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Forum Index : Windmills : Fisher & Paykel Micro Hydro
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| Hydro John Newbie  Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hi Everyone, I am working on a micro hydro system. I am using a 60 series (36 poles) Fisher & Paykel motor as a generator and a home made pelton wheel that I made from pvc elbows. The F&P is turning about 285 rpm and producing 128v on each phase with a 13 watt light bulb wired into each phase. The system is about 400 feet from my house and I would like to be able to use this power in my home. I am new to all this and not sure where to go from here. I thought about hooking up a preheater to heat water, but don't know if it could be done with the 3 phase AC that the F&K produces. Also I thought about changing the AC to DC with 3 ph rectifier and charge a battery, but the DC voltage produced would be much higher than 12,24 or 48 volts. Could I charge a battery with high voltage DC? Any suggestions would be appreciated. I have read about all kinds of controlers, inverters, MPPTs and other electronic gadgets and now I am totally confused. Hope someone can steer me in the right direction. If anyone is interested, I will be glad to post some pictures, that is if I can figure out how to do it. Thanks Hydro John |
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BobMann Senior Member  Joined: 30/06/2011 Location: United StatesPosts: 134 |
Hello I can help you very easy here seeing you are in the USA. I would keep the AC 3 phase all the way to the home 400 ft is far but will work. You will need a controller and rectifier. I would then use a grid tie to help off set the home enegy bill. Bob Mann Mann Smart Drive |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hey Bob, Thanks for the reply. I have a rectifier salvaged from a gm alternator. Would that be OK? What kind of controller would I need and will I be able to connect it directly to the grid through my home power panel? Hope I don't sound too dumb. Thanks again, John Hydro John |
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Don B Senior Member Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi John, A few comments that might help. First, Bob Mann is correct when he says that you should keep the feed to your house as 3 phase all the way to minimize voltage drop and losses. I assume that the 128V that you are measuring is with the 13 Watt light globes connected? If you try to measure the Volts with no load then at all they will be much higher. You could use the 3 phase supply to heat water, but you would then need 3 heater elements - one for each phase. Note also that a 117V (?) heater element will be a much greater load than your light bulbs, and may even stall the turbine. If you want to rectify the three phases to DC then you will need a rectifier with 6 diodes. Each diode will have to have a voltage rating of probably around 200 Volts or better, and be suitable to carry the current involved, which will depend on what your turbine can do with a bigger load connected. Even so, even 1 Amp rated diodes would probably be adequate at the voltage that you are operating at. I am not familiar with the GM alternator that you mention, but if it is an automotive type then the diodes would not be suitably voltage rated. By the way, voltages of 128V at AC or DC can be deadly, so be very careful never to work on any wiring with the turbine operating. If you do fit a rectifier, then you could use the resulting DC to heat water, and at least for that you would only need one element connected to the DC output. If you want to look into things like a grid tie inverter, or charging batteries, then I strongly recommend that you talk to someone locally with some expertise in the matter. Regards Don B |
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| davef Guru  Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Have you got an idea of what your head is and flowrate? IE, how much mechanical power you will be able to harness. A test, is to rectify the 3 phase AC and place various loads on your system to determine where your maximum power point is. OR, you can load the system up with different wattage bulbs and record both the AC voltage and AC current. You can also tweak the rotor speed as well as how the stator is placed relative to the rotor (shimming the rotor). EcoInnovation NZ describes the procedures for these tests. If you are running this unit at an appropriate speed, ie frequency, there is an option to use 3 toroidal transformers to get you down to a reasonable voltage before rectification. |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Thanks everybody, Penstock: 400 ' (buried 4" PVC) Head: 20' Flow: Minimum is about 50 gpm; Maximum is 300 gpm (depends on how much rain). Thinking about building a dam to give a constant flow and also increase head to 30'. I have run several test with different bulbs hooked up to each phase of the 3 phase wild AC. The maximum without stalling is three 13 watt bulbs, one hooked to each phase. Any more begins to stall the turbine. The RPMs of the turbine is 285 RPMs loaded with the three 13 watt bulbs. Yesterday, I hooked up the GM 3 ph rectifier. Recorded 390 DC volts with no load. I then connected a dead 12 battery. First recorded voltage was 12.1 volts. Subsequent readings continued to increase to 12.6 volts over about 30 min. I didn't really know what I was doing, so I terminated my test. Please let me know if I did anything right or if all was wrong. I like the idea of using a water heating element, but the AC heating elements that I have access to would be too high wattage and would probably stall my turbine. I don't know about a DC element, are they available in low wattage or would that matter? I also like the idea of a grid tie inverter, but I don't have access to anyone with this expertise in my area. I have read EcoInnovation NZ article on tweaking turbine with washers, but I'm thinking I have other problems before I begin fine tuning. Maybe I'm wrong, don't know. Two questions I have: 1. Can I charge a 12, 24 or 48 volt battery bank with the 390 volt DC produced by my turbine? 2. Can I hook my wild AC 3 phase to a grid tie inverter? If either of these is possible, what do I need to do to accomplish my objective? Thanks again Hydro John |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Bob Mann would be the one to talk to here. He's got some very good figures using a F&P Smartdrive and a programmable grid tie inverter. With a hydro you should be able to reach 600 or more RPM, its wild AC, but the gridtie Bob used can harness that sort of power. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
