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] ------------------------ Yahoo! Groups Sponsor --------------------~--> In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide! http://us.click.yahoo.com/EA3HyD/3MnJAA/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! 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 <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
