PSSE must be initialised with sufficient bus numbers
I wanted to know if initalising PSSE with a low number of buses would cause a crash, or give incorrect results. I wrote a small program that initialises PSSE with 10 up to 200,000 buses and observed the memory usage, and whether PSSE crashed.
The small program then loads a saved case with 1600 buses and solves it.
The tests crashed when the initialised bus number was less than the number of buses in a raw file.
Here is a chart showing the memory usage that I observed for each number of initialised buses:
I advise to select around 10,000 buses, which seems to be adequately sized, unless you know there will be more than that many in your system.
(edit)
Thanks to @EBahr for pointing out, but PSSE actually limits the number of CONs VARs, STATEs and ICONs available to the dynamics case depending on the bus limit.
So if you are doing some dynamics work, it would pay to have as many dynamic variables available to you as possible and you should set your bus limit at 150,000 buses which is the maximum number of buses.
I am going to try this later today. Wish me luck!