Thank you for another informing post.
I agree that the rotor dynamic analysis is important and will be performed at a later design stage by the machine manufacturer.
7anoter4: Thank you again for the informative post. It has put many pieces of information I have in perspective.
You say:
"Usually we state the stator inner diameter based on recommended tangential stress for a well loaded machine
and the ratio between pole pitch and the ideal core length."
I...
Thank you guys for the input.
LionelHutz: I will ask the manufacturer when the projects get to that stage. But I would like to be able to give somewhat educated guestimate of stator diameter and core length of units at an early design state of hydro projects, long before a machine manufacturer...
I'm looking for information on peripheral speed design limits of synchronous generators. More specifically for 50 Hz hydrogenerators with with rated speed 100 - 300 rpm.
As far as I understand the design limits of the peripheral speed is determined by mechanical stress (centrifugal forces) on...
Patrick7:"...there is another question that i have.
we have a 230 kv abb pmi typer circuit breaker.
the drawings show what appears to be an additional
bushing bolted alongside of the breaker bushing.
any information on what it really is?"
This is a capacitor. It helps the arc suppressing by...
Mr. Potter:
If I were you I would draw a multiline diagram including load connections, load sizes, voltages and currents. Send him the diagram, ask him to correct the miscalculations or connections and send it back.
marada93: youre understanding is quite accurate. In fact the grid's alternating voltage uses the stator winding to produce a rotating magnetic field in the airgap of the machine. (you could say this was the "magnetic field of the grid"). The rotor has it's own field that is "attached" to the...
Thanks to all of you guys.
We will look at the possible efficiency increasement, we are only considering keeping the core if it measures good and the efficiency increasement can not justify the cost of a new core.
mc5w: This surface etching thing is very interesting. The turbine wheels will...
We are at the moment looking at a couple of 14MVA ASEA hydro generators from late 1950's. Both stator windings and rotor poles will be replaced but is it completely ridiculous to consider keeping the cores? Of course given that they turn out ok in flux tests. How old can cores really get? All...
The Montsinger rule: "...thermal life of insulation is halved for each increase of 10°C in the exposure temperatrue" is a thumb rule and perhaps a bit to simple for this task. I would reocomend to use Arrhenius model:
L=B exp[phi/(kT)]
where L is life, B is a experimental constant, phi is...
