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Forum Index : Windmills : unloaded in high winds

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shawn

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Joined: 30/03/2010
Location: New Zealand
Posts: 210

Posted: 10:43pm 24 Oct 2013

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High guys ive had some high winds over here and found my mills new weekspot its the rectifire that turns the ac output into dc mine was two 100 amp brides connected in parallel , I was told that there will always be one that cuts in first and does all the work this is true because one got warm first
anyway long story but they died,I have used an old car alternator for a while but it fried quiet fast.
Any idears?? for those that do not know my mill its 4 meters diameter 24 volt and I see spikes of 180 amps often yes the furling works and it goes back to around 1200 watts but in crazy wind you get spikes like this.
I just want some diodes that will live.

Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498

Posted: 11:24pm 24 Oct 2013

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Sounds like you need a bigger "rectifire" or even a Rectifier. If you are seeing spikes of 180 it is possibly going higher than that but it happens to fast for you to see.

There are only 10 types of people in the world: those who understand binary, and those who don't.

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 02:41pm 25 Oct 2013

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Perhaps something like this.

http://www.ebay.com.au/itm/FKO-MDS200A-Bridge-Rectifier-3-Ph ase-Diode-200A-Amp-1600V-/151080008262?pt=AU_B_I_Electrical_ Test_Equipment&hash=item232d11fa46

Or even bigger like 300 amp

http://www.ebay.com.au/itm/300-Amp-STC-ST-Wind-Generator-Rec tifier-1-or-3-phase-/161048093868?pt=LH_DefaultDomain_0&hash =item257f36e4ac#ht_2333wt_932

I do much rather the rectifiers with screw terminals over the solder tag types.

Pete.

Sometimes it just works

shawn

Senior Member

Joined: 30/03/2010
Location: New Zealand
Posts: 210

Posted: 03:09pm 25 Oct 2013

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thanks pete im currently looking at building up somthing with 400 amp schottky diodes
I agree with the screw termanals while I was waiting I solderd a car alternator rectifire on it was only a 35 amp old lucas type it got so hot it unsolderd it self i woke up to a very noisy unloadid mill

Downwind

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Joined: 09/09/2009
Location: Australia
Posts: 2333

Posted: 03:57pm 25 Oct 2013

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Quote thanks pete im currently looking at building up somthing with 400 amp schottky diodes

If you are looking to use something like these modules, then be carefull of what you buy.

http://www.ebay.com.au/itm/MBRP400100CT-400A-100V-SBD-Schott ky-Barrier-Rectifier-Diode-Module-/300827183579?pt=AU_B_I_El ectrical_Test_Equipment&hash=item460ab289db#ht_2203wt_1170

As most modules are common anode or common cathode and what you really want for a 3 phase rectifier is the version that has the "D" prefix in the part number as it stands for doubler, and the base plate is connected to anode of one diode and cathode of the other diode (single bridge rectifier style) you would require 1 for each phase.

Personally i would just go for one of these.

http://www.ebay.com.au/itm/AC-1600V-300Amp-Black-Rectangle-P lastic-Case-5-Terminals-Diode-Rectifier-Module-/161044031189 ?pt=AU_B_I_Electrical_Test_Equipment&hash=item257ef8e6d5#ht_ 2176wt_1141

Pete.Edited by Downwind 2013-10-27

Sometimes it just works

anteror
Senior Member

Joined: 06/10/2009
Location: Finland
Posts: 189

Posted: 11:53pm 26 Oct 2013

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You have good loading power

I had the same problem, untill I made myself the tree phase rectifier with heavy-duty bolt diodes and they must be installed in big cooling plates and have button thermostats and some fans for extra cooling.

You need two cooling plates and 6 diodes.
(3 units bolt= anode and 3 units bolt= cathode, so the cooling plates are + and - )

Example of 200Amp diode.(You can find them locally from electronic shops also):

http://www.ebay.com/itm/1200V-200A-Recovery-Rectifier-Diode- Stud-Version-ZP200A-New-/400353886144?pt=AU_B_I_Electrical_T est_Equipment&hash=item5d36f37fc0

Here for example 24V fan;

http://www.ebay.com/itm/8025S-24V-Brushless-DC-7-Blade-2-Wir es-Cooling-Fan-80x80x25mm-JT1-/290986983343?pt=UK_Computing_ Case_Fans&hash=item43c02cffaf

When you go over 100Amps, you really need all this.

Here is a diagram of tree phase rectifier.
You do not need those varistors (voltage dependent resistor, VDR), which are connected to the diodes in parallel, when you use heavy duty bolt diodes.

I load all the power from my windgenerator directly to the batteries,with
self-made heavy duty rectifier, without any other controller.
I use this Dc monitoring relay, to prevent overvoltage in my 24V system;

http://www.takowa.fi/fi/kauppa/1-vaihe-ac-dc/hrn-64

It is very easy to use with screw controls.
You choose the voltage point, when this relay makes the contact and with the
percentage reading you choose, when the load is switched off.
It protects your batteries and you can choose, how deep you take energy from
the batteries. If you have lead acid batteries = longer life, for lead acid batteries, with not so deep cycles etc
The load must be AC from inverter and this relay can take loads up to 4kw.

AnteroEdited by anteror 2013-10-28

shawn

Senior Member

Joined: 30/03/2010
Location: New Zealand
Posts: 210

Posted: 04:55pm 27 Oct 2013

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Thanks guys ive built a tempory bridge up while i wait for the big one to get here i just hate to not have the mill spinning it just dos'nt seem right.

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