Energy-Jason 459 Posted February 20, 2017 Share Posted February 20, 2017 Pre-regulation of Turbine. To solve this put the bulk and float voltages of the Turbine 0.2V higher than that of the Solar. J Mark 1 Quote Link to post Share on other sites
DeepBass9 725 Posted February 20, 2017 Author Share Posted February 20, 2017 What Jay said should work if the settings are adjustable, he should be able to charge from both simultaneously. The controller I have has fixed settings for charging voltages, so it will charge up to 58V and apply the brake at 60V. Practically this works out so that if solar has the batteries at 59.2V, then the wind turbine brakes, but will generate at any other time. I/e if the sun is shining and the batteries are in absorb, then the the turbine will brake. There will be some confusion though if the solar MPPT changes to float voltage of 55V, then the wind generator will start up again, but I have yet to see that occur, and if it ever does will be exceptionally rare. How well does an MPPT work with wind? It seems like it will be constantly trying to hit a moving target with variations in wind speed and gusts etc? Quote Link to post Share on other sites
Energy-Jason 459 Posted February 20, 2017 Share Posted February 20, 2017 Midnite Solar MPPT- The Classics work great for wind. Very fast processing of changing wind. I always prefer PWM with wind. Unless its a Midnite :> Jay Quote Link to post Share on other sites
SilverNodashi 760 Posted February 20, 2017 Share Posted February 20, 2017 Ok, so if the turbine voltages are fixed, set the Axpert menu option 13 to 57V, and see how it goes? For fine control, i.e. to set the voltage to 57.5V, you would need to change option 05 to "USE", but then the Axper's own SOC calculations will be out. Quote Link to post Share on other sites
Mark 438 Posted February 20, 2017 Share Posted February 20, 2017 51 minutes ago, DeepBass9 said: The controller I have has fixed settings for charging voltages, so it will charge up to 58V and apply the brake at 60V. What is the float voltage of the turbine? I would be nervous of overcharging the bank on a windy day if the bank was kept at 58V continuously.. Quote Link to post Share on other sites
DeepBass9 725 Posted February 20, 2017 Author Share Posted February 20, 2017 14 minutes ago, Mark said: What is the float voltage of the turbine? I would be nervous of overcharging the bank on a windy day if the bank was kept at 58V continuously.. The turbine controller is not that smart, it charges up to 58V and then brakes at 59-60V. Never fear though, the wind is so erratic here that overcharge by the wind will never happen. Quote Link to post Share on other sites
Mark 438 Posted February 20, 2017 Share Posted February 20, 2017 6 minutes ago, DeepBass9 said: The turbine controller is not that smart, it charges up to 58V and then brakes at 59-60V. Never fear though, the wind is so erratic here that overcharge by the wind will never happen. Cool. I must admit its a risk. BUT... The clever guys will suggest a way to trigger a relay based on SOC that will disconnect it so it doesn't kill your battery bank. At least you have some wind now. Do you have an idea of how it holds the bank overnight. Especially given the influence of Dineo? Quote Link to post Share on other sites
DeepBass9 725 Posted February 20, 2017 Author Share Posted February 20, 2017 Currently I don't have a way to monitor the power produced. I popped 2 kWh meters from close by lightning strikes, but I now have a surge arrester installed and yet another kWh meter in the post so I should be able to measure it again soon. Most of our wind is during the day (once you start paying close attention to wind speed), and there are too many other variables to get a sense of it without actually measuring the power production. The idea was to generate some extra power in windy, which usually equates with cloudy weather, which it does do. The day that Deneo passed over I'm sure 1 or 2 kWh were produced. The windiest time of year on the highveld is September to November, so lets see then : https://www.windfinder.com/windstatistics/lanseria_airport I may look at raising the turbine a bit higher as well, its currently 4m high on a small hill, I may raise it to 7m. Mark 1 Quote Link to post Share on other sites
