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Forum Index : Windmills : Fisher & Paykel Micro Hydro
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Don B Senior Member  Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi John, Glad to hear that you have been able to make such a substantial improvement in output. I wonder, though, how you are measuring the Watts out? Measuring AC Watts can be tricky, particularly with a 3 phase set-up, which I think that you now have up to your house. If your measurements are after the rectifier (ie DC), then you should have a fairly accurate figure. Looking at the photographs of your nozzles, it looks as though you are now using a relatively short linear taper, although perhaps you have a different shape inside the nozzle. I am no expert, but I imagine that the most efficient shape for obtaining the maximum combination of flow and velocity from your head would be either a fairly long linear taper, or something shorter with a non-linear taper like half a venturi. Maybe having a look on the internet at "nozzles", or "nozzle design" would suggest the most appropriate shape and dimensions for your head and flow rate. With regard to doing something useful with the power, the suggestion to use the power to charge a battery, and then draw off the battery perhaps using an inverter to run your AC appliances is probably the best one. The only problem is that you have a relatively high and probably variable AC voltage of unknown frequency, and a three phase supply. Some modern switchmode battery chargers can probably accommodate a reasonable range of input voltages (as long as they are not above its rated voltage), and should not care particularly what frequency they are supplied with. This is because the first thing that a switchmode battery charger ordinarily does with its input voltage is to rectify it to DC. The only bother is that, with a 3 phase supply, you would probably need one charger on each phase. Using 3 chargers connected to the one battery should not be a problem, so long as the chargers are all the same make and model, and have identical settings The battery chargers should hopefully control the battery charging, so that the battery is kept properly charged. As each charger need only be, say, 60 Watt rated, they should be relatively inexpensive. You would need to took carefully at the charger specs, and maybe confirm the suitability for your application with the manufacturer. If you select 12 Volts, or even 24 Volts as your battery voltage, then you have a wide range of DC gear available that would not need an inverter to give you useful power from your set up. The only thing to watch with low voltage DC is that voltage drop can be a problem, and you need to use heavy gauge wiring for satisfactory performance. You can also readily get 12 or 24 Volt inverters to run your (small) AC appliances. Be aware though, that you will not be able to run high wattage appliances like a microwave or toaster, or an AC fridge. Remember also, that if you are only able to generate a steady 100 Watts or so, your average power draw can only be something less than this. Regards Don B |
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BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
Hello here is my Email bobtec@comcast.net Thank you for the call I will put a list together for you. Bob Mann |
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MacGyver Guru  Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Hydro John Thanks for posting that Web address. He's got lots of cool stuff that many here can take advantage of. I sent him some pointed emails asking specific questions about his PMAs (permanent magnet alternator) to see if it is really something cool or if it still needs to run at light speed using belts or gears. When I get the answers, I'll share them on the 4m. My guess is the alternators' cut-in speeds will be way higher than a direct-drive wind turbine can provide in normal winds, but I'll wait for the results before passing judgement. Here's a hot link to that Web page: Missouri Wind and Solar . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
Mac I have dealed driacly with Jeff it did not go well he had my VAWT for a year and over 17000 views and leads not one came to me.there is many youtubes on him on bad press. you should look at Coleman-Air-Parts http://stores.ebay.com/Coleman-Air-Parts?_trksid=p4340.l2563 Here makes all that stuff for jeff. |
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| Hydro John Newbie  Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hello Friends, [quote=Don B]Measuring AC Watts can be tricky, particularly with a 3 phase set-up, which I think that you now have up to your house. If your measurements are after the rectifier (ie DC), then you should have a fairly accurate figure. Looking at the photographs of your nozzles, it looks as though you are now using a relatively short linear taper, although perhaps you have a different shape inside the nozzle. [/quote] I am finding out that everything can be quite tricky, I was using a combination of 3 phase and rectified (DC) and I question the accuracy of my results. I am still awaiting the arrival of my clamp on amp meter and tachometer. Until then, I think that I will reserve posting any test results. I hope they will not be to far off. The nozzles are formed by using the end of a plastic soft drink bottle, which is cast, with body putty, in the end of the 2" PVC pipe, and forming a nozzle which is the exact shape as the bottle. The inside of the nozzle is now the bottle itself. It probably want last very long, but is cheap and fun to make. I can experiment with many different sizes and shapes to get the most effecient. Bob Mann is helping me piece together a system to harness my available power. I will keep you posted on the progress. John Hydro John |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
