[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] MMC design
In a message dated 1/16/08 11:00:29 A.M. Eastern Standard Time,
I'm going through some of the MMC calculators on the net trying to figure
this stuff out.
I have a 9kv NST and LTR capacitance is 12.5nF
output of the NST is ~13kv p-p (close enough)
so, assuming 0.1 2kv caps
1 string of 8 = 16kv and 13nf
2 strings of 16 = 32kv and 13nf
is 16kv "high enough" above the NST?
is it just a waste to go with 2 strings of 16, should I, in this scenario,
stick with 1 string of 8 and call it good?
if the caps were 0.047 and 2kv, then 2 strings of 8 = 16kv and 11.75nf
or 3 strings of 11 at 22kv and 12.82nF
which is more important in designing the MMC?
is it more important to be as close as possible to the LTR value or have
enough voltage "padding" above the xmfr? is there some other factor in here
to use (like the discharge energy or something?)
Paul (I didn't expect the Spanish Inquisition) in Michigan...
There is some flexibility around the LTR value; many folks consider 20%
tolerance as OK. In general, longer strings = more voltage-spike protection, more
strings = more current handling capability. Dr. R's suggestion will give you
a virtually bullet-proof design from a voltage standpoint. You didn't
mention the current rating of your transformer. Too few strings, and your caps will
heat up on peak currents, too many and your cost goes way up.
"NOBODY expects the Spanish Inquisition" Ximinez ;-))
**************Start the year off right. Easy ways to stay in shape.
Tesla mailing list