DeepBass9 725 Posted February 20, 2017 Author Share Posted February 20, 2017 I just looked up what the 'Beaufort Scale' is, referred to on www.windfinder,com . From my observations, you need wind at Beaufort 5 or greater to generate any wind power. Lower wind speeds just don't have enough power to harvest. (This is using the empirical 'land conditions' scale) Quote Link to post Share on other sites
zakzak 1 Posted July 3, 2017 Share Posted July 3, 2017 In this video, you will find a way to install the wind turbine by a hydraulic winch: wind turbine installation Quote Link to post Share on other sites
DeepBass9 725 Posted July 25, 2017 Author Share Posted July 25, 2017 A question for the electrical boffs. My wind turbine needs quite a lot of wind to get up to the +-37VAC that starts charging batteries. 20VAC happens more regularly at lower wind speeds, so what is the feasibility of using a 2:1 step up transformer to increase the voltage? I see that size transformer is quite common as it is used to step 110V to 220V and vice versa for US voltages. If I were to do that would I need 2 or 3 single phase transformers for the 3 phases, or should I try and find a 3 phase transformer? What would the wiring look like if I were to use single phase transformers? What I learn from this is you need a high wind speed to charge a 48V bank, but a 24V or 12V bank would be easier to charge at lower wind speeds. Quote Link to post Share on other sites
___ 4,126 Posted July 25, 2017 Share Posted July 25, 2017 16 minutes ago, DeepBass9 said: 20VAC happens more regularly at lower wind speeds Does it make any kind of significant power at 20V? I'm not fully familiar with the maths around wind speed, but from a basic understanding that energy is proportional to the square of the speed involved (e = 0.5 * m * v^2), my gut feeling is that at half the wind speed it makes a quarter of the power. So the volts might be good, but the current might be pitiful. I'd check that out before I spend money on a boost converter (that might be the better option, an MPPT that is buck/boost). Quote Link to post Share on other sites
DeepBass9 725 Posted September 14, 2017 Author Share Posted September 14, 2017 I have 3 x 110v to 220v 500w transformers in the post that I found on gumtree for cheap. So I'll step up the turbine voltage x 2 and see how that works. I still have to figure out the wiring, star or delta anyone? Quote Link to post Share on other sites
pilotfish 394 Posted September 14, 2017 Share Posted September 14, 2017 1 hour ago, DeepBass9 said: I have 3 x 110v to 220v 500w transformers in the post Hi @DeepBass9 What is the rated power of the turbine and what is the rated power of the transformers? If the transformers that you bought are under-rated they will be toast in the 1st decent wind! Is the output from the turbine 3 wire or 4 wire (excluding earth conductor)? If 3-wire then you should wire your transformers in delta, if 4-wire then you should wire in star (to match existing). The best place for a wiring diagram is Google you will find lots of examples, here is one... Note that if you wire in star then your output voltage between any phase (X,Y,Z in the above pic) and neutral (N in above pic) will be lower by a factor of 1.73 than the voltage between any of the phases. This may be an advantage in your case because doubling the voltage might lead to some tears. Good luck with the project! Quote Link to post Share on other sites
___ 4,126 Posted September 14, 2017 Share Posted September 14, 2017 The only thing that concerns me here is that a transformer is generally designed to work at a specific frequency (or a range of frequencies), while things like car alternators and wind turbines pretty much put out a frequency proportional to how fast they are turning. The voltage you can put in on the input and the efficiency depends on the frequency and the design frequency. Now this is completely out of my normal training, it's just something I picked up over the years. You may have to do some math homework. Quote Link to post Share on other sites
DeepBass9 725 Posted September 14, 2017 Author Share Posted September 14, 2017 But decent wind is the problem, I don,t have it! The turbine is rated at 800W, and the transformers at 500W each, so should be fine. The intended result is that on the days when the turbine runs at 20V all day, I can step it up to 40V and at least get 50 or 100W out of it. It needs quite a strong wind to get up to a high enough voltage to charge at 50V Dc, so hopefully this will do the trick ( or at least keep me amused for a weekend putting it together.) There is no neutral from the turbine, just the 3 phases, so delta would be the way to go? Quote Link to post Share on other sites
