I think this may be more of a powershell/cmd question...if you are going to launch a script like this, then try using -file instead of -command?
sess.addCommandFromString('powershell -file "C:/Users/Administrator/scripts/person.ps1" person place thing')
In general, i would suggest trying to get it working from a command prompt first. For example, i created a simple script and then opened a command prompt to see if i could get it working using this format (which is sort of what's happening in that session var i think).
cmd /c powershell -file "c:\users\meiguess\desktop\eric.ps1" you me
eric.ps1
param ($one,$two)
$myout = "hi there $one, this is $two"
write-output $myout > "c:\users\meiguess\desktop\eric.txt"