Connecting 20 wind turbines in series ?!

[elvis_asaftei]

As they're A/C they will always be out of sync phase wise, you cant connect them in series or parallel

I haves asked for solutions so the smartest around can give their solution about how to do this.

Each wind turbine will have its own controller that will provide 50V DC and I am searching for solutions how to connect output from wind controller. In series or parallel, series of DC with isolated DC-DC boost is very good because it can be feed into 120V - 450V input from solar MPPT inverter that will charge batteries and provide WIFI monitoring over the year.

So what is your solution ?

 

[Samueru]

I am searching for a way to connect 20 wind turbines to 48V battery bank, we have 10 wind turbines of 48v and 10 of 24V both are 10A wind turbines. Because distance is 100m to battery I wanted to connect output from wind controller in series and go to 350V input of standard MPPT solar inverter.
This seems it is not working because 2 or 3 of them always get locked and do not spin and also speed is not correctly optimized.

I wanted to have this setup to save a huge cost for 10 cables x 100m x 10amps

And use only 2 cables at 350V -400V with working mppt from 120v to 450V .

Anyone has any idea if this setup can work with addition of other diodes ?

My solution remaining to do ia that I will have 2 very large wires from 48V battery pack to the wind turbines and use one wind controller for each wind turbine .

Any suggestions how to connect 20 wind turbines ?

You can try to rectify the output of each wind turbine to DC right at the pole then wire all of that DC in series. And each rectified DC from each turbine gets its own bypass diode, just like series PV.

Here's an example with 3 turbines: Also the bypass diode isn't really 100% needed because the bridge rectifier can also work as one, the advantage is that it lowers the voltage drop when a turbine is not producing.

You should also add a brake switch to each wind turbine just in case btw, you can use a double pole switch like this:

https://imgur.com/a/fh8bOx2

You would do two series sets, one for all the 48V turbines and one for all the 24V ones.

 

[elvis_asaftei]

You can try to rectify the output of each wind turbine to DC right at the pole then wire all of that DC in series. And each rectified DC from each turbine gets its own bypass diode, just like series PV.

Here's an example with 3 turbines: View attachment 76843Also the bypass diode isn't really 100% needed because the bridge rectifier can also work as one, the advantage is that it lowers the voltage drop when a turbine is not producing.

You should also add a brake switch to each wind turbine just in case btw, you can use a double pole switch like this:

https://imgur.com/a/fh8bOx2

You would do two series sets, one for all the 48V turbines and one for all the 24V ones.

I have done a series of 6 exactly like you image, with an electrolytic capacitor of 5000uF for each of them in series and without the bypass diode as i was considering 3 of the diodes will bypass if that wind turbine is not spinning.

Problem is that 3 of them are always stalling never start to spin. As I disconnect their DC output from the series they they start to spin.
I have checked several times the capacitor connection and also checked 3-phase bridge rectifier and all of them are ok.

I will want to understand why this was not working. Stalling was happening also when there was no load on the entire series because load is applied only when voltage of the series is above 120V and mppt starts adding load.

Also I was noticing a voltage drop from 120V to 60V when circuit is closed by MPPT and this is probably because capacitors are not all at the same charged level so they can't equalize, this happens only when entire series is closed and than all capacitors will be equalized in voltage.

What might be the issue ?

 

[Samueru]

I have done a series of 6 exactly like you image, with an electrolytic capacitor of 5000uF for each of them in series and without the bypass diode as i was considering 3 of the diodes will bypass if that wind turbine is not spinning.

Problem is that 3 of them are always stalling never start to spin. As I disconnect their DC output from the series they they start to spin.
I have checked several times the capacitor connection and also checked 3-phase bridge rectifier and all of them are ok.

I will want to understand why this was not working. Stalling was happening also when there was no load on the entire series because load is applied only when voltage of the series is above 120V and mppt starts adding load.

Also I was noticing a voltage drop from 120V to 60V when circuit is closed by MPPT and this is probably because capacitors are not all at the same charged level so they can't equalize, this happens only when entire series is closed and than all capacitors will be equalized in voltage.

What might be the issue ?

You had the capacitor where the bypass diode would be on my diagram right? All 6 turbines are of the same voltage?

You made sure that you did not wire any of the capacitors backwards right? Because that would explain the stalling.

Try an add the bypass diodes, because that way the bridge rectifier is not conducting at all when a turbine is stalled. And since this only seems to happen with only 3, I would test different combinations to make sure that it is not an issue with a specific turbine or rectifier or something is miswired.

 

[elvis_asaftei]

You had the capacitor where the bypass diode would be on my diagram right? All 6 turbines are of the same voltage?

You made sure that you did not wire any of the capacitors backwards right? Because that would explain the stalling.

Try an add the bypass diodes, because that way the bridge rectifier is not conducting at all when a turbine is stalled. And since this only seems to happen with only 3, I would test different combinations to make sure that it is not an issue with a specific turbine or rectifier or something is miswired.

