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### Topic: Wind generators combined (Read 1 time)previous topic - next topic

#### elico

##### Sep 12, 2012, 11:34 amLast Edit: Sep 12, 2012, 11:43 am by AWOL Reason: 1
Hi all

What is the way to combine several wind generators output
to charge a common battery ?

Elico

Moderator edit. Shouting removed from thread title, spelling corrected.

#### mauried

#1
##### Sep 12, 2012, 01:25 pm
What type of wind generators?
Do they have inbuilt charge controllers.

#### elico

#2
##### Sep 12, 2012, 02:19 pm
No charge controllers inside
Just a dynamo that delivers synus oe rectified synus
output .

Elico

#### majenko

#3
##### Sep 12, 2012, 04:35 pm
The output of each turbine will first have to be regulated so each turbine gives the same voltage for a given rotational speed distribution.  These regulated output voltages can then be combined via identical power diodes.

If any one turbine drops below the power threshold rotational speed (i.e., the regulated output drops below what it should be regulated to) then that turbine will stop providing power to the main combined output.

Due to the fact that no two diodes have exactly the same forward voltage drop (unless you pay through the nose, ear, mouth, and any other bodily orifices that you may have), each turbine's regulated output should be adjusted so that the output voltage after its coupling diode is equal to all the others.  A slight difference in this output voltage could cause the diode to become reverse biased (if it is too low) and never provide current to the main output unless all the other turbines are stopped.

#### kf2qd

#4
##### Sep 12, 2012, 05:52 pm
The short answer is that you need a diode sized for double the highest charge current from the wind generator. As they are charging a battery they will all have a higher voltage than the battery - otherwise no current flows... Depending on the output voltage of each of the generators, the output current will relate to the output voltage, so if one generator has a slightly lower output voltage it will supply slightly less current. Output voltages need to be close, but If they vary by a volt the higher voltage generator will just do a little more of the work.

#### retrolefty

#5
##### Sep 12, 2012, 07:14 pmLast Edit: Sep 12, 2012, 07:16 pm by retrolefty Reason: 1

The short answer is that you need a diode sized for double the highest charge current from the wind generator. As they are charging a battery they will all have a higher voltage than the battery - otherwise no current flows... Depending on the output voltage of each of the generators, the output current will relate to the output voltage, so if one generator has a slightly lower output voltage it will supply slightly less current. Output voltages need to be close, but If they vary by a volt the higher voltage generator will just do a little more of the work.

That's not how I see it operating in practice. If the generators are isolated from each other by simply using  'Diode ORing' isolation to the battery, then the generator with the highest voltage will supply ALL the current flow and cause ALL the other generator's isolation diodes to be reversed biased and turn off ANY current flow from those other generators. Balancing current between separate voltage sources that use simple diode isolation from each other is extremely difficult, as trying to control the output voltage from each generator close enough to try and maintain a balanced current flow would require quite complex current and/or voltage monitoring and some kind of feedback control to the generators or their isolation device to force a balanced current situation between the generators. I would think high current MOSFET transistors might be a better method to allow sharing of current if the proper control algorithm is implemented to adjust the mosfets acting as current controllers?

Lefty

#### elico

#6
##### Sep 12, 2012, 09:09 pm
I have a crazy idea ..

All generators outputs will be rrctified and filtered without any
stabilisation at all .

Now a transformator with many primaries one for each generator
will genetrate square wave with stable amplitude.

Each primary will be fed by a sqare wave generated from its generator .

All primaries will be in phase .

The output of the transformer will supply squre wave with varying amplitude .

That output square wave will be rectified and filtered
and will chrge the batteries with a charging control .

How is that ?

Elico

#### winner10920

#7
##### Sep 12, 2012, 10:13 pm
I think the generators will self regulate, assuming they are under similiar situations with just the diode method
if one has more load than the restt because of a voltage drop, assuming the generator has the same power applied it will slow down due to the load and balance out with the others
kinda like how a generator for 120v mains would work, so long as the voltage and frequency match close enough it will be forced into sync, the few percent that it is off is corrected naturally by the larger network forcing it to match and follow the path of least resistance (matching voltage and frequency exactly)

#### elico

#8
##### Sep 13, 2012, 07:52 am
Wind generators plants are widely found
worldwide, where they are charging same battery pack .

So let us find how it is done by them ...

Elico

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