A wind turbine at home: Regulation for battery

[roro04]

Good evening everyone !

I posted a message about a regulator for a wind turbine some time ago. I had a project to build a wind turbine with a permanent magnet generator to supply an autonomous chalet (hut) with electricity via batteries. I had counted on a wind turbine that could come out 15A, I went back down to earth for ~ 5A under 14V which makes us ~ 70W!

Currently I have 50W of solar panels (yes it is not much) with a so-called integrated regulator ... Except that the charge of the batteries exceeds 15V with strong sunshine! So I thought of creating a system that cuts the battery charge automatically when the voltage of 14.4V is reached. Here is the system I imagined and the explanations:



So side solar panels I will be OK with this assembly. By cons wind level I can also use this system but since my generator is permanent magnets, if the wind turns quickly I can easily climb to 50V. The batteries may not appreciate. I think that a switching regulation (Modification of the duty cycle?) Can be not bad. Yes, but how to do it? I would like to avoid, as much as possible, integrated circuits. After another constraint, the current: if too much is asked of the generator, the torque will increase and the wind turbine will stall. The system should therefore be limited in current.

Do you have any leads? Suggestions ? Other systems to offer?

Thank you for your help,
Good night,
Best regards.

Roman.

[dede2002]

Hello Romain,

For the wind turbine I would do a reverse assembly, to dissipate in a resistance all that exceeds 14,4 V.

A car alternator regulator can be diverted, it supports small powers like yours (equivalent to the rotor, 4 to 6 amps)

[roro04]

Hello !

Thank you for your answer
I had thought of such a system but I am afraid that on such low powers there is nothing left for me to recharge the batteries when my generator gives 50V ...

Regarding the regulation of a car alternator, I don't really see how we could do it since it sends a certain amount of current into the alternator to excite it more or less.

The advantage of PWM is that the output is not bad at all and all the energy is used.

We look forward to seeing you!
See you soon

[dede2002]

For all the energy to be used, it must be used ...

In your case you have too much, when your batteries are charged, and it is only what you have too much that you must use (or waste) so that your wind turbine does not get carried away.

With the panels it's easier, just open the circuit.

[roro04]

Re,

Totally agree with you to use the excess energy produced when the batteries are charged.

But when they are charging and the wind turbine produces 50V? How to do ? You will tell me, with the current requested the wind turbine will slow down since the gene will ask for torque.

But precisely I will have to limit the intensity so that the wind turbine does not stall.

Thank you, ;)
++

[dede2002]

If your batteries are charging, the wind turbine will not be able to go up to 50 V.
It will provide 5 A at 14 V, 70 W, its nominal power.
It is when the batteries are charged that the voltage will rise.
The regulator will send the surplus to a resistor, for example 1 A in the batteries at the end of the charge, and 4 A dissipated, without exceeding 14.4 V.
A+

[roro04]

Ah ok I see it will be perfect then!

For the tilting system on a resistance for example you have a working principle to offer me?

If not to limit the current that will output the wind turbine (so as not to stall) a simple bulb of headlight or code can play this function right?

Thank you ;)
Good night.

PS: Besides, if I want my batteries to charge, I will have to find the right compromise between current and voltage ... If I have current but I only charge at 12v ...

[dede2002]

I never saw a wind turbine stall ...? (unless the wind drops)

Yes a bulb it can go, rather 2 even, to absorb 70W at most.


For the diagram it is necessary to reverse the principle of your circuit:
When the zener comes into action (14.4 V) instead of cutting the circuit, the bypass must be supplied.
The balance will be done automatically, the bypass will lower the voltage, the regulator cuts, the voltage goes up, etc. (about 200 Hz in a car regulator).

[roro04]

In my case, the wind turbine will slow down, because when power is requested from a generator with permanent magnets, it requires more torque; so it takes more strength to train it. The wind turbine stalls if the wind cannot overcome the requested force.

I see tomorrow to reverse my pattern

On the other hand it will surely be necessary that I add a diode between the batteries and the regulator because otherwise when my Mosfet will activate the discharge resistance it is the batteries which will discharge in it.

Do you think my setup will oscillate quickly when the batteries are charged?

To summarize :
• Voltage will not go up as long as the batteries are charged.
• The regulator will connect a "surplus" resistor at the output of the generator as soon as the voltage waits for 14.4V in order to drop it
• When the voltage drops the resistance will be disconnected until the next cycle?

Am i all good?

thank you
++

[dede2002]

OK but you can't ask for more than the power of the wind turbine.
Less wind, less amps, it will load less quickly.
No more wind, no more Amps, it won't stall.
It will also be necessary to provide storm security.

I don't know how fast your circuit will oscillate, maybe some capacitors are missing?

The relay is useless, it will remain stuck ...
It is better to have a non-return diode to prevent the battery from discharging in the generator (if it is not already integrated).

Good night.