Thanks for the reply. "Pumping" AC directly to the Grid is not a trivial task for any micro-hydro application and it is illegal here. A Phase Control/Flow Control system would be EXTREMELY difficult to develop to allow a true AC Direct-To-Grid system. A couple rpm drift would cause a short circuit. Additionally, these new high voltage DC Grid-Tie Inverters are amazing and very safe as well. They are UL approved and run at about 93%-95% efficiency and were originally designed for PV Solar Arrays.
--- H2MJD <[EMAIL PROTECTED]> wrote: > Hello Eric, > > I think its a great idea. > > Back in 1985 i installed a unit quite similar to > your site. The head was only about 80 ft if i > remember correctly but the flow rates were very > close. Anyway we used a small 4.5 inch pelton runner > directly mounted to a 1800 rpm 3 phase induction > motor shaft wired for 220 v and two nozzles. We > excited the gen with three small caps then rectified > the output and were rewarded with about 140vdc. > Almost perfect for charging a 120 v set of > batteries. From which the owner ran regular light > bulbs and 120vdc motors for his woodworking shop. > The system was very simple and robust....just add > water and watch it run and run and run. His only > maintanance was bearing replacement every five years > or so....oh and once a weld broke on the motor > rotor. > > If the windy boy allows for mppt i think the system > would be even better. > > The one question i have is....why use a windy boy at > all......just wire the 3phase motor for single phase > and pump it directly into the grid.........mark > ----- Original Message ----- > From: ericfusa > To: [email protected] > Sent: Monday, May 02, 2005 6:45 PM > Subject: [microhydro] Grid-Tie Inverter with > Induction Motor as Generator > > > Hello, > > I am new to the group. > I have a potential microhydro site of about: > -100 ft head > -100 gpm(Winter) to 30gpm(Summer). > -I plan to use 3" or 4" pvc piping with about a > 375 to 400 foot run > of the river. > -Pelton or Turgo Impact Turbine > > I had the idea to use a 3ph/4 pole 220VAC > Induction Motor as a > Generator and connect the rectified/smoothed > output directly to a > Grid Tie Inverter. I noticed that SMA makes a > version of their > popular Sunny Boy Inverters for Wind Generation > using the same > concept. SMA calls this version a Windy Boy. > According to SMA, this > inverter is designed to allow Maximum Power Point > Tracking(MPPT) for > an induction motor driven as a generator for Wind > Power applications. > > According to my calculations, the induction > generator should be able > to output a rectified voltage of about 310V DC or > higher which is > perfect fo the inverter. > > Questions: > > Does anyone have any experience with this type of > grid-tie/net- > metering system? It seems quite simple and > efficient to me but, I am > a micro-hydro newbie and may be making major > estimation errors. > > I've been told that a PM Generator is more > efficient than a driven > 3ph induction motor but, I feel that the overall > efficiency of the > system should still be quite good and simple. > > Any comments or critisism would be greatly > appreciated and will > surely save me time, frustration, and money. > > Kind Regards, > Eric Kunz > Camas, WA USA > > > > > > > > > Does your company feature in the microhydro > business directory at > http://microhydropower.net/directory ? If not, > please register free of charge and be exposed to the > microhydro community world wide! > > NOTE: The advertisements in this email are added > by Yahoogroups who provides us with free email group > services. The microhydro-group does not endorse > products or support the advertisements in any way. > > More information on micro hydropower at > http://microhydropower.net > > To unsubscribe: send empty message to > [EMAIL PROTECTED] > > > > ------------------------------------------------------------------------------ > Yahoo! Groups Links > > a.. To visit your group on the web, go to: > http://groups.yahoo.com/group/microhydro/ > > b.. To unsubscribe from this group, send an > email to: > [EMAIL PROTECTED] > > c.. Your use of Yahoo! Groups is subject to the > Yahoo! Terms of Service. > > > > [Non-text portions of this message have been > removed] > > > > > Kind Regards, Eric R. Kunz - Furuno USA Inc., Senior Product Manager ******************************** Furuno USA Inc. 4400 NW Pacific Rim Blvd. Camas, WA 98607 USA Tel. 360-834-9300 Fax. 360-833-5142 email: [EMAIL PROTECTED] web: www.furuno.com ******************************** __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------ Yahoo! Groups Sponsor --------------------~--> What would our lives be like without music, dance, and theater? Donate or volunteer in the arts today at Network for Good! http://us.click.yahoo.com/TzSHvD/SOnJAA/79vVAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! 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