Permanent Magnet Generator Wind Turbine
Free to think!
The picture above started all this.
On a rainy Sunday, some waste wood, a document and a saw.
The result is these propellers.
It\'s better to make good use of them!
First of all, you should take some safety measures when building/installing a windmill generator.
When you get better wind in the sky, you will want to put the generator on the pole.
Lightning Rod (
Before going out)!
Generators without loads will have no resistance, so in stormy weather your props may spin and disassemble wildly.
So please always provide the load or tilt mechanism!
High pressure can kill you, so please be careful with high pressure communication!
I see many people making props with PVC pipes cut into 3, but PVC is easy to become brittle in the sun, which is with fast rotation and. . . no thanks.
Items that are commercially available can be obtained, but they can become quite expensive.
Have I mentioned that I want free?
So the road to go is wood.
I will not repeat the shaping of props.
But in general: the angle near the center is larger than the angle near the tip.
This is because the prompt rotates faster, otherwise a drag will be generated!
This can be seen in the picture above (
Not my propeller. .
If you want to make sure the maximum output, look for a propeller designed professionally.
Note that professional turbines use lift-based blades instead of resistance-based ones.
The blade based on lift points to the wind, while the blade based on resistance is perpendicular to the wind.
So, what is the way to convert the kinetic energy of the propeller into electric energy?
We can generate AC or DC.
AC: magnetic motor: this is a generator that uses permanent magnets to generate periodic AC electrical impulses.
Also called permanent magnet generator (PMG).
AC generator: Although the magnetic motor is a type of AC generator, in general, the AC generator needs to apply power to the field coil to generate a magnetic field.
DC: Generator: a generator that generates DC current using a converter.
DC motors used as generators belong to this category.
I tried electric scooter motor for the first time (
24 v, 150 w, 1500 rpm).
They are easy to get, but since they are low-voltage, high-speed, they do not generate much voltage at the 300 rpm provided by the wind turbine.
I tested and confirmed this.
It\'s possible to use a treadmill motor, but it\'s hard for me to get it in Belgium.
Now I want to change the choice: in 4-
30-watt induction motor (see picture).
These can be found anywhere near!
The rotor is a squirrel cage rotor.
I have ordered the neoinder nedynium magnet for 8mm (1,3T)
And put them into the rotor.
I will try to write down all the measurements as many of the generator items here do not post their final wattage or kWh/Daily average compared to wind speed.
First of all, I already have a 24 v lead acid battery array, so my charging target is 27 v.
When the battery is full, the relay connects the generator to the water heater in the indoor water tank.
Since I plan to have AC output, I may be able to use a transformer to raise or lower the voltage.
Let\'s assume that the propeller rotates at 300 rpm.
This means it rotates at 5Hz.
Since the squirrel cage motor has 4 poles, I plan to use 4 magnets in the rotor, which means my AC frequency is 10Hz (
Since the magnets are arranged in N and S pairs, opposite each other, the flux increases by 2 per rotation of each coil, reducing by 2).
This may not be enough for a normal line transformer.
Gears increase friction for higher speeds, so we won\'t do that.
To provide any power at such a low frequency, the inductance must be very high and perhaps the microwave transformer can be rewired.
Another option to get a higher voltage is to use a voltage multiplier circuit.
Update: The squirrel cage motor provides only 12 v at the maximum speed of my drill bit, so it is not suitable for wind power at all.
It may be a larger magnet, or it may be an induction motor with more winding.
I have now circled 8 61 coils and connected them for 2-phase output.
I used 4 sets of 3 2, 5 kg lift magnets for the rotor.
Update of Squirrel Cage: I have doubled the magnet and now I can get the maximum output of 30 v with a drill bit of 3000 rpm but only 50 mA.
This may be due to the fact that the wires in the winding are very thin, since it has a rated power of only 30 W.
I stumbled across some DC hub motors for old electric bikes.
Many manufacturers now use their bike motors for three-phase communication.
The motor is a direct drive motor.
If I cut the output wire while manually rotating the motor, it really stops.
This motor can output 300 watts, so I expect to generate 150 watts.
Since this generator does not require much rpm to generate a 24 v charging voltage, I will use this generator.
We need to install the propeller on the shaft, add the gear on the shaft, add the chain on the generator gear.
For ease of assembly and lack of tools, I decided to use bike parts mainly.
There are threads of gears on the rear shaft.
You can use this gear directly or you can install a larger gear and use the pinion as a tension nut.