I wonder what the efficiency of a motor-generator system like that would
be. Back in the 1960's the marine radio on my father's boat had a
motor-generator to generate high voltage for the tubes (807s as I
recall). Every time you'd key the mic, the motor would rev up.
        Anyway, the PIC part of this would be to have it measure the power into
the motor (I'd probably measure the voltage using an on board A/D and
measure the current with one of those National current sense chips that
output PWM). Put a step up converter between the solar panel and the
motor with the PIC varying the duty cycle to the FET to give max power
into the motor.

Harold




On Thu, 8 Mar 2001 15:13:12 -0600 Lawrence Lile <llile@TOASTMASTER.COM>
writes:
> I"ve tried this with an induction motor connected to the mains, and
> driven
> by a gas motor (don't tell my power company).  We could rev up the
> motor and
> watch the power meter run backwards when we were leading, it'd try
> to start
> the gas motor when we were lagging.  Induction motors make neat
> connections
> to the mains - they will NOT produce power on their own without some
> exitation from the mains power.  We tried this as well, getting the
> motor up
> to speed and running the power meter backwards, then suddenly
> disconnecting
> it.  Voltage at the motor leads would quickly drop to zero even when
> driven
> by the gas motor.  How this works I wish someone would explain.  If
> you want
> a simple, and not inefficient, mains-synching solar system, a 12VDC
> motor
> running an induction motor might be simple enough!  Total mains
> isolation,
> automatic synchronization, lightning proof, and bonehead simple.
> Now - how
> to measure the power output of the motor, and use it to feedback to
> the 12V
> motor speed control?  Gotta have a purpose for the PIC, y'know!
>
> Not so interesting to us engineers, who want to make it too
> complicated,
> with all these PWM switching circuits, but maybe a really practical
> method.
>
> Lawrence Lile
>
>
>
> ----- Original Message -----
> From: "Jess Hancock" <jhancock@CWV.NET>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Thursday, March 08, 2001 1:52 PM
> Subject: Re: [EE] high efficiency feed to mains
>
>
> > Roman, What you want to do is similar to operating two ac
> generators
> > (alternators) in parallel to supply a load.  If you want
> alternator #2 to
> > supply more power (watts), then its phase angle must lead that of
> alternator
> > #1.  If you raise the voltage of alternator #2 you will supply
> more
> reactive
> > power (vars, not watts
>
> --
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>

FCC Rules Online at http://hallikainen.com/FccRules
Lighting control for theatre and television at http://www.dovesystems.com

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