18' Wincharger Axial Hybrid - Update 2929 Watts

[Dave B]

  We had gusts today up to 33 MPH and I continue to experiment with my hot water heating direct (no controller). Latest are 3  3600 watt 240 V elements each on a seperate phase direct wired to the wild AC no batteries no controller. To break stall requires about 10 mph constant wind to get up to around 60 rpm (30 volts) but will then accelerate quickly up to furling speed of about 180 - 200 rpm if the wind increases to about 20 mph. Very gusty conditions today briefly peaked the output at 2929 watts 125 volts @ 250 rpm during a wind direction change before the furling could catch up. I have a temp. sensor on my 50 gallon pre-heat tank now that is insulated from the ambient temp. and is monitored by my Weather Wizard (this was the outdoor  temp. sensor) so now this data is logged also. In 2 hours this afternoon the tank temperature indicated a 5 degree F. increase. Roughly crunching the numbers indicates an average output of around 300+ watts continuous for those 2 hours which works out about right. I am really getting a handle on my system by being able to log so much data. More testing and controller plans to follow.  Dave B.  

[hiker]

looked at your files..

145 winds per coil wired in star..have you tried using 110v elements-seems like thats more inline with your alts output..to big of a load and your coils and feed line just heat up..a short is a short--big short the coils and feed line heat up-little short

and the short heats up[heating elements]..just my simplex thoughts.nice work on the

alt and tower..wonder what it would put out  if you broke the star connection and used a heating element for each phase....most likly would have to use heavry wire going to your tanks...okay im starting to think to hard ..this is your project not mine!!!! :}

[Dave B]

Hiker,

  Thanks for the comments. I have had all kinds of combinations for loads while experimenting and have run 120 volt elements besides. Without running a controller or contactor of any kind yet it has been interesting to see how each reacts to start up and high end etc. The 240 volt elements if figured at the same rating for 120 volt seem to allow the start up easier but like you say are not the best choice overall. I am running each element as a seperate phase AC, no batteries. The simpler the better for me and maybe at best I'll end up with a contactor for switching the loads but it is amazing the amount of torque these Wincharger Blades develope once stall is broken. It's working for me and can only get better as I experiment further. I like keeping things safe and well under control, I know all too well that the big winds will come and it's only a matter of time. Updates to follow, thanks again.  Dave B.

[scorman]

Dave,

Few questions:

Have you calculated (charted?) the TSR at diff WS from 10mph startup to 20mph+ furl??

I thought you were shooting for something less than TSR=7

In hiker's previous comment about the "star" configuration ..are you running 3 or four wires down the tower? I had thought you were placing each load resistor across 2 of the three phases.

What is the actual resistance of each winding for each phase within the generator?

I think what hiker was getting at is that a 3600w/240v element has a resistance of 16ohms... if your internal winding resistance is <2ohms, then you are only wasting <12%

in heating up the generator (simple series resistance) ...the lower the generator winding resistance vs load resistor the better ...I don't see how a 1.5KW/120v element can do anything + for you, since it would have a resistance of 9.6ohms (wrong direction) and a 1KW/110v won't provide any overspeed protection. Maybe I am missing something obvious here?

Stew Corman from sunny Endicott

[Dave B]

Stew,

  Here is my latest performance graph with 3-240 volt elements wired direct and no controller. 3 wires down the tower wild AC 3 phase. Each element is connected to each phase. This is a 15 coil 20(40) magnets dual rotor. Each phase (10 coils wired series) measures approx. 4.5 ohms including the line resistance up to the load. Yes, these 240 volt 3600 watt elements measure very close to 16 ohms each.    It's obvious that the Wincharger blades are the reason why I am having success with a higher voltage stator and resistance heating even with no controller. They are high torque blades and yet seem quite happy to run 250 RPM + even at 18' diameter and under load besides. Maybe a contactor as a load controller is in the near future but I am also convinced the simpler the better in my case. If it's turning it's heating and so far it does that well. (high watt and low watt density elements of the same or different values and even 120 volt compared to 220 volt can run similar or  much different. Formulas and numbers don't always predict the whole story.) Thanks,  Dave B.    

[Dave B]

My mistake ! I accidentally overlayed plotted points from 2 graphs. Most of the graph shown is for 3 120 volt 1500 watt elements with the upper end being the 240 volt 3600 watt elements. I'll try to correct this and get it back up here proper, too much of a hurry sorry about that.  Dave B.

