[TCML] cap strings

[Antonio Carlos M. de Queiroz]

mark olson wrote:
> Hello group,
>
> Are there any advantages or disadvantages to connecting caps as 
> paralleled groups of
> series strings or seriesed groups of parallel.
>
> It occurred to me that value wise it makes no difference, but if the 
> series strings in parallel
> are modified such that the terminations between each individual cap 
> are connected to the
> corresponding terminations in the other strings the cluster has 
> effectively become parallel
> groups in series.
>
> It seems that these jumpers would even out the load, make the bank 
> more robust and decrease
> the number of bleeders required.
>
If everything is interconnected (series combination of parallel groups), 
you save some bleeders,
surely, and the total capacitance of each parallel group is more precise 
than the capacitance of
a single capacitor, resulting is slightly better distribution of the 
voltage among the capacitors.
There is the question about if this is good or bad when a capacitor 
develops a puncture,
and the discharge trough it "heals" the defect. With several capacitors 
discharging trough the
deffect, the discharge may result in more effective vaporization of the 
area around the puncture,
or may destroy the capacitor. I would take a look at capacitors of 
higher values made by the
same manufacturer, said to have this property of healing deffects too. 
If the parallel association
doesn't exceed the largest capacitance, I think that it's safe to leave 
them interconnected in
parallel.

Antonio Carlos M. de Queiroz