Ok after helping my neighbor build a 17ft Otherpower style turbine and quickly realizing it is to big for a single Classic I decided to try my hand at stacking 2 :o Luckily it worked as I planned and did not let the smoke out of the smoke filled box ;D Below is my explanation and a link to the wiring diagram that includes a couple power curves one for each Classic.
I used 2 bridge rectifiers and paralleled them on the 3 phase ac from the turbine. Then I fed dc from one rectifier to Classic A and dc from the other rectifier to Classic B. The heart of this stacking scheme was in the way I programmed the 2 Classics.
Classic A has its power curve programmed to cut in at 60 volts dc and 0 amps than I programmed a basic line up to 120 volts dc and 50 amps the next set point was 145 volts dc and 51 amps and the last set point was 146 volts dc and 80 amps.
Classic B has its power curve programmed to cut in at 95 volts dc and 0 amps the next set point is 120 volts dc and 1 amp than I made a basic line to the last set point of 145 volts dc and 80 amps. ( I found that if I have it cut in at 120 volts dc it did not wake up fast enough in a quick gust)
The way this works is Classic A takes the first 50 amps and controls the turbine than Classic B picks up control and continues to make even more power flawlessly the first Classic still continues to make power as well because we made the big jump in the power curve it just tries to let the Classics voltage rise thus giving control to the second Classic. This system has worked very well for us and this particular turbine has shown us 8-9kw at times in 55mph winds. You would need to adjust the power curves acording to the turbine you where controlling but I feel this would be a good system to control say a Bergey XL1 charging a 24 volt battery bank.
Here is a link to the diagram http://www.midnitesolar.com/pdfs/Ryans_stacking.pdf (http://www.midnitesolar.com/pdfs/Ryans_stacking.pdf)
great to here as Im working on a multi turbine with 4 turbine of different sizes 7 ft, 10 ft and 15 ft dim turbines all 24 volt battery bank other power style also one 17 foot 48 volt battery bank are you useing the 150 s or the 200 classics on the 17 footer at 24 volts? cheers to not let the smoke out of the boxes Mike ibeweagle@hotmail.com opps have to read all of the pdf see that it is a 48 volt bank Cheers
You could charge a 24vdc battery with the 17 foot machine and I would predict you would want 3 to possibly 4 Classics we have seen 9kw out of it and it had more but that is the current limit of the Classics and the 17 foot machine definitely needs some form of over voltage protection in front of the Classic or all the magic smoke comes out ::) ::)
thanks halfcrazy for the info will do over voltage protection for the classic on both systems 17 footer on a 48 volt bank , and the other system is 24 volt bank with a 7,10,and 15footer connected to it just wondered if the 150 modle will do for both systems or have you seen over 200 hypervolts open on the 17 footer on a 48 volt bank ? All other power type turbines cheers Mike
the 17 foot machine we built will reach 300 volts easy open I would use 200 volt Classics for this machine as ours seems to be very happy running up to 150 volts and I like the cushion
Thanks Halfcrazy for the info now of to anouther question could you take the output of the two rectifiers and series them to say a 24 volt turbine and charge a 48 volt battery bank have not done yet but think it might work with an 200 or 250 modle classic using your voltage clamp pdf and just series the 3 phase rectifiers yes I reallize you might run into the amp wall for the classic though cheers Mike
Good question theoretically it would work if both turbines where identical. Or you can wait a bit and one of the soon to come features is boost mode.
though to put two 3phase rectifiers on one turbine to see if it will work will do some testing before classic hook up not to let smoke out haha like to see some of the empty smoke boxes and see what actually let the smoke out am just tought enough about electronics to be dangerous haha AS degree in electronics in 1982 lot has change haha now Im dating myself cheers Mike
hello Halfcrazy question on stacking or clarification did you interconnect the two classics one master and one slave? or are they both masters? thanks cheers Happy New Year resolution to not let the smoke out of boxes haha p.s. thats for the 17 footer other power turbine
I don't think the upcoming boost mode will also work for wind. The boost mode is intended to act as a DC-DC converter only.
The way the Classic MPPT works for wind may allow a 24V turbine to charge a 48 volt bank. It all depends on the turbine. The Classic will try to allow the turbine to spin fast enough to put out the desired voltage for your charging set points. If the stator is capable of putting out a much higher voltage than the 24V battery, it can work. We have charged a 24 volt bank using the Chinook 200 12 volt unit. That said, you probably cannot use a Bergey XL.1 to charge a 48 volt bank. The XL.1 was designed to be in boost mode up until 15MPH or so. That means that until you hit 15MPH, you will still be around 24 volts. You would need to have some pretty terrific wind in order to get the XL.1 up to 60 or 70 volts. It may never get there? Tod at Bergey is going to see if offering an upgrade kit makes sense for the XL.1. IT would basically turn the XL.1 into a 48 volt machine. I do not know if the kit would also give you AC output like the new XL.1's will be?
Ryan's ten footer can put out over 200 volts in high wind conditions. That turbine was designed to charge a 48 volt battery bank. It seems that in some conditions, it would be capable of charging a 120V battery bank. Every turbine will have different characteristics. We will try to compile a list for all to look over. This list will take a lot of time to create as we need feedback from wind Classic owners. It will be extremely useful when completed.
thanks Robin for the info on boost mode will have all classics on line so you can see what they do as we make them here a little different in stator design but fallow Other powers lead and maybe lag now will see have a choice of 7 foot ,10 foot,12 foot ,15 foot charging 24 volt battery banks and one 17 footer charging 48 volt bank This will be an Exciting New Year with the Classic cheers Mike