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Forum Index : Windmills : Ultra simple grid interactive inverter

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nweeks

Newbie

Joined: 22/01/2007
Location: Australia
Posts: 36

Posted: 11:29pm 01 Apr 2007

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Well, not an inverter exactly.

My dad once had a novel idea for a dummy load for a combination hydro/wind setup.

Obtain a largish 4 pole squirrel-cage AC motor, and a similarly sized DC motor that will run from your battery bank(12, 24 VDC, etc).

Put a circuit breaker on the mains side of the AC motor to detect when the grid goes down for maintenance.

When excess power is available, fire up the AC motor, which will start spinning the DC motor. Start ramping up the drive voltage to the DC motor, until it tries to spin faster than the mains driven one.

Pour all the excess power you can get into the DC motor, and see the wattmeter fly backwards!

Sure, each motor is only 80% efficient, but if the power's going to waste anyway...

Nigel Weeks
nweeks at karbonit dot com

davef
Guru

Joined: 14/05/2006
Location: New Zealand
Posts: 499

Posted: 09:08am 02 Apr 2007

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And possibly electrocute the linemen trying to restore your power system!

Reading about approvals for commercial grid-tied inverters is in order.

nweeks

Newbie

Joined: 22/01/2007
Location: Australia
Posts: 36

Posted: 10:53am 02 Apr 2007

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Unfortunately I was on a roll from the 'new 36 pole stator' thread, and forgot to mention that we'd covered safety concerns there.

Sorry all.

Nigel Weeks
nweeks at karbonit dot com

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