Thanks for the good words. I will but a parts list up for him today. I had talked of a Smart Controller Steve is working on. The bourds are on the way and parts list on order. It will work here slike as S--t here is what it can do. Real world testing using my Mann Smart Drive and Modifed blades will start next week at a few location. I've just finished drawing the schematics for the MPPT and I wanted to list all the features and get some input before I start routing the board. I currently have 8 IO signals left over on the microcontroller so maybe someone can think of a good use . MPPT Features The MPPT controller board was designed for maximum flexibility. The board is very custimizable and can be used in many ways and it purchased in kit form or bare board, the user can make decisions about the input range, output range, on board memory, etc. Power Input: The on board 3 phase rectifier uses 6 15A 600v diodes that have only a 1v drop at 10 amps. This means the capacity of the rectifier as a whole is around 45 amps. The user can substitue in other diodes (for instance lower voltage and more current) as long as they are in the TO-220 package. The rectifier also contains a circuit that lets the microcontroller count AC pulses as a way to measure actual turbine RPMs. If the user doesn't want to use the on board rectifier, DC power can be brought in through another connecton. The disadvantage of this is there is no way to count RPMs. The CPU and other electronics on the board are powered by a power supply that can run on 10 600v, from either the output or from the input. In battery charging systems this will allow the controller to stay alive even with no wind. The power usage should be less than 5 watts or 83 milliams. The CPU is a 40 Mhz Pic microcontroller with USB interface, PWM outputs, 8 analog inputs, etc. The firmware in the microcontroller will be flash programmable via the USB interface so people can flash in updates or their own firmware. The USB interface goes through a chip that isolates the ground of the controller and the ground of your computer by up to 2500 volts. This will prevent damage to your computer if your turbine ground is floating. [However there is still danger to you, if you let that happen.] The interface will be USB2.0. The power switching can handle up to 600v on the input and 60 amps. (Based on the size of 3 transistors.) Three transistors are used in parallel, and if your turbine puts out less current, some of the transistors can be left off the board to save money. The output can also go up to 600v, but this circuit can only convert voltages downward, not boost them up. The switching circuit uses synchronous rectification, which means instead of a diode completing the circuit when the inductor is providing current, some transistors are turned on instead so there is less of a voltage drop and more efficiency. Again 3 transistors are used for this purpose and some can be left off for lower current applications. In an emergency both sets of transistors can be turned on at the same time, and the turbine will be shorted making it stop. There are analog circuits to monitor input voltage, input current, output voltage and output current. The stock configuration will read voltages up to 400v and currents to 60a, but I will include a spread sheet that will help you tune these inputs for lower voltage or current applications by changing some resistor values. These inputs go into a 10 bit A/D converter so there are 1024 levels. If the range is 400v then the resolution is 0.4 volts. If you tun it down to 50 volts the resolution will be .05 volts. There is an input on the board for an anemometer that closes a connection as it rotates. This can be used to log wind speed with the other data. There are 6 locations for memory chips. These can either be populated with 4Mx8 flash or 16Kx8 ram. The flash is permament but slow. Flash can also only be rewritten about 10000 times. The RAM is fast but forgets when power goes off. Chips can be mixed and matched as needed. There are 2 LEDs on the board, but I have 8 spare IO on the processor so I may add a few more LEDs for status displays, etc. There are 3 off board components. These are the input cap, the inductor, and the output cap. Depending on the user's turbine, these can range from fairly small and inexpensive components, to large expensive components. I could not come up with selections that would please everyone. With high current inputs the input cap can have a large effect on board efficiency. I will provide a spread sheet that will help with the selection of these components. I have only thought about the firmware and haven't written anything yet but I'm thinking that the controller could learn about the turbine through trial and error and record it's experiences in the RAM, then as it gets more data is can use that information to peak power track. This board should be able to be programmed as a battery charge controller or as a board to drive a low cost GTI. I'm thinking that the firmware, and any associated software will be open source with the GNU license. That way people can modify it as needed. Also the software's interface to the board will be documented. ========================================= If anyone has any comments or suggested features, now is the time to let me know, before I start routing the board. Steve's infomation above. |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi Bob I would post the MPPT stuff on a new thread to keep this one on topic. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hey everybody, Thanks so much for all the info. I am very anxious to see the parts list from Bob. In the mean time I am going to try to attach some pictures of my Micro Hydro. It's pretty crude now, but hope to make improvements as the projects proceeds. 
