On 12-24-96 ALEC CAMERON wrote to BILL BAUER about free power
AC> Good news, bad news. Your 10HP single phase induction motor will work
  > OK as a generator but ONLY while the grid is OK. Open the throttle ...
    ...
AC> The transfer of energy from the rotor of your induction
  > motor-cum-generator, is enabled by the magnetic field across the airgap
  > between the rotor and stator. As you have no source of magnetism within
  > the motor, this magnetism has to come from the utility supply. A rough
  > analogy, is that the magnetism works like a slipping clutch
  > communicating energy from the shaft of the engine, into the windings of
  > the motor stator and out thru the utility line.
AC> SO if you put a voltmeter across your supply, you will see that the
  > voltage drops! even tho your are sending power thru your meter into the
  > Utility system.
AC> Seems mad but it is so. The reason the voltage drops, is because
  > magnetising current is required by your motor. And it is a fact, that
  > magnetising current due to its rotten power factor, depresses voltage
  > much more than does "real" power ie load at a very high power factor.
  > Just believe this, the arithmetic that proves it is a headache and I am,
  > so pleased to have left Sydney Tech back in 1955 after I had been
  > converted to these evil beliefs!!
Well, I must admit to being a bit confused (not to mention ignorant,)
about these last two paragraphs. Maybe you would be so kind as to go
into a little more detail without necessarily clouding the issue with
a bunch of math :) I understand that the voltage and current get out
of phase with each other when feeding a load that is predominantly
inductive OR capacitive. But I am not so sure I follow the part about
the voltage actually reading lower with a voltmeter when the motor is
generating. Eli the iceman tells me that voltage leads current in an
inductive load, right? And as long as the voltage produced by the motor
is greater than that produced by the utility at any given time, the
current should flow _from_ the motor to either the utility (other
customers) or other loads on site. I am vaguely getting glimmers about
how the inductance might come into play here to prevent that current
flow, but it's _really_ vague as to where it fits in. So, can you maybe
describe in three words or less what I am missing in this picture?
Pretty please?
Regards,
Mike
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