[Dave B]

Here's the corrected graph overlayed for both the 120 volt 1500 watt and 240 volt 3600 watt elements. I tried to take readings during what I considered to be a fairly constant wind at each speed so that the blade rpm would be pretty well settled and fairly accurate at each point. Over time I have observed these figures to average out quite close. This is all fine and good but what you can't interpret from these graphs is the real time average power output and how this is affected by inconsistant wind speeds. Especially start up and the top end. In both graphs at the top end the mill is fully furled which is tough to draw the way I have it set up. This data will certainly help me dial in even a simple contactor as a controller. Fun stuff for sure.  Dave B.

[scorman]

Thanks Dave for your update.

I am now very confused by your comment that there is little difference in performance depending upon which load resistors you choose. Your graph clearly shows that 120v/1500watt/9.6ohm gives you much more delivered power than 240v/3600w/16ohm load?

If I look at a reasonable operating point below furl, I see at 18mph WS, that you get 2KW vs 1.2KW ..this is NOT insignificant.

As far as a contactor ..is it your intent to simply use a 3phase contactor to add more load at some voltage setpoint near the upper end ie 75v, to utilize that extra torque and possible reduce that 250rpm top end ( more power delivered, less noise, less vibration, less stress on mechanical parts)? Seems like a good idea to me after looking at your chart.

IMHO, a second set of 240v/16ohm elements would load even more than the 120v/9.6ohm, allowing you to use more of that torque with no chance of stall

" Each phase (10 coils wired series) measures approx. 4.5 ohms including the line resistance up to the load"

When you were using the 120v/9.6ohm elements, 1/3 of the power produced by the mill was dissipated as heat in the line wire and generator coils ..that is why for lower voltage systems, they use very heavy wire coming down the tower... but this is fine when the WS is high enough and the swept area big enough, that turbine efficiency % is irrelevant ..all you care about is how much power is "delivered"

I had asked you about TSR and did a few calcs off your graph data and I see TSR<5 at lower WS and TSR=5.5 at mid operating point ...if you send me the data set you used for that graph, I can do a plot of TSR for each of the loads you graphed ...it is important because it will show how loading effects the rpm and torque and ultimately the power produced. BUT, there is some point at which the TSR goes too low and you get into stall region (but not with these loads)

scorman@stny.rr.com

I can also send you my excel calculator which figures all this out

Stew Corman from sunny Endicott

[Dave B]

Stew,

  If you were able to observe the over all performance such as I do every day you would realize that although the numbers show very significant output differences it does not tell the whole story. I am talking about average output over time and this is what matters most for my application. With no controller (as yet) you would observe very quickly that from start up to say 1000 watts as an example the 3600 watt elements would start easier and produce on average much more power in watt hours than the 1500 watt elements. It is only on very rare occasions of "constant" wind where the 1500 watt elements can first start up and then hold long enough to win out over a significant period of time.  As I mentioned in my previous post the plotted points were each measured at a given "instant" in time and over time I was able to plot enough points to draw the graphs. You can not see the missing component of time on my graphs. All the info. is there for you to figure the TSR for any given point also if you want. Dave Moller and I were quite certain his blades with the Gottingen 222 profile would perform well for my application and  we were correct. It's up, it's running, it's heating and it's run time that's proving it's design every day. Thanks for the comments,  Dave B.    

[scorman]

Dave,

I am not picking on your project ..I only have compliments for a job well done and I agree with Dave Moller's comment that overbuilding is the way to go!

back to the thread ....I see where you are coming from ...if startup is your only problem, ie the 120v loads cause too much drag to get the rotor spinning early enough, then why not use a 3 phase contactor to leave the mill unloaded until you reach say 30v?  use two in parallel if you want it failsafe

I'd be interested to see if Flux or any other of the forum guru's think from the data you have presented, that throwing out 50% of delivered power is the correct design point.

I will post a chart of the TSRs from your data if I think that it shows something useful.

(Busy right now pouring a concrete footer for a new tiltover tower ...guy anchors next)

Stew Corman from sunny Endicott

[Dave B]

Stew,

  I didn't think you were picking on my project, I knew your intentions are positive. I am presenting my observations for my project which is not the same as the majority here who are charging batteries. Different profile blades, wired for higher voltage (in general) and exclusively AC no controller wired direct to resistive loads for heating is proving to be a very different animal from a battery charging system. It's exactly what I had hoped would prove out to be a working system. From the help of many others before I was quite certain of my changes to the electrical end of the design and Dave Moller was instrumental with the tower design and all fabricating as well as carving my blades also. I think the best advice I can offer to anyone is to design everything much stronger than you think it will ever need to be and then build it at least twice as strong as that. Keep us posted on your project, nothing better than learning from each other here on this board.  Dave B.