GM 3Ph rectifier 
F&P generator mounted in plywood box. Used bottom of washing machine for bearing mount. 
Home made pelton wheel. The nozzle is 3/4" hole drilled in a 1" PVC cap. I used 1" PVC elbows for cups and 1/8" aluminum (salvaged from old highway sign)for wheel. Aluminum wheel is 10" dia and total outside dia is 13 1/4". I'm sure a pelton wheel from EcoInnovation would be much more efficient. 
Another photo of pelton wheel. The cups are glued together and attached to the wheel with rivets. Hydro John |
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| davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Your head 7 metres and flowrate about 4 litres per second. 7m * 4L/s * 9.81m/s squared * 50% = 140 Watts. Your penstock losses are quite small with that size of pipe. As you are getting something like 3 * 13 = 39Watts, there should be some optimisation opportunities. Two questions I have: 1. Can I charge a 12, 24 or 48 volt battery bank with the 390 volt DC produced by my turbine? 2. Can I hook my wild AC 3 phase to a grid tie inverter? 1. I wouldn't do that. To get maximum power out of the system you want to make some attempt at "matching" the source to the load. Or you waste power in the generator internal impedance, which gets dissipated as heat. 2. I wouldn't even consider this as this power level. Also you are not generating 3 phase AC at the power line frequency, so some "conversion" would be necessary. I would suggest reading about rotor sizing, rotor speed and nozzle sizing. If you search carefully on the EcoInnovation site you should find quite a bit of free information. Increasing the head another 10' is a good move, a 30% increase in power. If the minimum flowrate is 50gpm, unless you have a lot of storage you are not going to get much more than 50gpm. A days storage at 50gpm = 72,000 gallons, etc. Neat idea for the buckets! Good luck, Dave |
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| Don B Senior Member Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi again John, I would like to endorse Dave's remarks - particularly about rotor sizing, speed, and nozzle sizing. It really is worth doing a little research here. While your Pelton wheel buckets look well done, it seems that your turbine diameter was dictated by the size of the piece of aluminium that you had to hand. If you could make your turbine diameter larger, then you would get more torque, although this may be at the cost of the turbine (and hence the alternator) speed. The nozzle is also worth more experiment. Your nozzle appears to be something that would be quite hydraulically "lossy", and you might well be able to gain some significant performance improvement by re-designing it. The best nozzles are more like a needle valve, with a tapered (ie venturi like) transition between the penstock diameter and the nozzle diameter, ideally with a central "needle" for adjustment and throttling. If you look at an adjustable garden hose nozzle, you will get some idea of shapes that are reasonably efficient. Just improving the characteristics of your nozzle may well give you a substantial performance increase without doing anything else. One further comment from one of your earlier posts. There is no such thing as an AC or a DC heating element - it does not matter whether the current is AC or DC - it heats them just the same. Ohms law is the operative principle here. Note though that most heating elements would be of the order of 1,000 Watts or more so that, even if you find one with, say, a 220 Volt or higher voltage rating, the load on your turbine with one of these fed with DC would be way higher than the present 39 Watts worth of lamps that you are running. Regards Don B |
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| BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
Here is the what I use Description: BRIDGE RECT MOD, 3PH, 50A, 600V, QC; No. of Phases:Three; Forward Current If(AV):50A; Diode Mounting Type:Panel; Bridge Rectifier Case Style:Module; No. of Pins:5; Diode Type:Bridge Rectifier; Current Rating:50A Part No: 18M3291 order here http://www.newark.com/jsp/home/homepage.jsp I would use large gauge work power cords with water tight ends. Lowes.HomeDepot cheap. run the three wires right from you Smart Drive and make up a end to go in to the this bridge rectfier. Below is a plan i put together for a iland wind mill. Hello I think for your needs we would go with one of my Vertical Axle Wind Mill It would be putting out high AC power so you could run it away from the home on a pole or something high up in the wind. My unit does not make any noise any way so it could be mounted to the side of the home too. Plan A I would build a control board it would include a emergence kill or lock down switch than a High Volt rectifier to convert the AC to DC. You have a DC to AC converter now that you use from the solar system now. (I would need the make and model with spec of it to see I what I need to work with it) My units can make very high Watts in good wind so some steps need to be taking for most DC converters that has solar in