pilotfish 394 Posted September 14, 2017 Share Posted September 14, 2017 If I was going to do I would do something like this... (he said gritting his teeth and looking away in anticipation!) Quote Link to post Share on other sites
pilotfish 394 Posted September 14, 2017 Share Posted September 14, 2017 Note that when I say "If I was going to do it", I wouldnt! Chris Hobson 1 Quote Link to post Share on other sites
DeepBass9 725 Posted September 15, 2017 Author Share Posted September 15, 2017 Fortune favours the brave...... Thanks for The sketch, but what would the problem be? Quote Link to post Share on other sites
DeepBass9 725 Posted September 15, 2017 Author Share Posted September 15, 2017 This morning is actually a good example of the problem I am trying to solve. There is a strongish breeze since early this morning and the generator is spinning merrily and making about 23V. How much battery charging does that translate to? Zero as you need 35V A.c. to get up to the battery charging voltage. If I step up the voltage then it would be charging this morning as the voltage would be high enough. If it is 50W it will help. Also if you look at wind systems, in a lot of them the turbines are the same, just the charge controller differs for 12,24,36,48V systems. I'll post a circuit diagram later as I need to include the lightning arrestor, a brake, the transformers and I can put a circuit and contactor to bypass the transformers if an hurricane arrives. Quote Link to post Share on other sites
pilotfish 394 Posted September 15, 2017 Share Posted September 15, 2017 The problem is that it is a "thought experiment", not something I have actually done myself - so in my head it should work but in reality it may smoke your equipment, so it had to come with some sort of disclaimer. There are guys on the forum who may identify problems with the idea, I suggest waiting for further comment on the setup before proceeding (which is the value of a forum). If you go ahead then on 1st run you will need to measure output voltages to see if they make sense. If the voltages on the outputs aren't similar then it is possible that one of the transformers is reverse phased which would require swapping either input or output wiring to correct the phasing so that the voltages are similar, on a wind generator with varying output I suggest using 3 multimeters to do this so that all 3 phases can be monitored at the same time. Also I suggest setting it up temporarily on a table next to your generator with something like a 6amp 3pole CB (or fuses if cheaper) between gennie and TNF, so that if high circulating currents arise the CB will trip before melting the transformers or alternator. Quote Link to post Share on other sites
___ 4,126 Posted September 15, 2017 Share Posted September 15, 2017 Okay, bear with me for a second. 1. MPPT controllers are generally buck converters. But you do get boost versions, such as this one. Also, the Solar Edge optimisers are really boost converters. 2. Many MPPTs can be employed with wind turbines, for example the Microcare or some Morningstar controllers. 3. As I recall, some Morningstar controllers are buck-boost, they can do both. It seems to me the right thing to do is find a buck/boost MPPT that has a wind turbine feature. That might cost more than the turbine. :-( Quote Link to post Share on other sites
___ 4,126 Posted September 15, 2017 Share Posted September 15, 2017 And someone already wrote a paper on this idea. Quote Link to post Share on other sites
DeepBass9 725 Posted September 15, 2017 Author Share Posted September 15, 2017 2 hours ago, plonkster said: That might cost more than the turbine. :-( I'm trying to keep the cost down here to avoid throwing good money after bad. The 3x 500W transformers cost me R750. Quote Link to post Share on other sites
DeepBass9 725 Posted September 24, 2017 Author Share Posted September 24, 2017 So I tried delta delta wiring, but that doesn't work for then simple reason that the 3 phases are essentially bridged which brakes the generator. I swapped the phase on one winding and got the required voltage on 2 phases, so I figure that star delta is probably the way to go. I,'ll rewire tomorrow and see how that works. Quote Link to post Share on other sites
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