Universal motor in wind generator

[nlc]

As a looping, you would need a mppt behind, because it can pull on the generator regardless of the wind speed. It will always extract the maximum that there will be to extract.

With a multiplier you add mechanical losses, your gen will turn faster but you will have less torque, the mechanical power will be the same (and even less because of the losses), so the electrical power would be similar. You really need a mppt, that simplifies everything.

[darwenn]

Yes but considering the price I will do without at least to start.

[Alain G]

As a looping, you would need a mppt behind, because it can pull on the generator regardless of the wind speed. It will always extract the maximum that there will be to extract.

With a multiplier you add mechanical losses, your gen will turn faster but you will have less torque, the mechanical power will be the same (and even less because of the losses), so the electrical power would be similar. You really need a mppt, that simplifies everything.

A generator that runs faster generates more watts, because for the same dimension if you spool with smaller wire, you will draw less amperage, on the other hand if you take a thick wire and you run it faster to obtain the desired voltage it will give you a higher output in watts.

It's all relative, higher voltage less output amps and lower spin to get voltage, lower voltage more output amps and higher spin to get voltage but ultimately more watts produced.

[darwenn]

Something escapes me when I look at the power curves of this type of generator from Future Energy.

If we take the 12 and 48 volt model, whatever the speed of rotation, the output voltage is stabilized at 14v for the 12 volt model and from 52 to 56 for the 48 volt model, i.e. + or - 4 volts. On the other hand the 24 Volts model, watch how the voltage evolves, from 26 to 33 volts or 7 volts difference.

http://4.bp.blogspot.com/_Osf5B1FbYIs/S ... 2Bvent.jpg


It makes sense that the voltage changes with the speed of rotation, but in this case it should also be true for the 12v model. And if it's the fact that the voltage is higher with the 24 model, the gap should be even bigger with the 48v, which it is not. Well these curves are provided as an indication, but good.

Also note in the 24 volts table, that it is indicated more RPM and more voltage and power with a wind 20kmh than with a wind of 27 but hey it just must be a mistake.

[nlc]

A generator that runs faster generates more watts, because for the same dimension if you spool with smaller wire, you will draw less amperage, on the other hand if you take a thick wire and you run it faster to obtain the desired voltage it will give you a higher output in watts.

It's all relative, higher voltage less output amps and lower spin to get voltage, lower voltage more output amps and higher spin to get voltage but ultimately more watts produced.

You did not understand what I was saying a priori.

He was talking about putting a multiplier between his propeller and the generator to increase speed on the generator, not changing anything at the winding level.

With the multiplication, at the same wind speed, the mechanical power on the gen is the same, it turns faster but with the multiplication there is less torque. Just because it spins faster does not mean that it will generate more watt, because there must be more mechanical power upstream for that! Watts don't come out of nowhere

[Alain G]

Sorry nlc

We do not agree on this point, the blades must be able to generate the power to provide the gen.

[loop]

Hello everyone,

Response to Darwenn

according to you can I use a multiplication as I do now (a multiplier of 3 per pulley / toothed belt) or connect the propeller directly to the shaft ?. A multiplier that can perhaps allow me to produce at a lower wind speed depending on the cogging of the generator + multiplier torque.

This type of alternator is precisely designed for direct drive. This is how I made my machine.
Thinking that multiplication will increase the yield of the set is a mistake (I agree with nlc)
At a given wind speed, and for a given rotor area, there is a single maximum power value that can be captured.
The final performance of the machine will obviously depend on the kinematic and electrical chain of the assembly.
Now we can effectively increase the surface area of ​​the rotor to recover more power, but it is to the detriment of the speed of rotation of the rotor, and what happens in high winds? Over-sizing the blades will not work miracles.

Remember that trying to get power with a wind less than 5m / s (18 km / h) is quite simply illusory.

For direct battery charging:
Yes it is possible but not recommended.
In reality the danger is minor if we monitor the power output and the voltage of the batteries. The voltage at the output of the diode bridge stabilizes on the battery voltage, unless the power becomes really too great. In this case there is a rise in voltage, dangerous if it exceeds 14V. If the batteries are full, it is the same.
In general, deep cycle batteries can absorb a maximum intensity equal to 10% of their capacity in Ah.

A+

[loop]

Reply to nlc

How can you know if the MPPT function has triggered? Normally it is continuous and transparent, whatever the wind speed.

We can, and fortunately, otherwise we could not say whether the mppt improves the performance of the machine.
You know the principle of mppt, it is constantly looking for the best result of P = U x I.
In other words, it lets the voltage rise (Ugen in three-phase AC, in my case) looks at the intensity and calculates the result.
If P is better with high U, we continue at U + 1V (example) otherwise we go back to U-1V etc ...
Well to observe what happens, I measure the voltage between 2 phases at the input of the diode bridge.
From 0 to 10 V AC (ie 14 V DC at the output of the bridge) the rotor of the wind turbine rotates without resistance (apart from friction). As soon as you start to charge the batteries, an electromagnetic brake is installed and the speed of rotation of the wind turbine stabilizes when the power absorbed = power supplied by the wind on the rotor.
This is where the role of the mppt comes in, because by more or less braking the rotor, it will guarantee that the angle of incidence of the relative wind on the blades is optimal. In other words, the rotor is rotated at the TSR for which it was designed, regardless of the wind speed.
This principle replaces the variable production optimization step (not everyone is necessarily in agreement with this because the notion of safety of the feathered blades is better)

A+

[nlc]

What I wanted to say is that the role of the mppt is to follow the maximum power point, this is its primary goal. But you were telling me in private that you weren't sure he was doing it and I wanted to know what made you think that.

You say that up to 14V your converter does not draw current on the gen. Would that mean that this MPPT model is a "buck" model only (voltage step-down) and that it is designed to manage only 12V output?

Suddenly it seems that he is obliged to wait to have Uin> Uout before starting?

[darwenn]

Thank you for all these details, so I plan a direct training, that suits me.

I have another question as to whether I will be using a 24 volt generator for 12v batteries and a 12v inverter.

I have a regulator that can accept up to 40v input and 14v or 26 output (depending on the diode that I put a planned for 12 or 24 volts) made according to a plan on the net and which works very well.

This is what I'm thinking of doing, two solutions

1: I calibrate my regulator for a 24v load and I charge two 12-volt batteries in series with a single regulator, but the problem is that I am with 24 volts, so how do I connect my 12v inverter. If I plug it into a single battery, then one of them will always be more discharged than the other, even if I do a relay switch. Does this pose a problem for the series charge of the wind turbine? Will the 24v serial charge balance naturally between the weakest battery and the other?

2: I connect in parallel at the output of the wind turbine, two regulators (I make a second one) 14v which will each charge me a 12v battery. Then I manage for the relay switch to the inverter.

Thank you for all of your valuable advice.