Brief tour of Banki turbine hydro system

[HungryGreeny]

How this system maintain constant frequency and vpltage?

[linschotenr]

@HungryGreeny

Frequency is designed in when building the wheel itself but It is very coarsely regulated. Only voltage is truly regulated using pulse-width modulated diversion controllers connected to hot water resistance heaters. This unit is primarily designed to charge large battery banks. That Dc power is then converted to proper AC via sine-wave inverters (Outback, Samlex)

R.

[toob247]

hello from Delaware usa. I wonder if i can bum a bit of info from you. I have a 1hp pool pump, 1 phase. What's a guy have to do to make power running it backwards? reverse connections or add a part? . one last question all things equal which is preferred, smaller generator run faster or larger generator slower? I understand the availability of torque to get it moving but besides that ? is one better or just depends on situation? thanks for letting me pick your brain. love your setup.

[linschotenr]

A 1 ph motor can be quite difficult to self-excite. If it is capacitor start, bridge the start switch, remove the cap and put a 20 to 40uF RUN capacitor (not START) across the main winding. For other motor types you will need to Google your options. Best choice is a 3-phase motor. Speed of generator is pretty much determined by RPM delivered by turbine. In my case I was getting around 300 rpm from the wheel so my only choice was a 1200RPM 6 pole motor to lower transmission losses.

Rob

[CurrentlyDisconected]

excellent vid mate its given me some great ideas

[stage4turbo]

your audio sucks, get a better quality vid man if you can. thnx. good video.

[badsaddamdotnet]

unreal. great work.

[linschotenr]

Thank you both.

[inventorisac]

mire!

[74VDC]

Would it be better to use a PM DC generator and then feed that DC into a grid tie inverter to "clean it up". I'm meaning so that grid tie would be a possibility. Do they sell small AC to AC inverters/controllers soley for the purpose of matching line voltage and frequency? Or instead, would it make more sense to use an induction motor above synchronous speed so it's automatically in step?

[linschotenr]

Unfortunately (fortunately?) no grid within 15 miles in any direction otherwise that would be areally good way to go. Most of those units rectify to DC and then start over, like a line-interactive UPS does. To save money i would go for the induction motor approach, vey simple in this case as that is what i am using. Specifically; a 3 phase motor running as a capacitor-excited induction generator.

Regards

Rob

[74VDC]

So you are indeeed using an AC induction motor as your generator? But, since you do not have a grid tie, you must use caps to begin initial excitation...do I have it right so far? What then, do you use to initiate excitation, or to energize the caps? How did you size the caps...trial and error or some mathmatical method? How do you prevent your generated AC from being "wild", that is to say; what keeps it clean enough to run sensitive electronics like computers or even CFL's for mthat matter?

[linschotenr]

Yes I am. At the beginning of the season I use a 9V battery to excite the generator. After that there is enough residual magnetism in the windings to restart. The output voltage is a regulated 240VAC (+/- 10 volts) with a triac-based load dump. The dumps are either a hot water heater or a base board heater. The sine wave can get very distorted under certain conditions so I am moving this winter to only using the system to feed rectifiers to charge batteries.

[linschotenr]

74DC,

Missed part of your question. Did the math first to get in the ball park, then fine tuned by hooking the genrator up to a 1 hp DC motor via a Variac and ended up adding some more capacitance. I believe the final C/C2 combo was 8/16mF.

[dawnrun911]

Great way to oxygenate a river or stream, an added bonus.

[linschotenr]

Indeed, although there are no fish in the river, keeping it oxenageted is a good thing for the other flora and fauna.

Rob

[WindyJAMiller]

Hello,

Where did you get the turbine from, is it a centrifugal fan form an AC or HVAC system?

Many thanks

Jonathan

[linschotenr]

Hi Jonathan

No, it is a properly built banki turbine with 21 blades around a 12" circumference.

Rob

[ilgalane]

hey hi, did you made it your self.or did you buy it and where i can find some thing like that? thanks

[linschotenr]

I made it myself from scrap 1/4" plate steel and a length of 4" ID schedule 40 pipe. Don't think they are for sale in sub 1KW sizes...

Rob

[vdani666]

Bánki...

[linschotenr]

Ahh, don't have that option on my keyboard...

Rob

[jthowery]

I've got a ? I've got a solid rock bottom creek that runs behind the house like constantly 12" deep and its 8 ' wide. can u help me figure out if i was to build a concrete inlet and run the 6" PVC from there how do i figure out what my head is ? and what my possible output is ? anyone understand?

[myrenmyst]

hi,

greetings! just wanna ask if possible for you to provide a water turnbine? my load is 1unit 3hp ac aircon, 20pcs 400 watts computer, 20 pcs crt monitor 15", 15 pcs light bulb white, 1 chest freezer (small) and 1 small refrigerator. additional load carwash machine 1hp, compressor 1hp(occasionaly usage).

please help about the unit.thank you

myren

[linschotenr]

Sorry, I only made this for myself and a neighbour. good luck.

Rob

[boristacconi]

Hi,

I am going to built a water turbine to help my father in law with his farmer and I think the model that match better is a Banki.

Do you mind to tell me which was the speed of your turbine? And which generator did you used?

Thanks,

Boris

[linschotenr]

Hi Boris

The turbine is running at approx 280RPM at 500W load.

[deerepuller02]

Have wired into home electric grid? Power bill offset? Or just stand alone genset.

[linschotenr]

It powers two homes. One directly;(240VAC/60HZ), and the other one through a charger/batteries (48V)/inverter 120VAC/60HZ/6KW) arrangement. There is no grid connection (nearest point is about 12 miles away).

Regards

Rob

[barbeau1981]

very nice setting, well put together. Does your belt ever slip?

[linschotenr]

Thank you. Not any more. I switched to 1 inch-wide Browning gear belts and pulleys. Pricey but they work soaking wet and with very little noise. Perfect tension not a problem anymore either.

Rob

[barbeau1981]

My dad and I were wondering, what is the pitch on the pipe that runs from the dam to the generator. ..or is the water pressure from the accumulated basin enough?

[linschotenr]

The 6" PVC schedule 40 pipe drops approximately 14 feet over 300 feet. The basin is about 4 feet above the pipe when full. Just enough to keep air from being sucked into the pipe.

[boristacconi]

Hi,

forgive me but I am customized with meter

Did you say your high was 300feet? My calculator say they are 91 meter, where did you get this huge hight?

Regards,

Boris

[linschotenr]

Boris

No the height is 14 feet (4.26M), the run is 300 feet (91.44M)

[linschotenr]

No, the length was 300 feet or approx 100 meters. The height is less than 30 feet or 10 m.

[marciano79]

genius!!

[Kupo]

hey, how did you get the dimensions of your turbine? can you give your dimensions?

[linschotenr]

I found an old pamphlet from the 40's on-line that had the calculations (published by a government organization called Vista, I believe)and currently available from the Microhydro group files area on Yahoo. Crossflow runner is 12"in dia, 7" wide, 21 blades. Nozzle is designed to convert 6" dia pipe to a 7" by 3" rectangular opening.

[linschotenr]

The load dump only operates when there is no load on the system. This is very rare, usually only happens when switching between houses or if the secondary (hot water tank) load dump fails or is turned off.

[apeppink]

Why the load dump. Seems like usable load could be added somewhere.

[apeppink]

Nice. WSeems like the power output s/b higher tho.

[linschotenr]

Thanks, I'm limited by the derating of the 1Hp 3ph motor wired as a generator.

Rob

[zz3astro]

Very well done!