the mix. I would for now use three torpedo transforms after the kill switch than the High volt rectifier to a dump controller in line to your battery bank. This would get you up and running in a day’s time. Plan B Is to run the power right from the turbine in to an emergence kill or lock down switch than a High Volt rectifier to drop the AC to DC than into a high end Grid Tie and that would be wired in to the AC wiring of the home. When the Wind is spinning the turbine it back feed the home with Good 110/220 AC And slowing down the drain on the battery banks. Plan C Is my plan I have been working on for the Small Wind Mill Market We have designed a Mann Smart Drive controller that would be wired right from the 3 AC wires of the turbine it will have the kill/lock down switch installed. It will learn the wind speed of the turbine on site and make adjustments to have it work in its most desirable power curve at all times kind of Traction Control for wind. It has a PC base board with many more controls and inputs like storm shut down, High Volt dump load, Than you would use the low cost grid tie on the power output side to back feed the homes 110/220 Volt needs with no needs of batteries for most homes as a supplement to their power needs. I would love to work with you on your needs I would even think of coming down to help on the install if we could work out the details. Bob Mann 781-588-3968 |
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| Don B Senior Member Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi again John, Thinking more about a nozzle for your turbine, something that you could try that would be cheap and simple to make would be to take a piece of PVC pipe, and heat and flatten one end so that the end looks something like a figure of eight. The point at which the two sides of the pipe meet in the centre of the figure of eight could be extended by flattening it along further to separate the two nozzles that this would now form. If necessary, you could use two metal rods as mandrels to form the actual nozzles while you are heating and forming the plastic pipe. This would give you a taper ending in two nozzles. If you can align each nozzle to be in line with the centre of each of your rows of buckets, you should gain an improvement in performance over the present single hole end cap arrangement. You may need to use bolts or screws to clamp the edges of the pipe together where they meet at the centre of the figure of eight to permit the two nozzles to be sufficiently separated to align with the rows of buckets. If you use a PVC coupling to connect your new nozzle to the existing piping, then it would be simple to change nozzles and try different shapes and sizes till you optimize the nozzle performance. Looking at your photographs, it appears that you have stepped down pipe diameters from your penstock size to your nozzle pipe size. Beware of sudden diameter transitions, as these are also hydraulically "lossy". Far better to stick with the larger diameter pipe right up to where it tapers down to your nozzles. If you do give this a try, please post your results. Regards Don B |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Hello everyone, I'm going to try to summarize the info from all the replies I have received. Flow rate and Head: I can increase my head by about 10' by extending the 4" PVC by about 200' or I can built a dam. I may choose the dam, since I would like to have a trout pond anyway. Pelton wheel and nozzles: My home made pelton wheel is about the same size as the wheel that EcoInnovation makes, so I'm not sure that increasing the size is going to help much, but it may be worth a try. I may order one of EcoInnovation's wheel. Will keep you posted. I like the idea of making a twin nozzle out of pvc pipe, although I am concerned that the stream of water may hit the back of the cups instead of going through the notch that is cut in the middle of the cups. Maybe I could cut a notch on each side of the cups, each stream of water would have it's own notch. I might also order one from EcoInnovation to compare. Convert 3ph wild AC to usable 1ph 110/220 volt AC: This is the part that is the most challenging for me. As I understand it, Don's plan B would be the following: 1) Run the unmodified 3PH AC to my house and install a kill switch. 2) Rectify the 3Ph AC to DC using a Bridge rectifier (Part No 18M3291) that Don suggests. Note: what will this rectifier do, that the GM auto rectifier that I already have, will not do? 3) Connect the rectified DC to a high end grid tie inverter and then to the home grid. Where would I get the inverter and what would be it's defining specifications? Don, do you make these and do you sell them or is it something that I could put together myself? Thanks so much to everyone for your help and your patience. Hydro John |
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| BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