John, I have been thinking about this a fair bit, and here are a few random thoughts. Hydro is very unlike wind power or solar, in that the water head and flow will not change, provided there is enough water to completely fill the penstock in the first place. Therefore electrical output is going to remain very constant, unless the system starts to go dry on you. That means you do not have all the problems associated with constantly fluctuating voltage or current, and it greatly simplifies battery charging, because you can match the generated voltage to the battery experimentally for best power transfer, and it will then stay pretty well optimal without having to change anything. Measuring dc watts after the rectifier, which is what I am assuming you did, is perfectly valid, and a much more useful figure to have. So don't go through all the mental contortions of trying to measure anything on the ac side, it is really an unnecessary complication. As the overall efficiency is already so admirably high, I doubt if the losses in your penstock and nozzle are significant. One interesting test would be to measure the static water pressure just ahead of the nozzle with the flow blocked, and with the turbine flowing. A transparent rising water manometer tube may be the simplest and most accurate way to measure this, and it will tell you the pressure drop in your penstock. The penstock pressure drop figure may be useful to know if you plan to design a larger system in the future. Fascinating stuff John, please keep us all in the loop. Cheers, Tony. |
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Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Hydro John Hi Looking at some of your older posts, I see a detail that could possibly improve on the torque of your Pelton ( unique use of Elbows)  !, DETAIL, The picture of your box and wheel with modified Nozzle, The Jet stream from the Nozzle may need to be a bit lower down ( nearer to a tangent to the turbine cups) maybe down 3/8", I say this because I have read various documents about the design of Pelton wheels and the principal of energy transfer from water to wheel,
The Idea being to totally reverse the direction of the water, when the jet hits the cup, the rebound is smooth and quick. the concave surface of the spoon or cup reverses the water direction completely. I notice that on your Wheel the jet is cut off by the Cup following, before the tangent cup has reached its position to fully reverse the Jet,. The Cups are exhausting water vertically at only 45 Deg. Moving it down may mean that the nozzle would need a longer taper to position it close, don'no. You are the man with the Machine and I just an onlooker, It could be that the Elbows have a different reaction than a standard Pelton Spoon. I thought it worth a mention. Great work here, would like to see you get the rest of your available head.-  ----------------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hello Friends, [quote=Greenbelt]The Jet stream from the Nozzle may need to be a bit lower down ( nearer to a tangent to the turbine cups) maybe down 3/8", I say this because I have read various documents about the design of Pelton wheels and the principal of energy transfer from water to wheel, [/quote] I have tried many different positions and the one pictured below seems to give the best results. 
I have come up with a way to measure the flow through the nozzles. This should give me more accurate information. I can now measure the real flow rate using different size nozzles. 
[quote=Warpspeed]One interesting test would be to measure the static water pressure just ahead of the nozzle with the flow blocked, and with the turbine flowing. [/quote] I have a simple water pressure gauge installed,although I don't think that it is very accurate. The picture below shows about 9 psi static pressure, which is very close to the calculated pressure at 21' head. 
From all the testing I have done so far, it is beginning to look like the F&P generater I have is not going to be able to effeciently use much more than 50 GPM at the 21' head I presently have. I think I have enough water to run at least one more generator and I am thinking about building another one. My question is, can I connect both 3 phase generators to the same line going to my house? Thanks John Hydro John |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Yes you can. If a second turbine is built to provide a similar output voltage (to suit the battery voltage) then it can be connected in parallel with the turbine you already have at the source. This absolutely must be done with dc voltage after the three phase rectifiers. You can stop both turbines, run one turbine, or both turbines by just shutting off the water without actually making any electrical changes. The rectifiers act like "one way electrical valves" and isolate a non rotating turbine from the battery and other turbine, and prevent reverse current flow. When a turbine starts up, it will automatically feed the battery via the common cable. Cheers, Tony. |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hello Friends, [quote=Warpspeed]This absolutely must be done with dc voltage after the three phase rectifiers.[/quote] I have been doing some research and have come up with the following: 1. 2 identical 3 phase F&P PMA used as generators 2. Both generators turning at the same RPM so each would be operating at the same hertz. 3. Both generators producing same voltage 4. Each phase of generator 1 connected in parallel to corresponding phase in generator 2. In other words, phase A of gen 1 connected to phase A of gen 2. Is it possible that this could work? Just a thought! Hydro John |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Yes it would work. The two generators will then become electrically joined at the hip. Essentially like a direct physical mechanical coupling between the two turbines and generators with a solid shaft. If you completely shut off the water supply to one turbine, it will continue to turn at the exact same speed, driven by the other turbine, directly drawing power from it. Full permanently locked synchronous rotation. The entire mains power grid operates exactly that same way. A much more flexible arrangement, with far fewer potential problems, will be to make the common connection on the dc side after the rectifier. Cheers, Tony. |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hi Tony, Thanks for the info. The reason I would like to keep the high voltage 3 phase is because of the distance from my generator to my house. It is now about 400' and if I increase the downstream head, it could be over 600'. John Hydro John |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I see the problem, but the difficulty is that connecting a pair of three phase power sources together, they will become tightly locked in exact speed synchronism. If the free rotational speeds are different, the faster turbine will pull the lower speed turbine up to it's own speed which will then be dragged down slightly. Rather like harnessing up a large horse, and a small horse to the same cart, (if you will pardon the analogy). You can still run high voltage dc to your house, even build a voltage doubling rectifier if you wish. What voltage are you actually seeing there from your F&P ? Cheers, Tony. |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hi Tony, Current conditions: Head = 21' Flow = 52 GPM Using 1 nozzles @ 15 mm No load line voltage = 362v Loaded line voltage = 211v (loaded with 3 - 40 watt bulbs 3 ph Y) Can't measure amperage (still waiting on amp meter) Have about 2 volts line loss from generator to house. John Hydro John |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