You had the capacitor where the bypass diode would be on my diagram right? - yes, electrolytic capacitor, with correct polarity
All 6 turbines are of the same voltage? -> yes , all 48V
You made sure that you did not wire any of the capacitors backwards right? Because that would explain the stalling. >> yes I checked several times
Try an add the bypass diodes, because that way the bridge rectifier is not conducting at all when a turbine is stalled. And since this only seems to happen with only 3, I would test different combinations to make sure that it is not an issue with a specific turbine or rectifier or something is miswired. >>>> yes, I will have to by separately single diode, probably you say that current will pass through a single diode insead of having to go through 2 in series from rectifier bridge.

I still can't explain this behavior. I have started to configure advanced controllers for each and add all of them in parallel, because I have noticed that if you add the same load in amps to all of them, the wind turbine that has highest RPM will continue to increase the RPM at the same load and as the MPPT increases the load as the voltage rises, the ones with highest RPM continue to increase and the ones with low RPM will have lower and lower RPM and this might be conclusive for me that it is not possible to have all of them in series without series side effects like too high rpm, magnets damaging, blades get broken...

I have controller with 5 point load that i will add one for each wind turbine and configure the points of load based on RPM and not voltage.

See all settings I have for the wind controller.

 

[joeblack5]

Why not take small 3 phase transformers and bring the voltage up to 240 volt 3 phase or higher if you dare.. then rectify each of them at the windmill or in the house .. now you can parallel them at high voltage DC . Use mppt if you feel it is efficient..
Or rewind the windmills for higher voltage.

Nice project and problem.

 

[elvis_asaftei]

Why not take small 3 phase transformers and bring the voltage up to 240 volt 3 phase or higher if you dare.. then rectify each of them at the windmill or in the house .. now you can parallel them at high voltage DC . Use mppt if you feel it is efficient..
Or rewind the windmills for higher voltage.

Nice project and problem.

Can you send some links with price for one 3-phase transformer from 48V to 240V ? I will need to use 20 transformers (and also add transformer loss) and that might be more expensive than having the additional wires in parallel instead of series.

 

[joeblack5]

My own projects involve scrapyards, fleabay, university salvage.. if you go a pro route with this then it will cost a lot of money... No doubt salvage aluminum entrance wire will be the cheapest.

Good luck.
Johan

 

[joeblack5]

One more thing depending how the windmill is wired.. star or delta...you might be able to reconnect to star for higher voltage.

 

[elvis_asaftei]

One more thing depending how the windmill is wired.. star or delta...you might be able to reconnect to star for higher voltage.

Hehe, already checked that and between 24V and 48 the factory only switch from delta to star and I am using 48V so I can't do that ...

 

[Smokin]

Hook windmill to bright light. Beam light to solar panels. Done. What's the problem now.!!!

 

[Hedges]

AC coupled wind turbines. Each gets its own GT inverter.
Those used to be available from SMA in the low kW range.

SMA to Part Ways with Windy Boy Inverters - Sunny. SMA Corporate Blog

SMA will withdraw from the small wind turbine industry at the end of 2013, ceasing all future production of the...

www.sma-sunny.com

Could Enphase microinverters handle rectified AC from the turbines? Seems like the right voltage range. What would be needed for protection?

 

[OzSolar]

I am searching for a way to connect 20 wind turbines to 48V battery bank, we have 10 wind turbines of 48v and 10 of 24V both are 10A wind turbines.

I know I'm late to the party but I would suggest that before you go too far down this road why don't you install one turbine and see how it does at your site?

 

[brandnewb]

I do not think that is feasible. Especially at that distance I would much rather either just go solar or try to find a single really large turbine for sale locally. 20 turbines is 20x the amount of moving parts and 20x the maintenance.

I strongly object to the 'go solar' default. Wind ain't over until the fat lady sings

 

[brandnewb]

AC coupled wind turbines. Each gets its own GT inverter.
Those used to be available from SMA in the low kW range.

SMA to Part Ways with Windy Boy Inverters - Sunny. SMA Corporate Blog

SMA will withdraw from the small wind turbine industry at the end of 2013, ceasing all future production of the...

www.sma-sunny.com

Could Enphase microinverters handle rectified AC from the turbines? Seems like the right voltage range. What would be needed for protection?

Rectified voltage is DC yes? Perhaps I missed something new

 

[brandnewb]

I found that zeroing in on the problem parts and ask on specialist fora could yield better results.
in this case a part might be 'how to combine multiple 3 phsse sources'
and if feadable deal with the rest later and/or elsewhere

 

[Warpspeed]

Can you send some links with price for one 3-phase transformer from 48V to 240V ?

You can use three separate single phase 48v to 240v transformers, each rated for one third the total power.
These are standard stock items and readily available.
With the 240v secondaries connected in star, and rectified you will get 415v phase to phase ac and around 580 volts dc.

That should be enough surely.