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| Don B Senior Member Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi again John, Some comments on your summary: The head that you have available is in the bottom of the range of what is suitable for a Pelton wheel. Anything that you can do to increase it by either increasing your pipe diameter, or raising the supply water level, will help. Maybe you should do both, if you can, then you can also enjoy the fishing. I am not sure what you mean regarding the "notches" in the buckets. Pelton wheels work by trying to extract all of the momentum from the water spray, and that is done by turning all of the water flow in the bucket so it has no more velocity, and literally falls out. Properly set up, Pelton wheels can be much more efficient than any other type of water or wind turbine. Note that the optimum speed of the wheel is half of the speed of the spray from the nozzle. If there is a "notch" in the bucket allowing some water to escape before its direction has been turned in the bucket, and its energy fully extracted, then you will lose efficiency. Maybe though I am missing the point of why you have these notches. Some other Pelton wheel installations use more than one jet on the rows of buckets to balance the torque on the wheel. Maybe you could consider this, and put another (twin) nozzle directed to the bottom of the wheel from the opposite side of the wheel enclosure. You should also have a look at how the water leaves the wheel, to make sure that it is as clean as possible, and does not fall back and interfere with the rotation of the wheel, hence slowing it down. Have a look at Wikipedia on Pelton wheels, as this gives a run down on the theory of operation, though I am sure that there are many more articles available on them. Regarding your comment about what a different rectifier would do better than the GM one that you are using, the answer is nothing. I would still expect that the diodes in the GM rectifier are not rated for the voltage that you are applying to them, but, while they continue to work, then the GM rectifier will do as good a job as anything. But I would suspect that the day will come when the magic smoke will escape from them, and they will stop working, so that you need a plan B. Before you worry about getting an inverter, etc, I would first get your turbine providing a useful amount of power, if you can. The present 39 Watts is really not worth the bother. When you can run 3 100 Watt lamps, or better, then you are getting into the range where it is worth looking into an inverter. Regards Don Don B |
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| Hydro John Newbie Joined: 31/10/2011 Location: United StatesPosts: 35 |
Thanks All, Looks like I've got some work to do, and I will keep you posted on how thing work out. And sorry about the name mix up BOB . Let me know when you get your controller going. Don, the notches I am talking about are the indentions at the top of each pair of cups. The notch is encircled by a red line. 
Hydro John |
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| Don B Senior Member Joined: 27/09/2008 Location: AustraliaPosts: 190 |
Hi again John, From my reading on Pelton wheels, I guess that the function of the notches you have used with a single nozzle would have been to permit the bucket on each side to get about the same amount of water This would even up the axial force that could otherwise be generated on the shaft and bearings if the water volumes were uneven, but perhaps, again, I am missing the point. Despite this, I still think that the suggested twin nozzle arrangement would work at least as well, and probably better, than the present single nozzle arrangement. More than one twin nozzle acting on the opposite side of the wheel would probably work even better. Your Pelton wheel is converting the momentum of the water hitting the buckets into rotational energy. You will get the maximum momentum from your water supply when you have the optimum combination of mass flow and velocity. This will be determined by the diameter of the nozzles and, ultimately, by the capacity of your water supply, and the losses in your penstock. If your nozzles are too large in diameter, then you will have a large mass flow, but little velocity. If your nozzles are too small, then you will have good velocity, but a low mass flow. The trick is to get the diameter just right, and this will be what you need to experiment with. Regards Oh yes, and some facility to tweak the aim of the nozzles would help to optimise the performance. I imagine that this could be quite critical. Don B |
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| BobMann Senior Member Joined: 30/06/2011 Location: United StatesPosts: 134 |
Don a stock 60 F&P at 200 RPM is good for 200+ volts and can do close to that in watts set up right. My Mann Smart Drives have pushed 1050 Watts out of a grid tie and into a home at 600 RPM with a stock stator.He will need to push the RPM up to run the 200 to 300 ft to the house and that stock delco will not last was never made for high volt.His test with the bulb is not a good test must use a meter. Bob Mann |
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