That is excellent John ! If you add a three phase rectifier to it, the 211v RMS ac loaded voltage per phase should increase to roughly around 290 volts dc (loaded) coming out of the bridge rectifier at about maybe half an amp dc at 150 watts. The voltage is high enough to significantly reduce line losses, but not inconveniently high. A couple of volts line loss is insignificant. Cheers, Tony. |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Hi Guys, You're Posting In windmills? You are pushing the tolerance Limit!. A friendly Reminder before Glen is all over you like Swamp Mud.---- ( Other Stuff), Pedal generators, hydro power, CNC, anything that wont fit in the other area's Warpspeed I learned something from your Post on 3 phase, I did not know that it will force synchronization if possible. I know about a Synchronous Motor In step with the Line Frequency but I had Not heard of this. -------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Thats OK Roe. Yeah this should be in Other Stuff, but its too late to move it now and I dont mind. I've actually been watching Hydro Johns build with interest. My new place has a running creek and I've been thinking of building a small hydro for when the creek is flowing fast, after a bit of rain. I dont have a lot of drop though. I posted a video on Youtube showing the creek flow. http://youtu.be/4DigfCZFDK0 Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Roe, All three phase alternators use either permanent magnets (like F&P) or have a dc winding on the armature fed by slip rings to create a suitable constant magnetic field (car alternator). As the machine turns it will crate sine waves in the stationary windings that have an absolutely fixed relationship to rpm. If you have (say) two diesel generator sets, if run in parallel they will ALWAYS run at absolutely identical speeds which will be 3,000 rpm for two pole alternators, or 1,500 rpm for four pole alternators, and lower speeds for even more poles. If you then parallel these with the grid, they will then be solidly locked in phase with every other generating machine on the grid. What actually happens is, if you increase the throttle opening on one of your diesels, it will try to overspeed, but cannot. It just drives more current into the grid. If you back off the throttle on your diesel, the output current will fall, but the speed will not change. The current can fall to zero if you back right off. If you completely cut the fuel to the same diesel, the diesel will still continue to turn at full undiminished speed, but the current reverses phase with respect to the voltage, and the alternator becomes a synchronous motor. This applies to hydro, steam turbines, everything connected to the grid. It is how generating loads are shared and controlled. With hydro there are usually control vanes on the turbine to adjust power production, but the turbine rpm can never vary from its required rpm at 50 Hz. By adjusting the "throttle" you can parallel a 10Kw alternator with a 100 Megawatt power station, and adjust the relative load of each. The trick is to maintain exactly 50 Hz on the entire grid, and that is done by cranking open the throttle on an underloaded source if the frequency is a bit low, or throttling back on a heavily loaded source if the frequency drifts slightly high. Induction motors are very different, they always run at below synchronous speed, with a certain amount of "slip". But alternators and synchronous motors, (and grid tie inverters) when connected to the grid are all locked solidly together in terms of both frequency and rpm. Sorry to get even further off topic, but it is sort of relevant to some of what we do here. Cheers, Tony. |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Hi Glen That U Tube Video shows 3 different animals, Hi Water, Low Water and a Dog. I believe You have under estimated the head available here unless some of this video is on other property? 2 rapids appear to be 50 meters apart and looks like each of them is a 3 foot drop, This is in the High water Video. The rest of the stream is moving Fast also and doesn't seem to Pool like a flat area would. Its difficult to see things as they are from the Video, I'm Guessing You could have 3 Meters head in 650 feet(200)m. Taming this will need pipe routing the water away from the creek to a stable location and go from there. Thanks for Sharing this, One Day I'll Get a Pic. of my little Creek way down in a narrow Canyon. Its 70m. from the House, EDIT; during the winter its flow Rate is about three time your Low water rate. EE; but nearly dries up in Summer. Maybe I'll Do something with it some day, maybe Not, Permits for everything and an engineers Stamp. Both Expensive. ----------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hello Friends, Sorry about the mistake in starting this topic. 
[quote=Warpspeed]If you add a three phase rectifier to it, the 211v RMS ac loaded voltage per phase should increase to roughly around 290 volts dc (loaded) coming out of the bridge rectifier at about maybe half an amp dc at 150 watts.[/quote] I'm afraid that I may have mislead you in how I measured the loaded voltage. The measurement was line voltage and not phase voltage. So, how do you figure the rectified DC voltage? I'm still searching for new ways to improve my pelton wheel and nozzles. The buckets on the original wheel cannot take the continuous pounding of the jet stream, and some of them are beginning to get loose. I have some ideas on how to strengthen them and will let you know how they turn out. Thanks for all the help and encouragement. John Hydro John |
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