9 coils of 60 turns, for this use an enameled copper wire with a diameter of 1 mm.
Next, the coils are soldered together: the beginning of the first coil with the end of the fourth, the fourth with the seventh. The second phase is connected in the same way through two coils, only they start to solder from the second coil. The third phase connection starts from the third coil.
A mold is made of plywood, parchment paper is placed in it, on top of which a piece of fiberglass and spools are placed.
All this is filled with epoxy resin. After 24 hours, the finished stator is removed from the mold.
All parts of the generator are ready, it remains only to assemble them.
The generator itself will be attached to the bracket with the hub using studs. Let’s take a closer look at the build process.
Generator assembly steps:
- 4 threaded holes for studs are made in the upper rotor. They are necessary in order for the rotor to smoothly “sit” in its seat;
- 4 holes are made in the stator for mounting the bracket;
- the lower rotor is placed on the bracket with magnets up, 4 holes for the thread for the stud are also drilled in it;
- a stator is placed on the lower rotor;
- the second rotor is placed on top with magnets down. All this is fixed to each other and the bracket with the hub with studs and nuts.
The hub (flange with bearings) must be purchased separately: the bottom of the hub must be 1.5 ” in diameter.
The sequence of fastening all parts is presented in more detail in the diagram below:
1 – connecting element; 2 – support of the blades; 3 – the upper part of the rotor; 4 – magnet; 5 – bushing; 6 – stator; 7 – the lower part of the rotor; 8 – nut; 9 – hairpin; 10 – hub; 11 – axis; 12 – bracket for stator fastening
We make blades
Blades can be made from wood, fiberglass, and other materials. It is faster and easier to make this part of the wind generator from a PVC sewer pipe. It is better to use orange pipes, as they have good density and are not afraid of direct sunlight.
For a vertical wind generator, you need 4 blades made of PVC pipes and 2 orthogonal (curved) blades made of galvanized sheet. This design will allow the wind turbine to rotate even in weak wind conditions at a speed of 2-3 m per second. We take meter-long pieces of PVC pipe and cut them lengthwise into 2 equal parts. We cut out semicircles from the tin according to the size of the future blade and fasten them with bolts along the edges of the pipe.
To make orthogonal blades, you need a standard 0.75mm galvanized steel sheet. First, with metal scissors, two pieces of 1×0.4 m in size and four pieces in the form of a droplet are cut out. Then the pieces of steel need to be bent and pieces of “droplets” are attached at the edges.
The blades are fastened in a circle to the frame, it can be welded from a 20×20 profile square pipe and 25×25 corners. The dimensions of the frame and the distance between the blades can be seen in the diagram below:
Assembling the structure of the wind turbine
A mast is welded from water pipes of various diameters, its height depends on the area where the wind generator will be located and the conditions of its operation, but in any case it must be above the roof of the house.
A three-point reinforced foundation must be prepared in advance for the sectional mast. The generator is screwed to the finished mast on the ground. Next, a frame with blades is bolted to the generator. The windmill mast is attached to the foundation by means of two articulated supports and is lifted to a vertical position by means of a winch. After lifting the mast, the third support is screwed to the base of the windmill with a bolt. Additionally, the mast needs to be fixed with a brace.
The wind turbine will supply 3-phase alternating current. Using a bridge rectifier consisting of 6 diodes, we convert it to direct current.
This makes it possible to charge the battery at 12 V. To control the charging of the battery and prevent it from overcharging, a standard car charging relay PP-380 is used..
An inverter is connected to the battery, which allows you to convert the obtained 12 V DC into 220 V AC with a frequency of 50 Hz.
Wind turbine result: efficiency calculation
Test tests of the wind turbine at different wind speeds showed the following results:
- at a wind speed of 5 m / s, we get 60 rpm – 7 V and 2.3 A = 16 W;
- at a wind speed of 10.6 m / s, we get about 120 rpm – 13 V and 3.4 A = 44 W;
- at a speed of 15.3 m / s about 180 rpm – 15 V and 5.1 A = 76.5 W;
- at a wind speed of 18 m / s we get 240 rpm – 18 V and 9 A = 162 W.
Basically, the wind turbine produces 16–45 W, since the wind over 15 m / s is rare. However, if you put a high-speed propeller, then you can get higher results.