I missed the start of this thread and have come in rather late, but I guess the O.P. wants to run an I G (Induction Generator) standalone, i.e. no connection to the grid.
The only way to do this is to supply the reactive energy requirement of the I G from an external source (normally the grid), i.e. capacitors. If a suitable set of delta connected capacitors are connected to the machine, and then the shaft rotated by a prime mover, it will begin to generate. This assumes residual magnetism in the iron of the machine, which is normal. However, if the machine refuses to start generating, which commonly happens after overload, flashing the windings from a car battery will do the trick.
--------- What field windings? Such a motor is (99.9% probability) an induction motor. However, flashing the winding will help if the machine is to be used "off line" with capacitive excitation.
-- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answe
Newsgroups: alt.engineering.electrical Sent: Tuesday, September 09, 2003 1:03 AM Subject: Re: AC Motor as an AC Generator
-------- I have looked at this site and also at the synchronous motor-so called- on this site. The section on the induction motor is pitiful and misleading (the motor as shown will work, provided it is started by some other means- it will not start by itself ) but the section on the synchronous AC machine is more than misleading- it is wrong on several points. I am afraid to look at what the reference does with other material.
The term "field winding" per se, in the appropriate literature, refers to a winding whose sole purpose is to make a magnetic field (i.e. as in a DC or a synchronous AC machine) and, if present, does not supply energy to the system. The use of the term "armature" according to my dictionary simply implies the rotating winding so that for a typical synchronous machine the armature winding is the field winding. However some texts do use "armature" to refer to the "power input/output" winding whether rotating or not. Most texts simply do not bother with the term "armature" for AC machines and use the term "field winding" where applicable, in the sense that I have indicated above. An induction machine cannot be said to have a "field" winding. It simply has two sets of windings, one stationary and the other rotating. The air gap field is due to all the current carrying windings in the machine, rotating and stationary. If you want some references to Electrical Engineering texts on electromagnetic energy conversion, I can cite you some older ones that are in my back closet but any EE department library should have these and others. Any of these will be better than the site that you have referenced.
Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer
And if you read the text to go along with the picture, you'll see that the 'field' windings in an induction motor are short-circuited loops on the rotor. There is no mechanism to carry DC current onto the rotor. The only currents in the 'field' winding of such a machine are induced by the relative motion between the winding and the magnetic field of the stator. Hence the name *induction* motor.
I must admit to a bit of lazyness there; I quoted the first eb page that showed a field winding. Looking at it again, I should have searched further for a higher-quality website. My apologies.
(The dinner that my lovely wife invited me to partake of if I would only hurry up and finish writing was excellent! )
----------- That's OK - I have been in contact with the author of the web site and changes will take place- I will try to get some diagrams and references to him.
-- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer
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