Well, when you look at it and have a setup like they way you describe, you use the "cap bank" as just that, a power "pool" for surge drain on the resources.
Switching power supplies do just that - but have a much higher overhead of voltage in which to deconvert down into current to keep their power output level - they use caps in a similar fashion but that is using an AC to DC conversion.. In the setup using a cap bank - you are making a DC to Pulse - DC to AC to DC again - reconversion using an extra bank to store the original energy the switching power supply offered.- to offset an inrush demand that would drop voltage and possibly damage regulation required systems.
I wish there was a way to offer infinite capacitance to offset the loading demands but then we wouldn't need AC to begin with...
There are benefits yes, but in the long term the bank or battery debate is on-going.
When you use a basic cap bank - you have two types of "impedance" you deal with. IN the DC realm, you also can look at it as a built in resistor - both to taking up a charge and releasing a charge - how efficient the bank can accept and deliver is that "resistive" effect. Then you also have to look as how the current capacity is delivered from the plates to the wire into the device - that level of resistance, or in AC an impedance, or as for both - delay in change of charge also plays a role..
As to look at it as impedance, the surge itself (not the DC element here - were dealing with how well the DC realm can maintain voltage when current demand is increased). We change from a simple steady state of a standby into a dynamic impulse similar to dumping of charge to make a spark plug fire, but in this case, we are dumping a current to sustain a voltage - not spike it. A little different in approach but not by much.
You should look at the load and how it ACCEPTS the power both as a current and voltage vector.
You have an "Inrush current" factor - which is how or why you use a cap bank in the first place.
But if the device demands current for long duration (as in a duty cycle) - better figure out how much that bank of caps can sustain that current demand and at the rated voltage - for then you lose the efficiency the cap bank is, and it now becomes a filter - even appears as a battery - event. It (that cap bank) is attempting to recoup a charge from the source at the same time the load is trying to operate as a device and not wind up shutting down, blowing a fuse or otherwise damaging a system from the now non-regulated or less than ideal - regulated power levels the source is trying to deliver into the entire system.
In the above affair, you can approach this as; you have surges requiring a heavy inrush current for only so many amps for several seconds and the load then "smooth's" out it's power demands once it's "inertia" has turned into a "momentum" then - the cap bank can provide that level of performance you need to sustain load demands for that short duration.
It's when you are in a realm of the length of time and the duty cycle involved - is where the battery bank tends to provide the better alternative to sustained loading - only bad part is the required reconversion of sulfides from one state (on the plates) to another (back into solution for reserves).
Your stations setup brings up some good points...Thank you.
